Mayans doomed by drought?
Scientists have offered many explanations for the collapse of Mayan civilization 1,000 years ago, including deforestation, overpopulation, and war. But researchers now think they have identified the real culprit: a crippling, decades-long drought. The team analyzed sediment under Lake Chichancanab on Mexico’s Yucatán Peninsula, the Mayan heartland. Specifically, researchers studied water trapped within gypsum crystals, which form at the bottom of lakes during extreme drought. They calculated that the area experienced a 50 percent decrease in annual precipitation from 800 to 1,000 A.D.—and that over some periods, rainfall declined by up to 70 percent. “A climate change was potentially a driving force of the downfall,” study co-author Nicholas Evans, from Cambridge University, tells The Times (U.K.). “A lot of the things that cause the disintegration of a civilization—lack of food, outbreaks of disease, environmental degeneration—can be a consequence of drought.” ■