Climate change is slowly drying up the Colorado River
Climate change is threatening to dry up the Colorado River — jeopardizing a water supply that serves some 40 million people from Denver to Phoenix to Las Vegas and irrigates farmlands across the U.S. Southwest. Computer simulations of the Colorado River Basin indicate that, on average, a regional temperature increase of 1.4 degrees Celsius over the last century reduced the annual amount of water flowing through the river by more than 11 percent. Researchers from the U.S. Geological Survey in Princeton, N.J., report these results online February 20 in Science. These findings “should be a cause for serious concern,” says climate scientist Brad Udall of Colorado State University in Fort Collins. As the world continues to warm, significant changes to the Colorado River’s flow — like other snow-fed waterways around the globe — could leave many communities with severe water shortages (SN: 5/29/19). For the study, research hydrologist Paul “Chris” Milly and physical scientist Krista Dunne simulated snow accumulation and water runoff in the Colorado...