The cost of keeping climate-chaos temperature rise under two degrees centigrade may be only 2 percent of world GDP, according to a new study by leading international scientists released in The Proceedings of the National Academy of Sciences into preprint on Dec. 22, 2008. But they say that spending much less than this will be of little value.

Two percent of the 2006 U.S. GDP would be about $262 billion. Several recent posts by me have suggested that, exclusive of the renewable tax credit, the right public investment by the U.S. in climate-chaos mitigation is about $265 billion, which I said would cover the cost difference between mitigation and no-mitigation scenarios. Given the imprecision of this sort of estimate, these are the same number. In a future post I’ll explain why I think the entire difference should be covered by public investment. But right now I thought I’d just point to the study, and also boast a little about my numbers being confirmed by one of the most respected scientific sources in the world.