Category Archives: Climate sensitivity

New study: ‘…climate system is only about half as sensitive to increasing CO2 as previously believed’

Warming since 1950s partly caused by El Niño HUNTSVILLE, Ala. (Nov. 11, 2013) – A natural shift to stronger warm El Niño events in the Pacific Ocean might be responsible for a substantial portion of the global warming recorded during … Continue reading

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Posted in Climate sensitivity, Modeling | Tagged , , , | 191 Comments

A Sea Change for Climate Science?

By David Stockwell writing in Quadrant Online As CO2 climate models falter and even the IPCC backs off its estimates, it just may be that a radical shift in thinking is looming. Wouldn’t it be funny if it was the … Continue reading

Posted in Climate sensitivity | Tagged , , , , | 127 Comments

Chylek et al 2013 shows a linkage between US Southwest climate and AMO/PDO cycles

This paper suggests that the CMIP5 models’ (which IPCC relies upon) predicted US SW temperature sensitivity to the GHG has been significantly overestimated by about a factor of two. Imprint of the Atlantic multi-decadal oscillation and Pacific decadal oscillation on … Continue reading

Posted in AMO, Climate sensitivity, PDO | Tagged , , | 28 Comments

The Cloud Radiative Effect, Take Two

Guest Post by Willis Eschenbach Well, in my last post I took a first cut at figuring the cloud radiative “feedback” from the CERES dataset. However, an alert commenter pointed out that I hadn’t controlled for the changes in solar … Continue reading

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The Cloud Radiative Effect (CRE)

Guest Post by Willis Eschenbach [UPDATE: An alert commenter, Ken Gregory, has pointed out that in addition to the temperature affecting the CRE, it is also affected by the changing solar radiation. He is correct that I did not control … Continue reading

Posted in Climate sensitivity, Uncategorized | Tagged , , , | 172 Comments

Dr. Kiehl’s Paradox

Guest Post by Willis Eschenbach Back in 2007, in a paper published in GRL entitled “Twentieth century climate model response and climate sensitivity” Jeffrey Kiehl noted a curious paradox. All of the various different climate models operated by different groups … Continue reading

Posted in Climate sensitivity | Tagged , , | 124 Comments

50:1 should now be 100:1

Low ECS doubles the cost:benefit shortfall Guest essay by Barry Brill Topher Fields’ excellent documentary video http://topher.com.au/50-to-1-video-project/ explains that the overall costs of any global effort to reduce greenhouse gas emissions will be at least 50 times greater than its … Continue reading

Posted in Climate sensitivity | Tagged , , , | 44 Comments

One Step Forward, Two Steps Back

Guest Post by Willis Eschenbach David Rose has posted this , from the unreleased IPCC Fifth Assessment Report (AR5): ‘ECS is likely in the range 1.5C to 4.5C… The lower limit of the assessed likely range is thus less than … Continue reading

Posted in Climate sensitivity | Tagged , , | 317 Comments

BREAKING: IPCC AR5 report to dial back climate sensitivity

Update: the IPCC edifice is crumbling, see The state of climate science: ‘fluxed up’ See also Willis’ article One Step Forward, Two Steps Back, and Lomborg: climate models are running way too hot This post will be a sticky for awhile, new posts … Continue reading

Posted in Climate sensitivity, IPCC | Tagged , , , , | 230 Comments

More low climate sensitivity

This paper A lower and more constrained estimate of climate sensitivity using updated observations and detailed radiative forcing time series from Skeie et al is now in open peer review at Earth System Dynamics. They say an ECS of 1.84 … Continue reading

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Quote of the week – on the usefulness of climate models

From Dr. Judith Curry:

Posted in Climate sensitivity | Tagged , , | 98 Comments

A low-sensitivity climate model that outperforms the Met Office’s HADGEM2

Climate sensitivity is IMHO, the most important unresolved issue in climate science. A number of recent papers, including the IPCC AR5 leak, plus the recent Economist leak of a later AR5 draft are pointing to lower climate sensitivities than what … Continue reading

Posted in Climate sensitivity, Modeling | Tagged , , | 29 Comments

Newsbytes: The Economist Reveals Sensitive IPCC Information

IPCC Draft Lowers Global Warming Projections on Climate Sensitivity “That report is going to scare the wits out of everyone,” said Yvo de Boer recently. He is a former United Nations chief climate negotiator and was talking about the forthcoming … Continue reading

Posted in Climate sensitivity, IPCC, Newsbytes | Tagged , , | 58 Comments

The Thousand-Year Model

Guest Post By Willis Eschenbach Back in 2007, Jeffrey Kiehl first pointed out a curious puzzle about the climate models, viz: (emphasis mine) [3] A review of the published literature on climate simulations of the 20th century indicates that a … Continue reading

Posted in Climate data, Climate sensitivity | Tagged , , , , | 50 Comments

Climate Sensitivity Deconstructed

Guest Post by Willis Eschenbach I haven’t commented much on my most recents posts, because of the usual reasons: a day job, and the unending lure of doing more research, my true passion. To be precise, recently I’ve been frying … Continue reading

Posted in Climate sensitivity, Modeling | Tagged , , | 291 Comments

Australian scientists take 6 degrees of global warming off the table, say it is closer to 2 degrees

From the University of Melbourne Scientists narrow global warming range Australian scientists have narrowed the predicted range of global warming through groundbreaking new research. Scientists from the University of Melbourne and Victoria University have generated what they say are more reliable projections … Continue reading

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Updated climate sensitivity estimates using aerosol-adjusted forcings and various ocean heat uptake estimates

Guest essay by Nic Lewis The Otto et al. paper has received a great deal of attention in recent days. While the paper’s estimate of transient climate response was low, the equilibrium/effective climate sensitivity figure was actually slightly higher than … Continue reading

Posted in Climate sensitivity | Tagged , , | 113 Comments

Model Climate Sensitivity Calculated Directly From Model Results

Guest Post by Willis Eschenbach [UPDATE: Steven Mosher pointed out that I have calculated the transient climate response (TCR) rather than the equilibrium climate sensitivity (ECS). For the last half century, the ECS has been about 1.3 times the TCR … Continue reading

Posted in Climate sensitivity | Tagged , , , | 133 Comments

Why the new Otto et al climate sensitivity paper is important – it’s a sea change for some IPCC authors

Yesterday, WUWT was honored to have a guest essay by co-author Nic Lewis on the new Otto et al paper that pegs Transient Climate Response (TCR) at 1.3°C along with Equilibrium Climate Sensitivity at 2.0°C. Lewis , who had previously published … Continue reading

Posted in Climate sensitivity | Tagged , , | 44 Comments

New paper shows transient climate response less than 2°C

See also: Why the new Otto et al climate sensitivity paper is important – it’s a sea change for some IPCC authors New energy-budget-derived estimates of climate sensitivity and transient response in Nature Geoscience Guest post by Nic Lewis Readers … Continue reading

Posted in Climate sensitivity | Tagged , , , , , , , | 194 Comments