Article by David Roberts taken from Grist (http://grist.org/)

How much will it cost humanity to avoid dangerous climate change?

Debates over this contentious topic inevitably focus on a set of economic models that seek to estimate those costs over the course of the next century. The latest such analysis is the 5th IPCC Assessment on Mitigation of Climate Change, which has people confidently asserting that properly addressing climate change will trim 0.06 percent a year off global GDP growth. Not 0.05 a year. Not 0.07. But 0.06. The much-ballyhooed New Climate Economy report, out earlier this year, draws many of the same conclusions.

Can we really know the costs of mitigation out through the year 2100 with that level of precision?