Climate change could have dramatic effect on US Southwest's water supply by end-century
Over the past few years, communities in Arizona, New Mexico and California have increasingly felt the devastating effect of drought and, according to a report by a team of scientists at the University of Arizona, the worst is yet to come.
In the past few decades the average temperature in the region has risen by two degrees Fahrenheit, said Gregg Garfin, a geoscientist at the university and lead author of the latest National Climate Assessment released on May 6. Based on current projections for greenhouse gas emissions, temperatures in the Southwest are predicted to continue rising, with an increase of up to 9.5 degrees by the end of the century. Estimates show that if emissions were cut dramatically now, the projected increase in temperatures could reach 4.5 degrees by 2050 and 5.5 degrees by 2100.
These figures raise further concerns regarding water, particularly in Arizona. An increase in temperatures would certainly affect the mountain snowpack, which is crucial for maintaining water supply in the Colorado River, the Salt River, Verde River and Little Colorado River. The latest projections forecast a 15-percent decline in the Colorado River flow by mid-century. This is well below estimates for water supply projections published by the U.S. Bureau of Reclamation in its 2011 report, according to AZ Central.