Snowpack Near Record Lows Spells Trouble for Western Water Supplies
University of Colorado hydrologist Keith Musselman's research in the southern Sierra Nevada shows how sensitive mountain snowpack is to global warming. Analyzing an extensive dataset from the western flank of the Sierra, he found that the snowpack shrinks by 10 percent for every 1 degree Celsius of warming. And winter rain storms will increase as global temperatures rise, melting snow that's already piled up and raising flood risks.
The middle elevations of the mountain range are most sensitive, Musselman found, standing to lose about 40 percent of their snowpack if average global temperatures rises by 2 degrees Celsius in the next few decades, and 50 percent at 3 degrees Celsius warming, a temperature increase that seems increasingly likely by the end of the century unless global greenhouse gas emissions start dropping quickly.