Full papers plus additional comments from co-author Nic Lewis follow. I have added some relevant diagrams and tables from the report, plus reproduced the foreword by Dr. Judith Curry as well as updated the summary Equilibrium Climate Response Graph originally by Dr. Patrick Michaels to include this new ECS value and range. – Anthony
Models per AR5 Table 9.5. The bar heights show how many models in Table 9.5 exhibit each level of TCR.
NEW REPORT: CLIMATE LESS SENSITIVE TO CO2 THAN MODELS SUGGEST
The GCMs overestimate future warming by 1.7–2 times relative to an estimate
based on the best observational evidence.
Press Release
A new report published by the Global Warming Policy Foundation shows that the best observational evidence indicates our climate is considerably less sensitive to greenhouse gases than climate models are estimating.
The clues for this and the relevant scientific papers are all referred to in the recently published Fifth Assessment report (AR5) of the Intergovernmental Panel on Climate Change (IPCC). However, this important conclusion was not drawn in the full IPCC report – it is only mentioned as a possibility – and is ignored in the IPCC’s Summary for Policymakers (SPM).
For over thirty years climate scientists have presented a range for climate sensitivity (ECS) that has hardly changed. It was 1.5-4.5°C in 1979 and this range is still the same today in AR5.
The new report suggests that the inclusion of recent evidence, reflected in AR5, justifies a lower observationally-based temperature range of 1.25–3.0°C, with a best estimate of 1.75°C, for a doubling of CO2. By contrast, the climate models used for projections in AR5 indicate a range of 2-4.5°C, with an average of 3.2°C.
This is one of the key findings of the new report Oversensitive: how the IPCC hid the good news on global warming, written by independent UK climate scientist Nic Lewis and Dutch science writer Marcel Crok. Lewis and Crok were both expert reviewers of the IPCC report, and Lewis was an author of two relevant papers cited in it.
In recent years it has become possible to make good empirical estimates of climate sensitivity from observational data such as temperature and ocean heat records. These estimates, published in leading scientific journals, point to climate sensitivity per doubling of CO2 most likely being under 2°C for long-term warming, with a best estimate of only 1.3-1.4°C for warming over a seventy year period.
“The observational evidence strongly suggest that climate models display too much sensitivity to carbon dioxide concentrations and in almost all cases exaggerate the likely path of global warming,” says Nic Lewis.
These lower, observationally-based estimates for both long-term climate sensitivity and the seventy-year response suggest that considerably less global warming and sea level rise is to be expected in the 21st century than most climate model projections currently imply.
“We estimate that on the IPCC’s second highest emissions scenario warming would still be around the international target of 2°C in 2081-2100,” Lewis says.
Full report attached.
Contacts:
Nic Lewis
e: nhlewis@btinternet.com
t: +44 (0)7462 155076.
Marcel Crok
e: marcel.crok@gmail.com
m: +31 6 16236275
Dr Benny Peiser
Director, The Global Warming Policy Foundation
t: 020 70065827
m: 07553 361717
e: benny.peiser@thegwpf.org
registered in England, no 6962749
registered with the Charity Commission, no 1131448
==============================================================
Nic Lewis comments in an email to me:
The report shows that – contrary to the impression given by the Summary for Policymakers – the observational, scientific evidence in the main IPCC AR5 report actually supports much lower estimates of how sensitive the climate system is to greenhouse gas levels, both in the long term and over the remainder of this century, than those exhibited by almost all of the CMIP5 climate models used for virtually all the projections of future climate change. The report develops sound observationally-based projections of future global warming, to the last twenty years of the century, that are 40–50% lower than the IPCC’s average projections on the same emissions scenarios.
I carried out the scientific analysis for the report and co-wrote it with Marcel Crok, a Dutch science writer. The foreword is written by Judith Curry.
==============================================================
Foreword
The sensitivity of our climate to increasing concentrations of carbon dioxide is at the heart of the scientific debate on anthropogenic climate change, and also the public debate on the appropriate policy response to increasing carbon dioxide in the atmosphere. Climate sensitivity and estimates of its uncertainty are key inputs into the economic models that drive cost-benefit analyses and estimates of the social cost of carbon.
The complexity and nuances of the issue of climate sensitivity to increasing carbon dioxide are not easily discerned from reading the Summary for Policy Makers of the Assessment Reports undertaken by the Intergovernmental Panel on Climate Change (IPCC). Further, the more detailed discussion of climate sensitivity in the text of the full Working Group I Reports lacks context or an explanation that is easily understood by anyone not actively reading the
published literature.
This report by Nic Lewis and Marcel Crok addresses this gap between the IPCC assessments and the primary scientific literature by providing an overview of the different methods for estimating climate sensitivity and a historical perspective on IPCC’s assessments of climate sensitivity. The report also provides an independent assessment of the different methods for estimating climate sensitivity and a critique of the IPCC AR4 and AR5 assessments of climate sensitivity.
This report emphasizes the point that evidence for low climate sensitivity is piling up. I find this report to be a useful contribution to scientific debate on this topic, as well as an important contribution to the public dialogue and debate on the subject of climate change policy.
I agreed to review this report and write this Foreword since I hold both authors of this report in high regard. I have followed with interest Nic Lewis’ emergence as an independent climate scientist and his success in publishing papers in major peer reviewed journals on the topic of climate sensitivity, and I have endeavored to support and publicize his research. I have interacted with Marcel Crok over the years and appreciate his insightful analyses, most recently as a participant in climatedialogue.org.
The collaboration of these two authors in writing this report has resulted in a technically sound, well-organized and readily comprehensible report on the scientific issues surrounding climate sensitivity and the deliberations of the IPCC on this topic.
While writing this Foreword, I considered the very few options available for publishing a report such as this paper by Lewis and Crok. I am appreciative of the GWPF for publishing and publicizing this report. Public accountability of governmental and intergovernmental climate science and policy analysis is enhanced by independent assessments of their conclusions and arguments.
Judith Curry
Atlanta, GA, USA
February 2014
===============================================================
PDF’s short and long (technical) versions
I am not surprised but I am delighted 😀
(I hate to think what the warmists are going to do with the author’s names when they can’t prove it wrong, though….)
One thing I think being overlooked in evaluation of this ‘climate sensitivity’ is incorrect use of OLS regression. One common way to measure it and AFAIK this is the main way that it is assessed for the various models, it to plot dRad vs dTemp and work out the slope by linear regression.
By convention it seems that dRad gets to be y axis.
Now this is NOT a legitimate use of OLS, which assumes and requires a “controlled variable” (ie negligible error/uncertainty) on the x-axis.
The very few people who are aware of this basic restriction seem to sweep it under that carpet as some kind of purist’s, pedantic knit-pick that doesn’t really “matter”.
Well, guys, it does “matter”.
What happens if this is not respected is called “regression dilution”. If you have significant error in the x variable the slope will (usually) come out less that the true slope. How much less depends upon the ratio of the respective x and y errors. The difference can be huge, easily a factor of two on noisy data – like climate for example.
So if we do a dRad vs dTemp plot the fitted slope will be notably less than “best unbiased estimation” of the slope we believe it to be.
A quick check is to plot the data as dTemp vs dRad and do the OLS that way around. If the result is consistent one slope will be the reciprocal of the other. When you do it on low noise data they are close when you do it on noisy data there is a huge disparity.
Since climate sensitivity is the inverse of this slope we get a spuriously high CS.
This is something I have been intending to write up in detail with example data to demonstrate it. Perhaps now would be a good time.
“In recent years it has become possible to make good empirical estimates of climate sensitivity from observational data such as temperature and ocean heat records. ”
How can one say this? Temperature and ocean heat can indeed be measured (sort of) but that does not mean that they have anything to do with increased CO2 hence the link with climate sensitivity is equally unknown.
“David Appell already remarked that he can’t take this report seriously because it wasn’t peer-reviewed.”
Climate “science” peer review = your mates give nodding approval no matter how bad the paper is.
“How can one say this? Temperature and ocean heat can indeed be measured (sort of) but that does not mean that they have anything to do with increased CO2 hence the link with climate sensitivity is equally unknown.”
wrong.
““The climate sensitivity” is a logically and scientifically illegitimate concept for there is no empirical support for the contension that either the equilibrium climate sensitivity or the transient climate sensitivity is a constant.”
wrong.
there is no “contension [sic]” that it is a constant. In fact there is literature supporting the notion that it is not constant. However, for the purposes of making an estimate of how the system may respond it is assumed to be constant over the period of interest.. the next hundred years.
you could assume otherwise and do the same calculations. However youd have to defend your choice of which form of inconstancy you selected.
“davidmhoffer says:
March 5, 2014 at 9:45 pm
There’s a model that comes in at 1.1 degrees? Curious to know which one that is. In fact it would be very interesting to contact the groups with models closest to observations and ask for their comment.”
FGOALS. is closest to “observations” well to surface temps.
Well this article is well-timed, because just this morning I completed a calculation on the ratio ECS/TCR. And you wouldn’t believe how low (i.e close to 1) that value is. This ratio is supposedly driven by the fact that the sea temperatures lag behind the land temperatures, so if CO2 stopped rising and land temperatures stopped rising then the seas would continue to warm for a while. But an analysis of the observed correlations suggests that the effect is rather small.
However, I’m going to ask a friend to check my calculations rather than put them out here just yet…
Rich.
Its not about the evidence. Deindustrialisation is ‘the right thing to do’ and the world would be much better in an anarchist eco utopia. Not sure where that leaves their ‘council of elders’ plan to run everything.
We should be looking at TCR = 1.35 C based on observation, not the ECS.
TCR is relevant for 100-year timescale. ECS requires thousands of years to attain. From IPCC 3AR:
“the climate sensitivity was obtained from calculations made with AGCMs coupled to mixed-layer upper ocean models (referred to as mixed-layer models). In that case there is no exchange of heat with the deep ocean and a model can be integrated to a new equilibrium in a few tens of years. For a full coupled atmosphere/ocean GCM, however, the heat exchange with the deep ocean delays equilibration and several millennia, rather than several decades, are required to attain it.”
In succeeding Assessment Reports, this fact is not mentioned anymore.
Ken, you are so correct.
What exactly is the “observed” in that graph at the top of the thread?.
Does it include all the manual “adjustments”?
Does it take account of some of the strongest solar cycles the planet has seen for a long time?
Does it take into account UHI effects?
Does it take into account other natural warming effects?
Almost certainly not.!
Even in the adjusted Hadley temp set, the 30 year period from 1977-2007 had almost exactly the same warming rate as from 1915-1945, yet CO2 and solar input increased significantly.
Maybe the CO2 was actually counteracting the effect of the strong solar cycles.
Steven, what does FGOALS do that’s different from the other 97% of incurably wrong models?
Does it use raw past temperature data, and set the CO2 sensitivity to basically zero ?
Visible huge area of operation of the stratospheric polar vortex. A height of 30 km.
http://earth.nullschool.net/#2014/03/09/0600Z/wind/isobaric/10hPa/orthographic=15.00,115.10,418
I find it hard to believe how much time and effort is spent on the utterly pointless exercise of trying to predict the future. We have Putin re-writing the Continental European Map, a completely insane tyrant in charge of nuclear bombs in Korea; A Jihadhist in charge of Iran, determined to remove every Christian from the planet; a psychopath in Syria bombing and gassing his own people and 845,000 people starving in Africa and Asia yet we have billions spent on a fruitless pursuit of an unknowable future that we can do nothing about. So what if so-called climate sensitivity to the demon plant food is minus 10 to plus 10, nothing can or will be done about it. We should get over it and move on.
strike says:
March 5, 2014 at 11:20 pm
“No, the sceptics are just trying to falsify the CAGW-theory, doesn’t matter which of your two or any other way.”
———————————————————
One strike and you’re out.
Falsifying CAGW is of no ultimate benefit. For democracy, science and reason to progress, the very idea that adding radiative gases to our atmosphere will reduce the atmospheres radiative cooling ability must be destroyed.
I do not truly have time for this. I have various day jobs –
http://i61.tinypic.com/2n7qukm.jpg
Step up to the plate “Strike”. Show the readers of WUWT why your claim that just killing CAGW is “A-Ok” for science, reason and democracy. Just why it it is that the very idea of additional radiative gases reducing the atmospheres radiative cooling ability is acceptable. Go on. Give it your best shot.
You know who most sceptics are? Engineers. Engineers don’t take s__t from squealing socialists. Public faces, punched to custard. Those are the rules. No exceptions.
This might be a good time to review
http://einstein.iec.cat/jellebot/documents/articles/Phis.Lett.A_2007.pdf
“In this work ice-core CO2 time evolution in the period going from 20 to 60 kyr BP [15] has been qualitatively compared to our temperature cycles, according to the class they belong to. It can be observed in Fig. 6 that class A cycles are completely unrelated to changes in CO2 concentration. We have observed some correlation between B and C cycles and CO2 concentration, but of the opposite sign to the one expected: maxima in atmospheric CO2 concentration tend to correspond to the middle part or the end the cooling period. The role of CO2 in the oscillation phenomena seems to be more related to extend the duration of the cooling phase than to trigger warming. This could explain why cycles not coincident in time with maxima of CO2 (A cycles) rapidly decay back to the cold state. ”
for perhaps a less anthropogenic perspective on CO2 ‘contamination’.
Which immediately leads to a rather uncomfortable possibility that if CO2 is not as capable a climate security blanket as we are supposed to believe (sensitivity) then what else could we deploy in the late-Holocene atmosphere to stave-off the now due glacial inception?
Might we not be sensitive enough to:
“Several features of the last interglacial/glacial transition resemble the recent temperature and precipitation trends.
“They are:
I) Preferential warming of the low latitudes.
2) Increasing meridional temperature gradient.
3) Increasing precipitation in cold season in the high northern latitudes (which supposedly also accompanied the ice build-up in MIS 5d).
4) Cooling of the northern North Atlantic with simultaneous warming of the equatorial one.”
Last Interglacial End, 2000, George Kukla, http://geolines.gli.cas.cz/fileadmin/volumes/volume11/G11-009.pdf
I would very much appreciate informed feedback on any of Kukla’s points above. One may also think of this as a possible delay of the glacial inception mandate. Meaning if you like your current climateplan you might or might not be able to keep it. Period.
It might just depend on how sensitive ‘WE’ really are……. http://scf.berkeley.edu/~aldous/157/Papers/social_consensus_xie.pdf
Ivor Ward says:
March 6, 2014 at 1:17 am
Well said.
Yeah, what Ivor said..
and Wiliam, too. 🙂
Dr Burns says: @ur momisugly March 5, 2014 at 6:29 pm
….. Based on the past hundreds of thousands of years, there is still no hard evidence that CO2 has any influence on climate…
>>>>>>>>>>>>>>>
This is especially true when you realise the CO2 records are as
fabricated‘adjusted’ as the modern temperature records.SEE page 163 Climate Change: Incorrect information on pre-industrial CO2 Statement written for the Hearing before the US Senate Committee on Commerce, Science, and Transportation, March 19, 2004,
Ron Richey says: @ur momisugly March 5, 2014 at 8:42 pm
What’s a flame war?
>>>>>>>>>>>
Nasty argument usually with high emotions and name calling. NOT a ‘learned discussion/argument’ which is what A. W. prefers.
Alan Robertson says: @ur momisugly March 5, 2014 at 10:05 pm
I just encountered the latest “Climate __________” catastrophic description today. Gone are Global Warming, Climate Change, Climate Disruption and Extreme Weather. It’s now Climate Shift.
>>>>>>>>>>>>>>>
At least that one is closer to the truth. Just remind people that NOAA say they haven’t got a clue as to what causes ‘Abrupt Climate Change’….
OH MY!!! Just think oddles and oddles of grant funds if the CAGW Climastrologists can morph CAGW into an ‘Abrupt Climate Change’ scare. I think you just found the loop hole the CAGW scammers are about to climb out of.
Good Catch!
SEE: NOAA – A Paleo Perspective … on Abrupt Climate Change Heinrich and Dansgaard-Oeschger Events
Darn! I forgot the / in the frist block quote close in the comment stuck in moderation.
Can’t spell worth a darn either. (Time for more caffeine)
jauntycyclist says: @ur momisugly March 6, 2014 at 12:00 am
Its not about the evidence. Deindustrialisation is ‘the right thing to do’ and the world would be much better in an anarchist eco utopia. Not sure where that leaves their ‘council of elders’ plan to run everything.
>>>>>>>>>>>>>>>
Deindustrialisation is just to make the threatening Middle class back into peasants. It never was meant to apply to the elite.
“It is clear that current lifestyles and consumption patterns of the affluent middle class, involving high meat intake, consumption of large amounts of frozen and convenience foods, use of fossil fuels, appliances, home and work place air conditioning, and suburban housing are not sustainable.” ~ Maurice Strong in his introductory speech Kyoto 1992.
Notice there is nothing said about the ultra-rich and their consumption habits just the middle class.
{:>)
thegriss says:
March 6, 2014 at 2:14 am
Yeah, what Ivor said..
and Wiliam, too. 🙂
>>>>>>>>>>>>
That makes three.
And do not forget China saber rattling in the South China sea and the BRICS countries thumbing their collective nose at the IMF while they amass gold.