The Stern Report shows, given certain assumptions, that adopting an aggressive near term policy may be better than never doing anything at all. However, the question policy makers should be asking is how aggressive do policies need to be in the short term. Society needs to weigh a number of alternatives besides just stabilising concentrations at 550 ppm... the analysis needs to be based on solid science and economics before hundreds of billions of dollars per year are invested in abatement.
Like several other contributors to the debate Mendelsohn argues that the Stern report overestimates the damages and underestimates the costs of abatement.
For anyone interested Richard Tol, David Maddison, Robert Mendelsohn, Cameron Hepburn and Nick Stern himself will be taking part in a BBC Radio 4 programme at 8pm on Thursday 25th January.