My Global Warming Skepticism, for Dummies

July 17th, 2010 by Roy W. Spencer, Ph. D.

I receive many e-mails, and a recurring complaint is that many of my posts are too technical to understand. This morning’s installment arrived with the subject line, “Please Talk to Us”, and suggested I provide short, concise, easily understood summaries and explanations “for dummies”.

So, here’s a list of basic climate change questions, and brief answers based upon what I know today. I might update them as I receive suggestions and comments. I will also be adding links to other sources, and some visual aids, as appropriate.

Deja vu tells me I might have done this once before, but I’m too lazy to go back and see. So, I’ll start over from scratch. (Insert smiley)

It is important to understand at the outset that those of us who are skeptical of mankind’s influence on climate have a wide variety of views on the subject, and we can’t all be right. In fact, in this business, it is really easy to be wrong. It seems like everyone has a theory of what causes climate change. But it only takes one of us to be right for the IPCC’s anthropogenic global warming (AGW) house of cards to collapse.

As I like to say, taking measurements of the climate system is much easier than figuring out what those measurements mean in terms of cause and effect. Generally speaking, it’s not the warming that is in dispute…it’s the cause of the warming.

If you disagree with my views on something, please don’t flame me. Chances are, I’ve already heard your point of view; very seldom am I provided with new evidence I haven’t already taken into account.

1) Are Global Temperatures Rising Now? There is no way to know, because natural year-to-year variability in global temperature is so large, with warming and cooling occurring all the time. What we can say is that surface and lower atmospheric temperature have risen in the last 30 to 50 years, with most of that warming in the Northern Hemisphere. Also, the magnitude of recent warming is somewhat uncertain, due to problems in making long-term temperature measurements with thermometers without those measurements being corrupted by a variety of non-climate effects. But there is no way to know if temperatures are continuing to rise now…we only see warming (or cooling) in the rearview mirror, when we look back in time.

2) Why Do Some Scientists Say It’s Cooling, while Others Say that Warming is Even Accelerating?
Since there is so much year-to-year (and even decade-to-decade) variability in global average temperatures, whether it has warmed or cooled depends upon how far back you look in time. For instance, over the last 100 years, there was an overall warming which was stronger toward the end of the 20th Century. This is why some say “warming is accelerating”. But if we look at a shorter, more recent period of time, say since the record warm year of 1998, one could say that it has cooled in the last 10-12 years. But, as I mentioned above, neither of these can tell us anything about whether warming is happening “now”, or will happen in the future.

3) Haven’t Global Temperatures Risen Before? Yes. In the longer term, say hundreds to thousands of years, there is considerable indirect, proxy evidence (not from thermometers) of both warming and cooling. Since humankind can’t be responsible for these early events, this is evidence that nature can cause warming and cooling. If that is the case, it then opens up the possibility that some (or most) of the warming in the last 50 years has been natural, too. While many geologists like to point to much larger temperature changes are believed to have occurred over millions of years, I am unconvinced that this tells us anything of use for understanding how humans might influence climate on time scales of 10 to 100 years.

4) But Didn’t the “Hockey Stick” Show Recent Warming to be Unprecedented? The “hockey Stick” reconstructions of temperature variations over the last 1 to 2 thousand years have been a huge source of controversy. The hockey stick was previously used by the IPCC as a veritable poster child for anthropogenic warming, since it seemed to indicate there have been no substantial temperature changes over the last 1,000 to 2,000 years until humans got involved in the 20th Century. The various versions of the hockey stick were based upon limited amounts of temperature proxy evidence — primarily tree rings — and involved questionable statistical methods. In contrast, I think the bulk of the proxy evidence supports the view that it was at least as warm during the Medieval Warm Period, around 1000 AD. The very fact that recent tree ring data erroneously suggests cooling in the last 50 years, when in fact there has been warming, should be a warning flag about using tree ring data for figuring out how warm it was 1,000 years ago. But without actual thermometer data, we will never know for sure.

5) Isn’t the Melting of Arctic Sea Ice Evidence of Warming? Warming, yes…manmade warming, no. Arctic sea ice naturally melts back every summer, but that meltback was observed to reach a peak in 2007. But we have relatively accurate, satellite-based measurements of Arctic (and Antarctic) sea ice only since 1979. It is entirely possible that late summer Arctic Sea ice cover was just as low in the 1920s or 1930s, a period when Arctic thermometer data suggests it was just as warm. Unfortunately, there is no way to know, because we did not have satellites back then. Interestingly, Antarctic sea ice has been growing nearly as fast as Arctic ice has been melting over the last 30+ years.

6) What about rising sea levels? I must confess, I don’t pay much attention to the sea level issue. I will say that, to the extent that warming occurs, sea levels can be expected to also rise to some extent. The rise is partly due to thermal expansion of the water, and partly due to melting or shedding of land-locked ice (the Greenland and Antarctic ice sheets, and glaciers). But this says nothing about whether or not humans are the cause of that warming. Since there is evidence that glacier retreat and sea level rise started well before humans can be blamed, causation is — once again — a major source of uncertainty.

7) Is Increasing CO2 Even Capable of Causing Warming? There are some very intelligent people out there who claim that adding more carbon dioxide to the atmosphere can’t cause warming anyway. They claim things like, “the atmospheric CO2 absorption bands are already saturated”, or something else very technical. [And for those more technically-minded persons, yes, I agree that the effective radiating temperature of the Earth in the infrared is determined by how much sunlight is absorbed by the Earth. But that doesn’t mean the lower atmosphere cannot warm from adding more greenhouse gases, because at the same time they also cool the upper atmosphere]. While it is true that most of the CO2-caused warming in the atmosphere was there before humans ever started burning coal and driving SUVs, this is all taken into account by computerized climate models that predict global warming. Adding more “should” cause warming, with the magnitude of that warming being the real question. But I’m still open to the possibility that a major error has been made on this fundamental point. Stranger things have happened in science before.

8 ) Is Atmospheric CO2 Increasing? Yes, and most strongly in the last 50 years…which is why “most” climate researchers think the CO2 rise is the cause of the warming. Our site measurements of CO2 increase from around the world are possibly the most accurate long-term, climate-related, measurements in existence.

9) Are Humans Responsible for the CO2 Rise? While there are short-term (year-to-year) fluctuations in the atmospheric CO2 concentration due to natural causes, especially El Nino and La Nina, I currently believe that most of the long-term increase is probably due to our use of fossil fuels. But from what I can tell, the supposed “proof” of humans being the source of increasing CO2 — a change in the atmospheric concentration of the carbon isotope C13 — would also be consistent with a natural, biological source. The current atmospheric CO2 level is about 390 parts per million by volume, up from a pre-industrial level estimated to be around 270 ppm…maybe less. CO2 levels can be much higher in cities, and in buildings with people in them.

10) But Aren’t Natural CO2 Emissions About 20 Times the Human Emissions? Yes, but nature is believed to absorb CO2 at about the same rate it is produced. You can think of the reservoir of atmospheric CO2 as being like a giant container of water, with nature pumping in a steady stream into the bottom of the container (atmosphere) in some places, sucking out about the same amount in other places, and then humans causing a steady drip-drip-drip into the container. Significantly, about 50% of what we produce is sucked out of the atmosphere by nature, mostly through photosynthesis. Nature loves the stuff. CO2 is the elixir of life on Earth. Imagine the howls of protest there would be if we were destroying atmospheric CO2, rather than creating more of it.

11) Is Rising CO2 the Cause of Recent Warming? While this is theoretically possible, I think it is more likely that the warming is mostly natural. At the very least, we have no way of determining what proportion is natural versus human-caused.

12) Why Do Most Scientists Believe CO2 is Responsible for the Warming? Because (as they have told me) they can’t think of anything else that might have caused it. Significantly, it’s not that there is evidence nature can’t be the cause, but a lack of sufficiently accurate measurements to determine if nature is the cause. This is a hugely important distinction, and one the public and policymakers have been misled on by the IPCC.

13) If Not Humans, What could Have Caused Recent Warming? This is one of my areas of research. I believe that natural changes in the amount of sunlight being absorbed by the Earth — due to natural changes in cloud cover — are responsible for most of the warming. Whether that is the specific mechanism or not, I advance the minority view that the climate system can change all by itself. Climate change does not require an “external” source of forcing, such as a change in the sun.

14) So, What Could Cause Natural Cloud Changes? I think small, long-term changes in atmospheric and oceanic flow patterns can cause ~1% changes in how much sunlight is let in by clouds to warm the Earth. This is all that is required to cause global warming or cooling. Unfortunately, we do not have sufficiently accurate cloud measurements to determine whether this is the primary cause of warming in the last 30 to 50 years.

15) How Significant is the Climategate Release of E-Mails? While Climategate does not, by itself, invalidate the IPCC’s case that global warming has happened, or that humans are the primary cause of that warming, it DOES illustrate something I emphasized in my first book, “Climate Confusion”: climate researchers are human, and prone to bias.

16) Why Would Bias in Climate Research be Important? I thought Scientists Just Follow the Data Where It Leads Them When researchers approach a problem, their pre-conceived notions often guide them. It’s not that the IPCC’s claim that humans cause global warming is somehow untenable or impossible, it’s that political and financial pressures have resulted in the IPCC almost totally ignoring alternative explanations for that warming.

17) How Important Is “Scientific Consensus” in Climate Research? In the case of global warming, it is nearly worthless. The climate system is so complex that the vast majority of climate scientists — usually experts in variety of specialized fields — assume there are more knowledgeable scientists, and they are just supporting the opinions of their colleagues. And among that small group of most knowledgeable experts, there is a considerable element of groupthink, herd mentality, peer pressure, political pressure, support of certain energy policies, and desire to Save the Earth — whether it needs to be saved or not.

18) How Important are Computerized Climate Models? I consider climate models as being our best way of exploring cause and effect in the climate system. It is really easy to be wrong in this business, and unless you can demonstrate causation with numbers in equations, you are stuck with scientists trying to persuade one another by waving their hands. Unfortunately, there is no guarantee that climate models will ever produce a useful prediction of the future. Nevertheless, we must use them, and we learn a lot from them. My biggest concern is that models have been used almost exclusively for supporting the claim that humans cause global warming, rather than for exploring alternative hypotheses — e.g. natural climate variations — as possible causes of that warming.

19) What Do I Predict for Global Temperature Changes in the Future? I tend to shy away from long-term predictions, because there are still so many uncertainties. When pressed, though, I tend to say that I think cooling in our future is just as real a possibility as warming. Of course, a third possibility is relatively steady temperatures, without significant long-term warming or cooling. Keep in mind that, while you will find out tomorrow whether your favorite weather forecaster is right or wrong, no one will remember 50 years from now a scientist today wrongly predicting we will all die from heat stroke by 2060.

Concluding Remarks

Climate researchers do not know nearly as much about the causes of climate change as they profess. We have a pretty good understanding of how the climate system works on average…but the reasons for small, long-term changes in climate system are still extremely uncertain.

The total amount of CO2 humans have added to the atmosphere in the last 100 years has upset the radiative energy budget of the Earth by only 1%. How the climate system responds to that small “poke” is very uncertain. The IPCC says there will be strong warming, with cloud changes making the warming worse. I claim there will be weak warming, with cloud changes acting to reduce the influence of that 1% change. The difference between these two outcomes is whether cloud feedbacks are positive (the IPCC view), or negative (the view I and a minority of others have).

So far, neither side has been able to prove their case. That uncertainty even exists on this core issue is not appreciated by many scientists!

Again I will emphasize, some very smart people who consider themselves skeptics will disagree with some of my views stated above, particularly when it involves explanations for what has caused warming, and what has caused atmospheric CO2 to increase.

Unlike the global marching army of climate researchers the IPCC has enlisted, we do not walk in lockstep. We are willing to admit, “we don’t really know”, rather than mislead people with phrases like, “the warming we see is consistent with an increase in CO2”, and then have the public think that means, “we have determined, through our extensive research into all the possibilities, that the warming cannot be due to anything but CO2”.

Skeptics advancing alternative explanations (hypotheses) for climate variability represent the way the researcher community used to operate, before politics, policy outcomes, and billions of dollars got involved. Gifts, gadgets, weather stations, software and here!

112 Responses to “My Global Warming Skepticism, for Dummies”

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  1. James Davidson says:

    CO2 levels in the atmosphere are increasing – from 290 ppmv in 1890, ( Siple ice core data) to almost 390 ppmv today. It is tempting to say that this is a relative increase of 34%, but it strikes me as being dodgy to take measurements in parts per million, and then express the increase in parts per hundred. In 1890 CO2 comprised 290 millionths of the atmosphere,- that’s 0.029%. The level has now increased to 0.039%, – an increase of 0.01%. Can anyone explain how an increase of one hundredth of one per cent over the last 120 years of a trace ingredient of the atmosphere is going to cause the disasters predicted by the IPCC?

    When the term “greenhouse gas” is used everyone thinks of CO2. If you look at an absorption spectrograph of the various ingredients of the atmosphere you will see that water vapour and CO2 absorb radiation over the same range of wavelengths. With CO2 at 390 ppmv and water vapour at between 10,000 and 40,000 ppmv, ( the higher value at the equator,) water vapour is the dominant greenhouse gas. As Dr Spencer points out in his book Climate Confusion, if you look just at the greenhouse effect, the average surface global temperature should be 60C, instead of the 15C we have. What is missing is water vapour, which causes weather. We talk of our “carbon based economy” when what we are actually burning is hydrocarbons. My home is heated by a furnace which burns natural gas, methane, CH4. The generic formula for aliphatic hydrocarbons is CnH2n+2. For every molecule of CH4 I burn I produce one molecule of CO2 and two molecules of H2O. So, does my burning of hydrocarbons produce a net heating or a net cooling effect?

    • Anonymous says:

      Exactly what I have been wondering too.

    • Anonymous says:

      Mr. Davidson — Because methane is 21-23 times more potent than CO2 as a GHG, releasing one molecule of CO2 is preferred to releasing one molecule of CH4 by the same order. This is the greenhouse benefit of burning the methane from landfills and agricultural processes, and it is amplified if the methane is burned as part of the process of generating electricity, as this will reduce the need to combust other CO2 generating fuel sources as well.

      In a vacuum, your burning of natural gas (methane) contributes to the GHG accumulation. But compared to other fuel sources like wood, coal or oil, it has less of an impact.

      • James Davidson says:

        Dear Anonymous. The good old methane myth! when a molecule of greenhouse gas absorbs a photon of energy three things happen. 1) It moves about a bit more, well, energetically. It collides with other molecules and transfers this kinetic energy. (Since both molecules are surrounded by a shell of negatively charged electrons which repel each other, they can’t actually collide, but we’ll let that pass.) 2) The electrons in the outer shell are bumped up into a higher orbital – the molecule goes from a “ground state” to an “excited state.” It can get back to the ground state by emitting a photon of the same energy that bumped it up into the excited state. This is the mechanism by which greenhouse gases delay the transfer of energy from the Earth’s surface to outer space. 3) The molecule vibrates. It is this vibration which is picked up by microwave sounding units on satellites to measure temperatures in the troposphere. CO2 is a carbon atom with two oxygen atoms attached. Water vapour is an oxygen atom with two hydrogen atoms attached. Methane is a carbon atom with four hydrogen atoms attached. This gives it more degrees of freedom to vibrate than CO2 or water vapour which presumably is the basis for the claim that CH4 is ” 21-23 times more potent as a greenhouse gas than CO2.”
        Some facts about methane. It’s concentration in the atmosphere is 1800 parts per billion, – that’s billion with a “B”, as in a thousand million. That translates to 0.00018%. Water vapour absorbs radiation between 0.6 micrometres and 40 micrometres. CO2 absorbs radiation between 0.8 micrometres and 40 micrometres. Methane absorbs radiation in two narrow peaks centred on 3 micrometres and 8 micrometres. Would you like cranberry sauce with this turkey?

      • Anonymous says:

        The point is the two molecules of H2O. If they add to clouds in a way that cools…

    • Anonymous says:

      Here is an interesting link:

      Of course, I am not expert enough to judge the reliability of the calculations, but it surely looks reasonable that water vapor should be much more relevant than the small amount of CO2 (especially manmade) and other trace GHGs.

      Another thing I don’t understand is how CO2 can cause warming in the lower atmosphere and cooling in the upper? Doesn’t an individual CO2 molecule constantly emit and absorb energy and eventually this energy escapes up through the atmosphere and out in space? Loss of energy from lower part to upper part means that lower part is cooling and upper part is warming. Loss of energy from upper part to outer space means that upper part is cooling and outer space is warming. So CO2 both warms and cools at all altitudes?

    • RnBram says:

      This is the kind of “let’s argue minutiae” nonsense has frustrated me since 1980!!

      One glance at this graph tells us, immediately that the entire, multi-$billion, AGW issue is a hoax.

      In the past, CO2 gas been 100x higher. The present SCARE is over an uptick from THE LOWEST CO2 LEVELS in the entire period shown in the graph. That uptick is at a time when we ought to be in an Ice Age, with severe glaciation —it is NOT the CO2 saving us from that, it is ocean currents and extra-terrestrial factors.

      The idea that sailors might fall off the edge of the Earth, or that massive monsters lived only a few days sail from known waters, are scares that are MORE sane than is Anthropogenic Global Warming. Back then, they did not have sufficient science, nor sufficient geographic nor oceanographic information, nor sufficient biological information, so their fears could be justified as the fears of the ignorant. Even high school graduates have NO SUCH EXCUSE, other than that *at the age of 50 or so years, they cannot think!!

      Today’s fears are a result of an utter, culture wide, inability to identify what is IMPORTANT/essential/fundamental in a mess of information.

      Ayn Rand predicted this kind of stupidity fifty years ago, and explains why it has been growing. Her technical writing on how ideas and concepts are formed and should function in the human mind, once understood, immediately reveals how the present insanity manages to exist.

      To better understand the truth of her ideas, read Leonard Peikoff’s “Objectivism: the philosophy of Ayn Rand” as if your life depended on it. Focus on each paragraph as if it were a month of a fourth year University program. You WILL and ARE being tested. When Peikoff redirects you to Ayn Rand’s “Introduction to Objectivist Epistemology”, mark your spot in OPAR, and read ITOE three times.

      First, read it as if your life depended on its instructions and methods; as if it was your bomb squad manual. Then read it again, trying to find fault, in her thinking OR IN YOURS. You are analyzing it, and will not move ahead one page until you are 100% sure you know everything described/explained in each paragraph. Then, the third time, you will read it bringing together all your new understandings & doubts, to see if one part, or another, really is what you understood it to be. You want to see if it really does make perfect step by step sense. Has she misused words… hey, check your own usage before simply saying hers is a mismatch.

      Return to OPAR, and see how entire books of arguments on ethics, on politics, on art, happiness and even sex, can then be reduced to a chapter, or so, once the proper bases are clear.

      Ayn Rand offers the only antidote to a return to The Dark Ages. Nowhere is Western intellectual impotence more blatant than in America’s President groveling before Muslims, and in its groveling to that President. Yes, those disparate facts ARE related… if you grasp essentials and properly connect (integrate) ideas & facts.

  2. Cassandra says:

    Thank you for this information Dr. Spencer. I am a college student and this “simply stated” info has helped me a lot for a paper I am writing opposing causes of global warmning.

  3. Ralf Dekker says:

    I understand the commonly held view today is that the recent (limited) loss of Arctic sea ice is mostly due to changes in wind patterns rather than rising temperatures.

    As to the supposedly rising mean global temperature the data used are very unreliable for two main reasons. The first being that accurately measuring temperature over a long period of time is far from obvious and prone to errors with the measuring bias almost invariably upward as a result of urbanisation. So one usually tends to measure too much rise in temperature over time. Secondly, the statistical handling, smoothing and the like of temperature datasets from all over the world by the official bodies like CRU and NASA seems to have a strong ‘warming’ bias: historical temperature records are adjusted downward for unclear reasons, from alternative datasets the ones with the strongest warming trend are chosen, measurement sites with the lowest temperature readings are discarded, etc. All in all it is hard to say whether there has been any significant global warming at all in the past 100 years. The only reliable record seems to be from the satellite measurements, but they have only been around for 31 years and do not show a clear trend, let alone anything alarming.

    • Anonymous says:

      Mr. Dekker — The satellite measurements show a 0.14-0.19 degree C rise per decade (variation between UAH and RSS, and the different adjustments made by daya interpreters), while the surface stations show a rise of 0.15-0.2 (variation between GISS, NOAA and HadCRU). Ever since HadCRU stopped having a monopoly on satellite date and the adjustment errors of Drs. Spencer and Christy were corrected, the satellite temps and the surface temps have aligned quite well.

      • Anonymous says:

        “Ever since HadCRU stopped having a monopoly on satellite date and the adjustment errors of Drs. Spencer and Christy were corrected, the satellite temps and the surface temps have aligned quite well”

        And that’s been for how long? Aren’t we still comparing apples to oranges w/o the Siberian and NW Territories data for surface temps?

        • Anonymous says:

          Well, the error in analyzing satellite data was first brought up in 1999, but wasn’t really confirmed until a 2002 (and arguably 2005) paper. Christy acknowledged the error in 2007.

          Satellite data goes back to 1979. The 0.14-0.19 per decade rise from the satellite readings can only go back that far. the 0.15-0.2 per decade rise from the surface stations if for the same period.

  4. Juraj V. says:

    Dr. Spencer, the late 20th century warming was probably weaker than early 1910-1940 warming.

  5. pochas says:

    Excellent article, Dr Spencer. But I am troubled by the concept that something can change “all by itself.” When we can explain what makes those clouds come and go, and why there are more of them at some times an less at other times, then we will truly have the beginnings of an understanding of climate.

    • Anonymous says:

      “When we can explain what makes those clouds come and go, and why there are more of them at some times an less at other times…”

      I think it’s called the water cycle, lol. La Nina and El Nino probably have a lot to do with it, as well as the input from the sun. Also, any warming is regional, since there are places where it’s actually gotten cooler over the last few years.

  6. JohnB says:

    pochas, I had similar trouble until I looked at things a bit deeper. I now think of climate as “Energy Distribution” around the globe, change the distribution patterns and you change the climate.

    As a major example, when North and South america joined some millions of years ago the circulation patterns of both Atlantics and the Pacific Ocean would have changed. This change in major currents would have resulted in climatic change and all without an external force.

    Since the end of the last Ice Age Oceans have been getting deeper (due to water weight) and land has been rising (rebound) new islands form and disappear. All these things cause changes to the energy distribution pattern over the globe and therefore must effect climate in some way.

    The effects may be small, but when expressed in W/m-2 the changes we have seen in the last 100 years are small too.

    • Anonymous says:

      The rise of the Panamanian Peninsula was a major source of climate change. Before this occurred, the Gulf Stream was able to carry cooler water into the Pacific Ocean, when after wards the water had to recirculate, leaving the cooler waters in the Atlantic to recirculate.

      My father (a geologist) and one of my college geology professors have said that this caused the North Atlantic region to be in a constant cool state since it happened, and the only way to truly get back to the temperatures of the Cretaceous, Jurassic, etc, would be to raise the sea level enough to re-submerge the Panamanian Peninsula. Until this happens, the climate will be in a constant state of flux which includes warmer periods like we have now, and ice ages, of which we have had numerous times throughout the millenia.

      Basically, this means that we haven’t seen anything regarding warming yet, and if this DID happen, we would eventually return to the giant plants and animals of the dinosaur era. All of that was able to happen without the help of humans, so who are we to think that we are significant enough to drastically alter such a dynamic, complex system as the climate of the Earth.

      Figured I’d throw this in to help clarify some previous comments (that, and I don’t know how to keep my mouth shut or mind my own business!).

      Thanks in advance for any clarifying comments, and thank you to everyone here for having a civilized, respectable discussion, and not resorting to the vitriolic hatred found on most websites.

  7. Anonymous says:

    I have a question Dr. Spencer: If we have increased the amount of CO2 in the atmosphere, did it displace another gas or is our atmosphere likewise increasing in size?

    • Anonymous says:

      When we make CO2, we combine a carbon atom with O2. So you could say we are changing an O2 molecule into a CO2 molecule. ie: no net change in number of molecules.

      However the same does not hold true for hydrogen.

      • Anonymous says:

        Yes, but not to forget photosynthesis, with the C goimg into organic material and the O2 going back to the atmosphere.

  8. toby says:

    Dear Dr. Spencer,

    Which came first – the observed warming, or the attribution to CO2? CO2 has been known to be a greenhouse gas since the 19th century. An increase of CO2 in the atmosphere was expected as a result of known radiative physics. CO2 increased, and so did temperatures. This is important – anthropogenic global warming is a prediction of physics, not a cause offered after the facts. If the current warming is not CO2-caused, then there is something wrong with the physics. The causal chain between CO2 in the atmosphere and global warming is reasonably well understood – more needs to be learned, but that is true about every science.

    Your admission is yours is a minority view is refreshing and praiseworthy.

    • Anonymous says:


      Your prejudices are showing.”anthropogenic global warming is a prediction of physics”

      This is not predicted by physics. Radiative absorption is a mathematical model which asserts that energy is absorped by all atomic structures but it also says that these ‘atoms’ will always seek their equilibrium energy level. CO² and H²O have overlapping absorption properties and because there are more H²O molecules in the atmosphere (not evenly distributed) they will absorp IR preferentially.

      There is nothing wrong with the physics just your rather prejudiced interpretation. There is NO physical model that predicts an increase in energy (temperature) of the atmosphere in direct proportion to CO². All of us would be absolutely delighted if a climate scientist could produce a CO² v’s Temp model of the same quality as the physics models that we currently use in our daily grind.

      SKR BSc physics MSc material Physics.

    • While I agree that predictions of a theory which end up being correct can be powerful support, in the case of an up-trend or down-trend in temperature one could, advance all kinds of predicted causes, but since warming or cooling will happen anyway, does that mean a specific theory is correct?

      • Anonymous says:

        It is my understanding that this “warming” due to greenhouse gases does not occur in a vacuum. In fact you have a complex system in which warming due to GHG can cause increase cloud formation which can counteract some or all that warming due to GHG.

        That in fact is the central issue of the argument between warmists and skeptics. Warmists see feedback in this system as large and positive while skeptics see it as negative. Don’t you think it would be a good idea to figure which it is before we go into panic mode?

  9. Frank Wood, Jr. says:

    Dr. Spencer, thank you for a very careful and well written summary of a complex subject. I recommend to your readers the following book:

    “Heaven and Earth, Global Warming the Missing Science” by Ian Plimer, Taylor Trade Publishing (2009), ISBN:-13:978-1-58979-472-6.

    Prof. Plimer’s book runs to over 500 pages and contains over 2000 references. Like Dr. Spencer, Dr. Plimer is sceptical of the IPCC outlook. Although Dr. Plimer does not write quite as well as Dr. Spencer, his book is fairly easy to digest except for chapter 3. Someone who takes the time to read the books of these two academics should have a reasonable understanding of why a large number of tehnically trained individuals are highly sceptical regarding the anthropogenic global warming theory.

  10. Dan Pangburn says:

    From 2001 through 2009 the atmospheric CO2 increased by 18% of the total increase from 1800 to 2001 while the average global temperature has not increased significantly and the trend of yearly averages through 2009 is down. The El Nino that made early 2010 look a bit warmer than the trend, peaked in March, 2010 and average global temperature is now dropping rapidly.

    Research, with latest findings regarding projected temperature trends is reported at It presents a rational equation that accurately calculates the average global temperatures since 1895 with a coefficient of determination of 0.87. That means that it explains 87% of the measured temperatures for 114 years and counting. The best that GCMs have done is less than 80%. The equation predicts that the trend of average global temperatures will decline. The above link and sub links, including links to the temperature data reported by the five reporting agencies, track the data back to the published credible sources.

    As the atmospheric CO2 continues to increase and the average global temperature does not, perhaps the comments of ill-informed people will subside.

  11. Morley Sutter says:

    Dr. Spencer, thanks for the this post. It is concise, clear and useful as a primer of the science of global warming. However, I think that the problems of dealing with causality in general and in particular with demonstrating causality of global warming should have been emphasized more. You touched on it in item 18 – climate models. Models cannot demonstrate causality except by showing that they are reliably predictive. Their mimicking the past is insufficient. You also suggest that the use of mathematics (numbers)is essential and I wholeheartedly agree, but their use does not obviate the need for any model they produce to be tested by its ability to predict the future. Any model must pass this test before it can be trusted. The financial industry in the US recently ignored this truism with disastrous results and climatolgy also should acknowledge this problem of models.

  12. c1ue says:

    Dr. Spencer,

    Thank you for the time and consideration you’ve spent writing this very information article.

    While I’d like to believe I already had understood your views from following your work, it is always best to have a clear position statement.

    I did have one question: what is your view on the position of Roger Pielke, Sr?

    To wit: that there are a number of 1st order human derived forcings which are effecting climate change?

    I bring this up because the rise of CO2 emissions also coincides with increased human population; increased urbanization and land use changes; increased human intervention in local water cycles via dams and irrigation and so forth.

    Admittedly I am a skeptic, but I have always been struck by how poorly these closely related circumstances are differentiated out by the ‘consensus’.

  13. Heber Rizzo says:

    Dear Dr Spencer:

    May I translate this article into Spanish and publish it in my blog, with due recognitions and link to the original, of course?

  14. passingBy says:

    Dr Spencer,

    You said

    “The very fact that recent tree ring data erroneously suggests cooling in the last 50 years, when in fact there has been warming, should be a warning flag about using tree ring data for figuring out how warm it was 1,000 years ago. But without actual thermometer data, we will never know for sure.”

    Perhaps not. Recent work using isotope ratios in very old clam shells in Iceland has been able to pinpoint the bottom water temperature in some bays down to the year or even the season. This extended (if I recall correctly) back as far as the Roman Warm Period. Tree rings can give us a very good to exact date for their formation. Examining the ratios of O2 and Be in the actual wood of the rings may be able to give us a reliable temperature proxy.

    Isotope work is currently very difficult and expensive, but if demand for the equipment surges the price will come down and the availability will expand (think DNA). Those barns full of old wood may yield some actual science after all.

    Thank you for the article and for your unremitting commitment to “getting it right”.

    • Anonymous says:

      It will be interesting to see if this continues to hold up. Right now we have a study that used 26 shells obtained from sediment cores taken from an Icelandic bay.

  15. JB in VA says:

    Thank you for the explanations. I find them very helpful.

    I have questions I can’t find answers for.

    In the process of turning hydrocarbons into CO2 and H2O, as well as the process of physical labor, and generating so-called renewable energy, heat is “created.” (OK, it is more like transferred.) That heat contributes to global warming or to regional warming by how much? Is there some sort of model that can estimate how much heat is generated by burning x amount of oil? And/or how much radiative heat is generated by solar panels or how much heat through friction is produced by wind turbines? A person creates about as much heat as a 100 watt light bulb, I have heard (iridescent I assume, not fluorescent). How much global heating is the result of population growth? Is it offset by the loss of animal life?

  16. Bill says:

    I’m a little curious about your comment in #2 that since 1998 one could say we have seen “cooling.” I’m no statistician, but just eyeballing your own plotted graph of temperature anomolies over time, it certainly appears that the decade after 1998 has had uniformly higher temperatures than the decade preceding 1998 – consistent with NOAA’s claim that the 2000’s were the warmest (arbitrary) decade on record. Isn’t it sorta unscientific to try to peg trends to one anomalous year? I noticed that in 2009, folks like Fox New’s Brit Hume began saying that there had been no cooling in “about” a decade; whereas in 2008 he would say there had been no warming in a decade – always needing to peg analysis to just 1998 – the warmest year on record. Doesn’t NOAA’s data set indicate that May 2009 through APril 2010 is the warmest rolling year in instrument recorded history? Don’t your own calculations show temperature increases to be following something like a 0.16 degree centigrade/decade trajectory?

    Regarding your answer to #13 that you are part of a minority that believes that natural factors can cause climate change; I think you underestimate the size of climate scientists who have your back on that belief. The difference, I believe, is that many of those believe that climate changes due to natural factors PLUS a delta attributable to anthropogenic factors which is pushing the observed warming over the past 50 years.

    Regarding your answer to #4, how is it that you cannot accept the instrumental data showing “warming” over the past 50 years except with skepticism; yet so readily accept extrapolations from forensic data (and mostly just from Europe) about the Medival Warm Period? Is it possible to accept both – or do you simply believe that forensic inference is more persuasive than direct measurements?

    • Regarding the questionable use of 1998 as a starting point for a temperature trend calculation, I am making the same point you are.

      Regarding my answer to #4, I never said that I don’t accept the instrumental data showing warming over the last 50 years.

      • Anonymous says:

        Sorry, I didn’t mean to isolate to #4 what I interpreted to be your reservations about what instrumental data over the past 50 years or so is saying. It was your #1 where it appeared to me that you might be having difficulty accepting whether instrumental data was showing warming over the past 50 years; while appearing to accept limited forensic data as validation of the Medival Warm Period. I see, though, that I am really parsing your caveats on temperature data since throughout most of your post you acknowledge that warming has occurred over the past 100 years of instrumental data, and most strongly over the last half. Sorry about that.

  17. John says:

    Have you got a reference for your assertion about antarctic sea ice? suggests

    Arctic -3.5±0.7 %/decade (of 12.2E6 sq km), Antarctic +1.4±1.2 %.decade (of 13.8E6 sq km)

    which is hardly “nearly as fast”.

    • Anonymous says:

      John, comparing the percentage change in area of sea ice from the Arctic to the Antarctic is not relevant. You will note that the actual area of sea ice in the Antarctic is much larger at its maximum (almost 50%)than the Arctic, so a similar change in area at both poles would show a bigger percentage change in the Arctic.

      • Anonymous says:

        Not according to NSIDC. Their figures (quoted in my original post) give the antarctic only 13% more sea ice than the arctic, on average.

  18. wfm says:

    I understand your viewpoint on evidence of past climate change, particularly those requiring the use of proxies, to be of uncertain value in guiding our understanding of future climate change. In reading most of your writings on climate I sense possibly a lack of appreciation as to “when” we are in climate. The recent (2009) paper by Tzedakis (updated and republished online in march 2010) where the subject of “when” we are is examined fairly well suggests that there is considerable uncertainty as to the length of the present interglacial, the Holocene. Orbitally, we are at an eccentricity minima, just as we were during MIS-11 and MIS-19 on the roughly 400kyr eccentricity minima cyclicity. We are also at the half-precessional cycle (11,500 years being half of 23,000 years) which has paced at least 5 of the past 6 interglacials, MIS-11 being the sixth. The best studied past interglacial is the Eemian (MIS-5) simply because it was the last one back and more evidence is therefore preserved. What appears striking to me is the data regarding the two warm pulses which occurred possibly on decadal to centennial timeframes at the end of the Eemian. What appears to be the case at the end post-Mid Pleistocene Transition interglacials is rapid temperature and sea level instability as climate destabilizes from the interglacial to the glacial mode. In the case of the Eemian, this appears to have resulted in a +6 meter sea level excursion which some workers ascribe to the melting of the West Antarctica ice sheet. Obviously such natural “noise” was not due to anthropogenic influence. This appears to me to be a rather simple signal to noise ratio problem. Given that climate appears to be a more or less non-linear chaotic system, some say stochastic, the question appears to be how will we be able to separate say the AR4 worst case of 0.59 meters by 2100 from what may have been a 6 meter rise that occurred over a similar period at the typically rapidly fluctuating end of a post-MPT interglacial like the Holocene? Taking Al Gore’s 20-foot predicted rise (~6 meters)just gets us to the outer envelope of what may be the natural range of end interglacial noise, making it also indistinguishable from the natural climate noise range.

  19. evilincandescentbulb says:

    Most of the warming seems to be the cause of political friction. The secular, socialist government-funded education complex has failed reason and objectivity, and it has failed humanity by undermining the objective search for truth as a means to overcome superstition, fear and totalitarianism.

    The nation’s dropout factories have given wings to the global warming hoax. We don’t need worshippers of Al Gore, Ward Churchill, Mao, Castro and Chavez French-frying American brains and declaring jihad on capitalism and Judeo-Christian ethics and morals.

    “The IPCC assessment reports do not contain any mathematical analysis based on the laws of physics to support their formulae or hypothesis. We are reduced to statistical correlation [like MBH98, aka ‘the hockey stick graph which is a proven scientific hoax] between the CO2 content of the atmosphere [The data coming from the site of an active volcano and measured by a father and son team who have turned falsification of data into a cottage industry] and the average global temperature [which is an intensive variable which cannot be meaningfully averaged and has no meaning in the real world] …

    “According to the satellite data, since 1979 there has been no significant increase in global temperature. We have had 20 years of increasing temperature and 10 years of decreasing temperature, while the CO2 content has shown a uniform increase. Hence there is no correlation. If there was, I would ask the question: ‘Is the CO2 causing a temperature change or is the temperature change causing a CO2 change?'” (Barry Moore)

  20. Ference Miskkolczi in Energy & Environment · Vol. 21, No. 4, 2010, claims “Simulated radiative no-feedback effects of
    measured actual CO2change over the 61years were calculated and found to be of magnitude easily detectable by the empirical data and analytical methods used. The data negate increase in CO2in theatmosphere as a hypothetical cause for the apparently observed global warming. A hypothesis of significant positive
    feedback by water vapor effect on atmospheric infrared absorption is also negated by the observed measurements. Apparently major revision of the physics underlying the greenhouse effect is needed.”

    I am not a physicist. I did read this paper and found it quite convincing. Even if his overstates this position it is clear that much of the warming is due to other causes, apparently natural ones. Unless of course it the all that body heat from the 6 billion of us.

  21. Mark Gordon says:

    Dr. Spencer,

    My first and lasting impression of this debate is that it involves some very, very complicated science, of almost every physical kind,and that mankind is probably not even near having a theory of climate change that they can take to the bank.

    Am I wrong? Is it possible to give an estimate, even a rough and dirty ball park figure, of how far away we are?

  22. Tidd Kidd says:

    Dr Spencer, you are wrong in one very important and crucial respect. I’m sure you know better (unlike many of your fellow-Americans who seem to prefer to wallow in ignorance on this matter).

    You have chosen to use the completely unscientific and media-originated term “global warming’. As you are a scientist yourself, I say “Shame on you!” You know, more than most, that the correct scientific term is “Climate Change”.

    This correct term recognises that the effects may manifest in different – even opposite – ways in different parts of the world at different times. In the Gulf of Mexico, for example, larger and more destructive hurricane-type storms; in the UK, wetter weather, and a smaller difference between upper and lower peak temperatures in summer and winter; in parts of Africa and Australia, extreme drought; and – the fact that has caused many Americans to falsely leap to the side of the sceptics – more severe winters in parts of N America.

    I have no hope of converting you from your position of ‘sceptic’, but I appeal to you as a scientist, to please use the scientific terminology, with its more precise connotations, and not the media catch-all which is actually more than 50% wrong, and 100% misleading.

    • Anonymous says:

      Tidd, what absolute nonsense. Your climate change makes any testing of your hypothesis worthless, because everything is compatible with Climate Change.

      This is the way science works for the supporters of AGW

      Increased warming means higher temperatures and therefore less snow. But increased warming means more water vapor in the atmosphere leading to more precipitation. Therefore AGW can cause big blizzards. So too little snow or too much snow is an indication of global warming.

      More warming can mean glaciers will shrink. But more precipitation means glaciers can grow. Therefore if glaciers are growing or shrinking it means global warming is happening.

      More warming means more energy for hurricanes and therefore more and stronger hurricanes are in the future. But more warming also means more wind sheer which cuts off hurricanes and can mean fewer hurricanes. So more or fewer hurricanes is caused by global warming.

      More water vapor means more clouds and more precipitation. More clouds and precipitation causes cooling which could lead to global cooling. So if it is warming or cooling, it is proof of global warming.

      No wonder Al Gore says the science is settled. It predicts everything that has and can happen.

      I would say your comment was 100% misleading and 95% wrong.

      • Tidd Kidd says:

        Anonymous, I don’t respond to people who hide behind anonymity and the Internet, in order to make personal attacks. I am impressed only by science, by facts. The global scientific community know what is meant by the term “climate change”. It is not defined by you.

        • Anonymous says:

          Nonsense, TK. Is Tidd Kidd really your name? Your grasp of science seems to be what your sister tells you. Climate Change is just a nonsensical way of justifying anything.

          BTW, I go by goodspkr, but it’s easier just to submit a comment.

          • Anonymous says:

            BTW, I didn’t make a personal attack unless you consider my saying nonsense to your comment that a real scientist would call it climate change not global warming. I then paralleled your comment about the media using global warming being 50% misleading and 100% wrong. The rest of my comments was about how screwed up a hypothesis is that defines nothing.

            If you can’t stand the heat, get out of the kitchen, TD.

          • Tidd Kidd says:

            Dr Spencer, if you approve of this crapulous level of non-debate, then I’m clearly in the wrong place. I’m only interested in scientific fact and debate, not this “throwing toys out of the pram” level of childishness. Perhaps we can meet somewhere else to discuss these matters rationally? You can speak to me on Twitter, @TiddK. Many thanks, Dr S.

    • Anonymous says:

      Tidd Kidd, “global warming” does not refer to a uniform increase of temperature over the whole globe. Scientists who earlier used the term but now use “climate change” were not so incredibly stupid as to expect a uniform increase. You are making no sense at all.

      • Anonymous says:

        If this shows me as “Anonymous,” I’m baffled. I’m the “Anonymous” who wrote the message I’m replying to. There was no opportunity to put in an id, so now I’ve put one in at the bottom of the page, but I’m using the “Reply” tag on the message I’m replying to. I wonder what’s going to happen. In case I show as “Anonymous” this time, Help! 🙂

    • Anonymous says:

      Except that the said manifestations have not manifested. And will not.

      Simply put the the energy differentials required to produce those “manifestations” is reduced by warming.

      The simplest and most well understood model of climate is based on energy transfer. The larger the differential, the more tranfer must take place to reach equilibrium, resulting in larger more violent storms as energy is tranferred from one extreme to the other, etc. I grant that the process in total is EXTREMELY complex and to simply say bigger temp diff makes bigger storms is simplistic, but it doesn’t negate teh fundamental truth of the simple model. AGW though, deliberately ignores this well understood basic model, and as such should be suspect.

      But, with GW producing smaller differentials the logical result, long term, will be less violence.

      I also take exception with jumping on the good Dr. for his use of the term “Global Warming.” Your characterization of the term as media derived is grossly inaccurate. The term “Climate Change” is a relatevily recent construct resulting from the understandably negative connotation of the original GW term. Working group records, videos of AGW proponents and policy makers are well documented as having made deliberate decisions to “adjust” the nomenclature in recent years to avoid the negative publicity as well as be able to sidestep the issues regarding recently notice temperature declines or lack of declines. In this fashion no matter what changes actually occur, “Climate Change” can be seen as being real, even if all the fuss still amounts to a “warming” trend.

  23. Wagathon says:

    Use of the term ‘climate change’ is disingenuous Tidd Kidd as the global warming alarmists do not fear global cooling and increases in atmospheric CO2 — natural or otherwise — cannot be the cause of both global warming and global cooling.

    • Tidd Kidd says:

      No, the term climate change is not disingenuous – it is the term that scientists (like my sister, who is a local authority “climate change specialist”) understands to be the correct term. Your use of the word “global” is, if anything, disingenuous, as it implies that the effects of CO2 increase manifest as a uniform effect (either “warming” or “cooling”), which is quite untrue and unscientific. For example, the gradual diminution and relocation of what is popularly called the “Gulf Stream” will have quite unpredictable effects on the UK : to date it has bee responsible for above-average ‘local’ temperatures and the general mild climate of the Southern UK. When this goes, no-one knows whether it will cause harsher extremes of weather – including colder winters – or not. However, its gradual disappearance is proven to be the direct result of the melting of the ice caps and the greater admixture of fresh water into the ocean where the Gulf Stream begins to sink.

      What this demonstrates is that the effects of CO2 increase are NOT global, but – as the term “climate change” indicates – manifest in different ways across the globe. Climate change IS global, its effects are not.

  24. TomT says:

    Dear Dr.Spencer..I wrote the “Please Talk To Us” e-mail
    and am totally thrilled you accepted my request. Your
    response is exactly what I wished for. Thanks,so much!

  25. Dan says:

    Thoughts of a dummy.
    1.Are global temperatures rising? Is there a “global temperature” or are the North and South autonomous as they seem to have been for 1000 years after the last ice age? Is the “global temperature” still settling after the Little Ice age, ie getting back to normal?
    2.Temperatures are measure at the earths surface, when the air mass meets the sea or the land mass.This is a boundary measurement which is surely one of the most difficult to interpret and unreliable measurements in science, even if the methodology was perfect.
    3.I thought the argument of the AGW was that there is 33 degrees unaccounted for, therefore there must be anthropogenic warming because nothing else accounts for it. If there was warming in a previous era, there must be another cause.
    4.The Hockey stick was contrary to accepted wisdom, namely the existence of the Medieval warming period and the Little Ice, yet the response from scientists was totally muted. Where was the powerful consensus when it was needed?
    5.The Arctic ocean sits in a basin and the floor of that basin has a large volcanically active rift. The heat from this phenomenon may be the main driving force in changes in the Arctic ice cover but nobody seems interested.
    6.After the last ice age the glaciers melted and the sea rose 140 metres and now with less that 5% ice cover left we can expect another 7 metre rise probably spread over 10,000 years. That is less than 4 inches per century at the very worst, but seems even this figure is not being achieved in the real world.
    7.Could the Tyndall experiment be repeated using say 20 x 1 mile-long tubes at the pressure and temperature of the atmosphere at the equivalent height and the matter be settled with change out of $1 million?
    8.Didn’t Callender cherry pick low CO2 readings from the 90.000 readings taken in the 19th century? Aren’t the Mauna Lowa readings suspect from their observatory setting and their continual retrospective corrections?
    9.If human CO2 amounts to less than 4% of the annual CO2 production from nature how can it selectively cause such a rise?
    10.This analogy assumes the CO2 increase in the atmosphere has nowhere to go but simple physics says it must dissolve in the oceans in the same ratio as it increases in the atmosphere, so the atmospheric increase is miniscule – way less that seasonal variation.
    12.See 7
    13.Or more to the point, what caused the Little Ice age? The answer to that question may also answer why it is now relatively warming, and actually returning to “normal”
    14.The Indian Ocean Haze, said to be 3 – 4 miles deep and the area of America could easily cause a 2 – 3 degree world atmospheric temperature change. Yet it is ignored by the AGWers.
    15 My personal suspicion is that the release of emails came from a very senior scientist embarrassed at the deceit of his work and fearing irreversible decisions at Copenhagen.
    17.Carl Popper
    18.In a chaotic system as climate is, modelling can only extrapolate on the momentum inherent in the current state of the system. Otherwise the climate modellers would have been running Lotto programs on the side and now be rich and retired.
    19.Agree. The world is overdue an ice age. Maybe we missed this cycle, maybe the Ice Age cycle is changing or maybe CO2 from fossil fuels saved us from freezing to death

  26. Wagathon says:

    Theory is one thing but in reality, Al Gore’s physics is generally, unprincipled–unless you can prove otherwise.

  27. I like to give people the benefit of the doubt. I suspect that the term “climate change” replacing “global warming” was an attempt to take into account that the warming effect of anthropogenic GHG emissions would be accompanied by other changes as well. In this sense, “global warming” causes “climate change”. Obviously, it can’t be synonymous with “manmade climate change”…unless the Ice Ages were caused by people, too.

    • Anonymous says:

      I suspect ‘climate change’ was coined to conjure up fear of all manner of foul weather conditions from hurricanes and tornadoes to floods and volcanic eruptions–under the global warming alarmist tent revival.

  28. Kevin says:

    Dr. Spencer,

    With respect, Thank You for your candor.

    In your point #7 regarding CO2’s role in “warming” You Wrote:

    “Adding more “should” cause warming, with the magnitude of that warming being the real question. But I’m still open to the possibility that a major error has been made on this fundamental point. Stranger things have happened in science before.”

    I have also seen you write admitting that the net heat flow is from the Earth’s surface to space. This is true. The Second law of thermodynamics states that the net flow is from the warmer (more active) to the colder (less active) location. One practical outcome of this law is that a colder location CANNOT raise the temperature of a warmer location, by radiation, conduction, or convection. All that a colder location can do is to slow the rate of cooling of the warmer location. Given the meager thermal capacity of the gases in the atmosphere this reduction in cooling is not sufficient to have much effect on the temperature of the Earth. The temperature of the Earth is predominately determined by the thermal capacity of the Oceans and the Rocks and the amount of radiation arriving from the Sun.

    I am of the opinion that increases in “greenhouse gases” actually cause more energy to flow through the atmosphere at the speed of light rather than at the speed of heat (thermal diffusivity). This causes the atmosphere to warm up ever slightly faster after sunrise and cool down ever slightly faster after sunset. I also believe that this effect is so small we probably could not measure it if we tried. The historical temperature record does not contain the necessary data.

    So I am postulating that indeed a fundamental error has been made in climate science and the “greenhouse effect” has little effect on the temperatures of the Earth. Thereby I am not a skeptic, I am a denier.

    Cheers, Kevin.

  29. Keith says:

    Thanks for your candid and simplified remarks. Your statements and position seem to be a rational response to the massive uncertainties currently inherent to climate research. Adding to the uncertainty through government, political and business interventions has certainly muddied the waters. I can only think that the whole CO2 debate has had a stifling effect on climate science, and one is left to wonder how and where climate science might have advanced had this road block to progress been circumvented at an earlier juncture.
    One specific comment about point 18 : In econometric modelling, when one is confronted with a lack of statistical significance in multi factor analyses, one resorts to models.
    Rather than a model reflecting statistically significant marginal and co-dependent relationships, it’s construction rather depends on the perspectives (or beliefs) of the model builders. This is possibly why the modellers resist making changes to their models – they have no basis upon which to make reasoned changes, or perhaps are unable to recall the specific reasoning within and between components of the model.
    Perhaps at present climate science is the dismal science of science 🙂

  30. ThomasJ says:

    Mny txs for this informative article, Roy! As the gentleman from Spain (?) asked for permission to translate + distribute w all ref’s, I’d very much like doing the same, however in Swedish. Ok?
    Pls. also try planning a tour of Scandinavia again… si?
    Brgds from the Bestcoast of Sweden!

  31. Bill V says:

    One more note on “Climate Change” vs. “Global Warming”

    Frank Luntz, a conservative politcal consultant and pollster, came up with the term climate change for the Bush administration for the purpose of making it sound less harsh than Global Warming.
    Rather ironic considering now who blames whom for the origin and purpose of the phrase.

  32. Tom Rowan says:

    Anonymous said…
    I have followed Dr Spencer’s analysis since he became the Official EIB Meteorologist at Rush Limbaugh’s Institute.

    However, I think Dr Spencer is being too cute by half.

    To ignore the documented fact that NOAA, NASA, and East Anglia have all been caught cooking the climate books red handed for years, (stretching back decades and centuries,) gives Dr Spencer the rotted limb to stand on “who knows?”

    To ignore Henrick Svenmark’s cutting edge research into the sun’s relationship to cloud cover goes begging.

    Dr Spencer should not assume the weak kneed stance taken by RINO Republicans like Lindsey Lohan Graham.

    To agree to half a lie is to give half credence to ALL of it.

    It used to be that scientists spent their entire lives researching and recording evidence to FALSIFY proposed hypothesis.

    In this respect, I am afraid Dr Spencer has fallen flat on his nose.

    Does he suppose he will be honored for being a “moderate” scientist? Do “middle of the road” scientists who will not point out the obvious be hailed?

    Or will they become roadkill when obvious facts come to light?

    Roadkill Dr Spencer, a mere statistic for those who would not stand up and demand “wait a minute.”

    Mega-non Dittos Dr Spencer.

    • Anonymous says:

      Tom Rowan,
      Please provide references to your claim that “NOAA, NASA, and East Anglia have all been caught cooking the climate books red handed for years” and is not good enough. Please show original references.
      Although those involved with East Anglia were found to participate in bad practices, nothing involved with them proved or disproved actual data. Regarding NOAA, and NASA, this is the first I heard.
      Did you only respect Tom Spencer in the past because of Limbaugh endorsements and because his research findings matched what you wanted to believe? What if by chance, more research is done by all scientists currently endorsed by Limbaugh and they all come to the consensus that AGW becomes more of a scientific probability? Will you still throw it out?

    • Anonymous says:

      I believe Dr. Spencer is exactly as a scientist should be. He is responsible for his research and no other. Why should he spent his time commenting the work of other scientists, when they are not pertinent his research?
      More, I don’t come here to read the same things that I can easily read on other AGW skeptic blogs.
      I wish I could read more and more scientists who share their knoweledge

      • Anonymous says:

        Sorry… I submit the comment above before I ended it.

        … I wish I could read more and more scientists who share their knowledge with the common people, instead of read many other ones who continue to exchange accusations of bad science each other.

        I don’t believe Dr.Spencer needs my defence too.

        Anyways, I hope he will continue this way.

        Dr. Spencer, jut to say, there should be a problem in submitting replies to a previous reply, since I filled the “Name” field but the reply get the “Anonymous says:” title.


    • Oh, I take sides strongly when I have the evidence. Too much in this field of research, though, is lacking that evidence.

  33. Ed says:

    On average world temperature is +15?C. This is sustained by the atmospheric Greenhouse Effect 33?C. Without the Greenhouse Effect the planet would be un-inhabitable at -18?C. The World and Mankind need the Greenhouse Effect.

    So just running the numbers:
    • Greenhouse Effect = 33.00?C
    • Water Vapour accounts for about 95% of the Greenhouse Effect = + 31.35?C
    • Other Greenhouse Gasses GHGs account for 5% = ~1.65?C
    • CO2 is 75% of the effect of all GHGs = 1.24?C
    • Most CO2 in the atmosphere is natural: Man-made CO2 is less than 7% of total atmospheric CO2 = 0.087?C: so closing the whole world carbon economy could only ever achieve a virtually undetectable <1/10 ?C.

    As the temperature reduction that could be achieved by closing the whole of the World’s Carbon economies is less than 1/10 ?C, how can the Green movement and their supporting politicians think that their actions can limit warming to only + 2.00 ?C?


    However in the light of the state of the current solar cycle it seems that there is a real prospect of damaging cooling occurring in the near future for several decades.

    Nonetheless, this is not to say that the world should not be seeking more efficient ways of generating its energy, conserving its energy use and stopping damaging its environments. And there is a real need to wean the world off the continued use of fossil fuels simply on the grounds of:
    • security of supply
    • increasing scarcity
    • rising costs
    • their use as the feedstock for industry rather than simply burning them.

    The French long-term energy strategy with its massive commitment to nuclear power is impressive, (85% of electricity generation).

    Even if one is concerned about CO2, it seems to pay off, French CO2 emissions / head are the lowest in the developed world. So a wholehearted commitment to nuclear power, is the only thing to make good common sense.

  34. Tom Rowan says:

    “Tom Rowan,
    Please provide references to your claim that “NOAA, NASA, and East Anglia have all been caught cooking the climate books red handed for years” and is not good enough. Please show original references.”

    Anthony Watts @ has documented NOAA, NASA, & East Anglia massaging the data for years. It seems that almost every data set has been massaged and cooked upward.

    There are simply too many examples to list, but the examples you seek are all documented at

    As for Climate Depot; I find the site as informative as the Drudge Report. Most of the headlines there are direct links to primary sources of information. For you to dismiss the site out of hand shows that you are close minded. The only websites I ever have problems with are commie lib green sites where they censor comments not in line with their own climythology of globalony.

    But you don’t have to take my word for it. Listen to the elder statesman of the global warming religion, Phil Jones…in his own words:

    If a climate hack like Phil Jones can admit that there has been no warming for 15 years, why are we even having this debate?

    If there is no warming, then mankind cannot be held responsible for something that is clearly not happening.

    Is that too much logic for you to handle? Do facts matter anymore to science? The entire hoax was based on a foundation of laughably lies. And the lies are easily disprovable in one is so inclined to disprove them.

    I like Dr Spencer. But to pen an outline “for dummies” and leave out the relevant facts of the matter is dumb.

    Global temperatures are falling. The sun is still not ramping up in sunspot numbers and the spots that it is producing are puny and weak. Everytime the sun went into hibernation in the past, global temps have seen a fall.

    Why do you think now will be any different?

    Glaciers around the world are growing. The small number of shrinking glaciers are due to a lack of precipitation, not warming.

    Sea levels are not rising and the polar ice caps have been growing.

    Every damn bit of information about globalony is a lie…every last bit of it. Mt St Helens has a growing glacier inside its volcanic basin for the love of God!

    Your demand for links to factual information is disingenuous because the information you claim to seek is not hard to find and everyone with half a brain knows it.

  35. Dr Spencer, you say “But it only takes one of us to be right for the IPCC’s anthropogenic global warming (AGW) house of cards to collapse”.

    I think this needs a bit of elaboration. A recent careful study shows that among scientists the warmist/sceptic ratio is 97/3, and at the same time, the warmists have superior qualifications to the sceptics.

    At face value, your statement reminds us of the proud mother who claimed that her son was the only one in step on the parade ground.

    • Anonymous says:

      “A recent careful study shows that among scientists the warmist/sceptic ratio is 97/3, and at the same time, the warmists have superior qualifications to the sceptics.”

      Ridiculous, who stated that that study is “careful”?
      And who decided what is “superior qualifications” in long term climate predictions?
      Long term climate predictions to became a real Science must agree with the physics of the real world, and as far I know there is no evidence of that till now.

      Science is never a matter of head counts. For me, Dr. Spancer’s statement means that if one of the many who opposed rational doubts against the AGW theory will result right in future, then all the AGW castle fall down because at the moment there is not proof of how much CO2 forces the climate (whenever it does, I add but I’ve no qualifications at all).

      Science is just a matter of truth.


  36. TheLastMan says:

    Thanks for the clarification, it is very helpful to know where you stand on the general topic.

    I actually don’t think you are as far removed from the consensus as some think. Scientists in the “non-sceptic” community disagree on “how much” it is going to warm, you are just separated from them by degree rather than a fundamental disagreement. Even the true believers acknowledge the uncertainty in cloud feedbacks.

    My conversion from “sceptic” to somebody who is “sceptical of sceptics” is the fact that many of the predicted finger prints of the effect of CO2 on the temperature record are showing up, but that the sceptical community seem to prefer to believe any theory so long as it disproves the influence of CO2.

    In particular the following results are predicted if CO2 is a major influence on global temperatures:
    1. More warming at higher latitudes than lower
    2. More warming at night than during the day
    3. Warming Troposphere coinciding with cooling Stratosphere

    All these effects are showing up in the temperature record to some degree.

    However the sceptics seem to be prepared to believe these results are more likely to be due to different unrelated causes rather than due to the more obvious, and predicted, single cause.

    For instance when I posted the above rationale on one site I got responses that:
    – faster than average warming in the west Antarctic peninsula is caused by volcanism
    – similar accelerated warming in the Arctic was faulty temperature records
    – warming at night is caused by more clouds
    – the Stratosphere was not cooling as much as predicted.

    This tendency to agree with any argument so long as it disproves CO2 as the cause, rather than to make an objective appraisal, smacks of “confirmation bias” or the tendency to favour theories that confirm your own prejudices rather than those that might disprove them, regardless of how unconnected or contradictory those theories may be.

    I do, however, have a lot of sympathy with the poster here who lamented the tendency of AGW proponents to blame all changes in climate on CO2, whether warming or cooling!

    Confirmation bias is evident on both sides of the argument.

    • 1. More warming at higher latitudes than lower
      Maximum warming in the Arctic, decreasing as you go south to the Antarctic, would be expected for any warming influence, because the heat capacity of land is so much less than the ocean. It’s not a fingerprint.

      2. More warming at night than during the day.
      This can be caused by a variety of natural factors, and again, warming of the oceans caused by decreased cloud cover will cause more humid air masses, which flow over land and cause effects that are essentially indistinguishable from increasing CO2.

      3. Warming Troposphere coinciding with cooling Stratosphere
      Only cooling of the stratosphere is a potential fingerprint…except for ozone changes, and possible natural changes in stratospheric water vapor.

    • Espen says:

      TheLastMan : Regarding “More warming at higher latitudes than lower”. The fact is that the previous Arctic warming (around the 30s and 40s) was about as strong as the current (in Greenland it seems to have been stronger, e.g. in the long-running temperature record of Nuuk). So while on a global scale the current warm period seems to be a little warmer than the previous period, in the Arctic this is less sure. Until AGW proponents come up with a really good explanation of how the two warming events could be so similar and still have completely different causes, this is a pretty strong falsification of mainstream AGW theory to me.

  37. harrywr2 says:

    In particular the following results are predicted if CO2 is a major influence on global temperatures:
    “1. More warming at higher latitudes than lower”

    Here is a chart of ‘climate change’ in Alaska.

    There was a ‘step change’ around 1976. No warming since. A 60 year average of Alaskan temperatures would show a warming trend consistent with CO2 theory, but there is nothing in CO2 theory to explain what actually happened, a 5F degree jump in 3 years then no warming for the last 30 years.

  38. F4 says:

    Very good post, thanks for your time.

  39. RaymondT says:

    Dr Spencer, I really appreciate the objectivity of your questions and answers and your efforts to investigate the role of natural variability in the radiative heat transfer in the atmosphere. Would you not admit though, that the explanation of the increase in global temperatures due to increased CO2 may be more complete AT THE MOMENT in the sense that we know fairly well the increase in CO2 due to mankind and the infra-red absorption characteristics of CO2. On the other hand, it seems to me that the mechanism by which the cloud cover would change by 1 % over MULTI-DECADAL TIMESCALES still needs to be investigated. Could multi-decadal fluctuations in absorption of SW and emission of LW radiation from the oceans also have an effect ? However, I think that until we can come up with climate models that can predict global temperatures (if at all possible) we should not use these models to estimate economic costs due to these hypothetical temperature increases and try to mitigate CO2 increases.

    • I agree, we know more about CO2 than any of the other potential warming mechanisms. But ancient peoples knew more about their infractions against the gods of nature, which is what some blamed bad weather on.

  40. Kevin says:

    Regarding the “confirmation bias” comments;

    As an engineer the lives of persons I will never meet depend on my sound engineering judgment. I am not afforded the luxury of confirmation bias. If I get it wrong, people will “very likely” die. When confronted by this conundrum I have to “err on the safe side” and strive to preserve the lives of people.

    As part of my responsibility I must fall back on the ”clearly demonstrated” science of the known and demonstrated LAWS that describe our current understanding of how nature (still not totally understood, i.e. “dark energy”) operates. Therefore I must retreat to the LAWS of THERMODYNAMICS until someone clearly, unequivocally, and independently (without political influence) demonstrates that the HYPOTHESIS of the “greenhouse effect” is correct.

    I hate to state it this way, but the folks that accept the AGW hypothesis have COMPLETELY FAILED (after two decades and 100 billion dollars) to approach this barrier. Therefore, I must revert to the NULL HYPOTHESIS that states that “we have no reason to expect” that the weather is now behaving in any measurable way that is different from how is has behaved in our recorded history.

    This is not meant to infer that new knowledge is not acceptable, for example until the Wright Brothers unequivocally demonstrated that a “heavier than air” machine could produce sustained flight the consensus was that this feat was impossible! So if the Wright Brothers could pull off that feat in less than two decades (with no computer models) why cannot the persons that believe in the AGW HYPOTHESIS repeat this feat with funding and political support that far exceeds the resources of Orville and Wilbur ????????????

    Now, of course some folks will state that the “unknowns” facing the Wright Brothers were trivial compared to what we face now. But think about it, back then we did not know; the speed of sound in air, the interaction of pitch, yaw, roll, etc., and they had no access to computer models anywhere near the capabilities available today. In fact the Wright Brothers INVENTED the wind tunnel to help them achieve their quest. So I offer the following challenge to the climate science community;

    Demonstrate the “greenhouse effect” in any environment that somewhat mimics the atmosphere of the Earth. I.E. show it to us with an experiment that;

    Demonstrates blackbodies that somewhat mimic actual blackbodies (thermal capacities, spectral content, emissivity, etc.)

    Demonstrates an open gaseous atmosphere with a composition that somewhat mimics the real atmosphere.

    Mimics the role of water vapor with any crude approximation.

    Surely an experiment can be designed that would lend credence to the AGW HYPOTHESIS even if it was very crude ?

    As an engineer with theoretical and empirical experience I am working on an experiment that will attempt to demonstrate the “greenhouse effect”. If the theory is correct I should be able to create something that may be crude but will lend some credence to the “greenhouse effect” HYPOTHESIS. I challenge others to create a similar experiment. If the “greenhouse effect” is such a sure thing surely somebody can create an experiment that shows it! And, no the simple experiments that show that CO2 trapped in a bottle warms more than “air” trapped in a bottle does not suffice.

    Cheers, Kevin.

  41. Wagathon says:

    I appreciate your candor at being a denier Kevin. The Earthshine project found as you say, i.e., the incomming solar energy is not also outgoing and that certainly debunks the AGW Weather Underground.

    The warmanists chant denying basic laws of thermocynamics is the pis aller of the falsified global warming alarmist movement. While CO2 is physically incapable of heating the world, they continue to insist that water vapor provides the needed positive feedback that their AGW theory demands.

    Unfortunately for their case, their only proof is their GCMs, i.e., failed toy models of reality, a notorious example of which is MBH98 (aka, the ‘hockey stick’ graph), a proven scientific fraud. Nice try but no free lunch: we now know that clouds provide a negative feedback.

    Something that has been happening on Earth for billions of years by definition is reality, not the toy models of the global warming alarmists. And, for as long as humans have been able to describe reality in words: they have called it ‘nature.’

    For the last couple of decades, a relatively few number of Western scientists have created a fictional world based on global climate models (GCMs) that defy reality. They call it the ‘greenhouse effect,’ which they say is the physical basis for their claim that “CO2 emissions give rise to anthropogenic [man-made] climate changes.” Real scientists call that science fiction.

    There is only one independent variable. It’s the sun, stupid.

    And, the big actor in Earth’s drama is water, oceans of it. The energy of the sun falls on the oceans and lakes, causing evaporation and resulting in water vapor. The water vapor mops up heat and rises, leaving a cooler Earth behind. As water vapor rises the atmosphere becomes cooler, thinner where it eventually condenses and eventually gives up its heat to the cold emptiness of space as the vapor returns to water, forming clouds or freezing and ultimately falling back to earth as rain, sleet, hail and snow.

    The global warming alarmists cannot change this process. They can only program GCMs depicting runaway global warming by treating water vapor as a contributor to global warming, i.e., a positive feedback by collecting heat like a greenhouse. In actuality, water vapor is a part of a holistic process that results in a negative feedback because the amount of solar energy that is reflected away by clouds during the day more than offsets the suppression by clouds of cooling during the night.

    The work of Gerlich and Tscheuschner clearly shows us that to believe otherwise is to believe that the Earth’s atmosphere acts like a perpetual motion machine. The secular, socialist Western academics’ greenhouse gas theory is based on conclusions about reality that contradict the basic laws of thermodynamics and do not correspond to observational evidence. The global warming alarmists’ GCMs have no forecasting ability because they erroneously calculate a doomsday scenario for one purpose only: to blame capitalism and Americanism for a non-existent problem.

  42. Les Elkins says:

    >Climate change does not require an “external” source of
    >forcing, such as a change in the sun.

    A couple of decades ago I read James Gleik’s “Chaos”, which among other things discussed for the layman the development of chaotic and fractal analysis of systems inspired by the mathematically chaotic nature of weather prediction. I’ve never understood how a global climate model- which I would assume be a summation of local weather models- would not be chaotic and therefore unpredictable, being the sum of inherently unpredictable systems… Any comments?

    Thanks for the article. I always seem to find discussions of what we don’t know, and why, more illuminating than discussions of what we do know…..

    • Anonymous says:

      The Earth’s climate is not random. But it sure is chaotic. How shall we model it? Can we model it?

      From our Earthly point of view, it is impossible to determine the future effect of solar activity on the Earth’s climate. And constructing an Earthly climate model that captures the holistic interaction of the myriad dependent variables is naturally daunting. But, that is what we must do to make long range climate change predictions.

      Moreover, the mathematics of modeling what for us is a chaotic system is an earthbound mathematical challenge. The mathematics of chaos makes the selection of a starting point a key element in the outcome of the modeling process.

      Let’s assume we had adequate data, knew how all of the variables were related, and could predict the future effects of the sun and the moon and the energy from the cosmos on the Earth’s climate. Still we must choose some starting point to initialize our Earthly climate model.

      Do we start our model from the last interglacial warm period, the last ice age, or shall we start a couple of ice ages back? Do we go back a millennium or a thousand millenniums? And that is a problem: Using the mathematics of chaos, our Earthly climate model will give us a different long term prediction of the future for every initial starting point we choose.

      The problem with long term climate prediction is that climate science is in its infancy. Some may believe we know more than we do and that is a problem too. “If we knew what it was we were doing, it would not be called research, would it?” (Albert Einstein)

  43. gregor says:

    as far as i remember the crucial difference between weather modelling and climate modelling is based in the fact, that the first is said to be primarily an initial value problem while the second is supposed to be predominatly a boundary value problem. from what i have read on this and other blogs as well from my own gentle experiences with modelling of complex ecological systems (i.e. food webs) i am convinced that there is never a black-or-white answer to the question, if a complex natural system is better treated as an ivp or a bvp. if you want to study complex natural systems you will face both mathematical problems to some extent and even the “world-leading scientists” can never tell with absolute certainty the “partitioning” between those two.

    ps: theres a paper from r. pielke sr on the topic

  44. Wagathon says:

    We cannot expect or trust backward-looking neo-ecology ideologues to have the honesty, integrity and intelligence to create climate models capable of divining the future 30-50 years out. And indeed all they have done so far is fabricate models out of whole cloth that have been shown to have no predictive ability whatsoever.

    We’ve seen examples before where a monkey throwing a dart delivers results superior to those of the best models science has to offer. For all we know, the Earth may not have a climate.

    It is possible that even chaos theory may provide superior predictive results than GCMs — but even if that were the case, like GCMs, we wouldn’t know it for another 30-50 years; and, all that would prove is the Earth’s climate isn’t really predictable at all.

  45. Dr Jonathan McKenna says:

    Roy –

    I just popped in to see what you were saying on this particular topic and I noticed that somebody called James Davidson had written this palpable nonsense:

    “It is tempting to say that this is a relative increase of 34%, but it strikes me as being dodgy to take measurements in parts per million, and then express the increase in parts per hundred. In 1890 CO2 comprised 290 millionths of the atmosphere,- that’s 0.029%. The level has now increased to 0.039%, – an increase of 0.01%.”

    Dr Spencer, I believe you have a policy of removing uncivil comments. Do you not also have a policy of removing comments by people who make arithmetical errors that would make a competent teenager blush?

    Dr Jonathan McKenna

  46. Dr Jonathan McKenna says:

    Come off it, Roy. An increase of 290ppm to 390ppm is an increase of 34%. Period. It is absolutely not – never has been and never will be – an increase of 0.01%.

    • Matt says:

      Ummm…except that 0.039% – 0.029% = 0.01%. It’s simply putting things into perspective, relative vs absolute. Or, relative to the atmosphere vs relative to just CO2.

      You may disagree about which is better to show, but do you truly not understand this?

  47. Dr Jonathan McKenna says:

    Oops, that should of course say “an increase FROM 290ppm to 390ppm…”

  48. Pierre Larsen says:

    Dr. Spencer,

    Thank you for a clearly written article. I have very little knowledge of your field and I am still unsure about the degree of AGW, the possible consequences and what should be done. As clearly the “consensus” on AGW is no such thing.

    However, I am firm believer in the scientific method. I wish more scientists would stick to logic reasoning and facts instead of presenting a hypothesis as factual theory. Some even seem to let their emotions rule their judgement. I would like to applaud you for keeping a cool head. That it is even necessary to applaud a scientist for sticking to scientific principles is a tragic indicator of where we stand with the climate debate.

    Anyway, based on what I have understood so far, I tend to be an AGW skeptic, simply because I find no proof that AGW is of such an magnitude as many believe. co2 is probably not a major risk and we probably create other kind of pollutions much worse (I am not even sure co2 can be called a pollutant). Furthermore, as your own research indicate, other reasons to global warming are more likely. Especially as we know Earth has had warmer periods in the past.

    The correct attitude seems to be one of waiting for empiric studies to eventually show cause and effect. Maybe global warming is even good for the planet? Could it even prevent an ice age? Also technology could surely be applied to remove some co2 in the atmosphere if necessary.

    I am worried, though, whether we can afford to wait. What if the worst alarmist were shown to be right? What if indeed human activities were to have a very negative impact? Could we at one point get to the a point of no return where AGW were to lead to a situation of a long period with grave adverse effects – or even a problem with no remedy?

    It seems to me, that from many different points of view, we as keepers of this our only planet, should stop polluting it. Why run the risk? Why be such pigs? Do we even have the moral right to spend the limited fossil fuels – what about the future? I teach my kids not to litter for a number of reasons. Reasons that also can be applied as a general principle.

    As we have the technology, such as nuclear energy, to drastically limit the amount of co2 and a lot of pollutants just by staying away from fossil fuels. Why not do so?

  49. David says:

    Dr. Spencer:

    I have a question for you:

    Do you still remain skeptical of evolution?

    Do you believe that the Bible is the inerrant word of God and that the talking snake of the Garden of Eden represents an actual historical event involving an actual snake that actually talked, tempting Eve?

    How old is the Earth?

    Do you believe that geologists, biologists, cosmologists, astronomers and paleontologists are all involved in a global conspiracy against your faith and the faith of like minded Christian fundamentalists?

    Are you standing up in defense of pollution because you believe that Jesus will rapture you to Heaven before the Tribulation occurs?

    Do you believe the book of Revelation and its description of humankind’s dismal future?


  50. Dr. Spencer,

    This is slightly off topic, but I believe that you have said that in the satellite measurements (or perhaps in general?) it is more appropriate to measure global temperature anomalies using lower-tropospheric temperatures than surface temperatures (or temperatures at other altitudes).

    Could you explain the logic behind a preference for using lower-tropospheric temperatures? Or correct me if I have misunderstood the condition…

    Thanks much.

    — Bob

  51. Dan Pangburn says:

    I first thought that your comment was completely irrelevant until I noticed the reference to pollution. Since we are talking about atmospheric CO2, global warming pollution, etc. you must be referring to CO2. You appear to be unaware that there would be no life on this planet without adequate carbon dioxide in the atmosphere. You probably also are unaware that many greenhouses artificially increase the CO2 level to enhance plant growth or that for most of the planets history the atmospheric CO2 level was higher than now, or that there is about 50 times as much carbon dissolved in the oceans in the form of CO2 and CO2 hydration compounds as there is in the atmosphere.

    I wonder if you have thought about the Biblical origin of your name.

    • Anonymous says:

      Hello Dan,

      Plants love greenhouses because of the increased carbon dioxide concentration and also because of the heat. Greenhouses are hot and humid, ideal conditions for a plant but not so ideal for a human. This is the reason why plants live in greenhouses and not humans.

      You defend carbon dioxide against the charge of pollution because carbon dioxide is plant food. Cow manure is also plant food but if a truck were to accidentally dump a ton of the stuff on your front lawn you’d probably complain.

      I really doubt that all these Christians are honoring God by destroying Nature. Did God create the Earth to serve as humankind’s sewer?

  52. Dan Pangburn says:

    And any CO2 level up to at least 12 times the current level is considered safe for humans. Find out more on page 8 at

  53. Don K says:

    Dr Spencer,

    I find your material to be refreshing although I do wonder if you are underestimating the affects of human generated CO2 a bit.

    I think you may be making a mistake in not paying attention to sea level rise. There really is a sea level rise data set and it has very clear trend that rises way above the noise. It tells a very odd story — a bit over a century of constant, very modest increase. The rate is somewhere around 30cm (10 inches) a century. That’s hardly frightening as it allows lots of time to move infrastructure out of the way. It certainly does not support run away global warming. The big problem is that measuring sea level rise with tidal gauges is fiendishly complex and has huge possibilities for error. But the 30 years of satellite data which gets around many of the tidal gauge difficulties don’t look much different from the century of tidal gauge estimates.

    I’m not sure what sea level rise is telling us, but whatever the message is, we don’t need controversial statistics to extract the message.

  54. Chuk says:

    Dr. S

    I’ve come up with a simple test to determine the validity of computer based climate models. Ask the scientists themselves if they would bet their life saving on the accuracy of their own models. Don’t accept platitudes or pleas that we are betting our grandchildrens future or any of that. “Would you bet your life savings on the accuracy of your climate models forecast? Yes or no? Even if not 100% confident what odds would you need to make the bet?”

    None of these guys are taking my calls, so if you have the opportunity perhaps you could ask them. I’d love to know the result.

  55. Regarding point 2, I think you’re being dishonest to claim “… if we look at a shorter, more recent period of time, say since the record warm year of 1998, one could say that it has cooled in the last 10-12 years.”

    I can’t paste in the graph of temperatures from the NASA GISS site here, but this is the URL:

    The five year running mean has bent downward as it has previously during the upward trend of the last 40 years, but there is no way one can claim that it has cooled in the last 10-12 years. That’s just dishonest.

    The question begs to be asked, who’s paying you to make these false claims?

  56. “Why Do Most Scientists Believe CO2 is Responsible for the Warming? Because (as they have told me) they can’t think of anything else that might have caused it.”

    This strikes me as very much like Newton’s classical error “There can’t possibly be anytihing up there pressing down on the apple, therefore there must be gravity pulling things down.”

    But Newton was wrong, and he must have known that forces press on objects, they do not pull. But, of course, that’s why it was only a theory, and Newton was never absolutely convinced that he was absolutelycorrect, just the opposite.

    Science believed in Newton’s concept of gravity for quite a while, however, but Einstein blew away Newton’s universe, to the consternation of the status quo.

    Yet, Enstein had to submit not just proper falsification of his theory (i.e., trying to prove himself wrong first, a.k.a. “first-level-proof”), he had to submit solid evidence, in the form of astronomical photo’s of an eclipse, that proved that light bent through space, because stars appeared to have moved during the eclipse.

    “Climatology” seems to work on another principal than science, since I don’t see much evidence of proper falsification, nor do I see the kind of evidence that science once had such a high standard for.

    In the climate/warming/cooling debate, the fact that politics is involved is part of the problem; politics is about money, and “When Money Talks, Virtue Walks.”



  57. Dan Pangburn says:

    Victor Tiffany,
    I can’t paste graphs here either but data from the five reporting agencies, including Dr. Spencer’s, from 1998 through 2009 and the average of all five agencies are graphed on page 9 of the pdf at . Noted offsets are applied, mostly to account for differences in reference temperatures. Links to all the data are included on pages 10 and 11 of that pdf. This shows that average global temperature has been quite flat for several years. Since 2001 the atmospheric carbon dioxide has increased by 20% of the increase from 1800 to 2001 while the average global temperature shows no significant increase.

    I am not paid by anybody.

  58. zero_gravity says:

    If CO2 and H20 have effectively the same thermal insulating effect (water actually works in a broader range than CO2), then it is a diabolical lie to suggest that an increase of one part per million, due to burning of fossil fuels will affect climate change, when in fact the whole planet experiences wild swings in atmospheric water vapor content from on the order of 5 to 10,000 times the ppm compared to CO2?

    That is pure evil! Seriously. How can you claim any scientific credibility by suggesting a one ppm change will affect climate change, when water vapor, a more powerful greenhouse gas, demonstrates the planet is capable of fluctuating patterns much more intense?

    Well of course Nitrogen plays a cooling role in the upper atmosphere, even if you bothered to spend some nuanced observations of how CO2 is absorbed and redistributed by water vapor (but not measured or discussed) since it is water soluble? The effects of Nitrogen at night and sunlight are the real climate regulators? Nitrogen atoms heating and cooling displace the effects of greenhouse gases because of the volume of Nitrogen, almost like an intelligent life form created the Earth? Imagine that?

    Why do they use liquid Nitrogen as a coolant in industrial applications — because of its natural cooing affects on other substances?

    Politics prevent change I can believe in, and I have no hope in the media? Yes we can, change that viewpoint?

    Freedom is not free, it takes all you can be.

  59. john says:

    Great site,

    Came here almost by accident — looking for news on the record cold in the Southern hemisphere. News about record cold, or cold temperatures in general, is much harder to find than anything on “warming” since everything is skewed by the MSM reporting.

    Anyway, I have been a AGW skeptic forever and think the fraudsters should be in jail for crimes against humanity.
    The whitewash was just as disgraceful. They will never sleep on this, so neither can anyone else.

    In case you were not aware, you(Dr.Spencer)and your book got an excellent shout out on the American Thinker Website last night with full credits, naturally, and a beautiful explanation and summary of your findings and conclusions dispelling AGW from your book.

    Won’t hurt book sales one bit! Thank you so much.

    Dr. Wm. Wyatt

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