Hé ben v'la aut'chose encore!
In 2003, the Pentagon commissioned a study on the impact of global warming on our national security which concluded that global warming “should be elevated beyond a scientific debate to a U.S. national security concern.”
UPDATE: The Pentagon is already doing this -- kinda, sorta, a little. According to Inside Defense, folks in the five-sided building are "drafting a new strategic construct that strives to better prepare for 'shocks' to national security and international order." They "could include major changes in global climate, a nuclear attack against a major western city, a new technology revolution or a financial market collapse that triggers a global depression."