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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I have a serious problem with the entire concept of “climate sensitivity”. I think it could actually be more ”cargo cult” than atmospheric physics.
Here is my problem:
Atmospheric CO2 LAGS temperature T at ALL time scales, from the 9 month delay for ~ENSO cycles to the 600 year delay inferred in the ice core data for much longer cycles.
When I studied this subject in 2007-2008, the only signal I was able to derive from the modern data was that [dCO2/dt varies ~contemporaneously with T and CO2 lags T by 9 months].
This physical reality has since been widely accepted, but dismissed as a “feedback effect”.
This is like saying you cannot hear the orchestra, but you can clearly hear the piccolo.
I say you ARE hearing the orchestra – atmospheric CO2 lags temperature because temperature drives CO2.
The observed rise in CO2 may indeed have a significant humanmade component – but is probably driven much more by deforestation than fossil fuel combustion.
Regards, Allan
http://wattsupwiththat.com/2013/03/30/the-pitfalls-of-data-smoothing/#comment-1265693
When I first pointed out this relationship in January 2008 (dCO2/dt varies with T and CO2 lags T by 9 months), it was deemed incorrect.
Then it was accepted as valid by some on the warmist side of this debate, but dismissed as a “feedback”.
This “feedback argument” appears to be a “cargo cult” rationalization, derived as follows:
“We KNOW that CO2 drives Temperature, therefore it MUST BE a feedback.”
More below from 2009:
__________________
http://wattsupwiththat.com/2009/01/21/antarctica-warming-an-evolution-of-viewpoint/#comment-77000
Time is limited so I can only provide some more general answers to your questions:
My paper was posted Jan.31/08 with a spreadsheet at
http://icecap.us/index.php/go/joes-blog/carbon_dioxide_in_not_the_primary_cause_of_global_warming_the_future_can_no/
The paper is located at
http://icecap.us/images/uploads/CO2vsTMacRae.pdf
The relevant spreadsheet is
http://icecap.us/images/uploads/CO2vsTMacRaeFig5b.xls
There are many correlations calculated in the spreadsheet.
In my Figure 1 and 2, global dCO2/dt closely coincides with global Lower Tropospheric Temperature LT and Surface Temperature ST. I believe that the temperature and CO2 datasets are collected completely independently, and yet there is this clear correlation.
After publishing this paper, I also demonstrated the same correlation with different datasets – using Mauna Loa CO2 and Hadcrut3 ST going back to 1958. More recently I examined the close correlation of LT measurements taken by satellite and those taken by radiosonde.
Further, I found (actually I was given by Richard Courtney) earlier papers by Kuo (1990) and Keeling (1995) that discussed the delay of CO2 after temperature, although neither appeared to notice the even closer correlation of dCO2/dt with temperature. This correlation is noted in my Figures 3 and 4.
See also Roy Spencer’s (U of Alabama, Huntsville) take on this subject at
http://wattsupwiththat.wordpress.com/2008/01/25/double-whammy-friday-roy-spencer-on-how-oceans-are-driving-co2/
and
http://wattsupwiththat.wordpress.com/2008/01/28/spencer-pt2-more-co2-peculiarities-the-c13c12-isotope-ratio/
This subject has generated much discussion among serious scientists, and this discussion continues. Almost no one doubts the dCO2/dt versus LT (and ST) correlation. Some go so far as to say that humankind is not even the primary cause of the current increase in atmospheric CO2 – that it is natural. Others rely on a “material balance argument” (mass balance argument) to refute this claim – I think these would be in the majority. I am an agnostic on this question, to date.
The warmist side also has also noted this ~9 month delay, but try to explain it as a “feedback effect” – this argument seems more consistent with AGW religious dogma than with science (“ASSUMING AGW is true, then it MUST be feedback”). 🙂
It is interesting to note, however, that the natural seasonal variation in atmospheric CO2 ranges up to ~16ppm in the far North, whereas the annual increase in atmospheric CO2 is only ~2ppm. This reality tends to weaken the “material balance argument”. This seasonal ‘sawtooth” of CO2 is primarily driven by the Northern Hemisphere landmass, which is much greater in area than that of the Southern Hemisphere. CO2 falls during the NH summer due primarily to land-based photosynthesis, and rises in the late fall, winter and early spring as biomass degrades.
There is also likely to be significant CO2 solution and exsolution from the oceans.
See the excellent animation at http://svs.gsfc.nasa.gov/vis/a000000/a003500/a003562/carbonDioxideSequence2002_2008_at15fps.mp4
It is also interesting to note that the detailed signals we derive from the data show that CO2 lags temperature at all time scales, from the 9 month delay for ~ENSO cycles to the 600 year delay inferred in the ice core data for much longer cycles.
Regards, Allan
Allan MacRae,
Thanks for your excellent comment above. This chart shows convincingly that ∆T is the cause of ∆CO2.
But I can find no comparable chart showing that changes in CO2 cause subsequent temperature changes. I like to see scientific evidence to support assertions, such as the assertion that CO2 causes global warming. But any such evidence appears to be completely lacking.
I think that the warmist side began by assuming an incorrect premise: they believed that CO2, in an atmosphere ruled primarily by convection, acts the same as it does in the laboratory, in a closed container.
But the real world acts differently, so starting off with the wrong premise has led the warmist crowd to a very wrong conclusion. Based on empirical evidence, ∆T causes ∆CO2 — not vice versa. “Carbon” does not cause any measurable global warming.
If I am wrong, I will accept that with no problem. But I need solid empirical measurements showing that I’m mistaken. So far, I have been unable to find any such measurements. But not for lack of trying to find them.
“””””…..tty says:
April 25, 2013 at 11:44 pm
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 a whole two holes, one of which was a “dry” hole.
So if we drill down ten feet on earth and stick a sensor on a shortened cable eight feet down that hole (well drill two, to be sure one will work) How much does simple physics predict; excuse me project, the Temperature will change over 24 hours; wll make it a month, since the moon going around might affect it.
Was there a point to doing this ? We have enough caves on earth to know, the Temperature doesn’t change down there over time. That’s why they don’t have weather or climate down in caves.
“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.” [Galloping Camel, 4/25/13 at 0933]
True, Mr. Camel, true. And, often, dignifying nonsense with a response serves only to promote the nonsense.
HOWEVER, noble warriors for truth such as authors Michaels and Knappenberger are dealing with a cult mentality (and, even more, in the cult’s leaders, with a deep-seated greed for money and or prestige or raw power). Cult members will cling ferociously to their fantasies (and con-artists, to their schtick). Deprogramming (or exposing a con) must be done in painstaking, orderly, steps. Leading off with a bold, grand proclamation of what is REAL is like having a sheepdog charge straight up to the sheep with a loud, “WOOF!” Result: terrified sheep who are listening to no one and running away pell mell.
Instead of saying to the members of the I Do Believe in Fairies Cult (most of the news media and many politicians fall into this category), “Now, look here, people. FAIRIES – DO – NOT – EXIST and that’s how we know they did not build that castle,” Michaels and Knappenberger are quietly but firmly saying to them, “We are not saying that fairies do not exist, but, we know that fairies did not make that castle because their hands are too tiny [please assume for this hypothetical that the cult defines fairies to be tiny beings who can only make buildings by building them, not using their magical powers which are for other things like sleeping potions and such like]. And, as to the cons, they are proceeding like a trial attorney, step… by careful……. step, demolishing the other side’s case by showing each piece of its evidence, one by one, to be false or irrelevant.
Knappenberger and Michaels have “pledged [their careers] and [their] sacred honor” in joining in the fight for truth. I feel about them as I feel about the signers of the American Declaration of Independence. Such men deserve our respect and wholehearted support. Your criticism touched a nerve and I leapt to their defense. Please forgive me if I have attacked your essentially true statement overzealously. We are both on the same side!
THANK YOU, Mr. Michaels and Mr. Knappenberger!
Roy Spencer says:
April 26, 2013 at 7:22 am
//////////////////////////////
Dr Spencer,
Do we actually possess the data?
Do we have albedo measurements in relation to height?
Is your figure (170 W/m2) at the height at which there is 1 bar pressure, or is an approximation of insolation at the surface?
Yes indeed, Dr Spencer, the implications of what the natural laboratories of Venus and elsewhere tell us, have revolutionized atmospheric physics. Though many have yet to realise this. GHE, my foot! BK