Nature - Controversy Grows Around IPCC Scenarios - May Have Seriously Underestimated Climate Problem

[hatrack]

Claims that the Intergovernmental Panel on Climate Change (IPCC) has seriously underestimated the challenge and costs of stabilizing greenhouse-gas emissions in the 21st century are fuelling controversy among climate and energy researchers.

Climate policy expert Roger Pielke Jr, climatologist Tom Wigley, and economist Christopher Green lay out in a commentary article published in Nature 1 today why they think that the emission scenarios the IPCC produced nearly a decade ago, which are still widely used, are overly optimistic. They note that most of the IPCC’s 'business as usual' emission scenarios assume a certain amount of 'spontaneous' technological change. The size of this assumed change is unrealistic, they argue, and deceives policy-makers and the public about the crucial role policy must have in encouraging the development of technologies to prevent dangerous climate change.

Such a large chunk of the needed energy-efficiency improvements is built in to these 'business as usual' scenarios that the degree of change requiring special effort seems artificially small, they argue. According to the authors' own calculations, IPCC scenarios make it seem as if the technical challenge of stabilizing greenhouse-gas emissions at around 500 parts per million — a concentration which scientists think will prevent average global temperatures from rising more than 2 °C — is a quarter of its true size.

Richard Tol, an energy and environmental economist at the Economic and Social Research Institute in Dublin, Ireland, also says that the IPCC has underestimated the cost of technology, and notes that the cost of mitigating against climate change increases as time goes on. If Pielke and colleagues are correct, the cost of controlling global warming could go up by a factor of 16, argues Tol.

EDIT

http://www.nature.com/news/2008/080402/full/news.2008.728.html

[kestrel91316]

1. Learn how to grow your own food, people. And invest in a good bicycle.

We aren't going to be able to afford food or gas in our lifetimes.

[XemaSab]

2. So what's the timeline they're projecting?

:shrug:

:hide:

[hatrack]

3. Whatever they're projecting, my money's on . . .

Faster Than Expected!!!!

:toast:

[bananas]

5. Pielke is a climate-change denier

Joe Romm discusses this on his blog:
http://climateprogress.org/2008/04/03/commenters-on-this-blog-and-a-joke-explain-things-better-than-i-do/
http://climateprogress.org/2008/04/02/nature-pielke-pointless-misleading-embarrassing-ipcc-technology/

[bananas]

4. Bert Metz, co-chair of IPCC Working Group III responds

http://www.nature.com/news/2008/080402/full/452508a.html

Bert Metz, co-chair of IPCC Working Group III

The claim that the IPCC has underestimated the technological challenge of stabilization is unwarranted and must be rejected. The fact that technological change is already significantly included in the reference scenarios is clearly stated in our report and its Summary for Policymakers.

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