UN Secretary-General Ban Ki-moon has said global warming is as threatening as modern warfare in its potential to highlight the vast differences in living standards between developed and developing nations, and several reports have been issued in the U.S. that support his claim.

The Pentagon believes resource scarcity will become the motivating factor of political violence, and a group of retired US military officials has published a report linking global warming to instability.

The Central Intelligence Agency, meanwhile, is working on a report that will focus on links between global warming and US national security.