Does Climate Change Cause Civil War?

A  relationship between climate change and armed confict is frequently invoked in policy debates. But does it exist? A paper in the Proceedings of the National Academy of Sciences published last October claimed to have found an empirical relationship between climate change (specifically temperature and precipitation) and civil conflict in sub-Saharan Africa. A new paper, published online today in the same journal, hits back hard, arguing that the original result was an artifact of sloppy modeling. It argues, in particular, that the original paper used an inappropriate definition for civil war, and failed to control for standard variables like ethno-political exclusion, macroeconomic fundamentals, and the collapse of the Cold War security system. (Nature has more on the debate between the authors.)