Is climate change the ultimate Black Swan? Martin Weitzman of Harvard University and co-author of Climate Shock talks with EconTalk host Russ Roberts about the risks of climate change. Weitzman argues that climate change is a fat-tailed phenomenon--there is a non-trivial risk of a catastrophe. Though Weitzman concedes that our knowledge of the climate is quite incomplete, he suggests that it is prudent to take serious measures, including possibly geo-engineering, to reduce the accumulation of carbon dioxide in the atmosphere.