The war of words between economist William Nordhaus and the sixteen scientists continues in the New York Review of Books. Cohen, Happer and Lindzen (CHL) seem to have been delegated to speak for the sixteen.
It's all interesting stuff. I was struck by this bit from Nordhaus's response.
The final part of the response of CHL comes back to the economics of climate change and public policy. They make two major points: that the difference between acting now and doing nothing for fifty years is “insignificant economically or climatologically,” and that the policy questions are dominated by major uncertainties.
Is the difference between acting now and waiting fifty years indeed “insignificant economically”? Given the importance attached to this question, I recalculated this figure using the latest published model. When put in 2012 prices, the loss is calculated as $3.5 trillion, and the spreadsheet is available on the Web for those who would like to check the calculations themselves. If, indeed, the climate skeptics think this is an insignificant number, they should not object to spending much smaller sums for slowing climate change starting now.
If your climate models cannot hindcast regional climate and they have not been shown to be able to predict either global or regional climate, what is the point of discussing a cost-benefit analysis based on their output? You might just as well have used a ouija board.