As one who advocates a rational and methodologically sound approach to global warming policy, I think that the just-published Stern Report provides a strong case that action should be taken.
Before I continue with why I still have some reservations, let me suggest that Grist readers who are critical of economics take a good look at this report. It is the breadth of the economic analysis, the attention to detail, and the range of policy options (informed by sound economic analysis) that make this report so powerful. It is also endorsed by some of the most prominent economists in the world, which gives it immense credibility. It is because it is the work of good economists that it is being taken seriously and may actually motivate government action. Whether you like it or not, the two most powerful groups of scientists engaged in global warming policy are climatologists and economists.
Now to why I am still wary of the conclusions.