Kyoto bashing and climate uncertainty

About ten days ago I described a talk by Steve Rayner titled It's the development path, stupid. The talk prefaced a paper co-authored by Rayner and Gwyn Prins which appeared in Nature on Wednesday (Time to ditch Kyoto). Clive Bates and Charlie Kronick made interesting comments on my post (scroll down here). Clive has developed his critique at Bacon Butty here.

Turning from policy to science, RealClimate has a useful post, The certainty of uncertainty, commenting on Gerard Roe and Marcia Baker's Why is climate sensitivity so unpredictable?. For example:

450 ppm is an oft-cited threshold since this keeps deltaT below 2°C using standard climate sensitivities. But the skewed nature of the distribution of possible sensitivities means that it is much more likely that 450 ppm will give us more than 4.5°C of global warming rather than less than 2°.