Hal Varian of the University of California, Berkeley, joins the ranks of distinguished critics of the Stern Report:
As these examples illustrate, the choice of an appropriate policy toward global warming depends heavily on how one weighs the costs and benefits it imposes on different generations. The Stern Review chose a particular way to do this, but many other choices could have been examined.
Exploring the implications of alternative assumptions is likely to lead to better policy than making a single blanket recommendation. At least at this stage of our understanding, exploration beats exhortation.
In other words, the Stern Report was deeply unprofessional, as I have been saying consistently, in not reviewing a range of scenarios and sensitivities.