Tree ring records in North America show evidence of a “mega-drought” in the 16th century that wreaked havoc for decades among early settlers and native populations.
Researchers used tree ring chronologies that extend back more than 500 years in Western North America, the Southeast and the Great Lakes. They found that dry conditions extended from Mexico and the Southwest to the Rocky Mountains and the Mississippi Valley throughout the last half of the 1500s.
Looking back as far as A.D. 1200, no other drought appears to have been as intense, prolonged and widespread as the 16th century megadrought, the researchers found. Severely dry weather may explain why some native populations in Mexico and the Southwest abandoned their pueblos between 1540 and 1598, the researchers contend.
The drought was not a consequence of global warming, said David Stahle, professor of geosciences at the University of Arkansas. He and the other researchers suggest long-term patterns in ocean currents may have played a role.
“If such a drought were to occur today, it would wipe out certain agricultural activities,” Stahle said. “It would change economic activities on the land. And it would put enormous stress on water resources.”