drought

Access to adequate fresh water supplies is a critically important societal challenge posed by climate change. With rising heat and shifting rainfall patterns, and reduced water storage resilience, fresh water supplies are already diminishing in the western United States, Mexico, the Middle East, and Mediterranean. Water shortages have been implicated in recent international conflict, and a recent Department of Defense study underscores the geopolitical importance of this problem.

As the American Southwest grows hotter, the risk of severe, long-lasting megadroughts rises, passing 90 percent likelihood by the end of the century if greenhouse gas emissions continue at their current pace, a new study says. If we aggressively reduce greenhouse gas emissions, however, we can cut that risk substantially, the authors write.