Still Another Low Climate Sensitivity Estimate
Guest post By Patrick J. Michaels and Paul C. “Chip” Knappenberger
Global Science Report is a weekly feature from the Center for the Study of Science, where we highlight one or two important new items in the scientific literature or the popular media. For broader and more technical perspectives, consult our monthly “Current Wisdom.”
As promised, we report here on yet another published estimate of the earth’s equilibrium climate sensitivity that is towards the low end of the United Nations’ Intergovernmental Panel on Climate Change (IPCC) range of possibilities.
Recall that the equilibrium climate sensitivity is the amount that the earth’s surface temperature will rise from a doubling of the pre-industrial atmospheric concentration of carbon dioxide. As such, it is probably the most important factor in determining whether or not we need to “do something” to mitigate future climate change. Lower sensitivity means low urgency, and, if low enough, carbon dioxide emissions confer a net benefit.
And despite common claims that the “science is settled” when it comes to global warming, we are still learning more and more about the earth complex climate system—and the more we learn, the less responsive it seems that the earth’s average temperature is to human carbon dioxide emissions.
The latest study to document a low climate sensitivity is authored by independent scientist Nic Lewis and is scheduled for publication in the Journal of Climate. Lewis’ study is a rather mathematically complicated reanalysis of another earlier mathematically complicated analysis that matches the observed global temperature change to the temperature change produced from a simple climate model with a configurable set of parameters whose actual values are largely unknown but can be assigned in the model simulations. By varying the values of these parameters in the models and seeing how well the resulting temperature output matches the observations, you can get some idea as to what the real-world value of these parameters are. And the main parameter of interest is the equilibrium climate sensitivity. Lewis’ study also includes additional model years and additional years of observations, including several years from the current global warming “hiatus” (i.e., the lack of a statistically significant rise in global temperature that extends for about 16 years, starting in early 1997).
We actually did something along a similar vein—in English—and published it back in 2002. We found the same thing that Lewis did: substantially reduced warming. We were handsomely rewarded for our efforts by the climategate mafia, who tried to get 1) the paper withdrawn, 2) the editor fired—not just from the journal, but from Auckland University, and 3) my (Michaels) 1979 PhD “reopened” by University of Wisconsin.
Lewis concludes that the median estimate of the equilibrium climate sensitivity is ~1.7°C, with a 90% range extending from 1.0°C to 3.0°C. (That’s almost exactly what we found 11 years ago.)
Based on this result, we welcome Lewis (2013) to the growing list of results published in the scientific literature since 2010 which find the climate sensitivity to be on the low side of the IPCC. God knows what the climategaters are emailing today.
Figure 1 illustrates all the new results as well as the IPCC’s take.
Take special note of the new findings (and their mean) in relation to the black bar at the top labeled “IPCC AR5 Climate Models.” Of the 19 state-of-the-art climate models used in the IPCC’s newest Assessment Report (which is still in its draft form) exactly zero have an equilibrium climate sensitivity that is as low as the mean value of estimates from the recent literature included in our Figure.
Based on the collection of results illustrated in our Figure, the future climate change projections about to be issued by the IPCC are off by an average of a whopping 70 percent.
No wonder the IPCC is reluctant to lower their best estimate of the actual value of the earth’s equilibrium climate sensitivity. If they did, they would be admitting that the collection of climate models they have chosen (there is choice involved here) to project the earth’s future climate are, well, how should we put this, wrong!…which would mean that so too is the rate at which the sky is falling, according to the USGCRP and the US EPA.
We, at Cato’s Center for the Study of Science, will continue our efforts to portray the evolving state of climate science and to convince the powers-that-be that national and international assessments upon which EPA regulations are founded (and loony proposals for a carbon tax are based) are fatally flawed. Or as we put it, in our recent (April 12) review of the USGCRP’s draft “National Assessment,” in its current form, “the NCA [National Climate Assessment] will be obsolete on the day of its official release.”
References:
Aldrin, M., et al., 2012. Bayesian estimation of climate sensitivity based on a simple climate model fitted to observations of hemispheric temperature and global ocean heat content. Environmetrics, doi: 10.1002/env.2140.
Annan, J.D., and J.C Hargreaves, 2011. On the generation and interpretation of probabilistic estimates of climate sensitivity. Climatic Change, 104, 324-436.
Hargreaves, J.C., et al., 2012. Can the Last Glacial Maximum constrain climate sensitivity? Geophysical Research Letters, 39, L24702, doi: 10.1029/2012GL053872
Intergovernmental Panel on Climate Change, 2007. Climate Change 2007: The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. Solomon, S., et al. (eds). Cambridge University Press, Cambridge, 996pp.
Lewis, N. 2013. An objective Bayesian, improved approach for applying optimal fingerprint techniques to estimate climate sensitivity. Journal of Climate, doi: 10.1175/JCLI-D-12-00473.1.
Lindzen, R.S., and Y-S. Choi, 2011. On the observational determination of climate sensitivity and its implications. Asia-Pacific Journal of Atmospheric Science,47, 377-390.
Michaels, P.J., et al., 2002. Revised 21st century temperature projections. Climate Research, 23, 1-9.
Ring, M.J., et al., 2012. Causes of the global warming observed since the 19th century. Atmospheric and Climate Sciences, 2, 401-415, doi: 10.4236/acs.2012.24035.
Schmittner, A., et al. 2011. Climate sensitivity estimated from temperature reconstructions of the Last Glacial Maximum. Science, 334, 1385-1388, doi: 10.1126/science.1203513.
van Hateren, J.H., 2012. A fractal climate response function can simulate global average temperature trends of the modern era and the past millennium. Climate Dynamics, doi: 10.1007/s00382-012-1375-3.
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“””””…..commieBob says:
April 25, 2013 at 7:08 pm
george e. smith says:
April 25, 2013 at 6:28 pm
So how does a rotating body like a planet, in the presence of a radiant energy source, such as the sun, ever rach thermal equilibrium ?
Just thought I would ask.
About ten feet below the surface of the moon, the temperature is pretty much constant. With no pesky atmosphere and ocean, the moon behaves exactly as the fairly simple physics equations predict…….””””””
Well I didn’t know we had ever drilled down ten feet into the moon. Didn’t know we had ever drilled down ten inches, or even ten centimetres.
So what if we put a thermometric sensor say, “about” ten mm below the surface on some ordinary equatorial region of the moon, and monitored that Temperature for say, “about” a month ?
Would that Temperature reading be “pretty much constant” as would be required for thermal equilibrium, or would it cycle much like the near surface of the earth does “about” every 24 hours.
If the earth was ever at equilibrium, there would be no weather and no climate. On any given ordinary northern midsummer day, the Temperature at the earth surface is likely to be anywhere (and everywhere) within a 120 deg C range, and it could be as much as a 150 deg C range. And any Temperature within that range could be found at a near infinite number of places on the earth (simultaneously).
And we are asked to believe that there is no heat (noun) flowing anywhere on that surface.
People should stop bandying about terms that have precise scientific meaning. Earth does not have any equilibrium Temperature, and never will have one.
Clouds are obviously negative feedback. My guess is <1C for a doubling of CO2. Since 1850, I'd say we've seen .3-.5 of the warming attributed to CO2.
Arno Arrak,
Thanks for that comment. Dr Ferenc Miskolczi indeed showed that there was no change in atmospheric absorption due to the rise in CO2 over the past six decades. Therefore, CO2 has had little if any effect on global warming. Which explains the absence of global warming during a time when CO2 has risen substantially.
dbstealey:
In proper philsophical terminology, Dr. Miskolsi “inferred” (rather than “showed”) that there was no change in atmospheric absorption due to the the rise in CO2 over the past six decades. One cannot conclude with you that the “CO2 has had little if any effect on global warming” as Miskolsi’s inference could be wrong.
Berniel,
Thanks so much for recounting the sad situation with John Mitchell and the IPCC. You remind me that I need to go down to Charlottesville, where my paper letters are in a U-Store-It. I also need to find a letter from Steve Schneider where he refuses to publish a paper of mine because he “had to hold it to a higher standard of review” because it was “counter-paradigm”, though his journal defined the paradigm.
Many thanks. Nice to see people have noticed the horrors of this war. Unfortunately, it is not over.
PJM
george e. smith says:
So how does a rotating body like a planet, in the presence of a radiant energy source, such as the sun, ever rach thermal equilibrium ?
Flat global means, not flat at a point location. Long term charts show we’re always changing though.
The Arrhenius theory is simply wrong. Doublings of CO2 have zero effect on global temperature. You are giving “Voodoo Science” credibility by discussing the climate sensitivity to doublings of CO2 concentration.
Doublings of CO2 have zero effect on global temperature.
So you’re not just saying there’s no scary rise in temperature, or any rise, you’re saying it has absolutely no impact on temperature at all.
Do you think dumping an atmosphere of CO2 on the moon would not change it’s surface temperature? Would it not serve to compress the day/night extremes?
DaveA says:
April 25, 2013 at 9:51 pm
Do you think dumping an atmosphere of CO2 on the moon would not change it’s surface temperature? Would it not serve to compress the day/night extremes?
<<<<<<<<<<<<<<<<<<<>>>>>>>>>>>>>>>>>>>>>>
it is water that produces the greenhouse effect, not CO2. It is a myth that CO2 contributes to the GHE here on earth. The absorption spectrum of CO2 is too narrow and can not significantly retard IR. Hansen’s greenhouse Venus is egregious error.
It is atmospheric mass (including liquids such as oceans as well as gases) that produce the greenhouse effect.
Composition changes only induce circulation changes.
Finally we are getting better and better pictures of the Coaliflower monster of Anthropocene!
george e. smith says:
“Well I didn’t know we had ever drilled down ten feet into the moon. Didn’t know we had ever drilled down ten inches, or even ten centimetres.
So what if we put a thermometric sensor say, “about” ten mm below the surface on some ordinary equatorial region of the moon, and monitored that Temperature for say, “about” a month ?”
“We” did exactly that on the Apollo 15 and 17 missions which inseted thermal probes in drilled holes to a depth of about 5 and 8 feet repectively (the Apollo 16 probe failed due to a broken cable). The holes were actually about 10 feet deep, but the probes could not be inserted fully.
At a depth below about 3 feet there was no diurnal (monthly?) temperature variation. Temperatures at this depth in the four probes varied from 250 to 255 K.
These results can be generalised to other areas by studying the thermal neutron flux as measured by the Lunar Prospectors.
mpainter says:
The absorption spectrum of CO2 is too narrow and can not significantly retard IR.
That statement puts you in a different category to someone like Stephen Wilde above, who doesn’t acknowledge IR as a factor. It sounds like you think there is a sensitivity to CO2.
Given how much energy is already in the climate system a 1 C increase from 15 C isn’t really adding much extra energy. It’s a 0.35 % increase in Kelvin, which starts at the null energy state (nothing about “big numbers”, energy). Is 0.35 % significant? To humans maybe, but our goosebumps aren’t a good indication of relative energy change.
Anders:
You mention “Anthropocene”.
Is that a region of Barsoom on Mars or have I confused it with some other imaginary fantasy?
Richard
Terry Oldberg says:
April 25, 2013 at 7:29 pm
Russ R.:
The post of Michaels and Knappenberger is not about your “climate sensitivity” (CS) but rather is about “the equilibrium climate sensitivity” (TECS). Though CS is a variable, TECS is a constant
An instantaneous constant ?? or quasi-constant ? Or constant of the moment ? The climate, I believe, has never reached equilibrium and never will and therefore TECS is an imaginary quasi-constant of no real value except in climate models.
Stephen Richards:
I prefer to describe TECS as a “non-existent” constant.
DaveA says:
April 25, 2013 at 9:51 pm
Do you think dumping an atmosphere of CO2 on the moon would not change it’s surface temperature? Would it not serve to compress the day/night extremes?
Mars’ atmosphere is 95% CO² and still bloody cold. Atmospheric pressure, on the other hand, is very low due to low gravity. It lost most of it’s atmosphere a long time ago due to it’s low gravity and inability therefore to hold onto the gases.
Friends:
I agree that radiative forcing changes affect climate. But I write to again remind that an explanation of observed climate changes in the holocene does not require existence of any driver of climate change.
Hence, assumptions that estimated climate sensitivity is indicated or constrained by recent temperature changes (over the last decade or the last century) are mistaken in principle.
An oscillating chaotic system can be expected to vary without any driver.
Chaotic systems vary, and purely harmonic variations may occur independently of any chaotic effects.
Please remember that global temperature rises 3.8 deg.C during 6 months of each year and falls by 3.8 deg.C during the other 6 months of each year. But global temperature only rose about 0.8 deg.C throughout the last century.
In other words, the rise in global temperature over the last century was about a fifth of the rise in global temperature which happens during 6 months of each year.
The trivial 0.8 deg.C rise throughout the last century could be an effect of harmonic oscillation.
An oscillating system can be expected to exhibit harmonics over periods much longer than a single oscillation. The observed changes in global temperature with apparent frequencies of ~900 years and ~60 years could be harmonics.
So, both chaos and harmonics could each be expected to provide variations to global climate of the form and magnitude recently observed. Therefore, such variations do not require any driver and the observed variations may not have had any driver.
The assumption that an estimate of climate sensitivity is indicated or constrained by recent temperature changes (over the last decade or the last century) is without foundation and is improbable.
Richard
Is it possible that all these studies have a built-in assumption: that the warming was caused primarily by CO2? Of course, if the lack of warming continues then the sensitivity values will continue to get smaller for the obvious reason.
But what if the basic assumption is wrong and that the 20th century warming had some other cause? Almost half of the warming occurred before there was enough CO2 to have an effect, even based on the AGW theory. And there have been numerous historical warming periods that could not have been caused by CO2.
It seems to me that the best evidence comes from the ice cores, which document an unending laboratory experiment conducted by Nature for almost the last million years. We now know that the CO2 levels follow the temperature, for the obvious eason, and so the temperature could not have been driven by CO2 changes. As far as I’m aware, the ice core records provide not a shred of evidence that changes in CO2 can cause a corresponding change in the temperature. In other words, the ice core records strongly suggest that the CO2 sensitivity is very close to zero.
It’s certainly good news that science is slowly correcting itself as more studies report lower sensitivity values. But I suspect studies that report a zero sensitivity are much closer to the truth.
As for the real cause of the warming, both in the 20th century, and in the distant past, here’s a clue: look up at the sky.
Chris
Well, the continued flogging of climate sensitivity is probably the best avenue for attacking the MMCC monster. Still, it doesn’t make any of these guesses any more valid. One of the problems is they are all based on incomplete knowledge instead of first principles. Until we can understand the first principles they are all suspect.
One of the first principles that keeps being ignored is the accelerated cooling effect of CO2. While CO2 does slow down the release of surface energy from the planet (the greenhouse effect), it also speeds up the release of atmospheric energy from the planet. This physics is just as valid as the GHE but is never acknowledged by climate scientists. It’s really quite simple.
When energy gets transferred to a CO2 molecule from O2 or N2 via a collision that energy is likely to be radiated in a random direction. The distance that energy travels before reabsorption is shorter when the energy is radiated downward due to the higher density. Hence, the average distance of any radiation event is towards space. Therefore, it can be said that CO2 statistically acts to accelerate energy flow from the atmosphere to space. The more CO2 … the faster the energy moves upward which increases the probability of a final radiation event to space.
Where is it coded into climate models? Where is it factored into sensitivity studies? Why is this process ignored?
Harry Huffman, please, your simple comparison between Earth and Venus temperatures at the same pressure altitude in the atmosphere ignores a much greater effect than just Venus being closer to the Sun: The albedo of Venus is so much higher than the Earth that it actually receives LESS solar input to its climate system than the Earth does (as I recall, about 170 W/m2 versus 240 W/m2). How do you factor that in? Are you saying that a planet’s atmospheric temperature does not depend upon how much sunlight is absorbed?..because you have totally ignored this variable (among others).
NIce Job compiling the graph.
The higher end bands, how much of that is due to inclusion of models which should have been considered invalid? I mean, surely most of the models that predict low emissions and high temps can’t be justified.
dbstealey says:April 25, 2013 at 7:46 pm
Arno Arrak,
Thanks for that comment. Dr Ferenc Miskolczi indeed showed that there was no change in atmospheric absorption due to the rise in CO2 over the past six decades. Therefore, CO2 has had little if any effect on global warming. Which explains the absence of global warming during a time when CO2 has risen substantially.
I agree, and to perhaps expand on Arno’s point of ‘no greenhouse effect’, I would say perhaps the GHE is maxed out at CO2=~300-400PPM, and further contributions of CO2 are negligible.
@Radical Rodent says:
April 25, 2013 at 3:16 pm
Could someone tell me why an increase of 2°C would cause such devastation as is forecast (without, oddly, any specifications as to what devastation) to this planet?…
Finally, could it be possible that this 2°C actually be of benefit to our life on this planet?
————————
The fact that warming not only is not (on balance) more harmful than helpful, but far more helpful than harmful entirely undercuts the AGW pseudoscience making it irrelevant nonsense. Students of the effects of climate change during the Holocene have known since the 1950s that generally warmer global climate has often coincided with great advances in civilization including the Roman Warm Period and the Medieval Warm Period.
Please see Thomas Gale Moore’s books:
Global warming : a boon to humans and other animals
& Climate of fear : why we shouldn’t worry about global warming
Skeptics sometimes estimate that the human contribution to the increase of CO2 is only 1/40th the total. Then at most 1/40th of the twentieth century warming of 0.6 degrees would have been due to humans.
Ring et al 2012, full copy online at
http://www.scirp.org/journal/PaperDownload.aspx?paperID=24283
CS estimates from their Table 4, let’s see if it copies:
OK, not well. Here’s the beef:
Table 4. Estimates of climate sensitivity, ΔT2x, total aerosol forcing for year 2000, FA, and oceanic thermal diffusivity κ based on each instrumental dataset.
Instrumental Dataset
GISTEMP
1.45 , CS est. from Instrumental Dataset
HADCRUT4
1.61
NOAA
1.99
JMA
2.01
Observation *always* trumps theory!
Cheers — Pete Tillman
Professional geologist, amateur climatologist