As we near peak water, hydroclimatologist Peter Gleick warns that skirmishes over resources will intensify. “Water can be—and often is—a source of cooperation rather than conflict,” Gleick notes, “but conflicts over water are real.” Already Gleick’s organization, the Pacific Institute, has created a 5000-year timeline of water-related conflict. Highlights include Assyrians poisoning enemy wells with rye ergot in the 6th century B.C., the World War II targeting and destruction of Soviet hydroelectric dams, the U.S. bombing of North Vietnamese irrigation canals in the 1960s, and riots in Cape Town, South Africa in 2012 sparked by insufficient water supplies. By 2025, scientists predict that one in five humans will live in regions suffering from water scarcity, areas with insufficient resources to meet water usage demands.

I wrote about the Politics of Drinking Water for The Atlantic.