Hot Under the Collar.
Prophecies of doom are also a winner for the media.
Combine the two and you've got an editor's dream. There is actually a pretty good prima facie case for a link between higher temperatures and increased crime. The problem comes when trying to say what the effect of global warming would be. To begin with, what warming there has been over the years doesn't seem to have affected the crime rate particularly. If there is an underlying temperature-related change much more detailed research needs to be done to isolate it.