Snow cover in the Sierra Nevada mountain range, a water lifeline for California’s cities and agriculture, has hit its lowest level in 500 years, a study said Monday. Measured on April 1, the natural, frozen reservoir was barely five percent of the 1950-2000 average, threatening tens of millions of Californians and the state’s $50-billion (44-billion-euro) agriculture sector with chronic water shortages, its authors warned. And things were set to get worse, they wrote in the journal Nature Climate Change.

“We should be prepared for this type of snow drought to occur much more frequently because of rising temperatures,” lead author Valerie Trouet, a professor at the University of Arizona, said in a statement. “Anthropogenic” –- or manmade –- global warming “is making the drought more severe,” she added.The “snowpack” of Sierra Nevada, central California’s 650-kilometre (400-mile) spine, provides more than 60 percent of the state’s distributed water supply, including all or part of the drinking water for 23 million people. FULL REPORT