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
This how to answer people who say that co2 is bad. What worries me is that co2 levels are too low.
http://www.ehleringer.net/Jim/Publications/329/Chapter%2011.pdf
Janice Moore says: @ur momisugly March 5, 2014 at 5:24 pm
Thanks for the tulip pictures, they look like the ones I had up north. I haven’t done any planting except grass since I moved south. Escape artist goats make it not worth the effort unless I goat proof the garden. (I am looking for a Round Tuit for my garden that I have been planning)
I do have some wonderful wild flowers though IMAGE
Sorry mods, the spring fever is breaking out, no doubt aided by all that man-made CO2.
GBmoore says:@March 5, 2014 at 6:16 pm
This how to answer people who say that co2 is bad. What worries me is that co2 levels are too low.
>>>>>>>>>>>>>
That is a definite problem. Part of our gain in crop production is because of increased CO2. We have closed to doubled our yield per ac here in the USA over the last century.
I use this as an illustration for others: Carbon starvation in glacial trees recovered from the La Brea tar pits, southern California.
Based on the past 17 years, climate sensitivity is zero. Based on the past hundreds of thousands of years, there is still no hard evidence that CO2 has any influence on climate, or that CO2 changes are an effect rather than a cause of climate changes.
What no catastrophe?
Another Howard Camping moment for the Cult of Calamitous Climate?
So far it would be just as reasonable, to assert that climate sensitivity is indistinguishable from zero.
If this nonsense survives to host a 6th Assessment report and the weather cycle has taken that imaginary AGT negative, will the IPCC then claim a negative sensitivity?
or will science break free of climatology?
What determines how much a peer reviewer earns for an article? How are they chosen?
Any empirical estimate of transient climate sensitivity (TCS) has to proceed by assuming some part of the recent warming is caused by CO2 or GHGs. It matters not what reasoning is used in the estimate. The analytical assumptions determine the outcome. That makes any empirical TCS circular and tendentious. Fun to play with but of no particular physical meaning.
By the way, as David Appell’s comment wasn’t peer-reviewed David Appell cannot take it seriously.
Lindzen’s seems the most likely.
This CO2 sensitivity value reminds me of the Millikan oil drop experiment to quantify the electon’s charge — the original result was a bit off, and subsequent experiments incrementally changed the result until the true value was reached — but the migrating results results showed that the science was a hybrid of observation and expectation — only when the expectations reached the true value were the observational results allowed to go there. And those scientists were not funded to cling to their previous expectations, like today’s climate scientists are.
Oh, hurrah! Thanks, Gail, for letting me know you received my bouquet. And, thanks for that gorgeous photo. WOW. Janice
It varies from discipline to discipline. Typically the editor of the journal chooses the reviewers. Some journals ask that the author name individuals considered authoritative to review the paper and also name those who, for possible reasons of conflict of interest or whatnot, should not be selected to review the paper. In those cases, the authors must explain why that person should not be selected.
In my field it is considered inappropriate to hame friends or colleagues to review a paper. Doing so will likely result in chastisement by the editor. In most cases peer reviewers are not paid (at least they are not paid in my field).
I dunno – when you take the longer view of temps since the last ice age, there does not seem to be much correlation to CO2 at all. Even this pro-skeptic report seems to concur that CO2 is the Earth’s temperature thermostat, just not as powerful a thermostat at the alarmists feel. Clearly the ice core graphs show CO2 is an effect to temps rather than a cause.
In the shorter time frame, you have the IPCC saying mid last century is when man’s CO2 contribution to climate started to be significant, yet we have the same general rate of increase coming out of the little ice age way before man’s 1950+ contribution to the rise in C02, yet the temps are not doing anything they have not done in the past.
Ultimately it will take some ‘unexplained’ cooling to break this meme that C02 is in any way a thermostat that can overcome nature’s own, as yet, not fully understood effects on climate that clearly dwarf any minor input man has made.
http://i.snag.gy/BztF1.jpg
I would say that Earth’s atmosphere is insensitive to CO2 in any presumed and measured concentration to date.
What’s a flame war?
In 1957,Hans Suess and Roger Revelle stated that human beings were carrying out a unique large scale geophysical experiment by increasing the amount of CO2 in the earth’s atmosphere.Scientifically, it is wrong to prejudge the outcome of a unique experiment.Beforehand ,the laws of physics don’t predetermine or mandate the climate sensitivity of greenhouse gases.Therefore, no one knows whether the climate sensitivity assumed by the IPCC will turn out to be correct.We must wait until the amount of CO2 in the atmosphere has doubled from pre-industrial levels some time later this century.
What is happening is a guessing game based on past indicia.
Another way of putting this is Nobel Prize Winner and Harvard Physicist ,Percy W. Bridgman’s view of the “inscrutable character of the future “-
” I personally do not think that one should speak of making statements about the future. For me, a statement implies the possibility of verifying its truth, and the truth of a statement about the future cannot be verified.”
Ron Richey says:
March 5, 2014 at 8:42 pm
“What’s a flame war?”
————————————–
RL or Internet? Context, as always, is everything 😉
In RL “flame war” may refer to violent conflict involving the use of Fuel Air Explosives (aluminium powder/kerosene), Thermo Kinetic weapons (requiring rail gun/gas cannon launch) or more advanced non air-burst variants thereof (hydrogen strippers).
On the Internet “flame war” refers to text based arguments starting with entrenched positions, escalated by misinterpretation and resulting in foul language and regrets. (Generally safer than the RL version, but still unpleasant).
[That RL = RealLife Mod]
A few hundred parts per million CO2 can not have an appreciable effect. The last 20 years have proved that is the case. Time to dump this theory and move on to the next one. Better luck on their next guess. Next, Man caused cooling due to the huge amounts of dandruff from the 6.5billon people that cover the earth! The Ice will soon be on the march destroying everything before it. pg
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.
Herbert says:
March 5, 2014 at 9:10 pm
“Another way of putting this is Nobel Prize Winner and Harvard Physicist ,Percy W. Bridgman’s view of the “inscrutable character of the future “-
” I personally do not think that one should speak of making statements about the future. For me, a statement implies the possibility of verifying its truth, and the truth of a statement about the future cannot be verified.”
I like Yogi Berra’s better – “Predictions are hard, especially about the future.”
This Lewis and Crok estimate of climate sensitivity is still too high because as I understand it still uses an estimate of the trend in the OHC which bears little relation to the current best estimate.
The best analysis of the changing OHC is at
http://www.pmel.noaa.gov/people/gjohnson/OHCA_1950_2011_final.pdf
Look at table1. This shows that the heat flux from 0-100 m dropped 90% when the period 1983 – 2011 is compared with 2004-2011. The flux at deeper levels also declined substantially. Trenberth’s hidey hole for the “missing ” heat is in reality non existent. This shows that, as one might expect on a cooling earth, the oceans are cooling from the top down.
Another problem with the Lewis and Crok analysis is that it follows the IPCC modelers simple minded and almost certainly wrong assumption that the natural trends can be projected forward on a straight line basis. This total disregard for the quasi periodic quasi repetitive periodicities in the temperature record perpetuates the gross scientific malfeasance which vitiates the entire IPCC modeling program and all the impact studies which derive from them.
Furthermore computer models are inherently useless for forecasting a system with as many variables as climate has , let alone the fact that the IPCC models are structured so badly that their range of outputs is likely mostly outside the range of the real climate system.For the inherent model limitations see
A new forecasting paradigm is required. The IPCC model outputs are not really worth discussing except to try to convince the politicians that their climate policies have no sound foundation. For estimates of the probable coming cooling based on the 60 year and 1000 year quasi periodicities in the temperature data and the neutron count as a proxy for solar “activity” see several posts at
http://climatesense-norpag.blogspot.com.
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.
This is a useful contribution to climate science, but many of the estimate are too high because they implicitly assume a total forcing that excludes indirect solar forcings, or century+ cyclical natural changes in ocean oscillations.
A recent addition to the list of ECS estimates was the study by Craig Loehle discussed at
http://wattsupwiththat.com/2014/02/28/more-evidence-for-a-low-climate-sensitivity/
which finds the temperature response (TCR =1.09 C) is 61% of the climate models, and ECS = 2.0 C. Unfortunately, the paper assumes without justification that the warming trend from 1950, after removing the affects of the PDO and AMO, is entirely due to greenhouse gas emissions. If this were true, there could not have been the Roman Warm period, the Dark Age Cold period, the Medieval Warm period. However, Craig writes in comments “I argue that the true equilibrium (or at least what we will see by 2100) is probably lower than my calculated value.”, but this disclaimer is not found in the abstract. These large changes in climate over the Holocene were not caused by PDO, AMO or SUVs, but correlate to solar changes. The solar magnetic flux increase throughout the 20th century, and likely had a significant affect on climate.
http://friendsofscience.org/assets/documents/HMF.jpg
Therefore, the warming trend net of PDO, AMO, should not be assumed to be all due to GHG emissions.
“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.
@Konrad
“So the question now is which of the sceptic paths is best supported by empirical experiment? They can’t both be right.”
No, the sceptics are just trying to falsify the CAGW-theory, doesn’t matter which of your two or any other way.
In my personal opinion, CAGW is FALSIFIED already, maybe the climatologists don’t realize the fail right now. So there has to be a follow-up-theory, that’s the scientific way. This new theory will be closely inspected by us, the sceptics. If there is no new theory there would be lots of unemployed climatologists, activists and politics looking for new jobs.
I personally think, climate sensitivity is a non-linear function and has no informative value, just history management. If global temperatures go down from now on, there will be a further lowered climate sensitivity, else it goes up again.