In 2003, the Pentagon hired Peter Schwartz from "Global Business Network," a scenario-planning think tank, to examine all available research and write a report about a plausible scenario on the national security implications of the threat.

The scenario they chose to examine is one that took place 8,200 years ago and is believed to have been caused by a shut down of the thermohaline conveyor belt. The report concludes that "the risk of abrupt climate change should be elevated beyond a scientific debate to a U.S. national security concern."

On Point talks with Schwartz about the chilling effects of global warming.