Why Atmospheric Pressure Cannot Explain the Elevated Surface Temperature of the Earth

December 30th, 2011 by Roy W. Spencer, Ph. D.


Ned Nikolov’s alternative theory that compression of the lower atmosphere can account for the Earth’s surface temperature being about 33 deg. C higher than calculations suggest it should be (based upon the rate at which sunlight is absorbed) is an admittedly attractive one.

The role of pressure on the average surface temperature of the Earth has been a point of confusion even among atmospheric science and meteorology students (it was for me). We were taught much more about the various processes which cause temperature to *change*, but not so much about the processes which determine what the average temperature *is*.

Background: The Dry Adiabatic Lapse Rate
The dry adiabatic lapse rate of temperature is the rate at which the temperature of a parcel of air decreases with altitude (9.8 deg. C per km) if no energy is gained or lost by that parcel to its surroundings (thus the term “a-diabatic”), or though condensation heating by water vapor (thus “dry”).

It is important to understand that the adiabatic lapse rate deals with temperature *changes* as a result of pressure changes, but it says nothing about what the average temperature will be at any given altitude. It starts with a parcel of air of known temperature, but does not explain why the parcel had that temperature to begin with.

Conceptualizing the Processes Controlling Atmospheric Temperature
The average air temperature at any altitude (including the surface) is an energy budget issue, not an air pressure issue. In fact, energy budget considerations explain the average temperature of just about everything we experience on a daily basis: the inside of buildings, car engines, a pot on the stove, etc.

One useful way to conceptualize the processes determining the time-average surface temperature (neglecting heat transport below the surface) is through this simple thought experiment:

1) start with an atmosphere at absolute zero temperature

2) turn the sunlight on

3) the surface warms as it absorbs solar radiation

4) the warmer the surface gets, the greater the rate at which it loses energy by IR radiation and convection

5) the temperature will eventually stabilize (albeit with a rather large day-night cycle) when the average rate of energy loss equals the average rate of energy gain from the sun.

Note I did not need to mention atmospheric pressure.

While the above steps sound simple, what complicates things in the real world is that these energy gain and loss processes are also occurring at all altitudes, and in different proportions, all of which influence the surface energy budget. This makes it very difficult to conceptualize how they all combine to produce the average temperature profile of the atmosphere observed today.

We (Danny Braswell and I) have found that physical intuition can be built if you construct a “simple” computer program to model the processes in one dimension (vertical). While computer modeling has a bad connotation among many global warming skeptics, it is just putting actual numbers behind hand-waving concepts. If you can’t do that, then all you have left is hand waving.

Many years ago Danny put together such a model so we could examine global warming claims, especially the claim that increasing CO2 will cause warming. The model was indeed able to explain the average vertical temperature structure of the atmosphere. We could initialize the model with an atmosphere at absolute zero, or at an absurdly high temperature, and it would still settle out to about the same temperature profile as is observed in the global average. (I continue to challenge those with alternative theories to do the same).

One of the first things you discover when putting numbers to the problem is the overriding importance of infrared radiative absorption and emission to explaining the atmospheric temperature profile. These IR flows would not occur without the presence of “greenhouse gases”, which simply means gases which absorb and emit IR radiation. Without those gases, there would be no way for the atmosphere to cool to outer space in the presence of continuous convective heat transport from the surface.

Indeed, it is the “greenhouse effect” which destabilizes the atmosphere, leading to convective overturning. Without it, there would not be weather as we know it. The net effect of greenhouse gases is to warm the lowest layers, and to cool the upper layers.

The greenhouse effect thus continuously “tries” to produce a lapse rate much steeper than the adiabatic lapse rate, but convective overturning occurs before that can happen, cooling the lower troposphere and warming the upper troposphere through a net convective transport of heat from lower layers to upper layers.

Now, it’s the downward component of IR radiative flow that many skeptics seem to have a problem with. They ask, how can IR radiation flow from colder temperature at higher altitudes to warmer temperatures at lower altitudes? That would contradict the 2nd Law of Thermodynamics.

Of course, it’s the *net* (upward plus downward) IR flow that must be from higher temperature to lower temperature, and so greenhouse theory does not contradict the 2nd Law of Thermodynamics. If you don’t like the idea of a downward flowing component to the ‘net’, then just conceptualize the effect of greenhouse gases as reducing the rate at which IR energy flows from higher temperature to lower temperature. There, 2nd Law problem solved.

But then, through energy budget considerations, if you reduce the ability of the surface and lower atmosphere to cool in the face of solar heating, the temperature must rise until the rate of energy loss equals the rate of energy gain. This is how greenhouse gases warm the lower atmosphere.

In any event, it is the processes which control the rates of energy gain and loss (not pressure) which determine what the average temperature will be, whether at the surface or any other altitude in the atmosphere.

Thought Experiment #1 on The Pressure Effect
If it is atmospheric pressure which causes the relative warmth of the lower troposphere versus the upper troposphere, then why is the average temperature of the stratosphere virtually constant with height, despite the air pressure at the base of the stratosphere (200 millibars) being about 100x that at the top of the stratosphere (2 millibars)?

If you say it’s due to sunlight absorption by ozone warming the middle and upper stratosphere, you would be correct. But how does the stratosphere then lose all of that extra energy it gains by solar absorption? Well, that occurs through IR emission, primarily from carbon dioxide. The temperature of the ‘ozone layer’ increases until the IR loss (primarily by CO2) equals the rate of solar absorption by ozone. Again, it’s an energy budget issue, not an air pressure issue.

The point I’m making with the stratosphere example is that greenhouse gases are necessary to explain the temperature profile of the stratosphere, not what the “pressure enhancement” theory of climate would predict.

And if greenhouse gases influence the stratosphere, then they must also be operating in the troposphere.

Thought Experiment #2 on the Pressure Effect
Imagine we start with the atmosphere we have today, and then magically dump in an equal amount of atmospheric mass having the same heat content. Let’s assume the extra air was all nitrogen, which is not a greenhouse gas. What would happen to the surface temperature?

Ned Nikolov would probably say that the surface temperature would increase greatly, due to a doubling of the surface pressure causing compressional heating. And he would be correct….initially.

But what would happen next? The rate of solar energy absorption by the surface (the energy input) would still be the same, but now the rate of IR loss by the surface would be much greater, because of the much higher surface temperature brought about through compressional heating.

The resulting energy imbalance would then cause the surface (and overlying atmosphere) to cool to outer space until the rate of IR energy loss once again equaled the rate of solar energy gained. The average temperature would finally end up being about the same as before the atmospheric pressure was doubled.

Conclusion
While I applaud Ned Nikolov’s willingness to advance a controversial alternative, at this point I still must side with the greenhouse effect (despite its terrible name) as an explanation for the average surface temperature of the Earth being considerably higher than that calculated based upon the rate of solar heating of the surface alone.

One of the more significant aspects of the above discussion, which was demonstrated theoretically back in the mid-1960s by Manabe and Strickler, is that the cooling effects of weather short-circuit at least 50% of the greenhouse effect’s warming of the surface. In other words, without surface evaporation and convective heat loss, the Earth’s surface would be about 70 deg. C warmer, rather than 33 deg. C warmer, than simple solar absorption by the surface would suggest.

Thus, weather cools the surface in the face of radiative heating.

And, yes, this effect is included in the climate models used by the IPCC. It would have to be, otherwise the average temperature distributions in those models would be wildly wrong: much too warm in the lower troposphere, and much too cold in the upper troposphere.

I continue to maintain that the major source of error in global warming predictions based upon the IPCC models is not in the physics of the greenhouse effect, but in the realm of feedbacks: especially, how clouds respond to a warming tendency. All of the 20+ models predict clouds will enhance warming; I believe they will reduce warming.

Unfortunately, determining cloud feedbacks from our observations of the climate system is an exceedingly difficult problem. Even more difficult is publishing any evidence of negative cloud feedback in the peer reviewed literature.

Epilogue
Finally, I want to address 3 stumbling blocks which people encounter in all of this.

FIRST, if you are still confused about whether greenhouse gases warm or cool the climate system, let me make the following 2 points:

1) For the atmosphere as a whole, greenhouse gases COOL the atmosphere, through IR radiation to outer space, in the face of heating of the atmosphere by the solar-heated surface.

2) In the process, however, greenhouse gases drastically change the vertical temperature structure of the atmosphere, warming the lower layers, and cooling the upper layers. Think of greenhouse gases as a “radiative blanket”…when you add a blanket over a heat source, it warms the air between the blanket and the heat source, but it cools the air away from the heat source.

Greenhouse gases change the energy budget of all layers of the atmosphere, and it is the energy budget (balance between energy gain and energy loss) which determines what the average temperatures of those layers will be.

SECONDLY, some people claim that IR emission and absorption cannot affect the atmospheric temperature profile because the rate of IR emission and absorption by each layer must be the same.

Wrong.

The rate of absorption of IR by a layer is mostly independent of temperature; the rate of emission, though, increases rapidly with temperature. In general, the rates of IR absorption and emission by atmospheric layers are quite different. The difference is made up by convective heat transport and (especially in the stratosphere) solar absorption.

THIRDLY, if you are wondering, “If temperature change is an energy budget issue, then why does the temperature of an air parcel change when you change its altitude? Doesn’t the temperature change necessarily imply an energy budget change?

The answer is no.

When an air parcel is raised adiabatically, it’s loss of thermal energy is balanced by an equal gain in potential energy due to its altitude. The ‘dry static energy’ of the parcel thus remains the same, which equals cpT + gZ, where cp is the specific heat capacity, T is temperature in Kelvin, g is the gravitational acceleration, and Z is height in meters.

Of course, averaged over the whole Earth, there can be no net change in altitude; all air parcels rising (and cooling) at any given pressure altitude must be matched by an equivalent mass of air parcels sinking (and warming) at that same pressure altitude.


291 Responses to “Why Atmospheric Pressure Cannot Explain the Elevated Surface Temperature of the Earth”

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  1. Jim Cripwell says:

    Thank you for this presentation, Roy. My physics is very elementary, and I am not sure I understand everything you have written, but one thing that has stuck in my craw ever since I read about it, is the idea that one can estimate something useful, namely no-feedback climate sensitivity, by ONLY looking at radiative effects in the atmosphere. This idea, or assumption, or whatever, has always struck me as being just plain wrong.

    Now, as I read what you have written, you seem to be saying that one can say nothing useful about what happens in the atmosphere unless you look at all the ways in which energy is transmitted through at the atmosphere at the same time. Is this, in fact, an absolute truth?

    • I would say it is as true as anything in climate science can be. Of course, the modelers will claim they already account for all of the energy exchange processes, or at least the “important” ones.

  2. bob sykes says:

    Dear Prof. Spencer,

    Thanks for yet another explanation of the the basic atmospheric science.

    I scanned Nikolov’s article and was more than unconvinced. There are so many pseudo scientific arguments out there that reject well-established physics that it is hard to see how anyone not already possessing a hard science degree can understand what is going on.

    Before I retired, I spent 37 years teaching and researching environmental engineering. Towards the end, the swamp of anti-scientific and anti-rational environmentalism had grown so wide and deep that I spent as much time debunking superstition as I did teaching. And some of my students did not appreciate learning that they had been lied to by the MSM

  3. Steveta_uk says:

    I was unconvinced by the Nikolov article, as it seems to think that the adiabatic lapse rate is intrinsic to an atmosphere independent of composition, and I can’t see how this can be true.

    Also, as pointed out by a comment on another site, if pressure alone is the determining factor, why does temperature drop so much faster on a clear night?

  4. Christopher Game says:

    Dr Spencer is supported by a grand tradition. Maxwell and Gibbs and Boltzmann all considered a column of air in a very tall isolating chamber, subject to a vertical graviational field, and left to reach thermodynamic equilibrium. However the air distribution starts out, when thermodynamic equiibrium is reached, the gravitational field makes the pressure at the bottom higher and at the top lower. Again at thermodynamic equilibrium, the temperature, however, is the same at every altitude. A pressure gradient does not create a temperature gradient in this situation of an isolated column.

    Dr Spencer then removes the isolation and lets the sun shine in and the earth radiate out. The sunshine preferentially heats the land-sea surface because it is opaque, in contrast to the semi-transparent atmosphere. The hot land-sea surface then heats the lowest atmosphere preferentially by conduction, evaporation, and convection. This makes the lowest atmosphere buoyantly unstable. Air circulates so as to carry internal energy upwards to altitudes where it can cool itself by radiation to space, greenhouse gases being its main radiators. The buoyancy effect nearly obeys the adiabatic gas law. There is also a small rate of radiative transfer of heat from the land-sea body to the atmosphere because of the absorptive power of greenhouse gases, but this is much outweighed by the other mechanisms just mentioned; Dr Spencer says by more than 50%; I would guess by perhaps 90% or more. The land-sea body also cools itself by radiation directly to space through the ‘atmospheric window’, discovered mainly by George Simpson in 1928.

    Dr Spencer is here pointing to a major factor that has yet to be understood in precise quantitative terms: how changes in the temperature of the land-sea body lead to changes in the generation and perishing of clouds, which affect the reflection of sunlight to space. This is called the feedback problem. I am hoping that he and Dr Braswell will use a second-order model for this purpose, rather than the IPCC first-order formalism, which in principle cannot solve the problem.

    • Christopher, when I read your first sentence I thought it said, “Dr. Spencer is supporting a grand illusion”.

      Then I read your post, which did not disagree with me (which you have not been shy about doing, BTW).

      The mind plays tricks on us as we get older, I guess.

  5. Eilert says:

    You claim that without greenhouse gases the atmosphere has no way. I interpret this that the bulk of the atmosphere (Nitrogen and Oxygen) do not radiate and thus cannot cool, which contradicts the fact that any body with a temperature above 0 degrees kelvin, does emit thermal radiation. Furthermore infrared thermometers are specifically calibrated at 8 µm to 14 µm, which is in the spectrum of the atmospheric window which is mostly transparent to infrared radiation. How than will it be possible to measure the temperature of the atmosphere if no radition is emitted in that spectrum.

    • It’s a matter of how efficiently different gases absorb and emit IR. While it is true that the other gases emit some small amount of thermal IR and microwave energy, they are so much less efficient at it than water vapor, CO2, and methane that they are for practical purposes considered transparent.

      I’m not sure what you are asking with your second question, or what point you are making.

      • clazy8 says:

        Dr Spencer,

        Could you be specific about how much better GHGs are as radiators than nonGHGs? You indicate that the latter are far less efficient. But they are also far more numerous. The actual values will make all the difference. You mention transparency, but that describes the ability to ABSORB, not the ability to radiate.

        As for whether there is a temperature gradient in a cylinder of gas, it doesn’t appear that the examples Christopher Game cites are useful for comparison, because they do not include the all-important element of a continuous energy flow into the system, at the bottom of the cylinder. Most of the atmosphere is transparent to the solar radiation; it is only after it has been absorbed by the surface that the atmosphere has the opportunity to acquire this energy by convection.

  6. iya says:

    I disagree with thought experiment #2:
    It’s a complex nonlinear system, but mainly doubling the amount of N2 will allow greenhouse gases to rise higher and establish the radiative equilibrium at a higher altitude. The troposphere will grow. Inside the troposphere the lapse rate is enforced by convection, and the surface temperature will rise.

    Radiative flows near the surface follow the temperature and do not cause it. The traditional model cannot explain why the atmosphere radiates >300W on Earth and >1000W on Venus. The temperature gradient is caused by gravity, and any model predicting a mid troposphere hotspot is missing basic physics.

    • The greenhouse gases will not “rise higher” in the atmosphere. They would remain relatively uniformly mixed, despite their difference in density, because molecules are so small that turbulent mixing forces dominate over gravitational forces. The same reason mineral dust floats, even though it is made up of tiny rocks.

      The convection you refer to cannot occur without the radiative destabilization of the troposphere by greenhouse gases. Did you even read my article?

      Your comment that “radiative flows near the surface follow the temperature and do not cause it” is wrong…causation flows in both directions.

      Yes, the “traditional” model does explain the temperature profile of Venus, the calculations of which have been published. Just like on Earth, those calculations do indeed involve *one-way* radiative fluxes which can exceed the incoming flux from the Sun.

      • iya says:

        Do you agree, the added N2 would increase pressure and lift the top of the atmosphere? Then the average greenhouse gases will also be higher, BECAUSE they remain uniformly mixed.
        I have read the article, and I agree with most of it, for example that all heights radiate somewhat to space. So there is not a single equilibrium height, but you can calculate a kind of average. On Venus that average is 50km, on Earth it’s 4km.
        The greenhouse gases are important for convection and they are still there. The top of the troposphere and the average radiation height would surely rise with added N2, at least a little. This average radiation height is in equilibrium with incoming solar and has the planets grey body temperature.
        You can also look at the opposite case; remove all N2 and O2, as on Mars:
        The atmosphere will be very thin, the equilibrium height will be very low (a high percentage of radiation leaves directly from the surface), and surface temperature is lower. It would be absolutely impossible to get the same surface temperature and lapse rate.

        • OK, I see what you are saying now. Yes, the atmosphere would extend to a higher altitude, and so the greenhouse gases would be distributed higher as well. This probably would, as you suggest, have some effect on the equilibrium temperature at the surface.

          There are a whole series of experiments that could be done with a 1-D radiative-convective model to look into issues like this. I wish I had time (which means funding) to do them.

        • iya says:

          I was probably mistaken, because the height of the atmosphere does not depend on it’s mass. Maybe for the gas giants, but not for the inner planets. Density and pressure scale approximately exponential, thus a low (as in height) CO2 atmosphere can only be considered hypothetically.
          Mars’ troposphere is ~50km, including winds and a lapse rate. Its CO2 is 10x Earths, but its greenhouse effect is only 4K, probably because of missing water vapor.

      • iya says:

        This is the theoretically highest possible greenhouse warming:
        Incoming solar and outgoing thermal radiation must balance at the TOA, thus the TOA cannot be warmer than the grey body temperature.
        The dry adiabatic lapse rate = g / c_p is the absolut limit for the temperature gradient.
        Thus ?T_max = h(TOA) * lapse rate

        The real ?T is lower, especially for semi infrared-transparent atmospheres, as on Earth.

        • The trouble with that is convection only exists in the troposphere, not up to the top of the atmosphere. Again, some modeling experiments could probably shed some light on all this.

          • iya says:

            Yeah, of course the Stratosphere is also warmer than the grey-body temperature. The argument should be formulated a little more carefully in regards to the troposphere, but is still sound.

      • Jon says:

        If you double the atmosphere you would be be doubling also the amount of water vapour and other greenhouse “gases” .
        The IR-radiation from the ground should be longer, take longer time, in the atmosphere before it escape. Thus making it warmer?

        • iya says:

          The idea was to double only N2, but you are correct that there would be many nonlinear feedbacks, especially in the extremer thought experiments.
          Increased water content, would not only increase albedo, but also decrease the lapse rate, both could lower the surface temperature.

          The theory once again in short:
          The greenhouse effect is due to adiabatic heating.
          The thermostat is set by the effective location of outgoing radiation, influenced by atmospheric mass, greenhouse gases, etc.

          The most prominent proponent is probably Leonard Weinstein:
          http://climateclash.com/2010/11/25/g1-the-atmospheric-greenhouse-effect-and-its-effect-on-agw/

          • Jon says:

            I think of earths atmosphere as insolation. So pressure is just a measure of how much. So the more pressure the more insolation. The year avg temp for my cabin at 1100 m height in the mountain is about 6 deg C colder than my house.at sea level. Even if my cabin probably receive a bit more sunlight than my house, due less atmosphere above.

            The nitrogen and oxygen in the atmosphere are also carriers of the most important insolation gas, water vapour. So even if you just doubled nitrogen you would still get a lot of additional water vapour and increased insolation and higher temps at all levels in the atmosphere.

            The area around the shores of the death sea is warmer than the hilltops nearby not because of higher pressure but because more pressure means more insolation.
            ?

          • iya says:

            First of all, density is the opposite of insulation; the perfect insulator is vacuum. Insulation cannot explain the temperature difference, in thermodynamic equilibrium.

            On Earth we never have thermodynamic equilibrium, because of day-night cycle, but in the “tall room” thought experiments you can consider a constant flux of 239 W/m2 with equilibrium.

          • iya says:

            Sorry, I misread that. (Stupid English)
            If you mean increased backradiation, than this is the standard greenhouse effect explanation.
            We’re not debating the facts of backradiation and temperature, but the interpretation/causality/mechanism. Someone called it a soup of molecules and radiation. Roy said causation flows in both directions.
            I think gravity and thermodynamics are the essential mechanism. In other words there can be no tabletop experiments which can simulate the radiative greenhouse effect.

          • Jon says:

            I should have used the word insulation , instead of the word insolation.
            Sorry about that.

  7. Christopher Game says:

    Reply to Dr Spencer’s post of December 30, 2011 at 11:39 AM.

    If I were a yes-man, I wouldn’t be on your side as I am. I would be chanting the IPCC mantras.

  8. Ron says:

    I won’t say that I completely agree with Nikolov’s theory as it currently stands. One point in favor of Nikolov’s theory is the altitude to temperature relationship on Venus. When you get to an atmospheric pressure equal to the Earth’s surface pressure the temperatures drop to nearly the temperatures found on the Earth. Even though the atmosphere is still mostly CO2.

    I also agree with him that convection will override radiative transfer by a large margin since it is more efficient.

    • The Venusian atmosphere has many differences from the Earth’s atmosphere…the albedo is much higher, most of the absorbed sunlight never reaches the surface, the sulfuric acid clouds not only absorb and emit IR, they also *reflect* IR, an effect which (I understand) essentially doubles the lower atmospheric warming from the regular greenhouse effect.

      If the temperature at one Earth atmosphere depth into the Venusian atmosphere is indeed about the same as the Earth’s surface temperature, I would guess that is coincidence. When Nikilov comes up with a time-dependent energy budget model which produces the observed temperature profile of the Venusian atmosphere, I will take his ideas more seriously.

      • Ron says:

        I thought Table 1 began to address that, it showed:
        1) where there wasn’t an atmosphere the observed temperature matched the Standard Planetary Grey Body model
        2) where there was an atmosphere (even as thin as Mars’) the observed temperate was more closely related to his gas law calculations.

        One of my concerns is that I thought his model was, probably, too simple. Removing the atmospheric composition as a significant factor needs to be proven (then again, so do the climate models)but he did pick atmospheres ranging from96+% CO2 to those with 99+% N2. Running these compositions through the current climate models would prove interesting (if not conclusive) and may point out further areas of research.

        One other concern I have is the 239 W/m2 solar input to the system. Is this just visible and IR? We know that the UV varies wildly with the sunspot activity and should be counted as part of the flux. Also, does the solar RF levels have any effects on our atmosphere (like your microwave oven heats food)? If so, how much?

        • iya says:

          “1) where there wasn’t an atmosphere the observed temperature matched the Standard Planetary Grey Body model”

          But it doesn’t. Moon and Mercury come out way too cold, because of their integration scheme, which they justify, but apparently is incorrect.

          • Ron says:

            “But it doesn’t. Moon and Mercury come out way too cold, because of their integration scheme, which they justify, but apparently is incorrect.”

            The way I read Table 1 the last row is the SPGB temperature, the row above it is the proposed gas law based temperature, and the row above that is the observed temperature.

            The gas law temperature is 0 for airless bodies, a total disconnect but expected (the pressure value is zero.)

            In the table the grey body temperature (last row) for Mercury and the Moon match the observed (3rd row up) surface temperatures.

            On the other hand, for bodies with an atmosphere, the gas law temperature (the 2nd row up) match the observed temperatures within 1 degree while the grey body temperatures deviate by large degrees.

  9. Dave says:

    Thank you for clearing a little fog from a complex topic!

  10. PeterF says:

    Am I correct in concluding from your Epilogue-First-#1 paragraph that having an atmosphere made up exclusively of non-GH-gases would with respect to the average surface temperature be largely the same as having no atmosphere at all?

    As such gases – N2 and O2 (but not Ozone) could be real world examples – do not absorb/emit in the relevant range, they could contribute neither to energy gains nor losses. They could only help in smoothing the surface temperature profile by redistribution of heat by convection and horizontal transport.

    Adding GH gases will only lower the global heat content, but they will also “tilt” the vertical temperature profile by keeping more heat at the bottom and less on top?

    Is the old model program still available, and could you provide it for download?

    • This question of what the atmospheric temperature profile would be if there were no greenhouse gases has not, at least to my knowledge, been addressed with a model and published.

      We (Danny Braswell and I) have discussed resurrecting the model (which is not trivial to run) to examine this question.

      Just thinking it through, we think the model would warm the atmosphere to be isothermal (constant temperature with height), with the same temperature as if there was no atmosphere at all.

      But this might have to occur largely through conduction, or somewhat arbitrarily imposed turbulent mixing, because the atmosphere would be too stable to initiate convective mixing. Since air is such a good thermal insulator, it would take a very long time for conduction alone to warm the entire atmosphere.

  11. DeNihilist says:

    I thought, well if this is right, then wouldn’t ocean water at the very depths be Gore’ean hot?

    • iya says:

      No, because water is not a gas. It does not heat much when compressed. Also the deep ocean is stratified, with little vertical motion. Then you have the density anomaly, with 4° being the densest, etc.

  12. kuhnkat says:

    Go back and read his paper again. He didn’t say that pressure set the temperature. He said it modified the temperature. Insolation sets the temperature.

    • Yes, I know that’s what Nikolov claims…maybe I didn’t reflect his position accurately enough. But I am claiming that pressure does not even “modify” the equilibrium temperature of the Earth.

  13. RW says:

    Roy,

    You say:

    “These IR flows would not occur without the presence of “greenhouse gases”, which simply means gases which absorb and emit IR radiation. Without those gases, there would be no way for the atmosphere to cool to outer space in the presence of continuous convective heat transport from the surface.”

    I’m not sure I understand what you mean by this. Doesn’t most of the radiative emission from the atmosphere that passes into space come from the heated gases of atmosphere itself (N2 and O2) and not that of narrow band greenhouse gas emission?

    I understand that it’s the initial absorption by GHGs that heats the gases of the atmosphere via collisions, but I was not aware that most of the power emitted from the atmosphere to space is from GHGs rather than mostly from broad band emission from the heated atmosphere itself.

    Can you clarify?

  14. RW says:

    Roy,

    “Most of the radiative absorption AND emission is by the greenhouse gases, very little from nitrogen and oxygen.

    So, when the greenhouse gas molecules absorb IR energy, that thermal energy is almost instantaneously distributed throughout the air. Similarly, when energy is lost by the greenhouse gases, heat is instantaneously transferred from the other molecules to the radiatively active molecules.”

    Yeah, but what about the radiative emission from the heated atmosphere itself? Are you saying the heated atmosphere does not emit broad band radiation according to its temperature like any other heated object? Why would that be?

    I understand that the non-GHGs (O2 and N2) of the atmosphere are very poor black bodies and without ‘help’ from GHG absoprtion would not absorb infrared radiation, but I don’t see how once they have been heated via collisions they would not emit radiation, a large portion of which would pass into space as part of the flux leaving at the TOA.

    Or I’m I missing something obvious?

    • No, O2 and N2 emit very little IR, no matter what their temperature. Gases which do emit IR also absorb IR, and vice versa.

      So, no, gases like N2 and O2 don’t emit broadband IR “like any other heated object”, unless you mean that they emit a non-zero amount. They do emit tiny amounts, but nothing like that emitted by greenhouse gases, which are in turn less efficient emitters than most solid objects. (There are a few materials which are nearly transparent to IR, which means they neither absorb or emit very much IR, even when hot.)

      Remember, the *rate* of absorption/emission is what really matters, which for a given temperature is determined by the IR *emissivity* of solid objects, which is usually quite high (close to 1.0), and the IR *absorption coefficient* of gases, which varies tremendously…e.g. very small for nitrogen, and oxygen, and very high for carbon dioxide and methane.

  15. RW says:

    Roy,

    I’m lost. Are you saying that a heated gas composed of of N2 and O2 molecules would remain at the same temperature forever? That it would not emit radiation like any other heated object?

  16. RW says:

    Mind you, I’m aware that without help from GHG absorption and transfer via collisions, the N2 and O2 would absorb little if any infrared radiation.

    Also, I assume by ‘heated’ you know I mean the kinetic energy of the N2 and O2 molecules in the atmosphere?

  17. Christopher Game says:

    The lower atmosphere is near enough in a condition called ‘local thermodynamic equilibrium’. This means that the energy levels of molecules are mostly determined by intermolecular collisions, which are frequent in comparison with absorptions and emissions of thermal radiation. The intermolecular collisions establish near enough a Maxwell-Boltzmann distribution of molecular velocities. Under these conditions, Planck’s law, coupled with Kirchhoff’s law of thermal radiation, and the specific characteristics of molecules, governs the radiation near enough. Under the condition of local thermodynamic equilibrium, for each molecular species, the wavelength-specific ratio of actual emission to conceptually potential ‘black-body’ emission is equal to the wavelength-specific ratio of absorbed to incident radiation. Good absorbers are good emitters, at each wavelength. Just so for oxygen and nitrogen gas molecules in local thermodynamic equilibrium; being poor absorbers they are equally poor emitters. Above 100 km altitude, the atmosphere is not in local thermodynamic equilibrium, and Kirchhoff’s law of thermal radiation does not work up there, because intermolecular collisions are not frequent enough.

    • RW says:

      I’m not quite sure I understand what you’re saying either. The vast majority of the atmosphere is N2 and O2, is it not? The energy of the temperature component of the air, especially drier air, in the atmosphere is almost entirely the kinetic energy of N2 and O2, right? You and Dr. Roy seem to be saying that the atmosphere only emits narrow band radiation from GHGs and the heated air of N2 and O2 does not emit radiation.

      Now, I certainly agree that some of the radiative emission from the atmosphere which passes into space is from that re-emitted by GHGs molecules, but I don’t think all or most of it is.

      In general, I thought GHGs primarily convert narrow band radiation into broadband radiative emission via collisions with N2 and O2, which heat the air of the atmosphere. This kinetic energy is then lost through broadband emission, a large portion which eventually passes into the space at the TOA.

      • RW says:

        The idea here being without GHGs, the atmosphere would be almost entirely transparent to outgoing LW radiation from the surface and we would not have a GHE.

        Is it not primarily the GHG collisions with N2 and O2 that heat the air in the atmosphere?

  18. EZ says:

    Dr Spencer,

    your statement re 2nd Law of thermodynamics re *net* IR flow……”just conceptualise the effect of greenhouse gases as reducing the rate at which IR energy flows from higher temperature to lower temperature”.

    How do the greenhouse gases CAUSE a reduced IR flow from higher temperature gas/surface?

    How do we conceptualise the action within the different lower tenmperature and higher temperature mediums… both emmiting/shooting “energy” at each other???

  19. don penman says:

    The “alternative theory” says that the temperature of the Earth historically has been determined by the pressure of the atmosphere which is related to the level of volcanic activity.Your view is that an increase in pressure only gives a temporary increase in temperature however the volcanic activity could be fairly continuous through a geological period and therefore the idea that warm periods are caused by an increase in atmospheric pressure cannot be ruled out.It does offer us a different explanation to the normal story we here of of massive increases of greenhouse gasses caused by volcanic activity leading to “a runaway greenhouse effect”.

  20. don penman says:

    I am sure I wrote “hear” not “here” I think my spell checker must be faulty.

  21. KevinK says:

    Dr. Spencer wrote;

    ”(neglecting heat transport below the surface)”

    And, He also wrote;

    “Note I did not need to mention atmospheric pressure.”

    Well… after you so conveniently discarded the “heat transport below the surface” term (Yes Virginia, you do indeed NEED to consider the thermal capacity and JUST AS importantly the thermal diffusivity of the materials involved in the the system, AKA the “SPEED OF HEAT”) you have quite an EMPTY argument left.

    I have posited a hypothesis regarding the effects of adding “GHG’s” to the atmosphere and I also did not mention atmospheric pressure. I suspect that the pressure of the gases in the atmosphere do indeed play a small part in the response of the complex system that some folks (some who posses PhD’s) claim to understand as a “science”.

    The whole calculation about WHAT the temperature of the Earth would be with/without “GHG’s” is flawed. I know that may be hard to accept since all of the climate “scientists” have “believed” it for the last few decades. But unfortunately, that seems to be the FACT.

    Cheers, Kevin.

  22. Ned Nikolov says:

    Hi Roy,

    Thank you for taking the time to respond to our paper. I highly appreciate your work and dedication to scientific truth. Your satellite temperature record is one of the most valuable observational data series we currently have to evaluate theory against physical reality, which is why I alway use the UAH series in my climate talks.

    I also firmly believe that open-minded professional debates (uncontaminated by politics) are key for advancing the science. I think that you are fully capable of carrying out such a debate.

    I have numerous comments/clarifications to your review points that deserve a separate paper. Therefore, I’m going to present those in a formal reply next week week, probably posted at WUWT. In the mean time, I’d like to ask you to take yet another careful look at our article and contemplate on the following points:

    1) How can one explain the fact that Equation 8 predict so accurately the the mean surface temperature of planets over such a broad range of environmental conditions in terms of radiative environments and atmospheric composition by using only 2 variables – TOA TSI and average surface pressure?

    2) What does the similarity in shape between the curves in Figures 5 and 6 indicate?

    3) What are your thoughts on the 3 main problems of the current GH theory identified in Section 2 of our paper?

    Happy New Year to you and your family!

  23. Christopher Game says:

    Reply to the post of Ned Nikolov of December 31, 2011 at 2:58 AM.

    Do you agree with the conclusions of Maxwell, Gibbs, and Boltzmann, that I indicated in my post of December 30, 2011 at 10:21 AM, about uniformity of temperature at thermodynamic equilibrium in a column of air in very tall isolation chamber in a vertical gravitational field, with high pressure at the bottom and low pressure at the top?

  24. Christopher Game says:

    Reply to the posts of RW of December 30, 2011 at 11:13 PM and at 11:35 PM.

    “Narrow band” and “broadband” are not precise enough for this purpose.

    Very much most of the radiative emission from the atmosphere is, as Dr Spencer says, from clouds, water vapour, and CO2; only a very small amount from O2 and N2.

    The majority of the atmosphere is O2 and N2 gas molecules, which do plenty of colliding but not much radiative emission and absorption. Collisions with O2 and N2 convey internal energy, mostly as molecular kinetic energy, to and from CO2 and H2O molecules, which do the radiative things.

    Continuing net radiative transfer from land-sea body to atmosphere is slight in comparison with massive conductive, evaporative and convective transfers. It is not primarily the GHG collisions with N2 and O2 that heat the air in the atmosphere; the land-sea body is the main heater of the atmosphere, by way of conduction, evaporation, and convection, not radiation.

    Sunlight also directly heats the atmosphere to a lesser but still significant extent, by way of absorption. Water vapour does most of this absorbing. Slight contributions also through ozone, CO2, and clouds. The absorbed sunlight excites these molecules which then pass most of that energy to O2 and N2 by collisions.

    The atmospheric heating is balanced by the cooling effect of radiation to space from CO2 and H2O molecules.

    • RW says:

      Christopher,

      By broadband, I mean a full Planck spectrum of radiation. By narrow band, I mean radiation only of a specific wavelength, such as an individual photon at a specific frequency re-emitted by a GHG molecule.

      The radiation emitted from clouds is primarily broadband emission, is it not? There is also broadband emission from the clear sky atmosphere that passes into space, which is primarily from the heated gases of N2 and O2 since they make up most of the air in the clear sky.

      I’m aware that much of the atmosphere is heated by convection and the latent heat of evaporation as well, but I substantial portion is still heated by the radiation from the Earth’s surface, which no doubt is subject to multiple absorptions and re-emissions along its path through the atmosphere before it eventually passes into to space at the TOA.

      • RW says:

        Christopher,

        Do you at least agree that the radiative emission from the cloud tops that passes directly into space is broadband emission as a result of the temperature component (kinetic energy) of the condensed H20 molecules that make up the clouds?

  25. Eilert says:

    The essence of the Greenhouse hypothesis was always that the long wave radiation, being trapped by certain gases, results in the extra warming above the black body temperature of a planet.
    It is thus not, repeat not, sufficient to show only that radiation is being blocked by the greenhouse gases (the Tyndall effect) or that back radiation does exist and is measureable, to proof this hypothesis.
    It is actually necessary to show that this (back, trapped) radiation actually causes extra warming of the surface – the latter is only assumed by all the proponents of the greenhouse effect, from Arrhenius onwards and was never experimentally proven.
    Woods, who did the first experiment disproving this hypothesis, about 100 years ago, not long after Arrhenius proposed it, understood this. To this day this experiment, repeated recently here: http://principia-scientific.org/publications/Experiment_on_Greenhouse_Effect.pdf, remains a falsification of the greenhouse hypothesis.
    Your simple radiative transfer model has this also as a fundamental assumption. If this assumption is incorrect, then your model is an incorrect description of physical reality, even if the outcome matches the observations. ‘Gedanken experiments’, which imply this assumption, are a waste of time until it can be proven that warming, or at least the reduction of cooling, which by the way is un-measureable according to the above Woods experiment, can be proven.

    Infrared radiation is heat in transit. This heat can only be stored in matter if it is transformed into thermal kinetic energy. Thus for a body to gain a higher temperature (gain a higher energy state), it needs to retain this as internal energy.
    Where does this extra energy then come from, in the case of radiation?
    We get a clue when we compare the wavelength being absorbed by the surface of a planet, which is short wavelength solar radiation and the emitted radiation, which is longer wavelength infrared radiation, where the two wavelengths virtually do not overlap.
    Bering in mind that the energy of radiation is proportional to its frequency, according to E= h f; where E = Energy of the wave, h = Planck’s constant and f = the frequency, with f being indirectly proportional to the wavelength according to f=c/lambda, where c is the speed of light and lambda the wavelength. Thus short wavelength radiation has more energy than longer ones.
    The energy difference between the incoming absorbed and outgoing emitted radiation is the energy retained by the surface as internal energy. This internal energy can then be transformed back into infrared radiation, if the state of the adjoining material allows transmission and has a lower energy state, thus cooling the body. (Cooling of a body can also be accomplished through conduction, in conjunction with convection (in the case of an adjoining atmosphere) and in the case of our planet, through evaporation. These latter processes (especially evaporation) are far more efficient, than radiation and are the dominating processes in the lower part of the atmosphere, the troposphere.)
    When however long wave radiation is emitted back to the surface by ‘greenhouse gases’, this radiation will have the same frequency (i.e. same energy) as that originally emitted from that surface. We thus will not have an energy difference, which can be retained and the surface cannot gain extra warming from it. This actually is also true for the ‘greenhouse gases’ themselves, which do not increase their temperature, if they absorb and emit at the same frequency. They fully and virtually immediately lose the same amount of energy they have gained previously. Technically they reach a higher energy state between absorption and emission, but the interval between these processes is very small, in the order of micro seconds. Thus absorption of radiation does lead to higher temperatures, only under certain condition and not always, as is usually assumed.

    The back, trapped radiation is certainly part of the energy budget of a planet, but it is not part of the thermal energy budget. It gets dispersed and eventually will find its way out of the atmosphere, since actually less than halve of the absorbed radiation is returned to the surface of a planet.
    By the way also often overlooked, is the fact that infrared, like visible radiation, can be reflected. Water droplets in clouds do have this property. Measurements of down welling radiation cannot distinguish between emitted and reflected types, which also lead to erroneous conclusions.

    For those interested, here is another experiment that shows that radiation from colder air does not warm a warmer surface: http://principia-scientific.org/publications/New_Concise_Experiment_on_Backradiation.pdf

  26. PeterF says:

    I am surprised to hear that you are expecting an isothermal atmosphere when no GH gases are present. The calculation of an adiabatic profile nowhere assumes nor needs presence of GH gases? The difference between day and night insolation should result in plenty of disturbances for good mixing of the atmosphere.

    Sure, heat transfer into the atmosphere will be only by conduction from the surface, enhanced by convection.

    Isn’t this question – isothermal vs. adiabatic – not at the heart of the differences to which Ned Nikolov refers (further below) with reference to his “equation 8″ ?

  27. Milton Hathaway says:

    Wow, I am really lost. Nikolov’s theory is getting apparently serious treatment here, so clearly I’m missing something pretty basic.

    If the pressure of the atmosphere affects temperature, how come I don’t burn my hand on a SCUBA tank filled to 200 atmospheres? Somebody mentioned insolation; if I made a couple of SCUBA tanks out of a transparent material and put them in the sun, the tank filled to a higher pressure would get hotter?

  28. Eilert says:

    IR absorbed and emitted by ‘greenhouse gases’ are not necessary having an effect on the temperature of the atmosphere (see my comment further down about the ‘Essence of the Greenhouse hyothesis’)
    Thus measurments of this back radiation will lead to misleading interpretation of the temperature of the atmosphere and only infrared radiation as a result of thermal emission (from the bulk of the atmosphere) can lead to reliable temperaure measurments. Thermal emissions cover the full infrared spectrum, but this is intermixed with ‘back radiation’ of greenhouse gases. The only part in the emission spectrum where this is not so (or greatly reduced) is the atmospheric window, where ‘greenhouse gases’ do not absorb and emit. That is why infrared thermometers are calibrated to these frequencies.

  29. DEEBEE says:

    If it is atmospheric pressure which causes the relative warmth of the lower troposphere versus the upper troposphere, then why is the average temperature of the stratosphere virtually constant with height, despite the air pressure at the base of the stratosphere (200 millibars) being about 100x that at the top of the stratosphere (2 millibars
    ====================================
    Need to make sure that n does not change. It is PV = nRT not PV = RT. Perhaps you have the numbers, Is the n per unit volume the same?

  30. Denis Rushworth says:

    Wow! A whole series of technical arguments put forth, rebutted, corrected, and adjusted without the use of words like “fraud” or “clueless” or any other ad homonym denigrations of other people that are all too common in climate science blogs. Maybe you guys are on to something here. Maybe I can learn something. Maybe we all can.

  31. Massimo PORZIO says:

    Hi Christopher,
    what do you think about the fact that the CO2 molecules are straight at rest while the H2O ones are already bent at rest?
    In my opinion this should make the CO2 a better absorber than an emitter when mixed with H2O. That because of the greater probability to bump against two other molecules to discharge the trapped energy than the three ones needed to absorb the energy from the surroundings.
    What I mean is that in troposphere the CO2 could work like a LW “photon collector” which “grabs” the photons and spreads the energy with the surrounding gases, while H2O clould work as a “photon spreader” due to its wide band emission spectrum.

    In the meantime I wish you and Dr.Spencer a very Happy New Year.

    Massimo

  32. Christopher Game says:

    Denis Rushworth, it’s ad hominem, not ad homonym!

  33. Christopher Game says:

    Massimo PORZIO, at altitudes below 70 km, where local thermodynamic equilibrium prevails, and the excitation states of the molecules are dominated by intermolecular collisions, Kirchhoff’s law holds quite accurately for every molecular species. The molecules interact with radiation independently of one another, as determined only by their own respective states of excitation. Happy New Year also to you.

    • Massimo PORZIO says:

      Hi Christopher,
      maybe I was not clear about what I wrote. I don’t argue the Kirchhoff’s law validity. In my opinion, at thermal equilibrium the air parcel containing a mixture of WV and CO2 receives and emits the same amount of energy via photons, I’m just arguing that the spectral distribution of the absorbed photons could be different from the emitted ones. That because the incoming photons are always absorbed by the unexcited molecules of both the GHGs involved and the same molecules, once excited share the absorbed energy with the very same probability because they are both bent. While when they have to be excited from the bumps with the surrounding molecules the CO2 molecule has a lesser probability than the H2O one, this because the CO2 molecule needs that the whole three atoms bump against the surrounding molecules to bend the in-line O=C=O molecular structure, the H2O instead needs just two bumps on the oxygen atoms to bend the molecule.
      If I’m right, this could explain why the spectral pit at 15um of the Earth outgoing emission is almost wide as the one of Mars and Venus, despite the big difference in concentration of CO2 amongst the planets. In fact (only if I’m right of course), until the CO2 is mixed with WV, it absorbs the photons around the 15um and re-emits them at a reduced rate because the WV do it more efficiently spreading the photons on a broader band.

      Maybe that what I wrote above is very silly, I’m not a scientist, but I would like to know where I’m wrong.

      Again, have an happy new year.

      Massimo.

      • Massimo PORZIO says:

        Hoops!
        Sorry, I’m always the same, I read my messages after I sent them! :(

        when I wrote “needs just two bumps on the oxygen atoms to bend the molecule” I was meaning “needs just two bumps on the hydrogen atoms to bend the molecule” of course.

  34. Ned Nikolov says:

    Eilert,

    I agree with you! We are discussing some of the same reasoning in our full paper on the subject including Wood’s experiment from 1909. One would think that the question about the role of back-radiation would have been settled over 100 years ago, but it had not.

    The confusion in modern times comes from the physically inappropriate use of models. Specifically, the decoupling between radiative transfer and convective processes in GCMs. The whole case of back-radiation causing surface warming rests on the use of radiative transfer models in ISOLATION. When convection and radiative transfer are solved SIMULTANEOUSLY (i.e. as part of one and the same system of equations), then and only then one gets an accurate simulation of the real system and could reproduce Wood’s experimental results.

    Solving radiative transfer separately from convection and then adding the two temperature solution, as done in current climate models, leads to violation of the First Law of Thermodynamics by creating EXTRA energy in the troposphere in response to increasing atmospheric emissivity … In reality, any change in the down-welling IR flux (due change in emissivity) will be completely compensated by a change in the rate of convective cooling. This is how the internal energy of the system is being conserved … We discuss this in our paper, but no one seems to have understood it so far … :-)

    There is so much confusion due to people operating in the wrong paradigm.

  35. Ned Nikolov says:

    Roy,

    You say:

    “… I am claiming that pressure does not even “modify” the equilibrium temperature of the Earth.”

    How do you explain then the accuracy of Equation 7 in predicting the relative thermal enhancement across the 8 celestial bodies? How come Europa, Titan, Mars, Earth, and Venus lay all on the same steep curve?

    BTY, the integral calculating the gray-body (no atmosphere) surface temperature shown in our Equation 2 is CORRECT! The Greenhouse effect on Earth is in fact 133K, and this is evident from recent IR observations of Moon’s surface temperature by the Diviner orbiter. I will discuss this in detail in my official reply next week… Due to Holder’s inequality, one CANNOT estimate the true MEAN temperature of a spherical body from the AVERAGE absorbed radiation by that body as currently attempted. Published ‘mean’ temperatures of the Moon and Mercury are based NOT on direct spatial observations, but on a simple inversion of the S-B equation. Such approach produces an ‘emission temperature’ that is NOT physically compatible with any palatable (measurable) average temperature precisely due to the Holder’s inequality between nonlinear integrals… There is a profound confusion on this topic.

  36. RW says:

    Ned Nikolov,

    Are you one who thinks the GHE violates the 2nd law?

  37. gallopingcamel says:

    Roy Spencer,

    I am staggered when someone of your eminence and erudition says it is a “coincidence” that temperatures associated with 1 bar pressure are similar on Venus and Earth.

    Your explanations and Nikolov’s poster have a common weakness. You ignore the effect of vapors in the atmosphere that create clouds and define a Top Of the Atmosphere.

    Radiative Transfer Equations are no help when applied to what is going on at the surface because the lower atmosphere is essentially opaque to the IR radiation associated with the typical surface temperature (750 Kelvin……4 micron spectral peak). Even if some of the direct radiation from the surface gets through the lower atmosphere it will be absorbed in the 100% cloud cover that exists on Venus.

    On the other hand, Radiative Transfer Equations can explain what is going on above the cloud tops of Venus (~250 Kelvin). CO2 is strongly absorbent around 15 microns so even at low pressures it has a significant role in the heat transfer that maintains the almost constant temperature above the cloud tops.

    Nikolov is saying that the mass of an atmosphere is more significant than its composition. He got that right. You could replace the CO2 in the Venusian atmosphere with the same mass of Nitrogen and the surface temperature would be unchanged.

  38. Ned Nikolov says:

    RW,

    Our analysis shows that the current GH theory violates the First Law of thermodynamics. This is worst than violating the Second Law because the first law (conservation of energy) is the only one that is numerically exact!

    The violation of the First Law is most apparent in climate model projections, where changes in atmospheric composition produces extra energy in the lower atmosphere leading to warming. This is a result of the fact that radiative transfer (RT) and convection are NOT solved simultaneously (see most post above). Instead, RT is solved at every other time step of the model. In the context of RT alone, any increase in atmospheric emissivity (due to CO2 increase for example) produces positive heating rates (K/day) due to the low efficiency hear export through radiation. These heating rates are then passed on to the thermodynamic portion of the model and distributed around the model Earth to produce warming. If RT were solved simultaneously with convective/advective transport, the above heating rates would be ZERO owning to the incomparably higher effectiveness of convective cooling …

  39. Ned Nikolov says:

    RW,

    Our analysis shows that the current GH theory violates the First Law of thermodynamics. This is worst than violating the Second Law because the first law (conservation of energy) is the only one that is numerically exact!

    The violation of the First Law is most apparent in climate model projections, where changes in atmospheric composition produces extra energy in the lower atmosphere leading to warming. This is a result of the fact that radiative transfer (RT) and convection are NOT solved simultaneously (see my post above). Instead, RT is solved at every other time step of the model. In the context of RT alone, any increase in atmospheric emissivity (due to CO2 increase for example) produces positive Heating Rates (K/day) due to the low efficiency of heat export through radiation. These heating rates are then passed on to the thermodynamic portion of the model and distributed around the model Earth to produce warming. If RT were solved simultaneously with convective/advective transport, the above heating rates would be ZERO owning to the incomparably higher effectiveness of convective cooling …

    • RW says:

      Thank you for your answer. I’ve read over your analysis over at WUWT, but I don’t understand large parts of it.

    • RW says:

      Ned,

      You say:

      “Our analysis shows that the current GH theory violates the First Law of thermodynamics.”

      Do you mean the 3C rise GH theory from 2xCO2 or just the generally accepted theory about the GHE? They are really two different things, which is why I ask.

      I do understand that convective cooling can offset radiative warming, but I’m pretty sure Dr. Roy would agree with this too. It is well known there is net convective loss from the surface to the atmosphere, as well as from the lowers layers of the atmosphere to higher layers of the atmosphere, etc.

      It seems some of the downward emitted radiation would pass straight to the surface just some of the surface emitted radiation passes straight into space.

      I really don’t know enough about how energy flow in the models is handled to assess the credibility of your argument.

  40. RW says:

    Ned,

    You say from WUWT:

    “C) Extra Kinetic Energy in the Troposphere.
    Observations show that the lower troposphere emits 44% more radiation toward the surface than the total solar flux absorbed by the entire Earth-Atmosphere System (Pavlakis et al. 2003) (Fig. 4). Radiative transfer alone cannot explain this effect (e.g. Figs. 2 & 3) given the negligible heat storage capacity of air, no matter how detailed the model is. Thus, empirical evidence indicates that the lower atmosphere contains more kinetic energy than provided by the Sun. Understanding the origin of this extra energy is a key to the GHE.”

    Radiative transfer from where cannot explain this effect?

    Yes, there is about 240 W/m^2 coming in from the Sun, but the surface is also emitting about 390 W/m^2 – only 240 W/m^2 of which exits at the TOA. In addition, there is non-radiative flux (evapotranspiration and thermals) of about 100 W/m^2 from the surface to the atmosphere, which also emits radiation – some of which back in the direction of the surface. Some of the post albedo of 240 W/m^2 is also absorbed in the atmosphere and emitted radiatively down in the direction of the surface. The bottom line is there is plenty of power remaining or available to account for 343 W/m^2 emitted down from the lower troposphere.

  41. RW says:

    BTW, 343 W/m^2 from the lower troposphere seems a little high for a global average. Isn’t it closer to about 300 W/m^2?

  42. Ned Nikolov says:

    RW,

    By “Radiative transfer alone cannot explain this effect” I mean that if you run an atmospheric RT model by itself (with no convection) starting with an isothermal (zero lapse-rate) atmosphere, and let the model equilibrate to a certain temperature profile radiative equilibrium temperature profile, you’ll find out that the average tropospheric temperature is MUCH lower than the actual one, and the modeled down-welling IR radiation (back-radiation) does NOT exceed the 239 W m-2 of absorbed solar flux. Yet, in reality we measure 343 W m-2 IR flux towards the surface. In other words, radiative transfer alone cannot explain the 343 W m-2, nor can it explain the much warmer troposphere. Therefore, attempting to describe the large tropospheric down-welling IR radiation through transformation of solar energy inevitably leads to collision with the First Law of thermo.

    The ‘extra’ energy manifested in the lower troposphere I refer to is with respect to the absorbed solar flux ONLY, not the overall energy balance of the system.

  43. RW says:

    What I mean is the GHE as it is put forth does not require that the 343 W/m^2 or so of downward radiation from the lower troposphere be accounted for by radiative transfer alone.

  44. Ned Nikolov says:

    RW,

    What violates the 1st Law of Thermo is the EXPLANATION of the GH effect proposed by the current theory. Therefore, this explanation cannot be true, since Nature does not violate natural laws … The lower atmosphere contains more energy that the current theory can account for WITHOUT violating the conservation law. Hence, this ‘extra’ energy must have other origin than IR absorption/re-emission. That other origin is the thermal enhancing effect of pressure!

    The amazing accuracy of our Equation 8 proves that pressure and solar heating are the actual drivers of atmospheric temperature. IR radiation within the atmosphere is merely a PRODUCT of temperature, NOT a cause for it. It is a COOLING mechanism for the atmosphere, not a warming one … In this regard, it is accurate to state that the current GH theory confuses cause and effect. This confusion is qualitatively similar to the medieval notion that the Earth ware at the center of the Universe, because it ‘looks’ to us as if the Heavens rotate around us … I call it the deception of ‘apparent’ reality!

  45. RW says:

    Ned,

    You say:

    “What violates the 1st Law of Thermo is the EXPLANATION of the GH effect proposed by the current theory. Therefore, this explanation cannot be true, since Nature does not violate natural laws … The lower atmosphere contains more energy that the current theory can account for WITHOUT violating the conservation law. Hence, this ‘extra’ energy must have other origin than IR absorption/re-emission. That other origin is the thermal enhancing effect of pressure!”

    I don’t see why. The ‘extra’ energy as you call it is simply sourced from the non-radiative flux circulating from the surface to the atmosphere and back to the surface (i.e. water vapor -> clouds -> precipitation). All the non-radiative flux from the surface is in addition to the surface radiative flux, thus it is all conserved, as is the 343 W/m^2 or so of downwelling radiation from the lower troposphere.

  46. RW says:

    Ned,

    If the surface is receiving a net of 390 W/m^2 and the Sun is providing 240 W/m^2 of this, that leaves only an additional 150 W/m^2 entering the surface from the atmosphere to be accounted for by radiative transfer alone. 150 W/m^2 is less than 240 W/m^2, so there is no first law violation.

    • iya says:

      Now do the same for Venus…

      The “circulating flux” can apparently be arbitrarily small or large. Is there a machine which can achieve that radiatively?
      The backradiation can only slow the energy loss of the surface and the highest entropy state will be isothermal.

      To get a temperature gradient, there needs to be thermodynamic work done, e.g. via convection in a gravity induced pressure gradient.

  47. Ned Nikolov says:

    RW,

    You are getting confused by the fact that ACTUAL radiation fluxes balance out. Think straight!

    - the atmosphere has a negligible heat storage capacity;

    - according to the GH theory, the downward IR has its ultimate origin in the solar flux, BUT the net absorbed solar flux is is NOT enough to account for the kinetic energy observed in the lower troposphere;

    You say that the surface provides the extra energy to the atmosphere to account for the additional 44% down-welling IR flux. My question is: what’s giving the surface this higher temperature (energy)? The bottom line is this – one cannot get 343 W m-2 downward flux by recycling 239 W m-2 absorbed shortwave radiation. It’s physically impossible, which is why such an explanation directly violates the 1st law of thermo, and any theory based on such an explanation is unphysical …

  48. Ned Nikolov says:

    This is why we state that “the lower atmosphere contains more kinetic energy than provided by the Sun” … It’s not a rocket science, but an obvious fact.

  49. RW says:

    Ned,

    You say:

    “- the atmosphere has a negligible heat storage capacity;

    - according to the GH theory, the downward IR has its ultimate origin in the solar flux, BUT the net absorbed solar flux is is NOT enough to account for the kinetic energy observed in the lower troposphere;

    You say that the surface provides the extra energy to the atmosphere to account for the additional 44% down-welling IR flux. My question is: what’s giving the surface this higher temperature (energy)? The bottom line is this – one cannot get 343 W m-2 downward flux by recycling 239 W m-2 absorbed shortwave radiation. It’s physically impossible, which is why such an explanation directly violates the 1st law of thermo, and any theory based on such an explanation is unphysical …”

    The observed downward flux of about 343 W/m^2 or so is not required to be solely that of ‘recycled’ absorbed SW radiation (239 W/m^2), because much of the 343 W/m^2 flux is either from the post albedo solar flux absorbed in the atmosphere itself or sourced from the non-radiative flux from the surface to the atmosphere. Power moved non-radiatively from the surface into the atmosphere that returns to the surface as radiative flux is a net zero flux entering the surface from the atmosphere, thus the energy is conserved.

    I agree the atmosphere has a negligible heat storage capacity, especially when compared the heat capacity at and below the surface. This is why the atmosphere is more or less just acting as an energy flux ‘filter’ between the surface and space, where the energy flux from the surface to the TOA and from the atmosphere to the surface is what is actually determining the surface temperature (and not the temperature or heat capacity of atmosphere itself).

    This seems to be a major source of confusion.

  50. RW says:

    Ned,

    You say:

    “- according to the GH theory, the downward IR has its ultimate origin in the solar flux”

    I would say NO to this. According to the GH theory, as I understand it, the net energy flux entering the surface from the atmosphere (about 390 W/m^2) has its ultimate origin in the post albedo solar flux.

  51. Ned Nikolov says:

    RW,

    What kind of a background do you have? It sounds like you are not a scientists …

    Do you understand that 239 W m-2 is the TOTAL absorbed solar flux by both atmosphere and the surface. There is no ‘post albedo’ flux in addition to the 239 !!! That is ALL solar flux available to the ENTIRE system … Period!!

    Do some racing on the Earth energy budget, and then we will talk again ..

  52. RW says:

    Ned,

    “Do you understand that 239 W m-2 is the TOTAL absorbed solar flux by both atmosphere and the surface.”

    I understand that 239 W/m^2 enters the system from the Sun.

    “There is no ‘post albedo’ flux in addition to the 239 !!! That is ALL solar flux available to the ENTIRE system … Period!!”

    I know. When I refer to the ‘post albedo’ I mean the 239 W/m^2 from the Sun.

  53. Terry says:

    Ned

    Consider this thought experiment. Take a cylinder of gas at atmos P T = 273K. Compress it to 2 atm P. The temperature will be 546K. Now imagine that the cylinder is kept in an environment that allows it to equilibrate with its surroundings at 273K. The cylinder will lose energy (by IR emission perhaps some conduction) so that it becomes equal to 273K. Now the internal energy of the gas is now the same as the surrounding environment before it was compressed. It can only remain at its initial 546K by the absorption of energy from an outside source. Now the same applies to an unconfined cylinder ie a column of air in the atmosphere.

    The intrinsic energy of a molecule (and thus a column of gas) is determined entirely by the temperature according to kT where k is Boltzmann const. Not the pressure. Pressure is a variable derived entirely from the energy imparted by the kinetic energy of the individual (and thus combined in a parcel of) molecules. Pressure is analogous to potential energy, and is the force exerted by the kT kinetic energy. Pressure on its own has no intrinsic energy storage other than that exerted by kT. Before you ask about background, it is Phys Chem. I’m interested in your take on what we normally teach in 101. Cheers

    • iya says:

      The internal energy of a ideal gas is:
      U = c_v * n * R * T

      Compressed air at room temperature will have energy, because of its high density (n). A lot of machines operate on compressed air; it’s a very useful energy storage.

  54. Terry says:

    Note my choice of 546K is not intended to be precise. In fact it will not be 546K because the compression is adiabatic, but it will elevated. I realized the inaccuracy on 2nd reading of my post. But the concept is the same.

  55. RW says:

    Ned,

    You say:

    “Do you understand that 239 W m-2 is the TOTAL absorbed solar flux by both atmosphere and the surface.”

    What I mean is I understand that 239 W/m^2 from the Sun enters the system. Most of this goes straight to the surface as SW radiation. A portion of it is absorbed in the atmosphere.

  56. shawnhet says:

    I would be very interested in hearing how Mr. Nikolov answers Terry’s thought experiment above. The GH effect (whatever its magnitude) is a persistent effect and temperature increases from an increase in pressure (or atmospheric mass) are only transitory(as the atmosphere is always emitting radiation to space).

    Mr. Nikolov *may have* potentially discovered an interesting set of correlations between the properties of some of the planets in the solar system, but that does not necessarily mean that his interpretation of the mechanism underlying that correlation is correct(or even that this is anything more than coincidence).

    Cheers, :)

  57. Stephen Wilde says:

    Very pleased so far that the Nikolov paper meshes very well with my stuff and a lot of the commenters seem to get the basic idea.

    However, doesn’t the general concept go back decades ?

    At some point someone seems to have decided that atmospheric composition involving radiative processes makes a significant difference to the temperature set by thermodynamic and gravitational influences.

    I think one can deal with the resulting confusion by accepting BOTH scenarios but putting them in proper proportions.

    As I see it the GHG aspect is in the air only and the gravitational pressure aspect is in air and ocean but mostly in ocean.

    Gravity is blind to anything other than mass so the thermal characteristics of GHGs are an irrelevance to that portion of the story.

    Since downwelling IR from GHGs cannot get into the oceans it is limited in its effects to the air but the oceans control air temperaure.

    The only way the system could deal with the GHG portion of the effect is to alter the rate of energy flow from surface to space.

    In other words the GHGs fractionally alter the balance between sea surface and surface air temperatures by increasing the energy content of the air (mostly in the form of latent heat) and (possibly to a small extent) reducing the energy content of the oceans by converting incoming solar energy to longwave before it can get into the oceans.

    The system then has to correct that GHG induced imbalance between sea surface and surface air temperatures and must do so by shifting the surface air pressure distribution and the positions of the permanent climate zones.

    I think that tops and tails it very effectively.

    But the GHG effect remains miniscule compared to what sun and oceans achieve on multicentennial timescales.

    Where I do agree with Roy is that one does need to additionally consider variations in gases with a GHG effect at different layers of the atmosphere and in that respect I find that by far the biggest effect is likely to be the recent observation that above 45km ozone quantities vary naturally in response to solar variability with an opposite sign to the variations below 45km.

    I don’t see the human portion of total CO2 amounts to be likely to achieve anything near what the natural variability can achieve via solar effects on ozone quantities differentially within the vertical column of the atmosphere.

    And in the end all that any forcing will do is alter the surface pressure distribution for shifts in the permanent climate zones.

  58. Stephen Wilde says:

    Roy Spencer said:

    “5) the temperature will eventually stabilize (albeit with a rather large day-night cycle) when the average rate of energy loss equals the average rate of energy gain from the sun.

    Note I did not need to mention atmospheric pressure.”

    But the point at which the temperature stabilises is pressure dependent isn’t it?

    That provides the baseline thermodynamic greenhouse effect for a planet of given mass.

    One can then go on to see how that might be modified by GHG induced changes in the vertical temperature profile of the atmosphere.

    But on a water planet with oceans the size of those on Earth the atmospheric effect on total system energy content will be trivial.

  59. Steve Fitzpatrick says:

    Terry,

    Thanks for that comment… you saved me a lot of time! :-)

    Considering the existence of clear and straightforward explanations like Roy’s, I remained astounded at the level of confusion that the rather simple concept of lapse rate causes. Your thought experiment offers yet another path out of the confusion many suffer, but I fear they will not actually do the thought experiment. Too bad. Convection (atmospheric or otherwise) is always due to heating from below and cooling from above. The observed atmospheric lapse rate is a consequence not a cause. (Studied quite a lot of pChem myself!)

  60. Stephen Wilde says:

    “It can only remain at its initial 546K by the absorption of energy from an outside source. Now the same applies to an unconfined cylinder ie a column of air in the atmosphere”

    There is continuing absorption of energy from an outside source for as long as the sun keeps shining.

    Ned is correct subject to the very minor consideration of tiny changes in the air alone as per Roy’s point.

    Those tiny changes in the air alone get cancelled out by changes in the rate of flow from surface to space as Ned says in his paper.

    The environmental ‘cost’ of whatever the net effect of human GHG emissions happens to be is simply an infinitesilmal shift in the surface air pressure distribution.

  61. Stephen Wilde says:

    “In reality, any change in the down-welling IR flux (due change in emissivity) will be completely compensated by a change in the rate of convective cooling. This is how the internal energy of the system is being conserved … We discuss this in our paper, but no one seems to have understood it so far.”

    I have four years of work in the public domain proceeding from that very point to my own version of a “Unified Theory Of Earth’s Climate”.

    Essentially the slowing down of energy loss to space due to GHGs is exactly countered by a speeding up of the rate of energy loss to space from a faster or larger water cycle.

    The logic behind that is the fact that evaporation being a strongly net cooling process there is NO surplus ‘downwelling’ IR left over once the increased rate of evaporation has done its work. It effectively mops up ANY such IR energy left over after conduction and upward radiation have played their part.

  62. shawnhet says:

    Steven Wilde:

    “There is continuing absorption of energy from an outside source for as long as the sun keeps shining.”

    Yes, this is true but you are missing the first part of Terry’s experiment whereby the air loses energy to its surrounding environment(in the case of Earth this is to space).

    Given that, the solar input is the same the only way for the temperature increase given by the addition of mass/increase of pressure is to *simultaneously* reduce the rate of cooling.

    This is the part of the Nikolov process where *detail* is nonexistent.

    Cheers, :)

  63. shawnhet says:

    Poor wording above

    The sentence beginning with “Given that…”

    Should read –Given that the solar input is the same, the only way for the temperature increase (caused by the addition of mass/increase of pressure) to persist is to *simultaneously* reduce the rate of cooling while pressure is higher.

    Sorry about that.

  64. Terry says:

    Steven Wilde:
    “The logic behind that is the fact that evaporation being a strongly net cooling process there is NO surplus ‘downwelling’ IR left over once the increased rate of evaporation has done its work. It effectively mops up ANY such IR energy left over after conduction and upward radiation have played their part”

    Dont forget about the latent heat release that occurs during rain, that in the absence of any net change in global water (a reasonable assumption) exactly balances the evaporative loss. So latent heat (evaporative) change is net zero on a macro scale.

  65. Joel Shore says:

    Dr. Nikolov: You say, “The bottom line is this – one cannot get 343 W m-2 downward flux by recycling 239 W m-2 absorbed shortwave radiation. It’s physically impossible, which is why such an explanation directly violates the 1st law of thermo, and any theory based on such an explanation is unphysical …”

    No…It doesn’t violate the 1st Law. If you look at Trenberth’s diagram, all the energy flows balance. What does violate the first law is your “unified theory” because the only way to explain how the Earth’s surface could be emitting 390 W/m^2 radiatively while the Earth (surface + atmosphere) absorb only 240 W/m^2 is if some of this 390 W/m^2 of radiation is absorbed by the atmosphere, which is, in the simplest sense, the definition of the greenhouse effect. [I am assuming here...with excellent data to back me up...that there is no other significant source of energy than the sun, i.e., that heat from the Earth's interior is too small to be significant and that the Earth and its atmosphere are not still undergoing significant gravitational collapse.]

    Here is an analogy that might help you to understand where you go wrong in your claim of a violation of the First Law: Imagine that we get so serious about recycling aluminum that 90% of our aluminum supply in some year comes from post-consumer waste and only 10% from virgin bauxite ore. Presumably, the Ned Nikolov in that world will tell us that what we are doing is impossible because all the aluminum must originally come from bauxite ore and so there is no way to get a supply of 9 times as much aluminum as the amount that is being produced from bauxite in that year.

  66. RW says:

    Hi Joel,

    You say:

    “If you look at Trenberth’s diagram, all the energy flows balance.”

    Actually, they really don’t balance because he incorrectly mixes the radiative and non-radiative flux in a way that doesn’t account for the non-radiative flux returned to the surface as the temperature component of precipitation, wind, weather, etc.

    Mind you, I fully agree the there is no first law violation with the GHE theory, but Trenberth’s depiction is really not accurate.

  67. Stephen Wilde says:

    “Given that the solar input is the same, the only way for the temperature increase (caused by the addition of mass/increase of pressure) to persist is to *simultaneously* reduce the rate of cooling while pressure is higher.”

    The way to maintain the temperature increase is for the continuing solar irradiation to continue adding energy to the molecules held within the gravitational field at a constant pressure and density.

    Only a reduction of intensity of the solar irradiation or a reduction of the pressure by weakening the gravitational field would allow the temperature to fall back.

    Adding mass would increase the gravitational field and so lead to a further rise.

    The rise in temperature results from the process seeking and attaining a new equilibrium temperature. If you keep pressure/density (which is mass related) and energy input constant then that temperature will be maintained.

    That is the essence of the greenhouse theory itself isn’t it?

    But AGW proponents think the cause is mostly radiative when in fact it is mostly or all thermodynamic

  68. Stephen Wilde says:

    “So latent heat (evaporative) change is net zero on a macro scale.”

    The upward transfer of energy in latent form by passes the radiative process from the point of evaporation to the point of condensation. The point of condensation being much higher, what we have is accelerated radiation of energy out of the system from that higher point in the atmosphere.

    So that acceleration of the energy transfer process offsets the slowing down caused by the GHGs in the first place for a zero effect overall.

    In my view there has been a problem caused by the definitions of the greenhouse effect because there are actually two which seem to be used indiscriminately as follows:

    i) AGW theory states that the greenhouse effect is caused by gases in the air with a high thermal capacity warming the surface by radiating energy downwards.

    ii) The Nikolov paper describes the greenhouse effect in the way I have always understood it i.e. ALL the molecules near the surface (of whatever thermal capability) jostle more tightly together under the influence of gravity (and the pressure that it induces) and share kinetic activity (provoked initially by solar irradiation but actually being a consequence of all energy transfer mechanisms combined) amongst one another until that kinetic energy can escape to space by radiative means albeit slightly delayed by all the jostling about.The delay results in a temperature rise because more energy is packed into a smaller space by the effects of gravity and the consequent pressure.

    The beauty of ii) is that it decouples the greenhouse effect from the matter of composition leaving atmospheric density/pressure as the controlling factor at any given level of solar irradiation. It is the matter of composition that so distresses AGW proponents but in fact it is largely or completely irrelevant. ALL molecules at or near the surface are involved whether they be GHGs or not.

    There has been some confusion caused by Harry Huffman, Claes Johnson and others by virtue of their contention that there is no greenhouse effect when actually they mean that i) above is untrue whilst they accept ii) to be true (I think).

    Option i) would appear to breach the Laws of Thermodynamics because it implies cooler air adding new heat to a warmer surface by radiative means when in fact all it is doing is reducing the cooling rate of molecules nearer the surface.

    Nikolov covers that issue by pointing out that what has been described as back radiation from above is in fact simply the temperature of the air at the surface AFTER the GHGs have slowed the rate of energy loss to space.

    I then go on to say that a faster water cycle with more evaporation upward convection and radiation simply speeds up the rate of energy loss to space again to offset the GHG effect in slowing it down.

    Nikolov seems to concur with that too.

  69. don penman says:

    The fact that the level of warming is as low as it is given the increase in co2 is an observation it has nothing to do with the clever theory that is being put here,this theory would not have predicted the low level of sensitivity.The politicians are quite happy to move the goal posts and call any level of warming we eventually see dangerous even if that is only one degree centigrade of warming.I think that the GHG do slow down the rate of heat loss to space but that the density of the atmosphere might have something to do with the rate of heat loss to space also.

  70. Terry says:

    iya says:

    “The internal energy of a ideal gas is:
    U = c_v * n * R * T

    Compressed air at room temperature will have energy, because of its high density (n). A lot of machines operate on compressed air; it’s a very useful energy storage.”

    Partly correct. Note the term T in your eqn. The energy per molecule is given entirely by T. The total energy or pressure (or energy available to do useful work) is ratio’ed up from the energy per molecule by the mass of the gas given by n and V.

  71. iya says:

    gallopingcamel gave me an idea to fix a small part in my preferred theory:

    Not just the height of the outgoing radiation is important, but also the height where the incoming solar radiation is absorbed.
    If the incoming shortwave radiation is absorbed by high altitude clouds, these will warm upto the greybody temperature and this is translated downward by the laps rate (adiabatic heating). The average atmosphere temperature will be higher, even if all infrared would hypothetically radiate from the planet surface directly to space.
    So the thermostat (boundary condition) is the height where the atmosphere gets its greybody temperature, with incoming absorbtion height possibly more important than outgoing emission height. This explains nicely the differences between all the planets.
    The AGW question then becomes: What determines the height of clouds and can CO2 raise them?

    • iya says:

      Well, the infrared cannot radiate from the surface, because then the flux would not balance at TOA, but the idea is that the intercept of the temperature gradient = the magnitude of greenhouse warming = height of grebyody temperature is determined by incoming and outgoing absorption and emission height.

  72. shawnhet says:

    Stephen Wilde:”The way to maintain the temperature increase is for the continuing solar irradiation to continue adding energy to the molecules held within the gravitational field at a constant pressure and density.”

    Let’s see if we can unpack this a bit. Given what you say here, let’s propose that we do add a given amount of mass to the atmosphere causing temperature and pressure to increase from P1 and T1 to P2 and T2. We then remove (magically) the solar heating (SH) for a period of time until until the atmosphere cools back to T1 with the pressure staying at P2. We then restore the solar heating at the same magnitude

    What precisely is it IYO that causes P2 + SH to yield T2 where P1+SH yields T1? How does this process work?

    “The rise in temperature results from the process seeking and attaining a new equilibrium temperature. If you keep pressure/density (which is mass related) and energy input constant then that temperature will be maintained.”

    In this context, it appears that by “that temperature will be maintained” you mean that T2 will be the new equilibrium temperature. Can you explain why you think T2(and not for instance T1 or some other value) is the new equilibrium temperature? Obviously, the mere fact that the pressure is P2 does not tell you what the temperature is. Do you mean to suggest that the process of raising the temperature to T2 by way of injecting mass into the system to raise its pressure to P2 is equivalent to *taking a system that is already at P2 and heating it to T2*?

    Cheers, :)

    • iya says:

      I suggest the higher pressure leads to clouds forming at a higher altitude. (saturation pressure?)

  73. Colin Davidson says:

    For much of the CO2 band the average height of radiation to space is above the Tropopause. (Av ht for wavenumber 630 through 710 is about 17km, Source, http://scienceofdoom.com/2011/09/02/radiative-forcing-and-the-surface-energy-balance/ Comment by DeWitt Payne, 1102, 4Dec) This band emits about 70% of all the CO2 emissions to Space. Increasing CO2 will cause Stratospheric Cooling (and no change in the Troposphere)in this band.

    Consider the remaining emissions. For strongly emitting lines, with average emission height above 10km, a doubling of CO2 means average emissions from above the tropopause for about half the planet, so probably little net global heating.

    It is only the remaining, weak lines which can warm the troposphere. Shall we say 25% of the emissions? So only about 6W/m^2 is attenuated due to a higher emission height The IPCC puts this attenuation (“Radiative Forcing”) at 3.5W/m^2. Is that credible?

  74. Colin Davidson says:

    Getting back on topic.
    Assuming a one-dimensional atmosphere, and a Kiehl-Trenberth planet. We allow the planet to warm by (say) 3 DegreesC.
    The Surface must be balanced (it’s a KT world…).
    Conduction from the Surface to the air must be the same as before (otherwise one assumes a different relationship between the warmed Surface and the warmed Air, and that seems unlikely).
    The energy entering the Surface from the sun remains the same, so the 3 quantities Surface_Radiation_direct_to_Space, Net_Surface_Radiation_into_the_Atmosphere, and Evaporated_Water sum to the same amount.

    IE Any decrease in Net_Surface_Radiation_into_the_Atmosphere and in Surface_Radiation_direct_to_Space is balanced exactly by an increase in Evaporated water.

    The change in Radiation balance required to maintain the 3 DegC temperature change at the Surface is between a massive 22 and 32W/m^2.

    Even to maintain an additional 1DegC requires 7 to 11W/m^2. Elevating the atmospheric temperature by 1 degC gives about 4W/m^2, so 1DegC looks about right if all the 3.5W/m^2 Radiative Forcing is translated to the Surface, and there is no feedback.

    • RW says:

      Colin,

      I’m not sure I understand your numbers. In order to effect and sustain 3C rise in temperature, about +16 W/m^2 are required to be entering the surface from the atmosphere.

      • colin davidson says:

        Sorry for the tardy response.

        In order to MAINTAIN an increased surface temperature, either insolation or back-radiation must increase by between 6.7 and 10.5W/m^2/DegC.

        The rate of increase of back-radiation due to temperature is very roughly 5W/m^2/DegC (probably less).

        If all of the 3.5W/m^2 “Radiative Forcing” is translated to the surface, I expect a no feedback response in the range 0.4 to 0.6DegC.

        Where I live, the difference in insolation between winter and summer is 150W/m^2. The difference in average temperature is 15DegC, giving a “sensitivity” of 0.1 DegC/w/m^2. As I live inland in a dry environment, this low sensitivity strongly suggests that feedback is in fact negative (I would expect a sensitivity of about 0.15 for a neutral feedback).

  75. Konrad says:

    After reading about the Nikolov and Zeller hypothysis at WUWT I have conducted a very basic empirical experiment to check Nikolov and Zellers claims. Initial results indicate they may be correct. I am hoping that Dr. Spencer or some of the readers of this blog may have links to other similar empirical experiments that could confirm or rule out the hypothesis.

    What was done -
    - 2 identical 1.25L PETG drink bottles recovered from the new years party detritus had one side spray painted black.
    - One bottle had a input port with tap attached though it’s lid
    - Both bottles had small holes drilled in their base and probe thermometers force fitted (0.1 degree resolution)
    - The lower ends of both bottles were shielded with foam and foil to prevent solar heating of the thermometer probes.
    - A fish tank pump capable of aprox 0.1 bar was attached to the input port of one bottle with 1m of pvc tubing coiled though a tub of ice water.
    - The bottle without the pump was squeezed slightly before the cap was attached firmly, and the bottle allowed to pop back to shape
    - The bottle with the pump was pumped up until rigid and the tap was then closed
    - Both bottles were left to equalise with indoor room temperature
    - Both bottles were placed in full sun on a sheet of EPS foam with their dark side down
    - Temperature rise in both bottles was observed
    - The experiment was repeated several times, swapping bottles, caps and thermometers to eliminate rig or instrument bias

    What was observed -
    - Both bottles internal temperature quickly rose around 25C above ambient air temperature reaching around 50C
    - The bottle with the higher internal pressure exceeded that of the low pressure bottle by around 1.5 degrees (typical readings 50.5C verse 49C)
    - When bottles were warmed then shielded from the sunlight with a sheet of EPS foam, the high pressure bottle appeared to initially cool quicker

    I was surprised to see such a small pressure differential created by a fish tank pump actually cause a measurable temperature differential. While the partial pressure of radiative greenhouse gasses would be raised in the higher pressure bottle, this could not account for the observed temperature difference between the bottles. This experiment, while crude, indicates that if the Earth had a higher pressure nitrogen and oxygen atmosphere, the surface air temperature may be higher for the same amount of solar input. Nikolov and Zeller may well be correct.
    Does anyone have any links to better empirical experiments that could answer the questions raised by Nikolov and Zeller?

  76. Christopher Game says:

    Stephen Wilde on January 1, 2012 at 3:21 PM writes:

    “The beauty of ii) is that it decouples the greenhouse effect from the matter of composition leaving atmospheric density/pressure as the controlling factor at any given level of solar irradiation. It is the matter of composition that so distresses AGW proponents but in fact it is largely or completely irrelevant. ALL molecules at or near the surface are involved whether they be GHGs or not.”

    Do I understand him aright when I read this as meaning that if H2O and CO2 had the same radiative emissivity/absorptivity as N2, but retained all their other actual properties, then the temperatures would be largely the same as they are in the actual situation?

  77. Stephen Wilde says:

    “What precisely is it IYO that causes P2 + SH to yield T2 where P1+SH yields T1? How does this process work? ”

    It is the interaction between the gravitational field and the kinetic motion of the molecules held within it.

    Motion within a gravitational field produces heat energy as per E=mc2.

    The kinetic energy is converted to heat by the interaction with the graviational field. Being a conversion process rather than a creation process the Laws of Thermodynamics are complied with.

    If one has a steady supply of solar irradiation and a steady gravitational field then the higher equilibrium temperature will be maintained because the incoming solar irradiation tops up the kinetic energy as fast as the gravitational field converts it to heat.

    This is far more important as a greenhouse effect than the minor composition variations of the air because ALL molecules are included in the process.

    Indeed N & Z’s calculations actually show that the portion arising from compositional changes is ejected straight out again by convective processes for a zero net effect from changes in the composition of the air.

    I have been claiming just that for some 4 years now.

    Of course there will be minor extraneous factors affecting the speed of ejection over time and that is where Roy’s comments do have some relevance but not much in the scheme of things.

    • iya says:

      So can this be measured in the experiment Konrad did, or does it only manifest in a pressure gradient?

  78. Stephen Wilde says:

    “Do I understand him aright when I read this as meaning that if H2O and CO2 had the same radiative emissivity/absorptivity as N2, but retained all their other actual properties, then the temperatures would be largely the same as they are in the actual situation?”

    Yes.

    Gravity is concerned only with mass. It is blind to radiative characteristics of individual molecules.

    The portion of the warming that is attributable to radiative characteristics is minor and limited to trhe air and not the oceans.

    Since the oceans control the air temperature the system is forced to eject the surplus over the gravitationally induced component

    It achieves that by increased evaporation and convection which does give a tiny climate effect but not measurable as against natural variability.

    • iya says:

      Why is the stratosphere or ocean not hotter at the bottom?
      I can’t wrap my head around a purely gravitational effect. How could a hypothetically 100% transparent gas support a warm surface, i.e. how will the radiative balance be achieved?

  79. Ned Nikolov says:

    Fellows,

    I’m addressing Terry’s thought experiment and other similar comments in my formal reply. Sorry, I need to focus on the new article I’m preparing for WUWT, and do not have much time to comment extensively on individual comments here …

    I’d only say here that Terry’s thought experiment is based on incomplete information about the role/origin of pressure on a planetary scale, and as such his conclusions are physically incorrect. Consider these points:

    1) Pressure is not a potential energy, but a force per unit surface area (N m-2). Force equals Mass x Acceleration;

    2) On a planetary level, the force is produced by the atmospheric mass and gravity (gravitational acceleration). Hence, on a planetary scale, pressure is INDEPENDENT of temperature! In other words, atmospheric thermodynamics close to surface is an isobaric process (operating under nearly constant pressure). Read carefully Section 3.1 of the paper.

    3) If you increase the pressure in a container, the equilibrium temperature inside will be continuously HIGHER than that of the outside environment AS LONG AS the interior of the container receives/absorbs the SAME amount of radiation (energy) as the outside environment. What the higher pressure delivers is NOT an absolute energy, but a RELATIVE (%) thermal enhancement! The actual increase of internal energy and temperature depend on the amount of EXTERNAL heating. What does this mean? For example, the NTE factor (relative thermal enhancement) of Earth’s atmosphere is 1.863 (see Table 1 in the paper). Under current solar isolation (of 1362 W m-2), this translates into 133K higher temperature than an equivalent dray body with no atmosphere. If you move the Earth away from the Sun to some distant location in the intergalactic deep space, where ambient temperature is 2.72K, then the temperature on the Earth surface will drop to 2.72*1.863 = 5.07K. The absolute magnitude of the GH effect will be then no longer 133K, but a mere 2.35K.

    A lot of folks on this blog and at WUWT have been confusing the RELATIVE enhancement due to pressure with an actual energy content. Pressure by itself is NOT a source of energy! It only ENHANCES (magnifies) whatever energy comes from outside through density-dependent rates of molecular collision. See Section 3.3 of the paper.

  80. Jon says:

    Warm air (that has been warmed indirectly by sunlight (converted to IR from the surface)) rises and ventilate energy high up in the atmosphere.
    Because a lot of IR (energy) from the ground is ventilated “bodiedly” horizontally towards the poles and vertically the global temp is around 15 deg C instead of around 70 deg C.
    So the “greenhouse house” has a lot of broken windows on top and on the side that self regulate the temp “inside” with negative feedbacks.
    Since the temperature on average falls with about 6,6 ºC per 1000 meter climb in the atmosphere (troposphere) it also means that temperature increases with about 6,6 ºC per 1000 meter descend. So if we added more atmosphere so that the 1013 hPa average ended 1000 meter above surface we should technically get a global temperature that would be 6,6 ºC higher than today.
    The reason is, as I see it, is that when you add more atmosphere you add more vertical insulation(water vapor, CO2, methane, Ozone etc) so the energy stays longer before it is finally ventilated.
    With an inside fixed heating setting, putting more insulation in the wall and ceiling of your house would increase the inside temperature, even if there where holes in the ceiling and the walls.
    ?

  81. ausiedan says:

    Anyone wanting to argue against Dr. Nikolov’s theory needs to do two things.
    1.Explain how he can calculate the temperature of the various heavenly bodies with only irridation and pressure and still be wrong.
    2. explain how his equations lock together as they do to produce accuracte grey body temperatures, and still be wrong.

    When I say “explain” I don’t want a lot of words – I want to see equations and numbers as Dr N and Dr Z have provided.

    I’m a great fan of Dr. Spencer, but I don’t think his thought experiments are of that quality.
    Sorry. Dr. Roy.
    I know that you can do just that, but you haven’t done it as yet.

  82. Christopher Game says:

    Responding to the post of Stephen Wilde of January 2, 2012 at 1:26 AM.

    Stephen Wilde replies yes to my question, and then goes on to sketch some lines of thought.

    I just want to follow up on his answer yes to my question. This means that he is asserting that: “if H2O and CO2 had the same radiative emissivity/absorptivity as N2, but retained all their other actual properties, then the temperatures would be largely the same as they are in the actual situation.”

    Following up, I say: if H2O and CO2 were poor radiative emitters like N2 , then the temperatures would not be largely the same as they are in the actual situation. Instead, the land-sea surface and atmospheric temperatures would be significantly lower.

    Thinking about how to explain why this is so, I see it would take up more than a fair amount of time and space in this blog. It would not be appropriate for me to try to do it in a few snappy lines. May I suggest to Stephen Wilde that he read some textbooks of physics and atmospheric science about it, and then make some simple quantitative calculations to satisfy himself that it is so. Thereby he will greatly enhance his credibility.

  83. ausiedan says:

    From the above, you could get the impression that I’m a fan or even a true believer of N&Z.

    I’m not.
    I’m a seeker after truth.

    Dr’s V&Z have come up with a number of uncomfortable arguements.
    They have theory – equations – data and results.
    Disconformation must be of the same quality.

    All I hear is arm waving.
    I’m not qualified to judge.
    But I’ve done a lot of work on the equations and data and am impressed by how it all locks together in practice.

    Tennis anybody – put up a better, operational theory and show how it works in practice.

  84. ausiedan says:

    Christopher Game – if what you say is correct – how can N&Z get their results without greenhouse theory, over planets with very differnt atmospheric constituents?

    That’s the bottom line.

  85. Stephen Wilde says:

    “if H2O and CO2 were poor radiative emitters like N2 , then the temperatures would not be largely the same as they are in the actual situation. Instead, the land-sea surface and atmospheric temperatures would be significantly lower.”

    I assumed that when you said ‘temperatures’ you meant the energy content of the entire system including the oceans. I see now that you meant atmospheric temperatures.

    The total system energy content (including the oceans) would be much the same but the water cycle would be slower and the air temperatures lower.

    For reasons that I have explained extensively elsewhere the slower water cycle would reduce the rate of energy loss to space AND increase global albedo for a reduction of solar energy into the oceans. The two processes cancel out to leave total system energy content much the same.

    The baseline energy content is set by solar input to the oceans,atmospheric pressure and the properties of the phase changes of water.

    The thermal properties of GHGs don’t change that. They only affect the rate at which energy is transferred by winds across the surface and from surface to space.

  86. gallopingcamel says:

    iya,
    With all due respect to Roy Spencer and Ned Nikolov, when it comes to the processes underlying the behavior of planetary atmospheres we can learn a great deal more from Rodgigo Caballero (University College, Dublin):
    http://maths.ucd.ie/met/msc/PhysMet/PhysMetLectNotes.pdf

    The part most relevant to the present discussion starts on page 133. In particular you will note that when an atmosphere is opaque to upward IR radiation the effective radiating surface is raised.

    That is why the radiating surface of Venus has an average temperature of ~280 Kelvin rather than the 750 Kelvin that applies at the surface.

    The idea that Venus is hot because of the CO2 in its atmosphere is a fantasy created by James Hansen. The real culprits are the clouds that would prevent the direct loss of radiation from the Venusian surface even if the atmosphere was primarily Nitrogen or Helium.

    Now here is something to ponder:
    Is it possible that clouds have a greater effect on Earth’s climate than CO2 does?.

    • iya says:

      So it’s actually taught at universities! Then I don’t understand why so many people still spread the “back-radiation warms the surface” myth.
      Caballero supports what I’ve been saying; the optical depth of the atmosphere is important, the rest is thermodynamics. There can even be a local anti-greenhouse effect, if the lapse rate is negative (inversion).
      I’d like to see more comments about Nikolovs integral for the greybody temperature. If it turns out to be correct, it would not necessarily be a deal breaker; if most of the warming is from the tropics, the height of the tropopause there could support 133K warming.

  87. Mydogsgotnonose says:

    GHGs do not cool the atmosphere as you claim. By restricting the amount of IR that travels directly through the atmosphere [increasing IR optical depth], they increase the temperature of the surface by increasing IR optical path length therefore raising the IR impedance of the atmosphere.

    The surface sees this as an increase in emissivity and absorptivity of the atmosphere. If there were no GHGs, there would still be aerosols and these would cause significant optical depth because of the highly sloping part of Beer’s law.

    The main GHG, water, also causes the atmospheric temperature gradient to fall thus raising the tropopause hence raising the limit of convective cooling. Apart from this there can be no deviation from the lapse rate driven temperature gradient in the atmosphere.

    To estimate present GHG warming, use the IPCC’s thought experiment. Remove the atmosphere and the surface would be colder. However the IPCC is wrong in one key issue: remove H2O and you have no clouds or precipitation so no ice. You still have seas though. Do the radiation calculation for 0.07 albedo [instead of 0.3] and the result is 0°C so maximum GHG warming is 15 K. I have seen a modelled estimate of 9 K.

    The claim of 33 K present GHG warming is bunkum. The other 24 K is lapse rate. The 9 K represents GHG warming offset by cloud cooling.

    Any thought that convection causes deviation from lapse rate has to be resisted because thermodynamics will simply rearrange total heat content between vapour and liquid or ice forms of water…….:o)

    Finally, ‘back radiation’ cannot exist. Imagine a vacuum containing two parallel, infinite identical plates at the same temperature with perfectly insulated faces pointing away from each other. Put a radiometer between them so it measures radiant flux perpendicular to one plate. Then rotate the radiometer by 180° to face the other plate. Subtract the first signal from the second and you get zero as must be the case at constant temperature equilibrium.

    Now repeat the experiment with one plate initially at a higher temperature. The net signal will be higher in the direction hotter to colder and according to accepted heat transfer theory will decay exponentially to zero with time as the two plates equilibrate in temperature.

    Yet according to climate science, the ‘back radiation’, colder to hotter, heats up the hotter plate thus creating heat energy and increasing its temperature hence maintaining a temperature difference. Because the enclosure is perfectly insulated, the temperature of the plates never equilibrate and will in time become infinite. This is impossible.

  88. Stephen Wilde says:

    Nikolov and Zeller suggest that there is no back radiation, just the temperature of the air above the surface. I agree and this is why.

    We do not need the GHGs at all in order to set the surface temperature of the atmosphere.

    Atmospheric pressure dictates the energy value of the latent heat of vaporisation so it is atmospheric pressure that dictates the rate at which energy can leave the oceans. The more it costs in terms of energy to achieve evaporation the warmer the oceans must become before equilibrium is reached.

    So the oceans will build up to whatever temperature is permitted by atmospheric pressure with or without any GHGs in the air at all.

    Once that ocean temperature is achieved the energy for the baseline temperature of the air above the surface is then supplied to the air by energy leaving the oceans and NOT by energy coming in from the sun and especially NOT by energy flowing down from above as so called back radiation.

    So the upshot is that the oceans accumulate solar energy until they radiate 390 at current atmospheric pressure, at that point 170 continues to be added by solar but to balance the budget the atmosphere by virtue of its density retains whatever energy is required to achieve balance.

    A feature of GHGs is that they add to the temperature of the air proportionately more than other gases in the atmosphere but in the end it is surface pressure that controls the energy value of the latent heat of vaporisation which is the ultimate arbiter of what rate of energy transfer can be achieved from oceans to air.

    So if GHGs add a surplus over and above that required by surface pressure for equilibrium then the system has to make an adjustment but what it cannot do is alter the energy value of the latent heat of vaporisation in the absence of any change in atmospheric mass or pressure. So instead it is the rate of evaporation that must change to balance the budget in the absence of a significant change in surface pressure. Thus a change in the size or speed of the water cycle removes in latent form any excess energy produced as a result of GHGs.

    There is no back radiation, merely a temperature for the atmosphere just above the surface and it is wholly pressure dependent. That temperature is a consequence not of downward atmospheric scattering of outgoing longwave but simply a consequence of atmospheric density slowing down energy loss first from sea to air and then by separate mechanisms from the air above the sea surface to space.

    So if one increases atmospheric pressure at the surface the amount of energy required to provoke evaporation at the sea surface rises and the equilibrium temperature of the whole system rises including the temperature of the air above the surface.

    The opposite if one decreases atmospheric pressure at the surface.

    We have been looking at back radiation from the wrong point of view. There is no such thing. What we see is simply the air temperature near the surface and it is pressure dependent and not GHG dependent.

  89. Mydogsgotnonose says:

    What N&Z have done is to re-invent lapse rate heating…..

  90. shawnhet says:

    Ned Nikolov says:
    January 2, 2012 at 2:58 AM

    “3) If you increase the pressure in a container, the equilibrium temperature inside will be continuously HIGHER than that of the outside environment AS LONG AS the interior of the container receives/absorbs the SAME amount of radiation (energy) as the outside environment.”

    I hope your reply has some more detail here. I would actually agree with this wording I think, but I believe equilibrium temperature would only be *trivially* higher. As evidence, if one observes the changes in the specific heat of air under increasing pressure we see that specific heat(cp) increases very slowly under increasing pressure. Since the lapse rate is determined by -g/cp, we see that if cp only increases very slowly under pressure, the lapse rate can only decrease very slowly. Not to put to fine a point on it, just because the equilibrium temp is higher under a current pressure regime *does not* establish that it should be as high as you say.

    When constructing your reply, myself (and others I’m sure) would really appreciate it if you *explicitly* dealt with the fact that any container is continually losing energy to its surroundings(for Earth its surroundings are space), so any transitory source of warming like the addition of mass to the atmosphere will not persist unless there is some other process acting to maintain it.

    Cheers, :)

  91. Ned Nikolov says:

    Reply to Konrad’s comment from January 2, 2012 at 12:02 AM

    Konrad,

    I’m impressed that, only within several days since our paper was released to the public, someone has actually gone through the effort to empirically test the pressure effect on temperature. I commend you for that!

    Although, this kind of physical tests are in some ways reminiscent of returning to the level of empirical science of the 1800s and rediscovering the Gas Law (which is sad in itself), I believe that these tests must be done again today in order to rescue our modern climate science from the misguided detour it took over the past 50 years under the influence of the radiative transfer (RT) theory. Not that the RT theory is wrong in itself (I’m far from that thought), but its current APPLICATION in climate science has been severely biased to the point of total misrepresentation (and misunderstanding) of the real atmospheric/climate system. The result has been a fundamental misconception about the very nature of the so-called ‘Greenhouse Effect’. Modern climate science has confused cause and effect. It is the atmospheric temperature (set by solar heating and pressure) that gives rise to IR radiation, not the other way around! IR raditive transfer in the atmosphere is a PRODUCT (EFFECT) of temperature, not a cause for it! … :-)

  92. Jon says:

    In addition to what I say” January 2, 2012 at 3:55 AM” I have another attempt at giving a popular explanation for the “greenhouse effect”.
    U = R x I
    Global Temperature = Density of Earth’s Atmosphere at sea level (1013.2hPa)together with the Atmosphere’s positive and negative feedbacks X Sun’s Irradiance on Earth.

    ?

  93. Joel Shore says:

    ausiedan says:
    “Anyone wanting to argue against Dr. Nikolov’s theory needs to do two things.
    1.Explain how he can calculate the temperature of the various heavenly bodies with only irridation and pressure and still be wrong.
    2. explain how his equations lock together as they do to produce accuracte grey body temperatures, and still be wrong.”

    All they are doing is fitting data. Their Equation (8) has 6 free parameters, for heaven’s sake (2 that you see in that equation and 4 more buried in N_TE.)

    As John von Neumann said: “With four parameters I can fit an elephant, and with five I can make him wiggle his trunk.” (In reality, things are a bit more complicated than von Neumann says, but for the simple empirical model relating T and P that he has created, Dr. Nikolov should indeed be able to do a very good job fitting the data.)

  94. Joel Shore says:

    Ned Nikolov says: “It is the atmospheric temperature (set by solar heating and pressure) that gives rise to IR radiation, not the other way around! IR raditive transfer in the atmosphere is a PRODUCT (EFFECT) of temperature, not a cause for it! …”

    What the heck does that mean? I understand the fact that radiation from any object does depend on temperature…But are you saying that all one has to do is set the surface temperature and the atmosphere automatically adjusts itself to absorb the appropriate amount of radiation independent of its composition?!? Exactly how does that happen?

    Frankly, your statements are starting to sound more and more desperate as you try to rescue your “theory” from its fatal flaws.

    • iya says:

      No, he’s saying the temperature is determined by insolation + pressure.
      I’ve not seen an answer to the problem that with an excessively transparent atmosphere of Nitrogen or Argon, this would violate radiative equilibrium.

  95. David L. Hagen says:

    Essenhigh has developed a thermodynamically rigorous lapse rate that incorporates the summary absorptive/radiative properties of the greenhouse gases. See:

    Robert H. Essenhigh, Energy & Fuels 2006, 20, 1057-1067, “Prediction of the Standard Atmosphere Profiles of Temperature, Pressure, and Density with Height for the Lower Atmosphere by Solution of the (S-S) Integral Equations of Transfer and Evaluation of the Potential for Profile Perturbation by Combustion Emissions”

    The solution predicts, . . . a linear decline of the fourth power of the temperature, T4, with pressure, P, and, at a first approximation, a linear decline of T with altitude, h, up to the tropopause at about 10 km (the lower atmosphere). . . .the variations of pressure, P, and density, ?, with altitude, h, are also then obtained, with the predictions . . .up to 30 km altitude (1% density). . . .

  96. Konrad says:

    Ned Nikolov says:
    January 2, 2012 at 10:47 AM
    ///////////////////////////////////////////
    Ned,
    I do believe that your hypothesis does lend itself to empirical experiment. Willis, a regular contributor to WUWT, did raise some concerns about the elasticity of the plastic bottles used in my basic test. However I did propose a more expensive test earlier on the WUWT thread. If the centrifuge option were included, the scale of the test chamber would probably need to be reduced for practicality. The speed of rotation would need to be very high to create a significant pressure gradient along a test chamber. One solution may be to increase the pressure of the gas in the test chamber to 10 bar. This could allow a higher pressure gradient to be achieved with lower centrifuge speeds. I do hope you can progress this hypothesis to more elaborate empirical testing, as this is something that is very lacking in today climate science.

    From the WUWT thread -

    An experiment designed to test this is not too difficult. All that is needed is to simulate a column of atmosphere.
    1. A tall (2m tall x 200mm diameter) pressure cylinder internally insulated with 5mm of white EPS foam with ultra thin reflective foil covering. All surfaces insulated except on underside of matt black alloy top cap.
    2. A second internal cylinder of 5mm foil coated EPS foam 1945mm long 140mm external diameter suspended inside the foam lining of the pressure cylinder 25mm away from all walls and end caps.
    3. A matt black grey cast iron target disk 125mm diameter 5mm thick placed internally in the centre of the pressure cylinder base.
    4. A pressure tight glass window 20mm diameter in the top cap of the pressure cylinder.
    5. Peltier or cryogenic cooling for the top cap of the cylinder (~ -50c).
    6. High intensity external light source focused through the window in the top cap to illuminate only the cast iron target disk in the base of the cylinder.
    7. Valves for the input of various dry gasses
    8. temperature sensors for the target disk and various points up the atmospheric column.
    9. Air speed sensor for the convection loop

    How it works -
    1. the external light source is intermittently switched on and off to simulate a planets rotation.
    2. The target disk heats up and thereby heats the gasses in contact with it and also emits LWIR.
    3. Heated gasses rise up the centre of the internal cylinder, are cooled by the top cap and descend outside the internal cylinder in a convection loop.
    4. The foil covered insulation also bounces most LWIR until it impacts the cooling cap and is absorbed.

    If a higher internal pressure of dry nitrogen yields higher internal temperatures with the same external light source then Nikolov and Zellers claims are proved correct. A further slightly expensive variation on the experiment would be to mount the cylinder on a centrifuge arm and spin it to such speed that a significant pressure gradient were created along the length of the cylinder, with the light source and cooling cap being at the low pressure end.

  97. Christopher Game says:

    Responding to the post of Stephen Wilde of January 2, 2012 at 8:36 AM.

    Stephen Wilde writes: “There is no back radiation.”

    What does he mean by this sentence?

    One reading of it might be that the atmosphere in its present state does not emit thermal radiation towards the land-sea surface.

    Another reading of it might be that the net exchange of thermal radiation between the land-sea body and the atmosphere in its present state is very small.

    Perhaps there are other readings?

    • RW says:

      Christopher,

      I think what he means by it is there is no ‘back radiation’ as defined as that which last originated from surface emitted radiation.

      • zeb says:

        Ok, I am aware that a correct scientific explanation can sometimes seem like a paradox for a layman’s observations. But still: My, and others, general observation is; A clear sky night is colder than a night when clouds form or slowly roll in during the evening. Is this temperature difference caused by (i) back-radiation, (ii) reduced vertical convection or (iii) other effects?

        • iya says:

          I think it’s mainly the infrared-radiation from the clouds and maybe a little “back-radiation” and scattering of the infrared from the surface.

          The clouds are radiating because of their temperature and thus slow the cooling of the surface. The “back-radiation” is just the surface slowing the cooling of the clouds.
          If the surface is warm enough, it could theoretically warm the clouds, but it doesn’t happen because the cooling to space is stronger.

          The temperature difference between the surface and the clouds is continuously getting smaller and the whole system cools relatively slowly because of the heat capacity of the clouds.

  98. RW says:

    I’m going to propose (somewhat boldly I admit) that nearly all of the enormous confusion and misunderstanding here is the fault of Trenberth’s inaccurate and erroneous depiction of the atmospheric energy flows that both supporters and detractors of GH theory are more or less using or have in their mind as a frame of reference.

    First of all, not all of the downward LW received at the surface is ‘back radiation’ as defined as that which last originated from the surface emitted LW radiation. Downward LW received at the surface has two other sources. Some of it is ‘forward radiation’ from the Sun absorbed in the atmosphere which has yet to reach the surface (key distinction), and the remaining portion is from the non-radiative flux moved from the surface into the atmosphere (evapotranspiration and thermals), which also radiates in the LW infrared – some of which back to the surface (clouds and water vapor, especially).

    Designating the 324 W/m^2 as all ‘back radiation’, as Trenberth does, is highly misleading and is apparently why so many people are so confused.

    What Trenberth does is lump the 67 W/m^2 of the post albedo ‘absorbed by the atmosphere’ and the 102 W/m^2 of non-radiative flux in the LW return path of 324 W/m^2 received at the surface. If these are subtracted out, only 155 W/m^2 of the downward LW received at the surface is ‘back radiation’ as defined as that which last originated from the surface LW flux. 324 – 67 – 102 = 155 and 155 + 235 (67 + 168) = 390, which is the net energy flux entering the surface from the atmosphere.

    The other problem is not all of the non-radiative flux moved from the surface into the atmosphere returns to the surface in the form of LW radiation, as what then is the source of the energy in the temperature component of precipitation, for example? It’s no where to be found in Trenberth’s depiction.

    In essence, the accepted GH theory atmosphere is just one that is acting as an energy flux ‘filter’ between the surface and space, where each pass through the filter about 60% of what’s emitted from the surface escapes to space at the TOA and about 40% is ‘blocked’ by the atmosphere and returned or re-circulated back to the surface (235/390 = 0.60; 155/390 = 0.40).

    All of the non-radiative flux from the surface to the atmosphere, from the atmosphere to other parts of the atmosphere, and from the atmosphere back to the surface has to be conserved. Some of ends up radiated into space, some ends up radiated back to the surface, and some returns to the surface in non-radiative form (as the temperature component of precipitation, wind, weather, etc.). The amount of it that returns to the surface in any form is a net zero flux entering the surface from the atmosphere, and thus is conserved.

  99. Ned Nikolov says:

    Konrad,

    These tests could (and perhaps should) be performed, although it’s a bit embarrassing to try reinventing the Gas Law after 160 years. But if that’s what is going to take to get us on the right track in climate science, I’m all for it …:-)

    Here is something I have not mentioned thus far in any of the blog discussions:

    In order to truly verify Eq. (7), a nested set of 2 sealed chambers will be needed. The outer chamber should have the capacity to create vacuum by pumping out all air. The inner (nested) chamber will be the one, where different atmospheric pressure can be simulated. Two flat hard surfaces of equal reflective / emission characteristics should be constructed. One surface is placed in chamber 2 (the nested one), the other is mounted inside chamber 1 (and outside of chamber 2). Temperature sensors are mounted at a small distance above both surfaces. Different pressures are generated in chamber 2 using say 100% nitrogen, while a vacuum is created in chamber 1, and temperatures are measured above the surfaces in both chambers. Of course, bot chambers need to absorb the SAME amount of energy from an external light source.

    The goal of the whole exercise is to test the temperature enhancement in chamber 2 resulting from various in pressures relative to the ZERO-pressure conditions in chamber 1. This is important, because Eq. (7) ONLY describes the pressure-induced thermal enhancement relative to a gray body with NO atmosphere. In other words, Eq. (7) CANNOT be expected to predict the temperature lapse rate in a free atmosphere. The latter rate is typically significantly higher than calculated from Eq. (7). That’s because the convective cooling is strongest near the surface and declines with altitude in the free atmosphere.

  100. Christopher Game says:

    Responding to the posts of RW of January 2, 2012 at 6:36 PM and at 7:47 PM.

    RW is trying to get us to confuse ourselves with one of the confusions that he has adopted for himself. He is trying to get us to use a special definition of the term ‘back radiation’. Better not to use it at all, perhaps, because it is open to various interpretations, and can be replaced by less ambiguous terms. And certainly better not to use it as RW is trying to lure us into using it, so as to share his muddled state of mind.

    RW wants to split the downwelling radiation from the atmosphere to the land-sea body into moieties on the basis of the source of energy for each moiety. As a start, he wants to define as ‘back radiation’ a moiety that is sourced “from the surface emitted LW radiation”. He has no direct way of tracing the mode of sourcing “from the surface emitted LW radiation” to his “back radiation”. He must rely on a calculational model to provide the mode of sourcing. Any such model must be nonsense, and so his splitting into moieties must be nonsense too. Needless perhaps to say, RW will insist that his model is sound, but this will reveal only that he does not understand the physics.

    But for the present, perhaps indeed Stephen Wilde, for all I know, may be using the same notion of ‘back radiation’ as does RW. We must wait for Stephen Wilde to put us right on that.

  101. RW says:

    Christopher,

    You say:

    “RW wants to split the downwelling radiation from the atmosphere to the land-sea body into moieties on the basis of the source of energy for each moiety. As a start, he wants to define as ‘back radiation’ a moiety that is sourced “from the surface emitted LW radiation”. He has no direct way of tracing the mode of sourcing “from the surface emitted LW radiation” to his “back radiation”. He must rely on a calculational model to provide the mode of sourcing. Any such model must be nonsense, and so his splitting into moieties must be nonsense too. Needless perhaps to say, RW will insist that his model is sound, but this will reveal only that he does not understand the physics.”

    You’re misinterpreting what I’m saying. I’m using the term ‘back radiation’ as I’ve defined it in the context of the specific flux quantities depicted in Trenberth’s diagram. I absolutely agree with you that there is no way of ‘tracing the mode of sourcing’ for the different moieties (the energy fluxes are far too complex and chaotic for that).

    My point is we know that at the TOA only radiation enters and leaves, and we know that, excluding an infinitesimal amount from geothermal, the only source of energy is that which enters from the Sun (235 W/m^2 according to Trenberth ’97). We also know that at a temperature of 288K, the surface emits 390 W/m^2 in the LW infrared, and that in the steady-steady this must also be the net energy flux entering the surface from the atmosphere. This leaves a deficit of 155 W/m^2 that has to be explained or effected by radiative transfer or so-called radiative effects in the atmosphere. Furthermore, we also know that all the non-radiative flux from the surface to the atmosphere is in addition to the surface LW flux and all has to be (and is) conserved.

    • iya says:

      “This leaves a deficit of 155 W/m^2 that has to be explained or effected by radiative transfer or so-called radiative effects in the atmosphere.”

      No, it’s fully explained by considering that the lapse-rate is the stable configuration of an atmosphere with convection, and that the 288K is reached in the atmosphere and not on the surface.

      • iya says:

        Sorry, I meant to say Earths gray-body temperature of 254 K (or 154 K if Nikolov and Zeller are right) is reached in the atmosphere and a part of the OLR is emitted from the there.

  102. Christopher Game says:

    Response to the post of RW of January 2, 2012 at 9:26 PM.

    Sorry that I misread RW’s post of January 2, 2012 at 7:47 PM, in particular the words “‘back radiation’ as defined as that which last originated from the surface emitted LW radiation” which I interpreted wrongly as meaning that his ‘back radiation’ is a moiety of the radiation from the atmosphere to the land-sea surface.

    He now writes: “I’m using the term ‘back radiation’ as I’ve defined it in the context of the specific flux quantities depicted in Trenberth’s diagram.”

    I have no idea what he means by that. Is it another private definition of his of ‘back radiation’ that he wants us to hunt up in his previous writings?

    He now writes: “the surface emits 390 W/m^2 in the LW infrared, and … in the steady-steady this must also be the net energy flux entering the surface from the atmosphere.”

    Unless I misread this, RW is here asking us to ignore the main pathways of transfer of energy from the land-sea body to the atmosphere, by conduction, evaporation-and-condensation, and convection, put by Trenberth et al. at
    the reasonable figure of
    about (17 + 80) = 97 W m^-2.

    If this reading of mine is right, it helps to show how RW is muddling himself and seeking to muddle us. A further potential source of muddle is RW’s modifying phrase “from the atmosphere”: does he mean ‘from the material of the atmosphere excluding solar radiation that passes through the atmosphere to the land-sea surface’ or does he mean ‘from the material of the atmosphere and from solar radiation that passes through the atmosphere to the land-sea surface’?

    I will await clarification from Stephen Wilde of the question I asked in my post of January 2, 2012 at 5:59 PM.

  103. RW says:

    Christopher,

    You say:

    “He now writes: “I’m using the term ‘back radiation’ as I’ve defined it in the context of the specific flux quantities depicted in Trenberth’s diagram.”

    I have no idea what he means by that. Is it another private definition of his of ‘back radiation’ that he wants us to hunt up in his previous writings?”

    What I mean is if you look at the Trenberth diagram, the only return path to the surface is that of the downward LW radiative flux. There is no non-radiative return path or non-radiative flux entering the surface from the atmosphere.

    You say:

    “He now writes: “the surface emits 390 W/m^2 in the LW infrared, and … in the steady-steady this must also be the net energy flux entering the surface from the atmosphere.”

    Unless I misread this, RW is here asking us to ignore the main pathways of transfer of energy from the land-sea body to the atmosphere, by conduction, evaporation-and-condensation, and convection, put by Trenberth et al. at
    the reasonable figure of
    about (17 + 80) = 97 W m^-2.”

    Yes, you misread it (as usual). I’m not asking you or anyone to ignore the non-radiative flux (24 + 78 = 102 W/m^2 in K&T ’97), as it’s no doubt playing a huge role in the whole energy balance of the system and the net resulting surface temperature. The point is, to the extent that non-radiative flux is leaving the surface, it’s also being returned somewhere else, largely in equal and opposite amounts. Energy can only leave at the TOA via radiation, so all of the non-radiative flux moved from the surface into the atmosphere has to be conserved. Of course some of the non-radiative flux from the surface to the atmosphere can ultimately end up radiated out to space without getting back to the surface, resulting in a net loss of energy at the surface. A good example of this is the large net convective loss from the surface to the atmosphere, which increase the rate at which the system can cool and ultimately emit energy back out to space, but power convected from the surface that ends up radiated out to space just offsets additional power that would otherwise have to be radiated from a warmer surface in order to achieve equilibrium at the TOA.

    You say:

    “If this reading of mine is right, it helps to show how RW is muddling himself and seeking to muddle us. A further potential source of muddle is RW’s modifying phrase “from the atmosphere”: does he mean ‘from the material of the atmosphere excluding solar radiation that passes through the atmosphere to the land-sea surface’ or does he mean ‘from the material of the atmosphere and from solar radiation that passes through the atmosphere to the land-sea surface’?”

    All I mean here is that if the surface is emitting 390 W/m^2 in the LW infrared in the steady-state, then 390 W/m^2 also has to be continually replaced from the atmosphere or else the surface will lose or gain energy owning to the basic T^4 relationship between temperature and emitted power (from S-B).

    Also, since the non-radiative flux from the surface to the atmosphere is in addition the surface radiative flux, whatever amount leaves the surface and subsequently returns to the surface is considered a net zero flux entering the surface from the atmosphere. Or that if there is an imbalance – say more non-radiative flux leaves the surface than is returned to the surface on average, the surface will lose energy, cool down, and subsequently radiate less as a result. This would be a net loss of the energy entering the surface from the atmosphere, but since we are in an assumed steady-state condition with the the surface emitting 390 W/m^2, any non-radiative flux net loss or net gain is already embodied in the net of 390 W/m^2 entering the surface from the atmosphere.

  104. RW says:

    Christopher,

    You say:

    “A further potential source of muddle is RW’s modifying phrase “from the atmosphere”: does he mean ‘from the material of the atmosphere excluding solar radiation that passes through the atmosphere to the land-sea surface’ or does he mean ‘from the material of the atmosphere and from solar radiation that passes through the atmosphere to the land-sea surface’?””

    I mean the latter. The solar flux and the flux from the material of the atmosphere that is entering the surface.

  105. Terry says:

    Hi Ned

    Yes my error in stating that P is analagous to PE. I was probably thinking of the broader audience. In a confined cylinder of course PV is PE. Also the wine late at night didnt help. :)

    On a more fundamental level, I am curious to know how they measure P on the planets you cite. Historically for most I would have thought spectroscopically. I am not sufficiently up on planetary measurements to know how they arrive at the numbers, or are some of the more recent ones taken from absolute measurements on probes for those recently visited. You probably have a good idea where I am leading to with this

  106. don penman says:

    I am not certain that the assumption “we can only lose energy to space if we have greenhouse gasses emitting radiation” is true.I think if there were no GHG then we would just lose more atmosphere to space to balance the earths energy budget.

    • Jon says:

      Dry air and clear sky usually means rapid cooling. So if we did not have water vapour or GHG in our atmosphere, only N2 and no water, I think the atmosphere would almost as easily let IR out as it lets sunlight in?

  107. Ned Nikolov says:

    Don,

    The whole concept of a ‘greenhouse gas’ is somewhat distorted in the mind of the average person and even the average scientist. Most people (including Roy Spencer) seem to think that what makes a GH gas is the molecular structure of the gas. This is only partially true! The other big component is pressure. There is a phenomenon in gas spectroscopy called ‘pressure broadening of absorption lines’. Higher pressure makes any gas absorb more IR due to broadening of its absorption spectrum by reducing the gaps between absorption lines. So, any gas can become a significant GH gas under high enough pressure! This physical fact is not widely know, and rarely emphasized in undergraduate school, which is why most people have this ‘black & white’ image in their minds about what constitutes a GH gas … :-)

    The reality is that N2 and O2 (the major gases in our atmosphere) are not at all totally transparent to IR radiation. My opinion is that the IR opacity of an atmosphere is closely related to (correlated with) total surface pressure (and the vertical pressure gradient), so that there CANNOT be an atmosphere of some pressure with a zero emissivity. The IR opacity grows in parallel with pressure …

  108. Bryan says:

    We need to remember the fact that the heat capacity of a gas(Cp) contains a lot of thermodynamics.
    Many treat it as a constant and leave it at that but that is an gross oversimplification.

    For instance the formula for the dry adiabatic lapse rate is given as

    DALR = -g/Cp

    Yet a moments consideration will tell you that the air contains CO2 with all its radiative properties.
    These radiative properties are included in the bulk quantity Cp

    If we examine how Cp changes with temperature for two different gases the point will become clearer.

    A range of 250K to 350K will cover most atmospheric situations.

    For Nitrogen (N2) the values vary by 0.2% i.e. almost constant
    For CO2 the values vary by 13.1%

    Why does CO2 change so much?

    Because other degrees of freedom besides translational become possible for CO2 as the temperature changes.
    These extra degrees of freedom correspond to the 4um and 15um thermal em wavelengths

    Point being that if accurate values of Cp are used as the temperature changes then all the radiative effect are included!

    IPCC advocates on the other hand want to deal separately with radiation forgetting that it has already been included in Cp.
    This leads to double counting and the absurd greenhouse effect.

    For air with a trace of CO2 the radiative effects are very small so there is a linear decrease in temperature with increasing altitude.
    The DALR would be almost constant at -9.8K/km.

    If the Earths atmosphere was 100% composed of CO2 then at;
    300K …………..DALR = -11.6K/km
    250K …………..DALR = -12.4K/km

    So no longer a linear relationship as Cp is no longer constant but varies significantly with temperature.

  109. Christopher Game says:

    Responding to the posts of RW of January 2, 2012 at 11:44 PM and at 11:51 PM.

    RW writes: “The point is, to the extent that non-radiative flux is leaving the surface, it’s also being returned somewhere else, largely in equal and opposite amounts.” Coordinate with this, he writes: “Also, since the non-radiative flux from the surface to the atmosphere is in addition the surface radiative flux, whatever amount leaves the surface and subsequently returns to the surface is considered a net zero flux entering the surface from the atmosphere.”

    I think this may put in a nutshell where RW is thoroughly mistaken.

    It is hard to know exactly how he thinks, but my guess is that he means by the above that he imagines a downward non-radiative energy flux from the atmosphere to the surface of the land-sea body, “largely in equal and opposite amounts” to the upward “non-radiative flux (24 + 78 = 102 W/m^2 in K&T ‘97)”.

    He misunderstands the physics. There is no such “equal and opposite … non-radiative flux” as he imagines.

    The quantity (24 + 78 = 102 W/m^2 in K&T ‘97) is one-way or net flux, by construction or definition of its meaning. Any ‘return’ (equal and opposite amount) component has already been algebraically summed in this quantity.

    The physical reason is that (1) conduction (24 W m^-2) is calculated one-way, up from hot to cold body, not separated into two ways, up and down. (2) The latent heat (78 W m^-2) transfer is also one-way. Internal energy of the land-sea body is imparted to water as it evaporates from the sea into the atmosphere. That water vapour with its contained latent heat is carried aloft to form clouds and rain and snow. As it does so it yields up the latent heat / internal energy to the higher altitude atmosphere, which radiates all of it to space. Stripped of its latent heat / internal energy, the water/rain/snow falls to the land-sea body ready to undergo another round trip.

    Rain can fail to reach the land-sea surface by evaporating on the way down, absorbing, as latent heat, internal energy from the air through which it falls, and cooling that air; this tends to produce a downdraught of that cooled air, which then provides local material ‘fuel’ for another local updraught that sustains the rainstorm, which has a transient local up-and-down circulatory structure. This can very properly be regarded as a local positive feedback transient dynamical structure, analogous to an explosion if you will, and is an explanation of the episodic or occasional character of the storm. This kind of transient local non-linear dynamical structure is characteristic and typical of non-equilibrium natural transport processes. Locally it is transient positive feedback, but overall it is part of a persistent global negative feedback dynamical structure.

    Cold material going down has a virtual effect of hot material going up. The storm carries internal energy / heat irreversibly upwards in the atmosphere. This is saying that there is no equal and opposite downward transport of internal energy / heat, such as RW imagines, as I understand him.

    I think RW will not at first agree with what I have just written above. But I hope he will change his mind, and if he does so, I think it will put him out of much of his misery on this matter.

    The Trenberth et al. diagram is near enough right for the present purpose, although RW doesn’t like it.

  110. Stephen Wilde says:

    “Stephen Wilde writes: “There is no back radiation.”

    What does he mean by this sentence?”

    Ok, I’ll clarify that.

    The term usually implies that there is a net downward flux adding energy to the surface.

    In fact the net flux is always upward so I don’t accept the term ‘back radiation’ as helpful.

    What we do have is a slowing down of the rate of energy flow from the surface by virtue of the air above carrying some warmth.

    So what we measure is just the air temperature at the surface after the air higher up has slowed down the rate of upward flow of energy.

    That which is often termed back radiation is in reality just the temperature of the air at the surface. Or more accurately the temperature of the molecules immediately above the surface of an upward pointing sensor.

  111. iya says:

    If there is interest in the question of the black-body temperature, I think this is the consensus:

    The simple formula (dividing the flux by the surface, then converting to heat) is correct, because the definition of a black body includes being a perfect conductor and having the same temperature throughout.

    The alternative formula (converting the flux to heat, than averaging the temperature) is arguably a more correct (but still simplified) model for the average temperature of objects with little heat redistribution, like the Moon.

  112. Mydogsgotnonose says:

    To Stephen Wilde: 2.31 pm.

    I’ve seen papers which do a spectroscopic analysis of ‘back radiation’, really ‘Prevost Exchange Energy’ as any metallurgical process engineer like me brought up on Hottell diagrams knows well.

    This energy can do no thermodynamic work. It’s offset by equal upward energy. It’s a measure of average gas temperature convolved with emissivity.

    From clear sky there’s a lot of GHG spectral information. This is no proof it can do thermodynamic work, only of what comprises its emissivity. Under clouds it’s black body. This indicates the optical path length from which comes the radiation.

    The underlying physics is way beyond climate science because it’s the interaction between the IR densities of states of the emitter and absorber.

    My analysis of the emissivity/absorptivity is that it is a measure of the resistance to IR flux to space through the atmosphere. I do not subscribe to the 100% thermalisation idea of climate science which appears extraordinarily naive.

    Climate science must bring in external experts to solve this physics. Will Happer is about the only guy in the US but presumably he is persona non grata from having expressed his scorn at what was happening in ‘climate science’. My knowledge is insufficient.

    • iya says:

      Somebody with enough knowledge should at least audit the GCMs.

      I expect of a GCM, which claims to be a good enough simulation of reality, that the following state variables should have the respective mean and variance actually found on Earth in each simulated cell, up to the thermosphere:
      - pressure, wind, temperature, humidity, precipitation
      - concentration of trace gases
      - cloud cover
      - radiation spectrum when measured from the ground and from space

      For example the tropopause must be higher in the tropics, the cloud cover stronger, the Sahara must be dry, hot and sunny and release a big amount of OLR, the arctic should have an ozone hole and frequent temperature inversion, etc…

      All of this preferably without any magic parameters or curve fitting, just universal physics and uncontroversial boundary conditions. Changing the boundary conditions to Mars and Venus, should produce the expected results.

      Would you add anything to the list? Do current GCMs already accomplish this? If not, are supercomputers actually fast enough for such a simulation?

  113. coturnix says:

    May be i would disagree with this

    ———————————
    Thought Experiment #2 on the Pressure Effect
    Imagine we start with the atmosphere we have today, and then magically dump in an equal amount of atmospheric mass having the same heat content. Let’s assume the extra air was all nitrogen, which is not a greenhouse gas. What would happen to the surface temperature?
    ———————————

    The temperature would rise slightly, for the next reason: the IR photosphere is roughly given by voluminous concentration of co2 (disregard water vapor and line broadening in this thought ‘experiment’). Today, if we assume that Tsurface=15C and IR window passes 20% of energy, IR photosphere is located close to 400mb, which is 60% up in atmosphere. Thus, If we increase pressure twice, but keep total co2 the same, IR photosphere would be at 800mb, which 1200mb above surface. How thick would be 1200mb? Pressure with altitude falls off exponentally, so probably not much thicker. But still, it would be thicker, and thus with given lapse rate and boundary condition – temperature at IR photosphere, surface would be much warmer, unless of course radiative-alone equillibrium lapse rate, which will decrease, falls lower than moist adiabate – but even then it would be much warmer than today.

    • iya says:

      That’s what I thought at first, but actually the height should not change at all.

      You said it yourself: Pressure with altitude falls off exponentally. If p = p0 * exp(-h), then h = -ln(p/p0) and
      h(p0/2) = -ln(1/2) = const.

      Another hint is the definition of ideal gases:
      The different gases do not obstruct another; there’s enough free space between the molecules, which the additional N2 simply fills.

      • coturnix says:

        Hey, makes sense, i guess i was wrong. IR photosphere would move in pressure coordinates, but stay approx. the same in altitude. 2 times pressure increase would add 5 km of troposphere beneath modern surface (or lift modern surface 5.5 km up), but ir photosphere would move too from 400 to 800 mb, which is 1.5 km above 1000mb surface. Therefore 5.5+1.5 ~ 7 rm above surface, just like today.

        • Jon says:

          But the density/thickness of the atmosphere up to 7 km would be very different with a doubling?

          What if we made a very large crater in Sahara that was 500 km in diameter and 5000meters below today’s Sahara. Would the IR photosphere over this area move from 400 mb to 800 mb?

          Or what temperature would one expect at the bottom with today’s atmosphere?

          • coturnix says:

            My version: If mid-day sun shone down the valley of crater, temperature there would rise relative to surface at dry adiabatic lapse rate, i think. Therefore, 5*10=50 C warmer than at the surface, provided that a crater is not too big. If little or no sun shone down, air at the bottom would be comparable to or colder than at the surface.

          • Jon says:

            With a slope 1:10 at the edge you would have 50 km distance to get down to 5 km and still a 400km diameter flat area there. The Nothern slopes would also be tilted towards the sun. Sahara is around 30 deg North and is a desert due descending dry air from above. Dry adiabat of about 9 deg C pr 1000 meter should give 45 deg C more daytime than present Sahara?

          • Jon says:

            And I really have problem understanding why the laps rate would change and give the same IR photosphere height over Earth, move from 400 mb to 800 mb, for a doubling of today’s atmosphere, water vapour and other GHG?

            What is Venus and Mars IR photosphere?

  114. Christopher Game says:

    Responding to the post of Stephen Wilde of January 3, 2012 at 2:31 PM.

    Thank you Stephen Wilde for this clarification.

    As you are obviously aware, your definition the term ‘back radiation’ contrasts with some other definitions, for example that of the celebrated diagrams of Trenberth et al..

    It is not hard to agree that the term ‘back radiation’ can lead to misunderstandings when it is not carefully defined. Consequently I agree with you that the term is not necessarily helpful.

    The definition that you now offer still leaves me in a little doubt about what you mean. My doubt arises from your use of the phrase “net downward flux” in this context, especially in the context of your use of the words “the net flux is always upwards”. You seem to be using the word net in two different ways.

    Textbooks define radiative flux in two main ways. In one way, it refers to an integral of spectral radiance over direction, all in one arbitrarily prescribed sense over an arbitrarily prescribed hemisphere. The result is a scalar with arbitrarily prescribed sense and direction. This leads for example to the definition of flux that is commonly used by practical workers. In the other way, it refers to the integral of spectral radiance over all directions in both senses, that is to say to a full spherical integral with no prescribed hemisphere. The result is a vector that defines its own sense and direction. This way is used by theoreticians, such as Mihalas and Mihalas 1984.

    In the first way, which I will here call the hemispherical way, it makes sense to speak of net flux, referring to the difference between two hemispherical integrals with the hemispheres sharing a common base, but in opposite senses. Such a difference is automatically built into the full spherical integral.

    The physics and observations are still of some interest.

    The basic physical idea was first clearly set out by Pierre Prevost in 1791. He took the view that heat rays pass through each other without interacting, and we still accept that profoundly importantly view today. That is the reason why the idea of net flux is used.

    Prevost also made it clear that every body emits heat radiation completely determined by only the internal state of its material constitution, including its material temperature if such exists, and absorbs radiation so emitted from other bodies. This is known as Prevost’s exchange principle.

    Prevost stated that two bodies are in radiative exchange equilibrium just when the radiation emitted by each and absorbed by the other exactly balances the reverse limb of the exchange. Traditional versions (e.g. by Maxwell and by Planck, who make the statement but do not use the label ‘zeroth law’) of the ‘zeroth law of thermodynamics’ require that for two bodies each having its respective definite temperature, radiative exchange equilibrium prevails just when the two definite temperatures are equal. (Versions of the “zeroth law” since Fowler and Guggenheim 1939 are slick, and leave out much of the traditional statement of the law, and think they are very clever by doing so.)

    If two bodies have different respective definite temperatures, then the hotter will overall heat the colder, by Prevost’s radiative exchange, again by traditional versions of the ‘zeroth law’.

    The difference of temperature does not affect the respective one-way rates of contributions to the radiative exchange. Both always run at their natural rates. The rate of net exchange can of course be viewed as depending on the temperature difference as well as on the actual temperature of one of them. In view of this I am not too enamoured of your statement “What we do have is a slowing down of the rate of energy flow” though it may be interpreted so as to make it reasonable as you intend.

    The atmosphere and the land-sea surface do not have overall respective definite temperatures. Each has a scatter of temperatures. Radiative exchange between the atmosphere and the land-sea body is therefore determined by integrals over space, and is not easy to calculate on each particular occasion.

    Atmospheric temperature inversion is defined in textbooks. When there is no inversion of temperature, the atmosphere is colder at all altitudes than the land-sea surface underneath it. In this case it is not necessary to calculate the space integrals to be sure that there is net transfer of heat from the land-sea body to the overlying atmosphere. This is the basis of your statement that “the net flux is always upward”, though your statement safely refers only to occasions when there is no temperature inversion.

    A temperature inversion means that some layer of the atmosphere is hotter than some lower layer or than the land-sea surface. If a layer of the lowest atmosphere is hotter than the land-sea body underneath it, it can in principle quite well be that locally the net radiative exchange flux is downward not upward.

    There are perhaps three main kinds of atmospheric temperature inversion.

    Polar inversions occur in the polar winter/night. An example of a reliable calculation of radiative exchange in a polar inversion is provided by Miskolczi 2010 (https://docs.google.com/leaf?id=0B74u5vgGLaWoNDFjODAwMWMtNmNmYS00NDhmLWI3NjItMTE0NGMwNWMxYjQ2&hl=en) in Figure 5 Antartic winter A. The basic reason here is that most of the radiative exchange takes place between the lowest atmosphere and the land-sea body because most of the water vapour is in the warmer lowest atmosphere.

    Other kinds of atmospheric temperature inversion are noctural inversions and frontal inversions. I am not aware of published reliable calculations of the net radiative exchange between land-sea body and atmosphere for them.

    In general the radiative exchange between land-sea body and atmosphere is not a major contributor to the energy exchange budget between land-sea body and atmosphere. By far the main contributions there are by conduction, evaporation/condensation, and convection, as you are well aware.

    If two bodies have different respective definite temperatures and there is path for radiative exchange between them, their radiative exchange can be described by a couple of ordinary differential equations, a second-order system. In suitable cases, these equations can be approximated as linear, and the eigenvalues of the rate matrix of such a system are always real and negative, because of the zeroth law of thermodynamics coupled with the second law. This is Newton’s law of cooling, for radiation. If both are in a general environment that is colder than each, to which both are radiating to cool themselves, the cooling of the hotter bosy will be slower in the presence of the cooler body than it would be in its absence. I have read stories of “positive feedback” in this situation, but such stories are not right, because they are based on an inadequate analysis, that does not use the appropriate second-order rate analysis in terms of Newton’s law of cooling and the eigenvalues.

    In summary, when you say that “There is no back radiation”, provided the term is used as you define it, one can agree that the overall net rate of radiative heating of the atmosphere by the land-sea body is always of relatively small magnitude, and locally is often but far from always in the sense of heating the atmosphere.

    Adding CO2 to the atmosphere can slightly tend to tilt this radiative exchange balance towards heating the atmosphere, because it tends to block the atmospheric window. This thought warms the cockles of the hearts of IPCC bureaucrats and politicians and other gullible people. Though they do not have reliable scientific proof of it, and though it is probably not so, they burn with zeal to believe that it is so important as to to justify massively expensive and risky action by governments. Fie upon them!

  115. don penman says:

    A point about “back radiation” is I think that it has less energy than photons from the sun it might not provide enough energy to lift an h2o molecule into the atmosphere .I am not sure if it raises the sea surface temperature or not it could just send the radiation back into the atmosphere but if it has to do this then it would limit the amount of its energy that it could radiate over a period of time.It would heat up because it is not cooling if that makes sense.

  116. Dave Salt says:

    Dr Spencer, you say (December 30, 2011 at 5:36 PM) that pressure does not even “modify” the equilibrium temperature of the Earth. However, pressure will change the temperature rise/fall you would expect for a given amount of energy absorbed/released (i.e. the basis of the Brayton Cycle).

    Is this one of the important factors in Nikolov’s analysis?

  117. Stephen Wilde says:

    “Christopher Game says:
    January 3, 2012 at 10:37 PM”

    Strewth, Chris. I feel like I’ve been caught in the ouflow of a fire hydrant !

    I don’t disagree much with what you say but I would have expressed a couple of minor points slightly differently.

  118. Phil. says:

    You’re missing the fact that gases are not bodies! Homonuclear diatomics have no way of absorbing or emitting IR because they have no dipole, unlike CO2 and H2O. Read an undergraduate text on Physics of Gases or Molecular Spectra.

  119. RW says:

    Christopher,

    You say:

    “I think RW will not at first agree with what I have just written above. But I hope he will change his mind, and if he does so, I think it will put him out of much of his misery on this matter.”

    No, I generally agree with you have written. All I meant was the non-radiative flux has to be conserved. For sure some of the energy in the non-radiative flux ends up radiated out to space, but some is also replenished by energy absorbed in the atmosphere from the surface radiative flux and the post albedo flux from Sun.

    Whatever amount of non-radiative flux that leaves the surface and does not return to the surface in some form, is a net loss of energy entering the surface from the atmosphere.

    I’m puzzled why this is apparently so difficult to understand?

    Do you agree that energy only enters and leaves at the TOA via radiation?

    Do you agree that, excluding a tiny amount from geothermal, the only source of energy is that which enters post albedo from the Sun (about 240 W/m^2).

    Do you agree that 390 W/m^2 is the net energy flux entering the surface from the atmosphere?

    Do you believe in Conservation of Energy?

  120. Christopher Game says:

    Responding to the post of Stephen Wilde of January 4, 2012 at 9:03 AM.

    Thank you Stephen Wilde. Yes, I have to admit I was pumping it out! My excuse to myself is that the blog form tends to clever one-liners that put things so smartly that one is left not sure what exactly is meant and how well it can be supported. This ‘back radiation’ phrase comes up often enough, and, as I think you agree, is open to misreading. I was trying to put it in clear and unmistakable terms.

  121. Christopher Game says:

    Responding to the post of RW of January 4, 2012 at 5:53 PM.

    Thank you RW.

    I don’t know what you mean by writing: “the non-radiative flux has to be conserved.” On the face of it it looks like nonsense. It is probably a main element of your muddled thinking.

    You write: “I’m puzzled why this is apparently so difficult to understand?”

    With respect, I think it’s because you continue to use confusing ways of expressing yourself, and are yourself confused because you refuse to read textbooks and refuse to think systematically; I think nearly always the latter, but your way of expressing yourself is so confused that I cannot be sure in every case. Looking it over, I may guess that perhaps part of the problem may be a confusion between the words ‘total’ and ‘net’, both of which can be tricky; that’s why it’s good to write correctly formed mathematical equations, which you don’t do.

    You have asked me a series of questions apparently designed to shepherd me into accepting you way of thinking. Are you a barrister habituated to trying to make witnesses say that black is white by asking them leading questions such as “Have you stopped beating your wife”, or perhaps a teacher who can bully his students with questions of the form “Guess what I’m thinking?”

    You write: “Do you agree that energy only enters and leaves at the TOA via radiation?”

    Enters and leaves what? Every picosecond saved for the writer by use of telegraphic language is a hundred hours of puzzlement for the reader trying to make out what is meant. You think ‘Oh, surely it’s obvious what it enters and leaves, and the blog doesn’t want to be filled with redundant words.” But the result is confusion, not saved time and space. The use of the acronym TOA makes it look as if you are very clever and familiar with the thing and just don’t have time to write top of atmosphere. But really the phrase ‘top of atmosphere’ is not necessary anyway.

    I agree that the energy exchange between the earth-atmosphere system and its surroundings is only radiative.

    You write: “Do you agree that, excluding a tiny amount from geothermal, the only source of energy is that which enters post albedo from the Sun (about 240 W/m^2).”

    Source of energy for what? Yes, I can decode this, but why should I have to? Yes I agree that the only energy that enters the system is what you call “post albedo from the Sun (about 240 W/m^2)”.

    You write: “Do you agree that 390 W/m^2 is the net energy flux entering the surface from the atmosphere?” You continue to use the words ‘from the atmosphere’ in a way that I have complained about as hard to read. I will not try to decode this one. I have to say NO, I don’t agree. Moreover, on my best guess, I think it is nonsense, and is an important part of your muddled thinking.

    You write: “Do you believe in Conservation of Energy?”

    Ahem, ahem. Are you feeling exasperated with me because I don’t accept your repeatedly and repeatedly and repeatedly expressed muddled thinking?

  122. Christopher Game says:

    Note to Stephen Wilde.

    Looking back over your posts in this thread, I find that you seem overall to discount the importance of greenhouse gases for atmospheric physics, and, against Dr Spencer, you seem to agree with Ned Nikolov that pressure can account for atmospheric physics that is customarily attributed instead to greenhouse gas effects. I think you are mistaken about this, and I would like to try to find the mistake.

    In particular I would like to ask of you the same question that I asked (in my post of December 31, 2012 at 3:42 AM) of Ned Nikolov that he did not answer: “Do you agree with the conclusions of Maxwell, Gibbs, and Boltzmann, that I indicated in my post of December 30, 2011 at 10:21 AM, about uniformity of temperature at thermodynamic equilibrium in a column of air in very tall isolation chamber in a vertical gravitational field, with high pressure at the bottom and low pressure at the top?”

    You write in your post of January 4, 2012 at 9:03 AM that you don’t disagree much with what I say (in my post of January 3, 2012 at 10:37 PM), but would have expressed a couple of minor points differently. Perhaps, if you will be interested to do so, you will kindly say exactly where you disagree, even if only not much, with that post, and why. We are looking here, eventually, at slight physical effects, and slight disagreements could turn out to be important.

  123. RW says:

    Christopher,

    Let’s look at the Trenberth diagram from ’97.

    There is total of 492 W/m^2 incident on the surface (324 designated as ‘back radiation’ and 168 W/m^2 SW flux from the Sun), right?

    The diagram is showing the surface emitted LW flux into the atmosphere of only 390 W/m^2, right?

    How can the surface be receiving a total of 492 W/m^2 and only emitting 390 W/m^2 in the steady-state?

    I’ll give you a clue:

    If you subtract 102 W/m^2 from the 324 W/m^2, you get 222 W/m^2. 222 W/m^2 + 168 W/m^2 = 390 W/m^2.

    Do you really think this is a coincidence?

  124. Stephen Wilde says:

    Chris,

    I’d like to go along with your suggestion but I have a day job and have to be disciplined with my time.

    I’ll look into it myself and try to think it through and most likely engage with you again at a later time.

    Nonetheless I am satisfied that a gravitational field does aggregate mass, creating pressure and generating heat when irradiated by an outside energy source.We can term that the Gravitational greenhouse effect.

    That is basic classical physics and independent of the thermal characteristics of individual molecules.

    There is a seperate process following from the radiative aspect which we can call the Radiative greenhouse effect. and I do not deny its presence.

    However I agree with Nikolov that on a water world the system response is efficient enough to deal with the radiative greenhouse effect by not altering the total system energy content but instead shifting energy faster through the system from the surface to space.

    In the process parts of the surface warm up as energy moves faster across it but the total system energy content does not change.

    So my position and that of Nikolov is far more nuanced than seems to be currently appreciated.

  125. Stephen Wilde says:

    Actually, Nikolov’s equations seem to show that the radiative greenhouse effect is cancelled out by faster energy flows on non water worlds too and I have no reason to disbelieve him.

  126. Jon says:

    Thought Experiment #3 on the Pressure Effect

    Imagine we start with the atmosphere we have today, and then magically dump in an equal amount of atmospheric mass. Let’s assume the extra air was a copy of today’s atmosphere with the same water vapour and GHG gases. What would happen to the surface temperature?

  127. Jon says:

    If I want to insulate my house to save energy (and money) it is not the weight of the insulation that matters and have effect, but volume?
    I could probably compress the insulation to a very thin plate, to get bigger rooms, but then the effect of the insulation would mostly be lost.

    So I agree that pressure in itself is not behind GHG in Earth’s atmosphere.

    Maybee volume(density) is behind and more important and with pressure as just an effect of volume?

  128. Christopher Game says:

    Responding to the post of RW of January 4, 2012 at 9:39 PM.

    Ok, I’m looking at Figure 7 of K&T97.

    I see coming down to the land-sea surface
    168 + 324 = 492 W m^-2, just as you do.

    I see 390 W m^-2 of surface upward emitted LW radiative flux, just as you do.

    I see 24 + 78 = 102 W m^-2 of conductive-evaporative/condensative-convective upward transferred flux, which I do not see you mention when it seems to me natural that you would mention it. This is what made me write above on January 2, 2012 at 11:12 PM: “Unless I misread this, RW is here asking us to ignore the main pathways of transfer of energy from the land-sea body to the atmosphere, by conduction, evaporation-and-condensation, and convection, put by Trenberth et al. at the reasonable figure of
    about (17 + 80) = 97 W m^-2.” As I read it you still seem to ignore it, at least at this stage when it seems most relevant.

    Now you ask “How can the surface be receiving a total of 492 W/m^2 and only emitting 390 W/m^2 in the steady state?”

    I have an answer to that one. And, so far as I understand them, K&T have the same answer to it as I do:

    102 + 390 = 492 W m^-2.

    In words, the land-sea surface is losing upwards the 102 W m^-2 of conductive-evaporative/condensative-convective flux and the 390 W m^-2 of radiative flux, totalling 492 W m^-2.

    As I see it, the energy supplied downwards to the land-sea surface is equal to the energy lost upwards from that surface, each with magnitude 492 W m^-2. No problem.

    But you then write: “I’ll give you a clue:”
    and at that point you utterly lose me as to your thinking. The arithmetic is right, that 324 – 102 + 168 = 390. But it baffles me entirely as to why you would do such a calculation. What is this 222 W m^-2 but a calculated artefact? The only explanation that I can see is that you have some bizarre notion that you want to support.

  129. Christopher Game says:

    Response to the post of Stephen Wilde of January 5, 2012 at 3:56 AM.

    Thank you Stephen Wilde. Because of what you write, I will not take up your comments now, but will wait for your further thoughts on another occasion.

  130. RW says:

    Christopher, I don’t know whether your being intentionally difficult or we are genuinely talking past each other. To me this is very basic stuff.

    Reading your responses, it’s hard for me to know how to respond to you, so let me first ask you a simple question:

    Why does the surface of the Earth emit a radiative flux of 390 W/m^2?

  131. Christopher Game says:

    Response to the post of RW of January 5, 2012 at 5:23 PM.

    Dear RW, I am not being intentionally difficult. I am trying to get you to put your view in intelligible systematic form. You are asking me to spoon-feed you, and to help you with your intention of putting out your bizarre doctrine without your ever having to look at a textbook or to think systematically. On this occasion, your plan for this is to try to catechize me with questions that you intend to coerce me into accepting your bizarre doctrine. I think you have some bizarre half-formulated fixed beliefs. You did not bother to try to answer my question “What is this 222 W m^-2 but a calculated artefact?”

    I will therefore return your question to you: Why do you think that the surface of the Earth emits a radiative flux of 390 W m^-2 ? I draw your attention to the diversity of meanings of the word why, and I expect you to make a fair attempt to address enough of them, if you want me to continue to take you seriously.

    It is not beneath anyone’s dignity to address very basic stuff. Indeed I generally try to address only or at least primarily very basic stuff. I am far from sure that you know the very basic stuff as you seem to make out that you do.

  132. RW says:

    Christopher,

    The surface of emits 390 W/m^2 of LW radiation due to its temperature and emissivity, and requires 390 W/m^2 of incident power to sustain.

    If this is your idea of “bizarre half-formulated fixed beliefs” then so be it.

  133. RW says:

    Christopher,

    If the surface is losing a total of 492 W/m^2 to the atmosphere and receiving a total of 492 W/m^2, why isn’t the surface temperature 305K instead of 288K?

  134. Joel Shore says:

    Stephen Wilde says: “Actually, Nikolov’s equations seem to show that the radiative greenhouse effect is cancelled out by faster energy flows on non water worlds too and I have no reason to disbelieve him.”

    Yes…It is truly amazing what you can do if you invent a universe where the convection drives the lapse rate down to zero! In the real world that we inhabit where convection only reduces the lapse rate down to the adiabatic lapse rate, that won’t happen, water world or no water world.

    Frankly, the only reason you have no reason to disbelieve him is that you haven’t a clue. It is not like I haven’t explained this 10 times over on WUWT.

  135. Bevan says:

    The Nikolov & Zeller paper confirms what has been happening in parts of the real world over the past 30 years, namely, that there is no experimental reason to suggest that the CO2 Greenhouse Global Warming conjecture is valid on Earth.

    There are hundreds of data files from all over the globe on the WMO World Data Centre for Greenhouse Gases. Ten of these have been selected because they cover about 30 years of monthly mean CO2 concentration listings thereby
    providing a solid statistical basis for analysis. Basic statistical analysis of these has shown that, for nine
    stations, Alert (Canada), Barrow (USA), Tenerife (Spain), Mauna Loa (Hawaii), Cape Kumukahi, Guam, Ascention Island,
    Ile Amsterdam and Cape Grim (Tasmania), the average correlation coefficient between the first difference of the mean monthly satellite Lower Tropospheric temperature for the appropriate zone and the first difference of the mean
    monthly CO2 concentration was 0.0022 with a 2-tailed t-statistic probability of 72%. That is, the data gives no
    reason to reject the null hypothesis that there is no causal relationship between changes in monthly mean satellite Lower Tropospheric temperature and changes in monthly mean CO2 concentration.

    The single non-conforming station was Cape Matatula, Samoa, where the correlation coefficient was -0.1089 and the
    probability was 4.7% indicating reason to reject the null hypothesis. That is, indicating that an increase in monthly mean CO2 concentration may be causally related to a decrease in monthly mean satellite Lower Tropospheric
    temperature.

    For another paper on the subject, readers are recommended to view “The Shattered Greenhouse: How Simple Physics
    Demolished the “Greenhouse Effect”.” by Timothy Casey at http://greenhouse.geologist-1011.net/.

    There are many more data files to be studied.

  136. Christopher Game says:

    Responding to the post of RW of January 5, 2012 at 9:13 PM.

    The reason is stated clearly enough in my post of January 5, 2012 at 7:43 AM.

  137. Gordon Robertson says:

    Roy…I have been totally supportive of you and John Christy based on your sat data sets, but you need to back off on your thought experiments and look at the physics. The atmosphere is not governed by man-made heat budgets, which are the thought experiment, but through the laws of physics, which are based on observations of gases at different pressures, temperatures and volumes.

    PV = nRT tells you more about what to expect at different altitudes, and though what is found is mitigated by different processes in the atmosphere, it is more accurate than any thought experiment.

    Your heat budget thought experiment does not allow for a planet with oceans which account for 73% of the surface area. Nor does the thought experiment that the difference in temp between a planet with no oceans and no atmosphere, and a planet with both, is 33C.

    When you consider that all GHGs account for roughly 1% of atmospheric gases, it’s like taking a greenhouse with 100 panes of glass and removing 99 of the panes. Exactly how much heat will that produce in the atmosphere…certainly not 33C?

    You produced a thought experiment to show how the 2nd law of thermodynamics does not necessarily claim that heat must flow from a warmer source to a colder source. Sorry, Roy, as much as I respect you as a climate scientist, I thought you were all wet on that one too.

    When you have a surface warming 1% of the gases in an atmosphere, and only 1/1000 of 1% in the case of anthropogenic gases, it’s absurd to claim that such a rare gas, radiating in a very narrow bandwidth, could possibly raise the surface temperature, as in AGW theory.

    The 2nd law claims it can’t yet you defending the theory that it can, through thought experiments. Physics doesn’t care what you or I ‘think’, Roy, no matter how clever we thing we are. Physics is based on the observation of phenomena, and I am very thankful for that. When the human mind gets involved, science goes out the window, as can be witnessed by the current popular paradigm of anthropogenic warming.

  138. Gordon Robertson says:

    RW “Let’s look at the Trenberth diagram from ‘97.
    There is total of 492 W/m^2 incident on the surface (324 designated as ‘back radiation’ and 168 W/m^2 SW flux from the Sun), right?”

    When Trenberth claims there is more back-radiation than incident sunlight, he is surely wrong. The AGW theory has concocted that back-radiation from a bizarre interpretation of the 1st law of thermodynamics which deals with the conservation of energy. If there was that much back-radiation available, we’d have a perpetual motion device, which the 2nd law was devised to prevent.

    I regard Trenberth as a political activist, not a scientist to be taken seriously. Chris Landsea, a hurricane expert recruited by Trenberth, resigned from IPCC reviews because Trenberth meddled in his field, claiming severe weather was increasing because of global warming. Landsea felt there was no proof of that.

    In Climategate 1, Phil Jones claimed he and Kevin would make sure that certain skeptical papers were barred from IPCC reviews, even if they had to change the rules. Both Jones and Trenberth are highly influential at IPCC reviews, being coordinating lead authors.

    Trenberth also meddled in the peer review process involving a recent paper of Roy’s, claiming it should not have been published. That is none of Trenberth’s business, and his meddling lends credence to Jones’s claim in the Climategate emails, that he and Kevin would take such steps.

    In the same batch of emails, Trenberth claimed essentially that the warming has stopped. He spun it later that it has not stopped, it just cannot be found due to processes like El Nino/La Nina masking it.

    For me, scientists like Trenberth have lost their credibility. In Climategate 2, Michael Mann refers to ‘The Cause’. I think a whole lot of bad science has been foisted on us for The Cause.

  139. Christopher Game says:

    Responding to the post of Gordon Robertson of January 6, 2012 at 6:43 AM.

    Gordon Robertson writes: “You produced a thought experiment to show how the 2nd law of thermodynamics does not necessarily claim that heat must flow from a warmer source to a colder source. Sorry, Roy, as much as I respect you as a climate scientist, I thought you were all wet on that one too.”

    I suppose he is referring to Dr Spencer’s post where it says: “If you don’t like the idea of a downward flowing component to the ‘net’, then just conceptualize the effect of greenhouse gases as reducing the rate at which IR energy flows from higher temperature to lower temperature. There, 2nd Law problem solved.”

    Supposing that is indeed what Gordon Robertson is referring to:

    Dr Spencer is right, and Gordon Robertson seems to have not thoroughly understood and fully grasped what Dr Spencer said.

    Dr Spencer is reading the second law correctly to refer to the net effect of radiative exchange. More simply, this is really covered by the traditional (Maxwell-Planck) basic statements of thermodynamics which admit as presupposed the ideas of heat and temperature.

    Since Fowler and Guggenheim 1939 invented the fancy name “zeroth law” these basic statements have been more or less expunged from some textbooks which feel they are very clever in so doing. More logically, these basic statements are included in a properly stated version of the zeroth law, as indicated by Mach 1900 and others since then. The second law as stated by Clausius is about the possibility of more complicated processes than the simple passive radiative and conductive heat transfer processes referred to in the proper zeroth law, and says more than is needed for the present argument.

    As described in 1791 by Prevost’s radiative exchange principle, any two bodies exchange thermal radiation, each body emitting as determined only by its internal state. The absorption depends not only on the internal state but of course also on the incident power. In the present case the atmosphere absorbs thermal radiation emitted by the land-sea body and the land-sea body absorbs thermal radiation emitted by the atmosphere. This means that as Dr Spencer says, there is a downward flowing COMPONENT (my emphasis) to the ‘net’ exchange. This is in accord with the zeroth and the second laws.

    Carbon dioxide partly blocks the atmospheric window through which the land-sea body cools itself by radiating directly to space. This has the result that adding CO2 to the atmosphere tends to delay the passage of heat from the earth system to space, and tends to require the system to be warmer than it would be without the added CO2. If Gordon Robertson will think through the consequences of this a little more he will see that Dr Spencer is right about it. CO2 tends to produce a greenhouse effect that is not explainable simply in terms of pressures.

  140. Christopher Game says:

    Responding to the post of Gordon Robertson of January 6, 2012 at 7:22 AM.

    Gordon Robertson writes: “When Trenberth claims there is more back-radiation than incident sunlight, he is surely wrong.”

    Gordon Robertson is entirely mistaken about that. Trenberth is right about that. The ‘back-radiation’ (to use that term as defined in Trenberth’s diagram) arises mostly from the water vapour in the lower atmosphere, and, near enough for the present purpose, is in about the amount that Trenberth says.

    Gordon Robertson may check this out for himself in any reliable textbook of atmospheric physics, for example Paltridge, G.W., Platt, C.M.R. (1976), ‘Radiative Processes in Meteorology and Climatology’, Elsevier, Amsterdam, ISBN 0-444-41444-4.

    Gordon Robertson above has a shot at Trenberth, that he is a political activist more than a credible scientist. Regrettably, Gordon Robertson is showing lack of knowledge of basic atmospheric physics and on this point is himself the advocate lacking scientific credibility, and his shot doesn’t come near touching Dr Trenberth’s diagram that Gordon is attacking.

    One may value the interest of Gordon Robertson, but if his contribution is to be have credibility, he needs to do some serious homework before shooting off as he has done above about Dr Spencer and Dr Trenberth.

  141. Alan D McIntire says:

    McIntire says:
    January 5, 2012 at 6:25 am
    We use models of frictionless surfaces to understand Newton’s theory of motion even though there’s no such thing as a frictionless surface in the real world. Cars don’t stay in motion without burning extra gasoline, they gradually roll to a stop. Just as there’s no such thing as a frictionless surface in the real world, there’s no such thing as a blackbody, though we need to understand the concept to tackle real world problems.

    A blackbody radiates away heat at the same rate that it is receiving heat.
    A blackbody earth would have a temp of (1368/390.7)^0.25 * 288K= 394 K at the equator at noon, and a temp of about 2.7 K- the amount of radiation we get from the “big bang” at night.

    An atmosphere reduces the day-night temperature difference through convection. The thicker the atmosphere, the less the tropics-poles difference in temperature and the less the day-night difference in temperature.

    Some posters have stated that nitrogen and oxygen are not greenhouse gases, but this is like treating an icy surface as a frictionless surface. Just as there are no frictionless surfaces in the real world, there are no NON-greenhouse gases. EVERY gas will radiate in SOME frequencies,
    In the case of Oxygen and Nitrogen, that radiation is insignificant in computing earth’s radiation balance, but it’s there.

    In sum, a thicker atmosphere will increase surface temperature, though maybe only a small amount. More importantly, a thicker atmosphere will distribute equator-pole and day-night temperatures more equably

    Since radiation is proportional to the 4th power of temperature, a surface with
    constant temperature T will radiate away less energy than a surface with the same average
    temperature distributed differently.
    T^4 < 1/2(T+X)^4 + 1/2 (T-X)^4
    That balancing out of temperature difference by a thicker atmosphere DOES have a greenhouse effect, lowering the loss of radiation to space.

    Having said all that, the "Unified Climate" hypothesis is a case of curve fitting. You have only
    3 independent cases, Earth, Titan , and Venus, and an equation
    T= e (k1 e^X1 + k2 e^X2).

    with only 3 independent data points, Earth, Titan, and Venus, you are GUARANTEED to be able to find a two part equation k1 e^X1 + K2e^X2 to fit those 3 data points.

  142. Stephen Wilde says:

    Joel Shore said:

    “In the real world that we inhabit where convection only reduces the lapse rate down to the adiabatic lapse rate,”

    Well Joel, are you aware that ‘adiabatic’ is another word for pressure driven.

    You have elsewhere accepted that there is a pressure driven lapse rate.

    So that pressure driven lapse rate is the baseline situation.

    GHGs in the air seek to alter that lapse rate.

    But you accept that convection can reduce reduce the actual lapse rate down to the adiabatic lapse rate.

    Therefore you agree with me and Ned Nikolov that the variation from the adiabatic rate caused by GHGs can be negated by increased convection.

    Checkmate.

  143. Christopher Game says:

    Response to the post of Stephen Wilde of January 6, 2012 at 5:00 PM.

    Now, now. You write: “‘adiabatic’ is another word for pressure driven.” In the present context, an adiabatic process is one that occurs without transfer of heat by conduction or radiation. The rapid rise or fall of a parcel of air does not allow time for significant conductive or radiative heat transfer. Such rising and falling of an air parcel is due to density difference, which translates to pressure difference, not to absolute pressure value. Your temperature story is not about pressure differences, but about absolute values of pressure.

    (Without prejudice as to your statement “the variation from the adiabatic rate caused by GHGs can be negated by increased convection.”)

  144. Stephen Wilde says:

    It can all be made very simple as follows:

    i) The Greenhouse Effect however caused results from a slowing down in the transmission of solar energy into the Earth system, through the system and out again to space.

    ii) Due to that slowing down more energy accumulates within the system which heats up.

    iii) The process is exactly the same whether the slowdown is caused by gravity or by GHGs. One cannot argue that one is a breach of the Laws of Thermodynamics and the other not. Either both are or neither are.

    iv) The gravitational effect involves every atom and molecule in the system including Oxygen and Nitrogen. It is too powerful for the non radiative processes such as conduction, convection and evaporation to negate it so radiative processes have to finish the job.

    v) Thus the gravitational effect sets up the baseline lapse rate which is set as an inviolable minimum.

    vi) The GHGs add another influence on top of the gravitational effect but it is the same effect in principle. However it is limited to the atmosphere and involves only a miniscule fraction of total mass.

    vii) The thermal effect of those GHGs is to add energy to the atmosphere alone andt it does seek to increase the lapse rate over and above that set by gravity and pressure.

    viii) Due to the GHG effect being limited to the air and being proportionately tiny compared to the gravitational effect the non radiative processes have little difficulty dealing with it and the vertical temperature profile of the atmosphere changes to on average and overall restore the baseline lapse rate set by gravity.

    ix) Thus the radiative component of the greenhouse effect caused by GHGs is neutralised .

    x) The climate consequence is a shift in the surface pressure distribution which has to occur in order to accommodate the change in the vertical temperature profile of the atmosphere but it is miniscule compared to natural variations caused by sun and oceans.

  145. Bevan says:

    Surely the lack of correlation between changes in the mean monthly satellite Lower Tropospheric temperature and changes in the mean monthly CO2 concentration is about as direct evidence one could hope to get that there is no reason to accept the CO2 Greenhouse Global Warming conjecture, as set out in my posting of January 6, 2012 at 12:19 AM.

    If back-radiation from CO2 in the atmosphere is to be the reason for the 33 degree Celsius supposed discrepancy between the theoretical and the measured temperature across the Earth’s surface, then, other than the variation in albedo, the surface temperature should be the same at every point along any given latitude regardless of altitude of the surface. Each such location receives the same insolation and is under the same atmosphere containing the same concentration of CO2 so the resultant temperature should be the same all along that latitude at a given solar time of day. That is, there should not be snow on mountain tops unless they are at a latitude where snow occurs at sea level. I have not noticed that this is the case.

    The fact is that the theoretical temperature must be at the thermodynamic centre of the surface ensemble of the Earth which is composed of the land, sea, ice and atmosphere and it is, at about 4 km above sea level, without any need to invoke CO2 atmospheric warming. From there the adiabatic lapse rate provides the temperature at any given altitude of the Earth’s surface.

  146. Christopher Game says:

    Response to the post of Bevan of January 7, 2012 at 8:43 AM.

    Bevan writes: “If back-radiation from CO2 in the atmosphere is to be the reason for the 33 degree Celsius supposed discrepancy between the theoretical and the measured temperature across the Earth’s surface…”

    Water vapour is the main greenhouse gas, not CO2 as suggested by this loose expression of Bevan’s. Bevan uses a bunch of technical terms, but his reasoning does not live up to the promise of his vocabulary.

    The greenhouse effect increases the land-sea surface temperature by relatively reducing the corresponding overall (mainly tropospheric) atmospheric temperature by way of a higher lapse rate. The lower tropospheric temperature is not the decisive variable which could provide direct evidence. The decisive variable is the land-sea surface temperature, and the lower tropospheric temperature is not an adequate proxy for it. The only reliable near-proxy is the very lowest tropospheric temperature, the very lowest 20 metres above the land-sea surface.

    Greenhouse gases work on several fronts. They partly block radiation direct to space from the land-sea surface. The blocked energy tends to heat the very lowest atmosphere. They also cool the atmosphere by enhancing atmospheric radiation to space, but concomitantly that also involves also relatively cooling the atmosphere by enhancing atmospheric radiation to the land-sea body. The energy that is prevented from escaping directly to space from the land-sea surface is largely returned from the atmosphere to the land-sea body, primarily by slowing conduction and evaporation-condensation heat transfer from land-sea surface to atmosphere, and by matching every increase in land-sea surface temparature by matched increase in lowest atmosphere radiation (both upwards and downwards).

    In contrast to CO2, water vapour also has an anti-greenhouse effect. It intercepts and absorbs into the atmosphere a significant amount of sunlight on what would have been its way to heat the land-sea surface. This tends to reduce the lapse rate, so as to improve atmospheric radiation to space.

    The difficulty for science is to precisely quantitate the CO2 effect including its vey important secondary effects (called “feedback” in the lingo, not examined in the above comments). To precisely quantitate.

  147. Bevan says:

    Response to Christopher Game of January 7, 2012 at 8:37 PM.

    I used the term “CO2 Greenhouse Global Warming conjecture” as it is the current political and media imperative. However I acknowledge that water vapour is by far the main, so-called, greenhouse gas, a term that is a complete misnomer for non-diatomic gaseous molecules, all of which exhibit intra-molecular vibrational modes in response to photons of appropriate frequencies and has nothing whatsoever to do with greenhouses.

    In dismissing the satellite, lower tropospheric temperature as a suitable proxy for the land-sea surface temperature, it is informative to view surface temperature measurements, ie measurement within a Stevenson screen. My study of 108 such temperature records from stations across Western Australia and four from the Australian Antarctic Territory gave a mean rate of temperature increase of 1.01 degrees Celsius per century for the mean annual maximum temperature and 0.9 degrees Celsius per century for the mean annual minimum temperature. Interestingly this contradicts the prediction by the IPCC that the diurnal temperature range will decrease as CO2 concentration increases.

    The rate of temperature increase did not correlate with the annual mean maximum or minimum temperatures, the mean temperature difference, the station height or latitude. Unfortunately there are no corresponding records of CO2 concentration so personal knowledge of the locations was used to conclude that there was no obvious relationship between location and likely CO2 emissions. For example, the greatest rate of temperature increase was at Murchison, an area in the mid-North of Western Australia far removed from any obvious sources of CO2 which might arise from human habitation or industry.

    The next source of information in my study was the annual energy statistics for 2007 published by the International Energy Agency. Here there was information on CO2 generation but searches did not reveal many sources for nation/state rates of temperature increase. However a dramatic result was that the third ranked emitter in terms of CO2 emission per square km was Hong Kong with a rate of emission of the order of 10,000 times that at Namibia, the 133 ranked nation/state out of 137 such states. Incredibly the rate of temperature increase for Hong Kong was 1.2 degrees Celsius per century compared to the greater 1.5 degrees Celsius per century for Windhoek, the capital of Namibia.

    These results together with those stated in my entry of January 6, 2012 at 12:19 AM, confirm in my mind that the Atmospheric Greenhouse Gas Warming conjecture is false. Could you suggest other sources of data so that I might precisely quantitate the CO2 effect? Meanwhile would you please quantitate the many claims of cause and effect stated in your comments so that I can study them further. I am still most interested to know why there is snow on mountain ranges in response to the Atmospheric Greenhouse Gas Warming conjecture.

  148. Christopher Game says:

    Responding to the post of Bevan of January 8, 2012 at 3:57 AM.

    Thank you, Bevan, for this reply.

    It is comforting to read of your collection of lowest atmosphere temperature records, though you do not here state the dates of the records.

    The comparison for 2007 between Namibia and Hong Kong might tell about a local effect, but hardly about a global one, considering the variability of climate processes.

    I am not clued up on data sources. I am more concerned with understanding the physics so as to enable a theoretical calculation of the global CO2 effect. I cannot quantitate all my claims. I said it was a task to do so, not that I know how to do it. I suppose that you know much of what I wrote is right, and do not need to study most of my claims, but are challenging me nevertheless. How much should I write in response?

    Perhaps it would be useful if you challenged one or two particular claims that I made?

  149. Joel Shore says:

    Stephen Wilde says:

    “But you accept that convection can reduce reduce the actual lapse rate down to the adiabatic lapse rate.

    Therefore you agree with me and Ned Nikolov that the variation from the adiabatic rate caused by GHGs can be negated by increased convection.

    Checkmate.”

    Statements like “checkmate” just show a sort of arrogance that is completely unwarranted in your case as you are missing the whole point: It is only by driving the lapse rate down to zero that you can negate the effect of GHGs by increased convection. If you take the simple greenhouse model that N&Z start with and assume that T_g – T_a is driven down to some temperature difference as determined by the lapse rate, then you won’t get rid of the GHG effect.

    You will in general reduce it, and indeed actual quantitative calculations with radiative convective models show that the greenhouse effect is reduced by convection. However, what this means is simply that if we could turn off convection, the natural greenhouse effect would increase to be more than the ~33 K it is now. (I seem to recall some number like 50 or 60 K.)

  150. Joel Shore says:

    Stephen Wilde says:

    iii) The process is exactly the same whether the slowdown is caused by gravity or by GHGs. One cannot argue that one is a breach of the Laws of Thermodynamics and the other not. Either both are or neither are.

    They are exactly the same except that the process by which GHGs do this involves known physical mechanisms and the process by which gravity does this involves no known physical mechanism.

    The only possible mechanism your bumbling at WUWT seems to have come up with is the gravitational redshift from general relativity. However I have shown over at that site that this shift produces an effect that is in the neighborhood of one part per billion change in energy which, needless to say, is many, many orders of magnitude too small to explain what we see.

  151. Joel Shore says:

    Stephen, by the way, your statement that I just commented on reminds me of the following elephant joke:

    What do a plum and an elephant have in common?

    Answer: They’re both purple except for the elephant.

  152. Stephen Wilde says:

    “The only possible mechanism your bumbling at WUWT seems to have come up with is the gravitational redshift from general relativity”

    That is a lie.

    The matter of the redshift was raised by another and after a little discussion it was accepted that it was not relevant as being a relativity issue whereby it is an artifact of the changing relative speeds of the observer and observed.

    The matter of the wavelength of incoming solar energy being changed to longwave from shortwave via an interaction with matter in a gravitational field is however an established physical process which adds kinetic energy to the molecules involved thereby raising the temperature.

    The rate at which that energy leaves to space is then related to atmospheric density and pressure and so is affected by gravity to produce the adiabatic (pressure driven) lapse rate.

  153. Stephen Wilde says:

    I’d better retract the suggestion of lying just to be on the safe side.

  154. Bevan says:

    Response to Christopher Game of January 8, 2012 at 5:12 AM.

    Thank you for acknowledging my postings. The Australian Bureau of Meteorology temperature stations used in my study were recorded between 1876 and 2009 with a range of 8 to 112 years and an average length of 52 years.

    Regarding the comparison between the emissions from Hong Kong relative to those from Namibia, I would have thought that a ratio of 1:10,000 would more than cover any local effect and indicate that a very large rate of CO2 emissions per square km, the third greatest out of 137 nation/states, does not seem to cause any anomalous temperature increase. This was supported by a comparison between Hong Kong and Bidyadanga in the North-West of Western Australia. Both are at roughly the same latitude on either side of the Equator, are on the coast backed by a large continent and have a rate of temperature increase of 1.2 degrees Celsius per century. However Hong Kong has a population exceeding 7 million persons while Bidyadanga has a floating population of less that 900 persons and again, must have a ratio of CO2 emission of the order of 1:10,000.

    In your earlier posting of January 7, 2012 at 8:37 PM, you state that the blocked energy from greenhouse gases tends to heat the very lowest atmosphere. Is it possible that atmospheric gases heated via the release of the vibrational energy of non-diatomic gases could cause increased convection of those gases and hence increased cooling of the earth surface below?

    So far most of the data that I have reviewed has shown no statistically significant correlation between changes in temperature and those of CO2 concentration. Where the correlation has been statistically significant, the coefficient was negative, that is, an increase in CO2 concentration causing a decrease in temperature.

  155. Hi Roy. (and I am addressing this to Roy)

    I may be completely wrong but if so please help me understand why.

    You correctly state that

    “When an air parcel is raised adiabatically, it’s loss of thermal energy is balanced by an equal gain in potential energy due to its altitude. The ‘dry static energy’ of the parcel thus remains the same, which equals cpT + gZ, where cp is the specific heat capacity, T is temperature in Kelvin, g is the gravitational acceleration, and Z is height in meters.”

    I completely agree with you that the energy budget is thereby unaffected, but since the elevated air parcel now has more energy locked up as gravitational potential energy, less of the overall energy is available to be thermalised in molecular collisions etc. Therefore, the air parcel at a higher altitude is going to be colder than air parcels of equivalent energy content at a lower altitude isn’t it?

    Isn’t this exactly why at energy equilibrium (taking into consideration the ongoing throughput of solar energy and the resulting convection) there will be a vertical temperature profile tending to match the dry adiabatic lapse rate?

    If so, then:-

    The second law is happy because energy is equal across the system even though temperature is not

    Energy conservation is happy because no ex nihilo energy is being invoked to explain a warmer lower troposphere

    Sceptics are happy because radiation from co2 assumes its proper role – providing minor assistance to radiation from water vapour in mopping up slight imbalances due to local thermal disequilibrium caused by turbulent convection eddys.

    What’s the problem?

  156. Joel Shore says:

    Rog Tallbloke says: “What’s the problem?”

    The problem is with the energy balance between the Earth+atmosphere and space. You keep focusing on the balance within the atmosphere…Yes, energy can be transferred from one place to another within the atmosphere. However, you also have to have energy balance for the Earth+atmosphere as a whole.

    In other words, no matter how the energy gets moved around in the Earth+atmosphere system, you have 240 W/m^2 being absorbed by this system from the sun…So, you have to have 240 W/m^2 being emitted by the system back into space. (If you violate this balance by any significant amount, the Earth+atmosphere system will warm or cool rapidly in order to restore the balance.)

    If you have an atmosphere transparent to IR radiation, that means that the surface of the Earth must be at a temperature where it is emitting 240 W/m^2 into space. It cannot be at a temperature that is emitting more than this. It is currently at a temperature where it is emitting 390 W/m^2 or so. The only way to explain this is that the atmosphere is in fact absorbing some of the radiation emitted by the surface (a fact that is empirically verified by satellites that look at what the Earth+atmosphere emit as seen from space).

    You seem to think that if you show that the surface can be warmer than higher up, you can somehow then have the surface be as warm as you like. You can’t. In the absence of any absorption of terrestrial radiation by the atmosphere, the constraint is on the surface temperature. (When you do have absorption of terrestrial radiation by the atmosphere, then the constraint on the temperature is no longer at the surface but rather it is up at the height of some “effective radiating level” where the radiation emitted can escape to space without being absorbed.)

    This really is not that complicated; I think you have the intelligence to understand it. Whether your ideology will allow you to is another question.

  157. Joel Shore says:

    Stephen Wilde says: “The matter of the wavelength of incoming solar energy being changed to longwave from shortwave via an interaction with matter in a gravitational field is however an established physical process which adds kinetic energy to the molecules involved thereby raising the temperature.”

    Fine, so some of the radiation is absorbed and this increases the kinetic energy of the molecules. Where did this energy come from? I would say it came from the sun; hence, it is already included in the accounting that we have been doing: 240 W/m^2 in so you have to have 240 W/m^2 out.

    The gravitational field has nothing to do with it. Gravity is not some magic source of energy. The only way that one can have gravity be a source of thermal energy is if one converts gravitational potential energy into thermal energy. That is not happening IN NET in the Earth-atmosphere system. It may be that a certain parcel of air going downward loses gravitational energy and gains thermal energy, but there will be other parcels going up where the converse is true. Only in a system that is undergoing continual gravitational collapse can you have a continuous process of gravitational potential energy being converted into other forms of energy.

    If gravity is not a net source of energy for the Earth-atmosphere system, then you must have only ~240 W/m^2 of energy being emitted by the Earth-atmosphere system into space, a fact that is indeed experimentally-verified to be the case.

    The rate at which that energy leaves to space is then related to atmospheric density and pressure and so is affected by gravity to produce the adiabatic (pressure driven) lapse rate.

    No…There is no such relation. The only way that energy leaves to space is via radiation. In the absence of any absorption of terrestrial radiation, then the amount that is emitted into space is simply determined by the Earth surface’s temperature and emissivity (or, more precisely, the distribution of these over the surface).

  158. I see Joel, so you are ideaology free, but anyone who disagree with your very poor understanding of physics is blinded by their ideology.

    Next!

  159. Joel Shore says:

    I didn’t say that I am ideology-free. But, I am not so slave to my ideology that I distort the science to fit the ideology. You clearly do.

    I noticed you haven’t addressed the substance of my explanation. That is probably a wise choice on your part.

  160. I notice you preferred to talk about radiation rather than the thermodynamics of atmospheric masses, so actually you are the one who failed to address what I was saying. I simply returned the compliment. No matter, I’d prefer an answer from Roy anyway.

  161. Stephen Wilde says:

    “I would say it came from the sun; hence, it is already included in the accounting that we have been doing: 240 W/m^2 in so you have to have 240 W/m^2 out.”

    Correct – AT EQUILIBRIUM.

    But that equilibrium will be at a higher temperature if the outgoing energy takes longer to pass through a denser atmosphere.

    The density of the atmosphere being dictated by pressure and volume with pressure being a product of the gravitational field generated by the mass of the planet plus atmosphere. That is, it is determined by mass and not composition so ALL the molecules in the air are involved including non radiative molecules.

    That relegates radiative molecules to a very low order effect which is then reduced further by faster non radiative processes such as convection and conduction.

  162. Christopher Game says:

    Responding to the post of Bevan of January 9, 2012 at 8:59 AM.

    Bevan writes: “In your earlier posting of January 7, 2012 at 8:37 PM, you state that the blocked energy from greenhouse gases tends to heat the very lowest atmosphere. Is it possible that atmospheric gases heated via the release of the vibrational energy of non-diatomic gases could cause increased convection of those gases and hence increased cooling of the earth surface below?”

    Christopher replies: Yes, it will tend to increase convection, and, relative to what would be if there were not such tendency to increase convection, increased cooling of the earth surface below. But it will also tend to reduce conduction from the land-sea surface to the lowest atmosphere because of a reduced temperature gradient. Also it will tend to increase thermal radiation from the lowest atmosphere to the land-sea surface. Before it has had time to increase the temperature of the land-sea surface it will also tend to reduce net evaporation from there. The overall short-time effect will be to warm the land-sea surface to some extent, with a warmer lowest atmosphere. The eventual long-time effect will be mediated by many secondary effects and that is hard to quantitate and is most important.

    Again, the correlations that you are finding are comforting. But was it a slip of the pen to say “causing” in your last sentence which reported correlations?

  163. Christopher Game says:

    Response to the post of Stephen Wilde of January 9, 2012 at 3:03 PM.

    Stephen Wilde writes:”But that equilibrium will be at a higher temperature if the outgoing energy takes longer to pass through a denser atmosphere.

    The density of the atmosphere being dictated by pressure and volume with pressure being a product of the gravitational field generated by the mass of the planet plus atmosphere. That is, it is determined by mass and not composition so ALL the molecules in the air are involved including non radiative molecules.”

    Christopher responds: Stephen Wilde is apparently downplaying or even trying to ignore the differences in radiative properties between N2 and O2 on the one hand and H2O and CO2 on the other hand. It is true that pressure broadens emission/absorption lines of gases, but it does so for all of them, so that the H2O and CO2 still come out doing by far most of the radiative emitting and absorbing. Emission and absorption are important in determining radiation to space which cannot be downplayed or ignored. This has two sides: radiation from the land-sea surface to space through the atmospheric window, and from the atmosphere to space through non-window wavelengths. CO2 tends to block the atmospheric window which is a radiative effect; that is why it has a greenhouse effect.

    Stephen Wilde also writes: “That relegates radiative molecules to a very low order effect which is then reduced further by faster non radiative processes such as convection and conduction.”

    Christopher responds: It is true that radiation is not very important in transferring heat from one part of the atmosphere to another, in comparison with the main effects, convection, conduction, and evaporation/condensation. It is also true that the non-radiative mechanisms are more effective at transferring heat between land-sea body and atmosphere, though in this case radiation cannot be ignored altogether. That doesn’t negate that radiation is the only factor that transfers energy to space.

  164. Stephen Wilde says:

    “trying to ignore the differences in radiative properties between N2 and O2 on the one hand and H2O and CO2 on the other hand.”

    Not so. I am fully recognising the differences but pointing out that there is a process capable of providing much or all of the observed temperature which does not recognise those differences.

    Gravity and the pressure it creates is blind to everything but mass.

    Not much point blaming the messenger.

    “It is also true that the non-radiative mechanisms are more effective at transferring heat between land-sea body and atmosphere,”

    That is important. Whereas there might be a net deceleration of energy loss to space from the downward IR from GHGs (not certain though because the upward radiation expels energy faster than Oxygen or Nitrogen would do it) the non radiative processes are strong enough to speed it up again by a corresponding amount.

    Radiation is indeed the only process that transfers energy to space but non radiative processes transfer it faster from surface to tropopause and thence by radiation to space.

  165. Christopher Game says:

    Response to the post of Stephen Wilde of January 9, 2012 at 4:16 PM.

    Stephen Wilde writes: “I am fully recognising the differences but pointing out that there is a process capable of providing much or all of the observed temperature which does not recognise those differences.”

    I would like your response to my post in this column, of December 30, 2011 at 10:21 AM. I also asked of Ned Nikolov the same in my post of December 31, 2011 at 3:42 AM, with no reply.

    For the reasons in that post I think you are very far from fully recognising the differences. The main driving factors of the lapse rate are radiation from the atmosphere to space and the non-radiative transfer from land-sea surface to atmosphere, but in the background there is a near balance of large amounts of radiative transfer between land-sea surface and atmosphere. Small disturbances of that radiative near-balance are important.

    The atmosphere at night, looking out at space, sees an environment at about 3K. That is one side of the main driving mechanism of the lapse rate. In the lower and middle tropopause, convection reduces that mainly driven lapse rate. If you doubt the power of radiation, consider the nocturnal inversions that one finds in the deserts or at the poles. The nocturnal inversions are best felt on windless nights.

  166. Joel Shore says:

    Stephen Wilde says:

    “Radiation is indeed the only process that transfers energy to space but non radiative processes transfer it faster from surface to tropopause and thence by radiation to space.”

    That is an interesting trick whereby an atmosphere transparent to terrestrial radiation nonetheless manages to radiate it!

  167. Joel Shore says:

    Rog Tallbloke says: “I notice you preferred to talk about radiation rather than the thermodynamics of atmospheric masses, so actually you are the one who failed to address what I was saying. I simply returned the compliment.”

    That is because thermodynamics of atmospheric masses have nothing to do with how much radiation the Earth’s surface emits at a given surface temperature.

  168. Stephen Wilde says:

    “That is an interesting trick whereby an atmosphere transparent to terrestrial radiation nonetheless manages to radiate it!”

    Haven’t you heard about water vapour?

    “thermodynamics of atmospheric masses have nothing to do with how much radiation the Earth’s surface emits at a given surface temperature.”

    It has very much to do about how the temperature was achieved in the first place.

  169. Stephen Wilde says:

    Christopher, your unanswered question was:

    “Do you agree with the conclusions of Maxwell, Gibbs, and Boltzmann, that I indicated in my post of December 30, 2011 at 10:21 AM, about uniformity of temperature at thermodynamic equilibrium in a column of air in very tall isolation chamber in a vertical gravitational field, with high pressure at the bottom and low pressure at the top?”

    That subject is currently under discussion here:

    http://tallbloke.wordpress.com/2012/01/04/the-loschmidt-gravito-thermal-effect-old-controversy-new-relevance/

    The answer seems far from clear at present.

    You said:

    “The main driving factors of the lapse rate are radiation from the atmosphere to space and the non-radiative transfer from land-sea surface to atmosphere,”

    I’ve always understod the baseline minimum lapse rate to be a product of atmospheric pressure at the surface with radiative and non radiative energy transfers tending to alter that basic lapse rate but at equilibrium (if it could be maintained) the system would return to the baseline lapse rate set by pressure.

  170. Joel Shore says:

    Stephen Wilde says: “Haven’t you heard about water vapour?”

    Yes, I have heard of it but the only way that water vapor can radiate is if it is what we call a “greenhouse gas”, i.e., a substance that can absorb and radiate terrestrial radiation.

    I am not disagreeing that the temperature of the Earth’s surface can be such that it is emitting 390 W/m^2 rather than just 240 W/m^2 but it can only be the case if there are substances in the atmosphere that absorb some of this terrestrial radiation, or in other words, if there is a greenhouse effect.

    “It has very much to do about how the temperature was achieved in the first place.”

    The point is that in the absence of an IR-absorbing atmosphere, the constraint is on the surface temperature because that will determine how much energy goes back out into space…and that amount must equal the amount absorbed from the sun. So, while issues of pressure and gravity et al. may come in when you want to determine the entire temperature structure, they won’t come in when you want to determine just the temperature of the surface.

    For the case of an IR-absorbing atmosphere, the constraint for the temperature is at the effective radiating level and the temperature at the surface is determined by extrapolating down from that height to the surface using the lapse rate. Since the dry adiabatic lapse rate is proportional to the gravitational acceleration, gravity is an important consideration in such a case. As I have explained before, the adiabatic lapse rate (and hence gravity) help to determine how much of the radiative greenhouse effect gets cancelled out by convection.

  171. Christopher Game says:

    Response to the post of Stephen Wilde of January 10, 2012 at 9:06 AM.

    Thank you for this response, Stephen Wilde.

    Some references on the matter are

    Chapman, S., Cowling, T.G., (1939/…) ‘The Mathematical Theory of Non-uniform Gases: An Account of the Kinetic Theory of Viscosity, and Thermal Diffusion in Gases’, Cambridge Uinversity Press, Chapter 4, ‘Boltzmann’s H-theorem and the Maxwellian velocity-distribution’.

    Coombes, C.A., Laue, H. (1985) ‘A paradox concerning the temperature distribution of a gas in a gravitational field’, ‘Am. J. Phys.’ 53: 272-273.

    Román, F.L., White, J.A., Velasco, S. (1996) ‘Microcanonical single-particle distributions for an ideal gas in a gravitational field’, ‘Eur. J. Phys.’ 16: 83-90.

    Velasco, S., Román, F.L., White, J.A. (1996) ‘On a paradox concerning the temperature distribution of an ideal gas in a gravitational field’, ‘Eur. J. Phys.’ 17: 43-44.

    I am not expert in this. My bet is that Spencer, Maxwell, Gibbs, Boltzmann, and Chapman & Cowling are right and Loschmidt is wrong. I will look further at the question.

  172. RW says:

    Christopher Game,

    You say: “The reason is stated clearly enough in my post of January 5, 2012 at 7:43 AM.”

    Not in my opinion.

    Can you answer these questions:

    Do you agree that the surface emits a radiative flux of 390 W/m^2 solely due to its temperature (288K) and nothing else (assuming an emissivity of 1 or very close to 1)?

    Do you agree that surface temperature is slaved to emitted power by the Stefan-Boltzman Law? That is, in the steady-state, the surface cannot be receiving more or less than 390 W/m^2, as if it were, it would be either warming or cooling, and thus not in the steady-state?

    Do you agree that, in the steady-state, simultaneously, there is 240 W/m^2 exiting at the TOA, 240 W/m^2 entering the TOA, and 390 W/m^2 entering the surface?

    Do you agree that atmosphere itself is part of the thermal mass of the planet?

    Do you agree that all the energy in the atmosphere is either on a path where it is eventually radiated out to space or returned to the surface?

  173. Christopher Game says:

    Further response to the post of Stephen Wilde of January 10, 2012 at 9:06 AM.

    Stephen Wilde writes: “I’ve always understod the baseline minimum lapse rate to be a product of atmospheric pressure at the surface with radiative and non radiative energy transfers tending to alter that basic lapse rate but at equilibrium (if it could be maintained) the system would return to the baseline lapse rate set by pressure.”

    We are asking questions about a steady state in a system, subject to an externally imposed gravity field with an externally imposed energy transfer; the presence of energy flux is externally determined, but not its magnitude, by the external constraints: there are two radiatively connected heat reservoirs, the sun (effectively about 5780K) and outer space (effectively about 3K), with geometry externally set; the actual externally set constraint parameters are thus radiative temperatures not flux. The system is of course not in thermodynamic equilibrium because of the energy flux. As it happens, the flux is slow enough to let most of the relevant parts of the system work in local thermodynamic equilibrium, which does not, however, prevail in the upper atmosphere.

    It is not clear to me what you mean by “the baseline minimum lapse rate” and by “at equilibrium (if it could be maintained)”.

    The solar radiation is partly absorbed into the troposphere by water vapour molecules, and in greater part absorbed into the land-sea surface. Some of the heat loss is by radiation direct to space through the atmospheric window not interacting with the atmosphere. Most of the heat loss is by radiation from the troposphere direct to space by water molecules, with a contribution from other radiatively active gases such as CO2.

    In the crudest view, the atmosphere is being heated by conduction and evaporation/condensation from the bottom and cooled from the top. If atmospheric convection and within-atmosphere conduction were magically ‘frozen’, the lapse rate would be greater than it is with those mechanisms actually operating. Atmospheric convection may be considered as reducing the lapse rate from its fictive ‘no-convection-no-intra-atmospheric-conduction’ value. Driven by gravity-buoyancy, atmospheric convection would like to reduce the lapse rate to zero as per the Maxwell-Gibbs-Boltzmann equilibrium, but friction and turbulence limit its efficacy to nearly the values given by the adiabatic gas law.

  174. Joel Shore says:

    Christopher Game writes: “Driven by gravity-buoyancy, atmospheric convection would like to reduce the lapse rate to zero as per the Maxwell-Gibbs-Boltzmann equilibrium, but friction and turbulence limit its efficacy to nearly the values given by the adiabatic gas law.”

    Christopher,

    I liked most of your post but I think you went astray on this last sentence. In fact, the adiabatic lapse rate is a stability limit; that is to say, lapse rates steeper than the adiabatic lapse rate are unstable to convection but lapse rates less steep than the adiabatic lapse rate are stable and convection is suppressed. So no, it is not friction and turbulence that limit the lapse rate to some rough compromise of the dry and saturated adiabatic lapse rates. It is the fact that convection will not drive the lapse rate lower than the adiabatic lapse rate. (See for example, here, for discussion: http://books.google.com/books?id=av7q4N8Ib6sC&pg=PA28&lpg=PA28#v=onepage&q&f=false )

  175. Christopher Game says:

    Response to the post of Joel Shore of January 10, 2012 at 9:36 PM.

    Thank you for this response, Joel Shore.

    You write: “lapse rates less steep than the adiabatic lapse rate are stable and convection is suppressed.”

    Yes. But stability is determined by the viscosity of the gases; that’s what “suppresses” the convection. I loosely wrote of “friction” thinking of viscosity as a kind of ‘microscopic friction’. In this loose sense that I intended of the word friction, I think what I wrote is right. But more strictly I should have written ‘viscosity, friction and turbulence’.

  176. Christopher Game says:

    Further response to the post of Joel Shore of January 10, 2012 at 9:36 PM.

    My reason for referring to viscosity as the factor which suppresses convection is my reading of S. Chandrasekhar’s classic, ‘Hydrodynamic and Hydromagnetic Stability’, Oxford University Press, Oxford UK, 1961, Chapter II, ‘The thermal instability of a layer of fluid heated from below’.

  177. Christopher Game says:

    Further response to the post of Stephen Wilde of January 10, 2012 at 9:06 AM.

    Looking at those references again, I find that they all agree with Maxwell.

    Within the blog that you referred to I find no well presented challenge to that. The book chapter page shown does not mention the concondance of Gibbs in this.

    The directly linked paper by Graeff also does not mention Gibbs. Loschmidt is quoted in a long sentence. He predicted that the lower temperature at the top would make “available an inexhaustible resource of convertible heat at all times”. Graeff writes: “No published treatise is known to the author for calculating the vertical temperature gradient (T(Gr)) in solids of liquids under the influence of gravity.” Graeff refers to liquids, not gases, because he will do his experiments with liquid water because it has a high density and will make the effects easier to measure. But it is odd that he fails to mention the results for gases of Chapman & Cowling, and of the later authors that I mentioned above. I did not buy the AIP conference proceeedings paper.

    The experiments seem to show an equilibrium state with the water cooler at the top. I do not believe this is sound experimental work, but at present I cannot justify my belief other than by appeal to theory, which I admit does not really settle the matter.

    Graeff comes up with an “improvement” on Clausius’ statement of the second law of thermodynamics. His “improvement” is to exclude [external] force fields from the isolated system. I will not detail his “improved” statement here, other than to say that it shows that Clausius was a giant of physics and Graeff is clearly a raw amateur in the area. Graeff concludes that only the future will tell if Loschmidt’s prediction of “an inexhaustible resource of convertible heat at all times” will become available. Graeff has been trying to build a perpetual motion machine of the second kind, or perhaps even of the first kind. This makes me think that Graeff is unreliable in this respect; I accept that this is ad hominem, but I recall something about “where angels fear to tread”.

    The lead of the blog writes: “Why has this enduring mystery not been attended to more carefully by mainstream science?”

    The answer to that is easy. Mainstream people, including Dr Spencer, rely on Clausius, Maxwell, Gibbs, Boltzmann, and Chapman & Cowling, not Loschmidt and Graeff.

    I find at home that, when a heater is going, the air in the room is hotter higher up. I suppose this is because of mixing driven by external factors beyond mere buoyancy.

  178. Reply to Christopher game:

    Hi Christopher. You may note in my article on Loschmidt’s that Sheehan, in reviewing the unresolved controvery, states that Maxwell presented no theoretical resolution beyond appealing to the second law, and that Boltzmann didn’t resolve it either, despite several attempts.

    Graeff may be an amateur, and his vision of a machine designed to extract energy from the Loschmidt gravito-thermal effect may be misconcieved. However, if loschmidt is correct, and he may be, then such a machine is not a perpetual motion machine of the second or first kind. That is the logic of the situation.

    Regarding Graeff’s experimental results: The results are the results. If they are wrong, they need to be shown to be wrong by further replication, not by appeals to the authority of Maxwell who appealed to the authority of his own theory. As Einstein said:

    “Experimentum summas judex.”

    Finally, the Coombes and Laue paper appears to make assumptions regarding the independence of relevant variables which is not supported within the body of their own work. It’s a knotty issue which people with greater ability than myself are currently working on, and I respectfully request that you do not pre-judge the issue.

    Regards

    TB

  179. Christopher Game says:

    Response to the post of Rog Tallbloke of January 11, 2012 at 1:31 AM.

    Thank you for this comment, Rog Tallbloke.

    “Sheehan, in reviewing the unresolved controvery, states that Maxwell presented no theoretical resolution beyond appealing to the second law.”

    In a note in ‘Nature’ of 29 May 1873, Maxwell answers a criticism by Guthrie. No mention of the second law there, and a comment about Maxwell’s detailed paper of 1867, which he indicates is statistical mechanical, not thermodynamical, in such a way as to seem not to refer to the second law, but I may be mistaken about that, of course.

    As for Loschmidt versus Maxwell and Boltzmann, I would say it’s a case of the ant versus the elephant. Loschmidt was an assistant to Planck, who in those early days did not believe in the statistical mechanical approach to such questions; only in 1900 did he change his mind. Loschmidt is known for another attack on Boltzmann, an attack that does Loschmidt no credit. Boltzmann was concerned largely with proving stability, a bit more of a task than simply finding the equilibrium state.

    I noted in my post that I admit that appeal to theory does not settle the matter against a purported experimental fact, and that my comments on Graeff were ad hominem.

    Coombes and Laue 1985 give a simple argument, but ultimately they refer to Chapman & Cowling. My post mentioned that Coombes and Laue agree with Maxwell, but it did not specifically rely on them. So for the present I will stay with direct criticisms of Maxwell and of Chapman & Cowling. Chapman & Cowling look carefully at the problem and say that Maxwell’s proof is not perfect, but they still hold to his result, and present a proof of their own. As I read them, they hold that the temperature must be uniform throughout the gas. So far I have not noticed any attack on Chapman & Cowling, nor on Gibbs, who used a method of the calculus of variations and thermodynamics.

  180. Christopher Game says:

    Further comment on the temperature profile of an isolated column of gas in an externally determined gravity field.

    Suppose (contrary to fact I believe) the fictive thermodynamic equilibrium were hotter at the bottom than at the top.

    Then radiation would carry heat from the bottom to the top. It is not so obvious what conduction would do. In this case, one cannot a priori rule out a violation of the Fourier conduction equilibrium condition, that relies on the idea that heat is always conducted down a temperature gradient. For balance against the upwards radiative transfer, maintenance of the fictive equilibrium would thus involve conduction of heat downwards, from cold to hot in violation of the usual idea that conduction is always down a temperature gradient. We would have a ‘circulation’ with radiation carrying heat one way and conduction back the other. A violation of the principle of detailed balance, not a happy thought for students of statistical mechanical equilibrium of gases. Maxwell’s ‘Nature’ note of 1873 seems to argue against it happening.

    According to Goody and Yung 1989, the Planck and Boltzmann distributions are mutually implicate when one has local thermodynamic equilibrium, not assuming full thermodynamic equilibrium. This does not feel like a good fit with the above fictive thermodynamic equilibrium. It must be admitted that this argument also does not seem explicitly to take into account any possible gravity effect.

    Chapman & Cowling do not mention radiation in their treatment in Chapter 4. If their conclusion is right, then of course radiation will not, in net, transport heat in this situation.

  181. Joel Shore says:

    Christopher Game says: “My reason for referring to viscosity as the factor which suppresses convection is my reading of S. Chandrasekhar’s classic, ‘Hydrodynamic and Hydromagnetic Stability’, Oxford University Press, Oxford UK, 1961, Chapter II, ‘The thermal instability of a layer of fluid heated from below’.”

    My problem was not with your use of the word “friction” instead of “viscosity”. It is more fundamental than that.

    I don’t have Chandrasekhar handy but my guess is that in that Chapter he is considering incompressible fluids or compressible fluids with a height difference small enough that any difference in density between the top and bottom is small enough to be neglected. I recommend that you read what I linked to or something similar that talks about the case of the atmosphere, where the heights involved are large enough that differences in density with height and the adiabatic lapse rate become a significant issue.

  182. Christopher Game says:

    Response to the post of Joel Shore of January 11, 2012 at 7:18 AM.

    Joel Shore proposes that Chandrasekhar’s stability story is irrelevant because it refers to liquids in which the vertical density gradient is small, with a small average density difference bewteen top and bottom.

    The question was what stabilizes against convection. I think that is not determined by average density difference between top and bottom, but is determined by local factors, the competition between buoyancy and viscosity as considered by Chandrasekhar.

    Joel Shore recommends that I read his reference. I had already done so. That is why I referred to Chandrasekhar. Joel Shore is concerned about large density differences. They will make the buoyancy factors stronger and make convection more likely, that is to say density difference will make for instability, but it will still be viscosity that is the opposing factor. His reference does not mention this.

  183. Fernando (in Brazil) says:

    I am inclined to defend the N / Z

    Hopefully there is robust evidence to solve the paradox of weak sun.

    Earth and Mars: Evolution of Atmospheres and Surface Temperatures
    Carl Sagan and George Mullen.

    Solar evolution implies, for contemporary albedos and atmospheric composition, global mean temperatures below the freezing point of seawater less than 2.3 aeons ago, contrary to geologic and paleontological evidence. Ammonia mixing ratios of the order of a few parts per million in the middle Precambrian atmosphere resolve this and other problems. Possible temperature evolutionary tracks for Earth and Mars are described. A runaway greenhouse efect will occur on Earth about 4.5 aeons from now, when clement conditions will prevail on Mars.
    http://www.sciencemag.org/content/177/4043/52.abstract?ck=nck

  184. Stephen Wilde says:

    “the conclusions of Maxwell, Gibbs, and Boltzmann, that I indicated in my post of December 30, 2011 at 10:21 AM, about uniformity of temperature at thermodynamic equilibrium in a column of air in very tall isolation chamber in a vertical gravitational field, with high pressure at the bottom and low pressure at the top?”

    I’m not sure about the relevance of the above issue since there is apparently no energy source at the bottom and no energy sink (in lieu of space) at the top.

    The observations made by Nikolov depend on a continuing solar energy source irradiating the surface of the Earth and somewhere for that energy to flow to namely space around the Earth.

    If one were to remove those factors (at thermal equilibrium) then conduction alone could well equalise the energy distribution from top to bottom in an isolated column. There might be a seperate gravitational effect that ‘sorts’ the molecules in some way so that those at the bottom are warmer than those at the top but that is not a realistic illustration of real world events.

    The effect of gravity out in the open is simply to increase density nearer the surface which gives more opportunity for molecular collisions to obstruct the upward energy flow.

    I don’t think anyone is suggesting that gravity itself pulls energy down to the surface. Gravity only acts on mass. Gravity doesn’t pull hotter molecules downward. All it does is enable molecules at the surface to absorb more energy from a hotter surface due to density obstructing energy dissipation.

  185. Christopher Game says:

    Response to the post of Stephen Wilde of January 11, 2012 at 9:20 AM.

    Yes, the isolated column has no energy sources at top and bottom to drive things. But it has gravity, and that is not establishing a temperature lapse rate according to Maxwell. If it doesn’t establish a lapse rate then, why would it do so in the presence of other drivers?

    I am not talking just about thermal equilibrium, but, as I said, about thermodynamic equilibrium. As you say, “then conduction alone could well equalise the energy distribution from top to bottom in an isolated column.” I think this is right, allowing that radiation may also act.

    “Gravity doesn’t pull hotter molecules downward.” I think this is right.

    “All it does is enable molecules at the surface to absorb more energy from a hotter surface due to density obstructing energy dissipation.”

    I do think that some people, though not you it seems, are saying that gravity in effect pulls energy down. That seems nonsense to me.

    I don’t think there is any reason why density will obstruct energy “dissipation”. Here I don’t think you mean “dissipation” in the usual sense of conversion of bulk flow kinetic energy into molecular kinetic energy by viscosity or friction. I think you mean thermal conduction as you said before. Maxwell points out that the denser lower layer has numerically more molecules available to carry momentum and energy upwards.

  186. Joel Shore says:

    Christopher,

    If you have read my reference, you have apparently failed to absorb it. Note in particular the sentence, “Indeed, in subadiabatic conditions (those characterized by a lapse rate less than 9.8 deg C per kilometer), convection will tend to be suppressed.”

    It is really not that hard to understand this: Imagine giving a parcel of air an initial upward motion. As it rises, what happens? Well, the pressure decreases so it expands in volume. By doing so, it does work on the surrounding air and hence its internal energy decreases and thus its temperature decreases.

    So, if at ground level it was at the same temperature as the surrounding air, is this parcel of air now at a higher temperature than the surrounding air (and thus positively buoyant) or at a lower temperature than the surrounding air? The answer lies with the lapse rate of the surrounding air: As the parcel rises, it cools via this expansion process at the adiabatic lapse rate. If the lapse rate of the atmosphere is greater than this, then the parcel of air always finds itself to be warmer than the surrounding air and positively buoyant. However, if the lapse rate of the atmosphere is less than this, the parcel of air finds itself cooler than it surroundings and hence the forces on it are down, slowing and stopping its rise.

    Hence, from this stability analysis, we see that an atmosphere with a lapse rate steeper than the adiabatic lapse rate is unstable to convection, i.e., a parcel given an initial upward velocity experiences forces that act to re-enforce this upward motion. However, an atmosphere with a lapse rate shallower than the adiabatic lapse rate is stable to convection, i.e., a parcel given an initial upward velocity experiences a force that acts to counter the motion, i.e., a restoring force that suppresses the upward motion.

  187. Christopher Game says:

    Response to the post of Joel Shore of January 11, 2012 at 9:54 AM.

    Yes, convection will tend to be suppressed, but will still have a driving factor in its favour. The suppression is by viscosity.

  188. Joel Shore says:

    Christopher,

    I just demonstrated to you why there is no driving force in its favor when the lapse rate is less than the adiabatic lapse rate. This is really basic stuff.

  189. Ned Nikolov says:

    To All:

    Just want to let you know that Karl Zeller and I are working on our official reply to the blog comments. Due to unexpected work load last week, we could not finish it as planned. The article is now coming along pretty well, and we’ll be able to share it with you soon.

    Thank you for your patience!
    -Ned

  190. Christopher Game says:

    Response to the post of Joel Shore of January 11, 2012 at 10:23 AM.

    I will think about it some more.

  191. Christopher Game says:

    Response to posts of Joel Shore of January 11, 2012 at 10:23 AM and at 12:32 PM.

    Thank you for these suggestions, Joel Shore.

    I have read over and thought often about many presentations of the kind that you suggest. You say that this is really basic stuff and you want me to absorb it. I can agree that it is repeated in many textbooks in forms more or less like your presentation.

    But, sad to say from one point of view, I am not spongelike, and do not readily absorb what I read. I find the arguments presented more or less unpersuasive for the present purposes. Here and now is not a good occasion for me to expand on this. Perhaps a brief comment: I find Iribarne & Godson second edition 1981 helpful; on page 186 they have a nice diagram showing relations between ranges of absolute instability, conditional stability, and absolute stability. The isothermal atmosphere falls within their range of absolute stability. I will continue to think about this. I am unlikely to reach a conclusion quickly.

  192. Bevan says:

    Response to Christopher Game of January 9, 2012 at 3:37 PM

    Yes, “correspond” may have been more appropriate. It is a pity that the IPCC and the AGW promoters are not as careful with their claims.

    Further, in deference to your statement of January 7, 2012 at 8:37 PM that “The decisive variable is the land-sea surface temperature, and the lower tropospheric temperature is not an adequate proxy for it.”, I got the Australian Bureau of Meteorology temperature data for the station nearest to the Cape Grim CSIRO CO2 station in Tasmania, namely Marrawah, which is 25.67 km SE of Cape Grim in North-West Tasmania.

    For the first difference of the monthly mean CO2 concentration at Cape Grim as the independent variable vs the satellite Southern Hemisphere Lower Tropospheric first difference of the monthly mean temperature, the correlation coefficient was 0.011 with least square linear regression result giving a t-statistic of 0.21 with 371 degrees of freedom for a 2-tailed probability of 83%, that is, a high probability of acceptance of the null hypothesis of zero correlation between the variables.

    For the first difference of the monthly mean CO2 concentration at Cape Grim as the independent variable vs the Marrawah ground station first difference of the monthly mean temperature, the correlation coefficient was -0.341 with least square linear regression result giving a t-statistic of -7 with 371 degrees of freedom for a 2-tailed probability of 0.000000001%, that is, a high probability of rejection of the null hypothesis and the likelihood that there is a negative correlation between changes in CO2 concentration and associated changes in temperature.

    Further, cross-correlation between the first differences of the Cape Grim CO2 concentration and those of the Marrawah monthly mean temperature gave a highly significant correlation of 0.61 when there was a 7 months lag of the CO2 changes verses the temperature changes.

    This would appear to me to clearly contradict the claims of the IPCC and the AGW promoters and perhaps warrant a rethinking of some of the physics behind global warming. I will certainly be looking at other data sets.

  193. Christopher Game says:

    Responding to the post of Bevan of January 12, 2012 at 5:00 AM.

    Bevan’ local correlations are interesting. But they are not nearly decisive for the physics of CO2-induced global warming. The word global is the key here. Bevan’s work to find data sets illustrates the problem. Global statistics are very hard to get right, and we do not know well enough how to analyze for this question what little we have.

  194. Christopher Game says:

    Further response to the post of Joel Shore of January 11, 2012 at 9:54 AM.

    The present discussion is about the putative relative contributions of gravity and greenhouse gases. It’s not easy to formulate a precise question. Dr Spencer writes: “When an air parcel is raised adiabatically, its loss of thermal energy is balanced by an equal gain in potential energy due to its altitude,” and “over the whole Earth, there can be no net change in altitude; all air parcels rising (and cooling) at any given pressure altitude must be matched by an equivalent mass of air parcels sinking (and warming) at that same pressure altitude.”

    You were commenting on my post of January 11, 2012 at 8:04 AM which wrote: “The question was what stabilizes against convection.”

    Convection is not just a matter of isolated parcels of air. It’s about circulations. One distinguishes diverse kinds of stability. Here the main relevant kind of stability is that of circulations. The “basic stuff” of your comment is about isolated parcels of air.

  195. Joel Shore says:

    Christopher: What I am doing is called a “stability analysis”. By considering an individual parcel of air and what the forces are on it, I derive a general result about whether convection will be supported or suppressed in various environments.

  196. Joel Shore says:

    Bevan: What you are presumably seeing is the effect that the solubility of CO2 in the oceans changes with temperature.

    It is not in any way in contradiction with AGW. Local CO2 levels do not determine local temperature; on a local level, there are other influences (atmospheric circulations, etc.) that completely dwarf this. What increasing CO2 levels do is create a small but significant imbalance in the global energy balance between the Earth and space. As a result, the Earth overall must warm but how that overall warming is manifest at a particular location is not easy to determine…and the smaller scale you look over, the larger is the variability due to other factors.

  197. Christopher Game says:

    Response to the post of Joel Shore of January 12, 2012 at 6:49 AM.

    Indeed you are doing a stability analysis. So was Chandrasekhar, but the kinds of stability being investigated were different. There are diverse kinds of stability. The stability of a circulation needs a global analysis as distinct from a local one such as yours.

  198. Bevan says:

    Response to Christopher Game of January 12,2012 at 5:44 AM

    Surely this situation is unsatisfactory. Humanity is being asked, prompted, provoked into changing the whole of society to a “low carbon” lifestyle without clear experimental evidence that global warming arises from increased CO2 concentration. It reminds me of the snake-oil salesman – “Believe me, it works, now just give me your money”.

    I keep finding examples that appear to contradict the AGW conjecture. Where are the evidence-based examples that tilt the ledger towards a dominating AGW effect? The entries on this site are merely opinions until evidence is presented that confirms the likelihood of a conjecture.

    In this regard the adiabatic effect was successfully invoked throughout the 20th century by surveyors to produce accurate terrain maps and by pilots flying between airports at various altitudes using instruments calibrated via the gas laws. No consideration of changes to the properties of the atmosphere with regard to warming by the ill-named greenhouse gases was necessary. How was this possible if the anomalous surface temperature was not a result of the adiabatic effect?

  199. Christopher Game says:

    Response to the post of Bevan of January 13, 2012 at 2:30 AM.

    I am not defending the AGW dogma. I am just trying to get an accurate and precisely quantitatively remediated replacement for it. I don’t regard it as conjecture that CO2 must have some effect on the global climate. The present state of knowledge is that it is likely small or very small. That means the effect is likely enough too small to justify governmental actions. The AGW dogma is that the effect is not small. The scientific task is to reliably quantitate it.

  200. J J says:

    I like some aspects of Ned Nikolov’s theory.

    Increasing the pressure of the lower atmosphere must increase the thermal mass of the air in the lower atmosphere. With the air having a greater thermal mass, this should change the energy budget by slowing losses.

    Given that global temperatures haven’t risen recently as the CO2 models predicted they should, I think that there are factors which have a much greater influence on the climate than greenhouse gases.

    Ned’s theory might fall over when tested, but I think it should be properly tested before we write it off.

  201. Ned Nikolov says:

    JJ,

    In order for our theory to ‘fall over’, the Gas Law and classical thermodynamics have to fall over! What is the chance for that happening?

    A major reason for the confusion on this blog and others is that the atmospheric physics education has been severely crippled in the Western world over the past 30 years by overemphasizing the radiative aspects of the phenomenon … It’s a shame that we now have to re-test the effects of pressure on the thermodynamics of a gas, as these were discovered 150 years ago.

    We have become slaves to a blatant mathematical error in climate models caused by the decoupling between radiative transfer and convection. The ENTIRE ‘CO2 warming’ case is a model artifact resulting from that error, which should have been caught some 30 years ago!

  202. Alan D McIntire says:

    In response to Ned Nikolov

    There are only 3 planets with significant atmospheres used in your model: Venus, Earth, and Titan.

    Your equation 7 had 2 parts
    T = K0 e^( e^k1 + e^k2). That’s a case of curve fitting to
    get an equation to fit only 3 data points.

    We’ll need results from terrestrial sized planets in other solar systems before we can conclude whether or not your equation has any validity.

  203. Rod Gill says:

    I’m happy with the idea that there is a flow of LWR up and down and that the nett flow is out to space. However I’m trying to reconcile this with Pierre R Latour, PE, PhD words that a warm body cannot absorb IR from a colder body: teh photons are merely scattered or reflected. Comments please?

    See: http://www.slayingtheskydragon.com/en/blog/185-no-virginia-cooler-objects-cannot-make-warmer-objects-even-warmer-still?showall=1

    Thanks.

  204. Joel Shore says:

    Ned Nikolov says: “In order for our theory to ‘fall over’, the Gas Law and classical thermodynamics have to fall over!”

    Wow…That has to be one of the most absurd and ridiculous statements I have seen from you…And, that’s saying something!

    “We have become slaves to a blatant mathematical error in climate models caused by the decoupling between radiative transfer and convection. The ENTIRE ‘CO2 warming’ case is a model artifact resulting from that error, which should have been caught some 30 years ago!”

    Nonsense…All quantitative calculations of the greenhouse effect account for convection. And, unlike what you did, they put it in correctly: I.e., they recognize that convection only drives the temperature profile to the adiabatic profile and not to an isothermal profile with height.

  205. Joel Shore says:

    Rod: The way to reconcile it is to realize that Pierre Latour is simply wrong. Whether it is a profound error or a purposeful deception is hard to tell.

    For the rest of the world, the Second Law works like this: Hotter and colder objects exchange radiation but the colder object always absorbs more radiation from the hotter than the hotter from the colder. In fact, Kirchoff’s Law of Radiation ( http://en.wikipedia.org/wiki/Kirchhoff%27s_law_of_thermal_radiation ) is sufficient to guarantee that this will always be the case.

  206. don penman says:

    Kirchoffs law does not always hold on what I have been reading about atmospheric physics on wuwt but energy is still conserved.I cannot accept a law as proof that a theory is true laws have to be confirmed empirically,they may be useful in guiding thought experiments.

  207. Ned Nikolov says:

    Joel,

    You have rudimentary understanding of both physics and math. You do not even understand what I am saying, nor what our paper has stated very clearly and demonstrated with a simple system of energy balance equations … Of course, GCMs have convection and radiative transfer in them. But they do not solve them simultaneously in one iteration. Do you know what a system of simultaneous equations is?? It looks like you do not! Do you know that radiativevtransfer in GCMs is not even solved at every model time step, but at every other time step?

    Just go back to school and get some education before trying to spill nonsense on every blog you can put your hand on … Thank you!

  208. Christopher Game says:

    Response to the posts of Joel Shore of January 14, 2012 at 9:25 PM and of don penman of January 14, 2012 at 11:54 PM.

    Pierre R. Latour, PE, PhD is wrong to propose that a warm body cannot absorb any thermal radiation from a colder one. Joel Shore is right to say that “Hotter and colder objects exchange radiation but the colder object always absorbs more radiation from the hotter than the hotter from the colder.” This was well known before Kirchhoff’s law. Perhaps it may be attributed most to Prevost’s 1791 paper, describing experimental tests.

    Kirchhoff’s law of thermal radiation does not hold in the upper atmosphere because there the condition of local thermodynamic equilibrium does not hold.(Milne 1928 http://articles.adsabs.harvard.edu/full/1928MNRAS..88..493M) Nevertheless the Prevost radiative exchange will see the hotter body passing heat in net to the colder one. The definition of temperature needs special attention to the absence of local thermodynamic equilibrium. In this sense, Kirchhoff’s law is not a sufficient guarantee.

    Dr Spencer is right that under suitably specified conditions, the presence of a colder body will lead to a warmer warm body than would be the case in the absence of the colder body. The basic condition here is that both bodies are exposed to a common still colder environment, in this case outer space. The colder body shields the warmer one from the still more intense cold of the environment, with which also of course the Prevost exchange is also happening.

  209. Joel Shore says:

    Ned: Quelle horreur! The radiative transfer is only solved for every second time step! That must be why you guys get a result different from everybody else…It surely can have nothing to do with the fact that you put convection into the simple radiative model of the greenhouse effect completely incorrectly! This is one of the obvious errors that we will probably not find corrected in your long-awaited “reply” since putting convection in correctly would completely destroy your argument that convection makes the radiative greenhouse effect go away. (Do you want me to demonstrate that to you or are you able to figure it out yourself?)

    “You have rudimentary understanding of both physics and math…Just go back to school and get some education before trying to spill nonsense on every blog you can put your hand on … Thank you!”

    Ned: Since I have a PhD in physics from one of the top physics graduate schools in the country and several publications in the top physics journals (e.g., Physical Review, including Physical Review Letters), exactly what additional education are you suggesting that I need? Could you remind me what your educational and research background is again?

  210. Joel Shore says:

    Ned,

    Just to spell it out for you a little more: Your paper says “Equation (4) dramatically alters the solution to Eq. (3) by collapsing the difference between Ts, Ta and Te and virtually erasing the GHE (Fig. 3).”

    Are you unaware of the fact that in the real troposphere there is a lapse rate, which in practice usually tends to be close to the (appropriate, dry or saturated) adiabatic lapse rate and that this is so because the atmosphere is only unstable to convection when the lapse rate exceeds the adiabatic lapse rate?

  211. Bevan says:

    Response to Christopher Game of January 15, 2012 at 3:00 AM

    Surely what is relevant to the AGW proposition is the claim that long wave infrared radiation increases the temperature of a body already emitting shorter wavelength infrared radiation not whether bodies of various temperatures allow IR radiation to enter their surfaces. Infrared
    radiation is simply a limited range of wavelengths of electromagnetic radiation. The interaction of electromagnetic radiation with a given surface can take many forms depending on the wavelength of the radiation and the nature of the surface. A rise in temperature is only one of the forms under specific conditions.

    In general, we know from personal experience that a warm body causes an increase in temperature of a nearby colder body. We do not experience a cold body causing an increase in temperature of a hotter body. If both of these happened then everything in the Universe would be increasing in temperature because of the infrared radiation received from the surroundings. That is, the whole Universe would be increasing in temperature, creating energy out of nothing.

    Another way of looking at the proposition is to consider that if long wave radiation could increase the temperature of a body already emitting shorter wavelength radiation that would mean that the emission spectrum of the body is pushed to even shorter wavelength, higher frequency, higher energy emissions again creating energy out of nothing.

    If the possibility of long wave radiation, from CO2 in the atmosphere, raising the temperature of the already warmer earth below, is untenable that only leaves a change in the atmospheric lapse rate to be caused by a change in the concentration of CO2. We know from experience that a change of humidity alters the lapse rate. However Gerlich and Tscheuschner have already shown that a theoretical doubling of CO2 concentration would produce changes in atmospheric thermal conductivity and isochoric diffusivity that are too small to be measured. Hence no detectable AGW.

  212. Christopher Game says:

    Response to the post of Bevan of January 15, 2012 at 9:04 AM.

    Dear Bevan, I suggest you read considerably more carefully what I wrote, check my references (which you can chase up for yourself if you are serious), and think about it carefully. Your arguments are well meant, but are invalid because you are not thinking soundly in physics, and consequently you are just bandying words and waving your hands. You will not be able to frame valid arguments in this area till you learn to think soundly in physics. Gerlich and Tscheuschner are not adequate guides.

  213. Joel Shore says:

    Bevan: You are right…The colder atmosphere cannot heat the warmer earth surface in the sense that the heat flow will always be from the warmer Earth to the cooler atmosphere. However, what you are forgetting is that there is also another body involved, the sun.

    The temperature of the Earth is then determined by the balance of what it receives from the sun and what it radiates back out into space. In the absence of an IR-absorbing atmosphere, all of the radiation that the surface radiates would escape to space. In the presence of an IR-absorbing atmosphere, some of the radiation does not escape and, in fact, some of it is returned to the surface. As a result, the surface temperature of the Earth must be higher in order for the Earth-atmosphere system to radiate back out into space the same amount of power as it receives from the sun.

  214. JT says:

    Christopher, I quoted your remarks above relating to the lapse rate at Roger Tallbloke’s blog and read the various references he referred me to. In this reference
    http://tallbloke.files.wordpress.com/2012/01/s-velasco.pdf I find the following, “for a finite adiabatically enclosed ideal gas in a gravitational field the average molecular kinetic energy decreases with height.” This statement clearly implies that the temperature decreases with height.

    I then conceived the following thought experiment. As no one there has demonstrated a calculation of the entropies of the two states described below I re-post an edited version of it here as I think such a calculation would dispose of the Loschmidt/Maxwell controversy.

    Imagine that a very tall ( 5 miles high) cylinder was built to enclose a portion of the extant atmosphere with its extant pressure and temperature gradients. Seal it all around and insulate it perfectly. Leave the gravitational field on. Allow no radiation in or out. Will it retain its extant pressure and temperature gradients or will the temperature equilibrate throughout the column? Note that if the temperature does equilibrate throughout the column that would be a spontaneous thermodynamic change. Such a change would require a corresponding increase in the entropy of the gas within the cylinder. So the question reduces to: which state has the higher entropy? The state with a pressure gradient coupled with a temperature gradient in which the portion of the gas at higher pressure has higher temperature; or said pressure gradient with equal temperature throughout? It seems to me that a mathematical thermodynamicist should be able to calculate the total entropy of each state by integrating an entropy function dependent upon molecular concentration and temperature from one end of the cylinder to the other. Sorry, can’t do the math myself so is there anyone out there who can?

  215. RW says:

    Does anyone know what fraction the total thermal energy of the planet is in the atmosphere compared to that below the surface?

    Is it generally about 1% in the atmosphere and 99% below the surface?

  216. Christopher Game says:

    Response to the post of JT of January 15, 2012 at 1:35 PM.

    Thank you for this comment, JT.

    The reference you give is one that I gave further up this blog, not at that time knowing it was also on the other blog. The reasoning you offer (“clearly implies”) in your post looks persuasive, but is not rigorously valid. If you read the reference more carefully, and the other closely related references, you will find that they eventually agree with the Maxwell-Gibbs-Boltzmann-Chapman&Cowling view that at thermodynamic equilibrium the temperature is uniform. The thought experiment you describe is the one considered by these authors (M-G-B-C&C) for their calculations. They conclude that there will be a spontaneous change to uniform temperature, the pressure still eventually being low at the top and high at the bottom, but not at the precise same values as initially. They are the most reliable mathematical thermodynamicists to my knowledge and I see no reason to fault their work. You may like to consult also Bailyn, M. (1994) ‘A Survey of Thermodynamics’, American Institute of Physics, ISBN 0-88318-797-3.

  217. Christopher Game says:

    Further to my post of January 15, 2012 at 1:35 PM.

    A list of experiments that tried but failed to detect a temperature gradient is given by Partington, J.R. (1949),’An Advanced Treatise on Physical Chemistry’, volume 1, ‘Fundamental Principles. The Properties of Gases.’, Longmans, Green and Co., on page 276. Loschmidt’s papers on the subject are also listed there.

  218. Leonard Weinstein says:

    Roy,
    I did not read all of the replies, so if I am repeating someone it is not deliberate. I agree with most of all you say with a major exception. This is in regard to “Imagine we start with the atmosphere we have today, and then magically dump in an equal amount of atmospheric mass having the same heat content. Let’s assume the extra air was all nitrogen, which is not a greenhouse gas. What would happen to the surface temperature?”

    The addition of the extra atmosphere would not change the lapse rate, but it would make the atmosphere somewhat taller to a particular pressure. The taller atmosphere would have mixed CO2 and water vapor from the original atmosphere, although at a lower concentration. Nevertheless, the average effect altitude of outgoing radiation would be slightly raised, just due to the greater height. This would slightly raise the ground temperature. The added temperature would be the added average height to outgoing radiation times the lapse rate. I did not do the numbers, but it likely would be a few degrees.

  219. Olavi says:

    Roy wrote

    Now, it’s the downward component of IR radiative flow that many skeptics seem to have a problem with. They ask, how can IR radiation flow from colder temperature at higher altitudes to warmer temperatures at lower altitudes? That would contradict the 2nd Law of Thermodynamics.

    Let’s make test to solve meaning of backradiation. Now we have winter in Finland. Snowcover is about 30 cm and it’s -2 celsius. Upper atmosphere radiates 150W/m2 downwards if I block that radiation with mirror made from polyurethane and is coated with foil both sides, I’ll put it 1 meter above snowy surface. That cover radiates 200w downvards. Radiation increase is 50w/m2 but the temperature remains the same. If i put heating element to snow and 50W power snow start’s to melt. If you want, that I believe that that radiation wich comes down from upper atmosphere can make earth warmer, you have to make some epirical test that it increases temperature and prove I’m wrong. Otherwise climate sensitivity to CO2=0.

  220. Svend Ferdinandsen says:

    I have thougt of the article from time to time, and have still some points that could make some sense.
    The rising air would in general have a lower lapse rate, because it has more humidity, whereas the sinking air is quite dry and will have the full lapse rate.
    All in all it would mean that the surface should be warmer than the upper parts, because these convections transport heat to the upper atmosphere and also heat to the lower atmosphere. I would not leave it out of the calculations, but it is not the only part of the elevated temperature at ground.

    A side effect is eventually rain, that in simple calculations will give ~15W/m2 for each mm/day.

    P.S. I have seen some comparisions of planetary temperature at hights of 1 atm, and they were comparable to what we see at Earth.

  221. Jeff Id says:

    Dr. Spencer,

    There are multiple effects to remove heat from the planet surface. Only one effect to space.

    For communication purposes, let’s say we have a gas which blocks/emits zero IR yet has mass and we increase the mass of the atmosphere to 10x using only a special non- IR absorbing/emitting gas.

    Of course in this 10x world, the same amount of the heat from the sun is still surface absorbed. The heat removal mechanisms from the surface are obviously not totally IR and include conduction and convection. Assume for this concept that convection doesn’t change from this huge change in thickness.

    The greenhouse effect is a delay in energy release from earth to space. If surface heat has any increased delay in reaching emission altitude, temps go up. Consider that increased conduction time causes the same sort of delay as increased emission time.

    The sun in this model would hit the surface of our planet with the same intensity, yet IR would not be emitted or absorbed by our special gas – with a non-zero energy content. Conduction would obviously create a delay in release of energy from the surface to emission altitude – space.

    While I don’t know if the paper you discussed above is correct, it does seem that the addition of insulating and energy storing materials deserves a proper mathematical treatment analyzing the delay in heat transport.

    To continue the concept, the paper referenced discussed “pressure” as the primary motivator of surface temp. Pressure in their model is certainly not correct as a primary independent variable. Were Earth two times the mass and the same diameter, the atmosphere would be denser, pressure would double, but this planet would not likely fall on the pressure/temp curve of the paper above.

    Pressure is a proxy for heat transport, as are greenhouse gases. It would take something new and convincing for me to see either as unimportant in result.

  222. John Millett says:

    Dr Spencer
    “If you don’t like the idea of a downward flowing component to the ‘net’, then just conceptualize the effect of greenhouse gases as reducing the rate at which IR energy flows from higher temperature to lower temperature. There, 2nd Law problem solved.”

    Would that it were that simple. If atmospheric IR is to slow the rate of surface cooling (as distinct from warming the surface which violates the second law of thermodynamics) it would have to increase the temperature of the surface’s surroundings which also implies violation of the second law. Atmospheric back-radiation is incompatible with thermodynamic laws. Which do we jettison? Has Prevost’s 1792 theory of radiative exchange been demonstrated experimentally?

  223. John Millett says:

    Dr Spencer

    “…it is the processes which control the rates of energy gain and loss (not pressure) which determine what the average temperature will be, whether at the surface or any other altitude in the atmosphere”.

    I respectfully disagree in part. Pressure does play a part by fixing, via gravity and the Ideal Gas laws, the adiabatic lapse rate. Both convection and IR emission (not absorption) independently “try” to push the actual lapse rate away from adiabatic in opposite directions (convection towards uniformity) resulting in an actual rate a bit steeper than the adiabatic one. These processes determine the atmospheric temperature profile relative to the surface temperature; they don’t determine that temperature. The surface temperature surely reflects the energy content of the entire planet, not just the fraction comprising the climate system?

  224. Stephen Wilde says:

    As is implicit from the Gas Laws which have a provenance of about 150 years and have never been falsified it appears that pressure (arising from the gravitational effect from the combined mass of planet and atmosphere) plus energy input from the local star determines the extent to which ANY planetary atmosphere will cause the surface temperature to diverge from the S – B equations.

    Composition of the atmosphere only seems to matter in so far as different compositions require a different atmoapheric structure in order for the Gas Laws to be obeyed.

    Thus the answer to the entire conundrum is simply that for ANY planet with an atmosphere of ANY composition the atmosphere simply restrutures itself as necessary to produce the lapse rate determined by pressure and energy input.

    So if humans add GHGs to the atmosphere there will be no change in equilibrium temperature but there will be a change in the distribution of the climate zones and weather systems to change the globally averaged rate of energy flow from surface to space and thereby comply with the Gas Laws.

    There will be slight climate effect from that redistribution in terms of a change in the sizes positions and relative intensities of the permanent climate zones but that would be unmeasurable as compared to the changes that occur from natural variations forced by sun and oceans.

    There would simply be an energy redistribution and NOT any change in system equilibrium temperature.

  225. Peter Ellis says:

    Imagine we start with the atmosphere we have today, and then magically dump in an equal amount of atmospheric mass having the same heat content. Let’s assume the extra air was all nitrogen, which is not a greenhouse gas. What would happen to the surface temperature?

    Adding extra gas gives you a load of dilution effects that potentially confuse the matter. What happens if instead you double atmospheric pressure by keeping the atmospheric content exactly the same and doubling Earth’s gravity? If a mechanism’s needed, say a mini black hole happened to collide with the planet and fall through to the centre :-)

  226. Tom says:

    I’ve come late to this discussion. As a geophysicist who has spent a lot of time using numerical models to understand complex observations, this really caught my eye:

    “We (Danny Braswell and I) have found that physical intuition can be built if you construct a “simple” computer program to model the processes in one dimension (vertical). While computer modeling has a bad connotation among many global warming skeptics, it is just putting actual numbers behind hand-waving concepts. If you can’t do that, then all you have left is hand waving.”

    That’s exactly right. You use simplified models to UNDERSTAND how the processes work, not to PREDICT the future. It doesn’t seem that many people understand the distinction. The most sophisticated climate models can’t begin to quantify the real complexity of the system, so they are loaded up with assumptions and approximations. It is absolutely foolish to believe that such a model can predict the future in any useful way. That doesn’t mean they have no value. What they can do is to help us understand, via sensitivity analyses, how the various components of the system work. If the IPCC were to correctly characterize their work as “Sensitivity Analysis” instead of “Projection” or “Prediction”, it would actually be useful.

    Cheers,
    Tom

  227. George E. Smith says:

    Roy,

    I believe that the “star formation” model is not a correct view that is applicable to a planet like earth. In the case of a star formation, a massive cloud of gas, exceeding a certain mass, is unstable (a calculation by Sir James Jeans I believe) collapses, and a region of higher density (and hence gravity) starts attracting more gas to it, which accelerates the collapse.
    As a result the potential energy represented by the gravitational attraction of all that scattered mass, starts converting to kinetic energy, as the molecules start rushing towards each other. Eventually the molecules approach close enough to start colliding with each other, resulting in a randomizing of the molecular motions, which manifets itself as Temperature. So the “heating” is a direct consequence of the mechanical work done by the gravitational force acting over the distance of the collapse.
    This gravitationally driven collapse will continue unabated, without limit, as the work done increases, so will the heating, and eventually the Temperature and pressure, and interraction time reaches the critical surface at which thermo-nuclear “burning” begins, releasing energy which raises the Temperature and pressure till the collapse stops. If by this time, the upper levels of the atmosphere are dense enough to become opaque to the Planckian radiation generated at the thermo-nuclear burning region, then the material is unable to rapidly cool the material, and the star settles down to it’s life of Hydrogen burning.
    The point is that it was the kinetic energy of the collapse that raised the Temperature; not the static pressure.

    So I agree with you, In a planetary environment, the static pressure isn’t responsible for the steady state Temperature.

    And the Temperature/altitude lapse rate is a simple consequence of the fact that upper atmosphere is cooling by radiation to space, while the ground level atmosphere is heated by contct with the earth surface which itself is heated by solar radiation.

    I don’t see how you apply the ideal gas law to a completely non-uniform and unbounded quantity of gas.

  228. John Millett says:

    Dr Spencer:
    “…the rate of IR loss by the surface would be much greater, because of the much higher surface temperature brought about through compressional heating”.

    Wouldn’t the rate of IR loss by the surface depend not only on its temperature but also on that of its surroundings. Both would respond to the doubling of pressure. Any change in the rate of surface cooling would probably be quite small?

  229. Russell says:

    To avoid further confusion, Roy should explain that the lapse rate on Venus is not due to the thermal mass of the benthic bacteria in underwater Antarctic volcanos to Marc and Rush, so they can explain to callers that trapping of gravitational radiation by marsh gas is the greatest hoax since whatever they said last week.

  230. Doug Cotton says:

    When will people stop talking about that 33 degree figure which is based in the -18 degree figure which itself is based on a false assumption by Hansen in 1981 that the Earth’s surface acts like a blackbody, even though it has an atmosphere above and a crust, mantle and core below?

    A blackbody has to be totally insulated so that it only loses thermal energy by radiation.

    That is not the case for the Earth’s surface.

    Secondly, backradiation from a colder atmosphere cannot be converted to thermal energy if it meets the surface.

    Not only has this been proven computationally, but it is a well known fact which, in the real world, is clearly demonstrated: a modern IR camera (microbolometer) which is at surface temperature has sensors which are warmed by IR radiation. But these are not warmed by backradiation from a cloud at about -40 deg.C for example. (The specifications confirm minimum temperatures of about -20 to -30 degrees.) Neither will such backradiation warm the surface.

    See my site (first two pages at least) for more detail http://climate-change-theory.com