Rise of no more than 1ºC by 2100 -Will IPCC admit this?

Matt Ridley, writing in the Wall Street Journal (link) talks with IPCC expert reviewer, Nic Lewis. Nic Lewis, with a strong mathematics and physics background, has made significant contributions to the subject of climate change.

Image: Link
He exposed major statistical errors in a 2009 study of Antarctic temperatures. Mr. Lewis also found that the IPCC had misreported the results of another study, leading to the IPCC issuing an Erratum in 2011.
Mr. Lewis is an expert reviewer of the recently leaked draft of the IPCC's WG1 Scientific Report. The IPCC forbids him to quote from it, but he is privy to all the observational best estimates and uncertainty ranges the draft report gives. What he has told me is dynamite.

Given what we know now, there is almost no way that the feared large temperature rise is going to happen. Mr. Lewis comments: "Taking the IPCC scenario that assumes a doubling of CO2, plus the equivalent of another 30% rise from other greenhouse gases by 2100, we are likely to experience a further rise of no more than 1°C."

A cumulative change of less than 2°C by the end of this century will do no net harm. It will actually do net good—that much the IPCC scientists have already agreed upon in the last IPCC report. Rainfall will increase slightly, growing seasons will lengthen, Greenland's ice cap will melt only very slowly, and so on.
As the IPCC's previous estimate is
A doubling of CO2 will lead to a warming of 1.6°-1.7°C (2.9°-3.1°F).
Matt Ridley then asks: 
Will the lead authors of the relevant chapter of the forthcoming IPCC scientific report acknowledge that the best observational evidence no longer supports the IPCC's existing 2°-4.5°C "likely" range for climate sensitivity? Unfortunately, this seems unlikely—given the organization's record of replacing evidence-based policy-making with policy-based evidence-making, as well as the reluctance of academic scientists to accept that what they have been maintaining for many years is wrong.
A version of this article appeared December 18, 2012, on page A19 in the U.S. edition of The Wall Street Journal, with the headline: Cooling Down the Fears of Climate Change. 

Anthony Watts' WUWT (link) has published a Guest post by Nic Lewis.
There has been much discussion on climate blogs of the leaked IPCC AR5 Working Group 1 Second Order Draft (SOD). Now that the SOD is freely available, I can refer to the contents of the leaked documents without breaching confidentiality restrictions.

I consider the most significant – but largely overlooked – revelation to be the substantial reduction since AR4 in estimates of aerosol forcing and uncertainty therein. This reduction has major implications for equilibrium climate sensitivity (ECS). ECS can be estimated using a heat balance approach – comparing the change in global temperature between two periods with the corresponding change in forcing, net of the change in global radiative imbalance. That imbalance is very largely represented by ocean heat uptake (OHU).
Read the rest at Watts up with That.

H/t for Update Climate Depot (link)


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