A U.S. Geological Survey study finds that snow cover in the Rocky Mountains is down 20 percent since 1980, according to Discovery News. The implications are big, as nearly 70 million Americans are supplied with drinking water from the snow’s melting.
The decline was found to be most extreme in the northern Rockies, though it was also significantly reduced in the lower and middle latitudes. Changes in the timing of the annual melt also threaten electricity production from hydroelectric dams as well as irrigation water supplies.
The researchers say that – regardless of the ultimate cause of the snow cover decline, be it from El Nino effects or climate change – the continuation of present snowpack trends in the Rocky Mountains will pose difficult challenges for water planning in the western United States.
Image: Dust-covered snow in the San Juan Mountains of the Upper Colorado River basin, May 2009. (Credit: NASA/JPL-Snow Optics Laboratory)