Much of the U.S. West's water supply is under threat as rapidly warming temperatures melt more snowpack annually than is created by precipitation, a new government study suggests.
Each spring, melted snow and ice from the Rocky Mountains recharge up to 80 percent of the Columbia, Missouri, and Colorado River Basins. Together, these basins form the primary water source for nearly 70 million people in an area plagued by droughts—ncluding Denver, Las Vegas, Los Angeles, and Salt Lake City.
The new study, by the U.S. Geological Survey (USGS), appears to confirm a key source of the droughts: Snowpack has been disappearing over the past several decades. What's more, 60 percent of the decline is due to greenhouse gas-induced warming, the researchers conclude.
