NEW YORK, March 11 (UPI) -- Coming decades could see delays in summer monsoon rains in the U.S. Southwest and northwestern Mexico that water crops for 20 million people, researchers say.
The North American monsoon delivers as much as 70 percent of the region's annual rainfall, but much of the arid southwestern United States is expected to get even drier as winter precipitation declines under climate change, scientists as Columbia University report.