Summer Causes Climate Change Hysteria

July 3rd, 2018

Summers in the U.S. are hot. They always have been. Some are hotter than others.

Speaking as a PhD meteorologist with 40 years experience, this week’s heat wave is nothing special.

But judging from the memo released on June 22 by Public Citizen (a $17 million per year liberal/progressive consumer rights advocacy group originally formed by Ralph Nader in 1971 and heavily funded by Leftwing billionaire George Soros’s Open Society Foundations), every heat wave must now be viewed as a reminder of human-caused climate change. The memo opines that (believe it or not) the news media have not been very good about linking weather events to climate change, which is leading to complacency among the public.

The June 22 memo focus was on the excessive heat in New York state, so let’s begin our journey down Hysteria Lane there. The official NOAA average maximum temperatures for every June since 1895 in New York looks like this:

Fig. 1. Average June maximum temperatures in New York state for every year from 1895 through 2017 (Source: NOAA)

The long term trend is not statistically different from zero. June 2018 is not yet available at the NOAA website, but from what I’ve seen for the global June Climate Forecast System map at WeatherBell.com, it looks like it was near the long-term (20th Century) average.

The memo also made mention of the widespread record warmth the U.S. experienced in May, 2018. New York had it’s 7th warmest May on record this year, and the long-term linear warming trend there since 1895 is weak (0.22 F/decade) and not statistically different from zero at the 95% confidence level. The May warmth in the U.S. was regional, as expected for weather variations, with much of Canada being exceedingly cold:

Fig. 2. NOAA CFS model-diagnosed surface temperature departures from normal for May, 2018, showing the regional nature of the record U.S. warmth that month (graphic courtesy of WeatherBell.com).

When do you suppose the hottest temperature ever recorded in New York was? Clearly, with global warming, it must be in the last 20 or 30 years, right?

Wrong.

It was 109 deg. F. on July 22, 1926 in Troy, New York. In contrast, the state record for the coldest temperature was much more recent: -52 deg. F on Feb 18, 1979, at Old Forge, New York.

What about this week’s heat wave? Let’s look at NOAA’s GFS forecast model 5-day average temperatures for this week (Monday through Friday, July 2-6, 2018, graphic from WeatherBell.com):

Fig. 3. 5-day forecast average temperature departures from average over North America from the GFS model (graphic courtesy of WeatherBell.com).

As you can see, the excessive heat is (again) regionally isolated, which is exactly what we expect for weather… not for climate change. See those colder than average areas? Why aren’t those being blamed on climate change, too? They look like they approximately cancel out the warm area over the Northeast U.S., which is often the case for weather (not climate change) variations.

That was a 5-day forecast for this week. Next let’s look at what was actually observed over the last couple days (July 1-2), which were very hot in the Great Lakes and Northeast:

Fig. 4. Oregon State University Prism temperature analysis for July 1-2, 2018, as departures from the 1981-2010 average.

What we see is that there were unseasonably cool temperatures in the western U.S., again an indication of a temporary and localized weather pattern… not “global warming”, which would be warm everywhere.

How about extreme high temperatures in the U.S in general? Here are the yearly total number of days above 100 and 105 deg. F, again for the years 1895 through 2017, based upon official NOAA data:

Fig. 5. Yearly average number of days per U.S. station having at least 100 or 105 deg. high temperatures, 1895 through 2017.

We see no trend in the number of days with excessive heat.

So, what do we make of the claims in the Public Citizen memo? Well, they mention that we have seen 1.1 deg. C of warming since the Industrial Revolution. Think about that. Less than 2 deg. F warming in about 200 years, part of which is likely to be natural, based upon temperature proxy estimates over the last 2,000 years for the Northern Hemisphere:

Fig. 6. 2,000 years of Northern Hemisphere temperature variations from an average of a number of temperature proxies. The period of substantial human-caused warming is generally agreed to be only since 1950 (U.N. IPCC AR5).

Am I claiming that there is no such thing as human-caused warming? No. I’m claiming that it is overblown. The Public Citizen memo makes much of recent record warm years clustering together, which sounds alarming — if one doesn’t mention the small fractions of a degree involved. If there was no natural year-to-year variability, and the temperature was increasing at 0.01 or 0.02 deg. F every year, then every successive year would be a record warm year…but who would care? The rate of ‘global warming’ is too weak for any one person to notice in their lifetime.

Furthermore, we already know the climate models (which are the basis for proposed changes in energy policy to get us away from fossil fuels) are producing generally twice as much warming of the atmosphere-ocean system as has been observed. The most recent energy budget analysis of surface and deep-ocean warming suggests that the climate system is only half as sensitive to our CO2 emissions as you are being told…. maybe 1.5 deg. C of eventual warming from a doubling of atmospheric CO2. At 410 ppm, We are currently half way to doubling.

And even THAT reduced estimate of future warming assumes ALL of the warming is human-caused! If a portion of recent warming is natural, the less the human-caused global warming problem becomes.

Finally, the Public Citizen memo claims that today’s technology would already allow 80% to 100% of our energy to come from renewable sources. This is patently false. Solar and wind are relatively diffuse (and thus expensive) sources of energy which are intermittent, requiring fossil fuel (or nuclear) backup. It would be exceedingly expensive to get even 50% of our energy from such sources. Maybe someday we will have such technologies, but until that day arrives, the massive amount of money that would be required to achieve such a goal would worsen poverty, which historically has been the leading cause of premature death in the world.

UAH Global Temperature Update for June, 2018: +0.21 deg. C

July 2nd, 2018

The Version 6.0 global average lower tropospheric temperature (LT) anomaly for June, 2018 was +0.21 deg. C, up a little from the May value of +0.18 deg. C:

Global area-averaged lower tropospheric temperature anomalies (departures from 30-year calendar monthly means, 1981-2010). The 13-month centered average is meant to give an indication of the lower frequency variations in the data; the choice of 13 months is somewhat arbitrary… an odd number of months allows centered plotting on months with no time lag between the two plotted time series. The inclusion of two of the same calendar months on the ends of the 13 month averaging period causes no issues with interpretation because the seasonal temperature cycle has been removed, and so has the distinction between calendar months.

Some regional LT departures from the 30-year (1981-2010) average for the last 18 months are:

YEAR MO GLOBE NHEM. SHEM. TROPIC USA48 ARCTIC AUST
2017 01 +0.33 +0.31 +0.34 +0.10 +0.27 +0.95 +1.22
2017 02 +0.38 +0.57 +0.20 +0.08 +2.16 +1.33 +0.21
2017 03 +0.23 +0.36 +0.09 +0.06 +1.21 +1.24 +0.98
2017 04 +0.27 +0.29 +0.26 +0.21 +0.89 +0.23 +0.40
2017 05 +0.44 +0.39 +0.49 +0.41 +0.10 +0.21 +0.06
2017 06 +0.22 +0.33 +0.10 +0.39 +0.51 +0.10 +0.34
2017 07 +0.29 +0.30 +0.27 +0.51 +0.61 -0.27 +1.03
2017 08 +0.41 +0.40 +0.42 +0.46 -0.54 +0.49 +0.77
2017 09 +0.54 +0.51 +0.57 +0.54 +0.29 +1.06 +0.60
2017 10 +0.63 +0.67 +0.59 +0.47 +1.21 +0.83 +0.86
2017 11 +0.36 +0.33 +0.38 +0.27 +1.35 +0.68 -0.12
2017 12 +0.41 +0.50 +0.33 +0.26 +0.44 +1.37 +0.36
2018 01 +0.26 +0.46 +0.06 -0.11 +0.58 +1.36 +0.42
2018 02 +0.20 +0.24 +0.16 +0.03 +0.92 +1.19 +0.18
2018 03 +0.25 +0.40 +0.10 +0.06 -0.32 -0.33 +0.59
2018 04 +0.21 +0.31 +0.10 -0.13 -0.01 +1.02 +0.68
2018 05 +0.18 +0.40 -0.05 +0.03 +1.93 +0.18 -0.40
2018 06 +0.21 +0.38 +0.04 +0.12 +1.19 +0.83 -0.55

The linear temperature trend of the global average lower tropospheric temperature anomalies from January 1979 through June 2018 remains at +0.13 C/decade.

The UAH LT global anomaly image for June, 2018 should be available in the next few days here.

The new Version 6 files should also be updated in the coming days, and are located here:

Lower Troposphere: http://vortex.nsstc.uah.edu/data/msu/v6.0/tlt/uahncdc_lt_6.0.txt
Mid-Troposphere: http://vortex.nsstc.uah.edu/data/msu/v6.0/tmt/uahncdc_mt_6.0.txt
Tropopause: http://vortex.nsstc.uah.edu/data/msu/v6.0/ttp/uahncdc_tp_6.0.txt
Lower Stratosphere: http://vortex.nsstc.uah.edu/data/msu/v6.0/tls/uahncdc_ls_6.0.txt

Antarctic Ice Sheet Collapses, Nobel Prizes, and the Psychology of Catastrophism

June 17th, 2018

John Christy examines one of the seven bullet holes in our NSSTC building, fired on the weekend of the 2017 March for Science.

Last week I had the privilege of being invited to present a talk at a small conference of world experts in a variety of disciplines. The venue was spectacular, on the French Riviera, and we had an entire late-1800s hotel to ourselves, right on the Mediterranean. For me, it was a once-in-a-lifetime experience. I had the feeling that the organizers wanted the event to have a low profile, and so I won’t mention names.

I had about 12 minutes to lay out the case for climate skepticism. My talk was generally well-received and led to many follow-up discussions over the following days.

One of the attendees was an elderly particle physicist who was also a Nobel Prize winner. During Q&A, he mentioned how he had been teaching a climate class at his university for several years, and that he thought my skepticism was unwarranted. He was convinced that the Antarctic ice sheet was headed for collapse and we would have to deal with a 30 m rise in sea level as a result.

What was more than a little disturbing was that he openly declared that climate policy would not be able to move forward like it needs to until old skeptics like me die out. Part of my talk was about the fact that credentialed and published skeptical climate researchers are indeed slowly dying out, with an average age of around 70 now, and that governmental bias in climate funding will basically kill off skeptical research if things don’t change.

I approached him afterward and politely said I didn’t think either one of us was going to change our minds, and hoped we could just enjoy the nice dinner that was planned for us. He politely smiled and agreed to that.

I guess what was interesting to me is that the “belief” (his word) in catastrophic climate change, like religion, exists at all education levels. One also can’t help but notice how Nobel Prize winners tend to also be experts in all disciplines after they win their prize. Stephen Hawking comes to mind.

The whole experience was quite fascinating.

UPDATE: It has been pointed out to me that Hawking never received a Nobel Prize. The fact is that I can’t account for the lack of Hawking’s Nobel Prize at the moment, and it is a travesty that I can’t.

UAH Global Temperature Update for May, 2018: +0.18 deg. C

June 1st, 2018

The Version 6.0 global average lower tropospheric temperature (LT) anomaly for May, 2018 was +0.18 deg. C, down a little from the April value of +0.21 deg. C:

Global area-averaged lower tropospheric temperature anomalies (departures from 30-year calendar monthly means, 1981-2010). The 13-month centered average is meant to give an indication of the lower frequency variations in the data; the choice of 13 months is somewhat arbitrary… an odd number of months allows centered plotting on months with no time lag between the two plotted time series. The inclusion of two of the same calendar months on the ends of the 13 month averaging period causes no issues with interpretation because the seasonal temperature cycle has been removed, and so has the distinction between calendar months.

Some regional LT departures from the 30-year (1981-2010) average for the last 17 months are:

YEAR MO GLOBE NHEM. SHEM. TROPIC USA48 ARCTIC AUST
2017 01 +0.33 +0.31 +0.34 +0.10 +0.27 +0.95 +1.22
2017 02 +0.38 +0.57 +0.20 +0.08 +2.16 +1.33 +0.21
2017 03 +0.23 +0.36 +0.09 +0.06 +1.21 +1.24 +0.98
2017 04 +0.27 +0.29 +0.26 +0.21 +0.89 +0.22 +0.40
2017 05 +0.44 +0.39 +0.49 +0.41 +0.10 +0.21 +0.06
2017 06 +0.22 +0.33 +0.10 +0.39 +0.50 +0.10 +0.34
2017 07 +0.29 +0.30 +0.27 +0.51 +0.60 -0.27 +1.03
2017 08 +0.41 +0.40 +0.42 +0.46 -0.55 +0.49 +0.77
2017 09 +0.54 +0.51 +0.57 +0.54 +0.29 +1.06 +0.60
2017 10 +0.63 +0.67 +0.59 +0.47 +1.21 +0.83 +0.86
2017 11 +0.36 +0.33 +0.38 +0.27 +1.35 +0.68 -0.12
2017 12 +0.41 +0.50 +0.33 +0.26 +0.44 +1.37 +0.36
2018 01 +0.26 +0.46 +0.06 -0.11 +0.58 +1.36 +0.42
2018 02 +0.20 +0.24 +0.16 +0.03 +0.92 +1.19 +0.18
2018 03 +0.25 +0.40 +0.10 +0.06 -0.32 -0.33 +0.59
2018 04 +0.21 +0.31 +0.10 -0.13 -0.01 +1.02 +0.68
2018 05 +0.18 +0.40 -0.05 +0.03 +1.93 +0.18 -0.40

The linear temperature trend of the global average lower tropospheric temperature anomalies from January 1979 through May 2018 remains at +0.13 C/decade.

The UAH LT global anomaly image for May, 2018 should be available in the next few days here.

The new Version 6 files should also be updated in the coming days, and are located here:

Lower Troposphere: http://vortex.nsstc.uah.edu/data/msu/v6.0/tlt/uahncdc_lt_6.0.txt
Mid-Troposphere: http://vortex.nsstc.uah.edu/data/msu/v6.0/tmt/uahncdc_mt_6.0.txt
Tropopause: http://vortex.nsstc.uah.edu/data/msu/v6.0/ttp/uahncdc_tp_6.0.txt
Lower Stratosphere: http://vortex.nsstc.uah.edu/data/msu/v6.0/tls/uahncdc_ls_6.0.txt

Sea Level Rise: Human Portion is Small

May 25th, 2018

There is a continuing debate over sea level rise, especially how much will occur in the future. The most annoying part of the news media reporting on the issue is that they imply sea level rise is all the fault of humans.

This is why the acceleration of sea level rise is what is usually debated, because sea level has been rising naturally, for at least 100 years before humans could be blamed. So, the two questions really are (1) Has sea level rise accelerated?, and (2) how much of the acceleration is due to humans?

Yesterday’s spat between Gavin Schmidt and Willis Eschenbach dealt with the question of whether sea level rise has accelerated or not. Gavin says it has. Willis says not, or at least not by a statistically significant amount.

I’m going to look at the data in a very simple and straightforward manner. I’ll use what I believe are the same data they did (Church & White, from CSIRO, updated through 2013 here), and plot a trend line for the data before 1950 (before humans could reasonably be blamed), and one for the data after 1950:

If we assume that the trend prior to 1950 was natural (we really did not emit much CO2 into the atmosphere before then), and that the following increase in the trend since 1950 was 100% due to humans, we get a human influence of only about 0.3 inches per decade, or 1 inch every 30 years.

Even though it looks like there is some evidence of even stronger acceleration more recently, sea level has varied naturally on multi-decadal time scales, and it is dangerous to extrapolate any short term trends far into the future. Climate models aren’t of much help in determining the human contribution because we have no idea how much of recent warming and glacial melt was natural versus human-caused. Models still can’t explain why glaciers started melting in the mid-1800s, just like they can’t explain why it warmed up so much from the mid-1800s to the mid-1900s.

The bottom line is that, even if (1) we assume the Church & White tide gauge data are correct, and (2) 100% of the recent acceleration is due to humans, it leads to only 0.3 inches per decade that is our fault, a total of 2 inches since 1950.

As Judith Curry mentioned in her continuing series of posts on sea level rise, we should heed the words of the famous oceanographer, Carl Wunsch, who said,


“At best, the determination and attribution of global-mean sea-level change lies at the very edge of knowledge and technology. Both systematic and random errors are of concern, the former particularly, because of the changes in technology and sampling methods over the many decades, the latter from the very great spatial and temporal variability. It remains possible that the database is insufficient to compute mean sea-level trends with the accuracy necessary to discuss the impact of global warming, as disappointing as this conclusion may be.”

NASA satellite reveals extensive Hawaii SO2 cloud

May 22nd, 2018

The eruption of Kilauea volcano on the Big Island of Hawaii has been unleashing a huge cloud of sulfur dioxide (SO2), which has been showing up in NASA’s Suomi satellite imagery every day. Yesterday, May 21, the cloud is shown here in false color, based upon measurements from the OMPS sensor on that satellite.

NASA Suomi satellite false-color imagery of the sulfur dioxide cloud flowing downwind from the eruption of Kilauea volcano on the Big Island.

Carried by the northeasterly trade winds, the SO2 cloud can be discerned in true-color imagery extending about 1,300 miles downstream. The eruption site is indicated by the red dot, where the satellite picks up a hot anomaly in its infrared channels.

In Defense of the Term “Greenouse Effect”

May 9th, 2018

Over the years I have gone along with the crowd and derided the term “greenhouse effect” as a poor analogy between the atmosphere’s ability to keep the Earth’s surfce warmer than it would be without IR-absorbing (and thus IR-emitting) gases, versus a greenhouse in which plants are grown.

But the more I think about it, the more I realize that “greenhouse effect” is a pretty accurate term.

The main objection has been that the warmth within a real greenhouse is primarily due to the roof’s ability to keep warm air from escaping, thus inhibiting convective heat loss. While that is true, it is also true of the atmospheric greenhouse effect.

Remember,

1) the roof of the greenhouse is also an IR absorber and emitter, like water vapor and CO2 do in the free atmosphere, and

2) the atmospheric greenhouse effect is only fully realized in the absence of convective heat loss.

Let’s start with that second point. As originally calculated by Manabe and Strickler (1964, see slide #10 here), the greenhouse effect does not explain the average surface temperature being 288 K (observed) rather than 255K (the effective radiating temperature of the Earth absent an atmosphere). Instead it is actually much more powerful than that, and would raise the temperature to an estimated 343 K (close to 160 deg. F.) It is convective heat loss generated by an unstable lapse rate caused by the greenhouse effect that reduces the temperature to the observed value.

This is the actual “greenhouse effect” on Earth’s average surface temperature: not the oft-quoted 33 deg. C, but more like 88 deg. C of warming. (We can quibble about the calculations of surface temperature with and without greenhouse gases because they make unrealistic assumptions about clouds and water vapor.)

The point is, the atmospheric greenouse effect is radiative only, and does not include the cooling effects of convective heat transport away from the Earth’s surface.

Kind of like in a real greenhouse.

So, this actually is what happens in a real greenhouse:

1) sunlight warms the interior

2) infrared radiation absorbed and emitted by the roof reduces radiative energy loss by the air and surfaces within the greenhouse

3) convective heat loss is minimized (although it is generated on the outside surface of the roof, thus keeping the interior cooler than if there was no convective heat loss at all)

So, all things considered, I think we need to embrace the “greenhouse effect” concept. Plants like it so much, we artificially enhance Nature’s greenhouse effect (which existed before greenhouses were invented) for their benefit.

Next, let’s pump some extra CO2 in there to help the plants even more.

UAH Global Temperature Update for April, 2018: +0.21 deg. C.

May 1st, 2018

The Version 6.0 global average lower tropospheric temperature (LT) anomaly for April, 2018 was +0.21 deg. C, down a little from the March value of +0.24 deg. C:

Global area-averaged lower tropospheric temperature anomalies (departures from 30-year calendar monthly means, 1981-2010). The 13-month centered average is meant to give an indication of the lower frequency variations in the data; the choice of 13 months is somewhat arbitrary… an odd number of months allows centered plotting on months with no time lag between the two plotted time series. The inclusion of two of the same calendar months on the ends of the 13 month averaging period causes no issues with interpretation because the seasonal temperature cycle has been removed, and so has the distinction between calendar months.

Some regional LT departures from the 30-year (1981-2010) average for the last 16 months are:

YEAR MO GLOBE NHEM. SHEM. TROPIC USA48 ARCTIC AUST
2017 01 +0.33 +0.31 +0.34 +0.10 +0.27 +0.95 +1.22
2017 02 +0.38 +0.57 +0.19 +0.08 +2.15 +1.33 +0.21
2017 03 +0.23 +0.36 +0.09 +0.06 +1.21 +1.24 +0.98
2017 04 +0.27 +0.28 +0.26 +0.21 +0.89 +0.22 +0.40
2017 05 +0.44 +0.39 +0.49 +0.41 +0.10 +0.21 +0.06
2017 06 +0.21 +0.33 +0.10 +0.39 +0.50 +0.10 +0.34
2017 07 +0.29 +0.30 +0.27 +0.51 +0.60 -0.27 +1.03
2017 08 +0.41 +0.40 +0.42 +0.46 -0.55 +0.49 +0.77
2017 09 +0.54 +0.51 +0.57 +0.54 +0.29 +1.06 +0.60
2017 10 +0.63 +0.66 +0.59 +0.47 +1.20 +0.83 +0.86
2017 11 +0.36 +0.33 +0.38 +0.26 +1.35 +0.68 -0.12
2017 12 +0.41 +0.50 +0.33 +0.26 +0.44 +1.36 +0.36
2018 01 +0.26 +0.46 +0.06 -0.12 +0.58 +1.36 +0.42
2018 02 +0.20 +0.24 +0.16 +0.03 +0.91 +1.19 +0.18
2018 03 +0.24 +0.39 +0.10 +0.06 -0.33 -0.33 +0.59
2018 04 +0.21 +0.31 +0.10 -0.13 -0.01 +1.02 +0.68

The linear temperature trend of the global average lower tropospheric temperature anomalies from January 1979 through April 2018 remains at +0.13 C/decade.

The UAH LT global anomaly image for April, 2018 should be available in the next few days here.

The new Version 6 files should also be updated in the coming days, and are located here:

Lower Troposphere: http://vortex.nsstc.uah.edu/data/msu/v6.0/tlt/uahncdc_lt_6.0.txt
Mid-Troposphere: http://vortex.nsstc.uah.edu/data/msu/v6.0/tmt/uahncdc_mt_6.0.txt
Tropopause: http://vortex.nsstc.uah.edu/data/msu/v6.0/ttp/uahncdc_tp_6.0.txt
Lower Stratosphere: http://vortex.nsstc.uah.edu/data/msu/v6.0/tls/uahncdc_ls_6.0.txt

New Lewis & Curry Study Concludes Climate Sensitivity is Low

April 24th, 2018

Global warming “problem” cut by 50%

As readers here are aware, I don’t usually critique published climate papers unless they are especially important to the climate debate. Too many papers are either not that important, or not that convincing to me.

The holy grail of the climate debate is equilibrium climate sensitivity (ECS): just how much warming (and thus associated climate change) will occur in response to an eventual doubling of the CO2 concentration in the atmosphere?

Yesterday’s early online release of a new paper by Nicholas Lewis and Judith Curry (“The impact of recent forcing and ocean heat uptake data on estimates of climate sensitivity“, Journal of Climate) represents one of those seminal papers.

It is an extension of a previously published paper by Lewis & Curry, adding more data, and addressing criticisms of their earlier work. Its methodology isn’t entirely original, since previous (but somewhat preliminary) work along the same lines (Otto et al., 2013) has resulted in observational estimates of relatively low climate sensitivity compared to the IPCC climate models.

But what is notable to me is (1) the comprehensive extent to which methodological and data uncertainties have been addressed, and (2) the fact it was published in the relatively mainstream and consensus-defending Journal of Climate.

Basically, the paper concludes that the amount of surface and deep-ocean warming that has occurred since the mid- to late-1800s is consistent with low equilibrium climate sensitivity (ECS) to an assumed doubling of atmospheric CO2. They get a median estimate of 1.66 deg. C (1.50 deg. C without uncertain infilled Arctic data), which is only about half of the average of the IPCC climate models. It is just within the oft-quoted range of 1.5 to 4.5 deg. C that the IPCC has high confidence ECS should occupy.

The last I knew, Lewis’s belief is that the biggest uncertainty in the ECS calculation is how accurate the assumed forcings are that must be used to make the ECS computation (over the last ~130 years, the climate system has stored a certain amount of extra energy in the ocean, and shed a certain amount of energy to space from increased surface temperatures, in response to assumed changes in radiative forcing…. a big uncertainty in which is assumed anthropogenic aerosol-related cooling).

I’d like to additionally emphasize overlooked (and possibly unquantifiable) uncertainties: (1) the assumption in studies like this that the climate system was in energy balance in the late 1800s in terms of deep ocean temperatures; and (2) that we know the change in radiative forcing that has occurred since the late 1800s, which would mean we would have to know the extent to which the system was in energy balance back then.

We have no good reason to assume the climate system is ever in energy balance, although it is constantly readjusting to seek that balance. For example, the historical temperature (and proxy) record suggests the climate system was still emerging from the Little Ice Age in the late 1800s. The oceans are a nonlinear dynamical system, capable of their own unforced chaotic changes on century to millennial time scales, that can in turn alter atmospheric circulation patterns, thus clouds, thus the global energy balance. For some reason, modelers sweep this possibility under the rug (partly because they don’t know how to model unknowns).

But just because we don’t know the extent to which this has occurred in the past doesn’t mean we can go ahead and assume it never occurs.

Or at least if modelers assume it doesn’t occur, they should state that up front.

If indeed some of the warming since the late 1800s was natural, the ECS would be even lower.

Now the question is: At what point will the IPCC (or, maybe I should say climate modelers) start recognizing that their models are probably too sensitive? Remember, the sensitivity of their models is NOT the result of basic physics, as some folks claim… it’s the result of very uncertain parameterizations (e.g. clouds) and assumptions (e.g. precipitation efficiency effects on the atmospheric water vapor profile and thus feedback). The models are adjusted to produce warming estimates that “look about right” to the modelers. Yes, *some* amount of warming from increasing CO2 is reasonable from basic physics. But just how much warming is open to manipulation within the uncertain portions of the models.

Maybe it’s time for the modelers to change their opinion of how much warming “looks about right”.

The 100th Meridian Agricultural Scare: Another Example of Media Hype Exceeding Reality

April 18th, 2018

A new paper published in the AMS Earth Interactions entitled, Whither the 100th Meridian? The Once and Future Physical and Human Geography of America’s Arid-Humid Divide, Part II: The Meridian Moves East, discusses the climate model-expected drying of the western U.S. and how this will affect the agricultural central- and east- U.S. as the climatological boundary roughly represented by the 100th Meridian moves eastward.

This paper has become a good example of media hype overwhelming actual substance. For example, take this headline from Doyle Rice at USAToday on April 13,

“A major climate boundary in the central U.S. has shifted 140 miles due to global warming”

So, what’s wrong with the headline? Nowhere in the original scientific study can I find any observational evidence of such a shift.

The fact is, the study is a modeling study — not observational. They tell us what might happen in the coming decades, given certain (and numerous) assumptions.

Since I’ve been consulting for U.S. grain interests for the last seven or eight years, I have some interest in this subject. Generally speaking, climate change isn’t on the Midwest farmers’ radar because, so far, there has been no sign of it in agricultural yields. Yields (production per acre) of all grains, even globally, have been on an upward trend for decades. This is fueled mainly by improved seeds, farming practices, and possibly by the direct benefits of more atmospheric CO2 on plants. If there has been any negative effect of modestly increasing temperatures, it has been buried by other, positive, effects.

And so, the study begs the question: how has growing season precipitation changed in this 100th meridian zone? Using NOAA’s own official statewide average precipitation statistics, this is how the rainfall observations for the primary agricultural states in the zone (North and South Dakota, Nebraska, Kansas, and Oklahoma) have fared every year between 1900 and 2017:

Jun, July, August average monthly precipitation as observed over 5 U.S. states encompassing the 100th Meridian, and as predicted by a CMIP5 (RCP8.5 forcing scenario) multi-model mean from 35N to 50N, and 95W to 105 W (observational data from https://www.ncdc.noaa.gov/cag/statewide/time-series; model data from https://climexp.knmi.nl/selectfield_cmip5.cgi?id=someone@somewhere)

What we see is that there has been, so far, no evidence of decreasing precipitation amounts exactly where the authors claim it will occur (and according to press reports, has already occurred).

To the authors’ credit, in their final “Discussion and Conclusions” section of the research paper they admit:

“First, we have shown that state-of-the-art models simulate the aridity gradient across North America poorly.”

“Second, while current Earth system models predict widespread declines in soil moisture and increases in continental aridity, they also simulate increases in net primary productivity. This is because, within the models, the beneficial effects on photosynthesis and water-use efficiency of increased CO2 overwhelm the effects of increased temperature and vapor pressure deficit.” (emphasis added)

The positive effects of more CO2 on global agricultural yields have been tallied, as I have previously discussed here.

Yet, the popular press emphasizes the alarmist nature of the article, even going so far as to make as the central claim something that, as far as I can tell, isn’t even in the paper (!)