Correlation or causation?: climate change and increased violence

Few recent scientific studies have received as much media coverage as one published recently in Science, arguing for a causal link between climate warming and violence.  The range of media sources covering it is as impressive as the number:  not just general news media at all levels, in many parts of the world, and not just science journals, but also those with particular perspectives, among them religious (or, at least Christian) environmental, police-based, medical and business.  Why should this particular ...