One problem that has dogged the debate on carbon emissions from the beginning has been trying to construct a cost-benefit result that justifies the trouble of major cuts to emissions. Findings on this point have varied from the British Stern Review of 2006 which found that the damage would be so great that early, strong action was justified through to those of William Nordhaus, a professor of economics at Yale University who found much milder effects, and a lot in between.

Then there is Robert S Pindyck, a professor of economics and finance at the Massachusetts Institute of Technology, who earlier this year declared the whole debate bunkum. Specifically he has declared that the various climate models on which future damage is assessed as "worse than useless" in setting policy.