Pentagon study suggests potentially catastrophic consequences of climate change 

Commissioned by highly respected Defense Department planner Andrew Marshall, a Pentagon study raised the possibility that global warming could prove a greater risk to the world than terrorism. Among the potential consequences, if climate change occurs abruptly or at the high end of scenario projections, might be catastrophic droughts, famines and riots. The study's principal authors were Peter Schwartz, former head of planning for Shell Oil, and Doug Randall of the Global Business Network, a California think tank.

Pentagon Report (PDF file)

Fortune article

Grist article

The Observer/Guardian