A physicist speaks: Dessler on climate sensitivity – very unlikely to be less than 2ºC

There’s been much ado about climate sensitivity — the amount of warming we expect for a doubling of CO2 in the atmosphere — in the last month or two. A couple of recent papers, and an expected slight adjustment to the likely range in the upcoming IPCC fifth report1, has led to speculation that we might have less to worry about, or more time to get emissions cuts in place. It would be great if it were true, but it isn’t. In this excellent short video, Andrew Dessler, professor of atmospheric sciences at Texas A&M university, explains why atmospheric physics means it’s very unlikely that the climate sensitivity can be below 2ºC.

For lots of other reasons why the most likely value remains about 3ºC, see this Skeptical Science post.

  1. From 2ºC to 4.5ºC in AR4 to 1.5ºC to 4.5ºC in AR5, with the most likely value still around 3ºC []

Introduction to Modern Climate Change

I wouldn’t normally seek a text book for review, but a pre-publication recommendation described this one as excellent reading for any lay person interested in the subject. I’d also seen the author, Andrew Dessler, in an television interview which I wrote about, which was further encouragement. The book is An Introduction to Modern Climate Change. Dessler is a climate scientist but he’s also versed in the politics of the matter, having worked as a Senior Policy Analyst during the Clinton administration. His text book, a little unusually, covers both the science of climate change and the policy response to the issue.  It makes excellent sense to consider them together.

The science carries such grave implications for human welfare that it demands policy responses. Dessler sets much store by an electorate educated in both the science of the changing climate and the steps that are needed to avoid its worst consequences in the future.  Not all of the electorate is likely to become as educated in the science as this book allows, but the broad scientific outline on which the book is based is certainly capable of wide dissemination across the community.

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