Climate change, water shortages conspire to create 21st century Dust Bowl

By SCOTT STREATER, SPECIAL TO E&E, Greenwire Dust storms accelerated by a warming climate have covered the Rocky Mountains with dirt whose heat-trapping properties have caused snowpacks to melt weeks earlier than normal, worrying officials in Colorado about drastic water shortages by late summer. Snowpacks from the San Juan Mountains to the Front Range have either completely melted or will be gone within the next two weeks, said Tom Painter, director of the Snow Optics Laboratory at the University of Utah and a leading expert on snowmelt. The rapid melting is linked to a spate of intense dust storms that kick up dirt and sand that in turn are deposited on snow-topped mountains. The dust darkens the snow, allowing the surface to absorb more heat from the sun. This warms the snow — and the air above it — significantly, studies show. The problem has been particularly acute in the semiarid Colorado Plateau region encompassing parts of Utah, Colorado, New Mexico and Arizona. An unprecedented 12 large dust storms have occurred so far this year in the region, and at least two more are projected in the coming months, officials say. “Already we have more than doubled the amount of dust we’ve typically observed during the last six years,” Painter said. The early snowmelt could spell disaster for thousands of farmers and ranchers in the region who depend on slowly melting snow to provide water flows over the dry summer months, said Scott Brinton, assistant division engineer in the Colorado Division of Water Resources’ Southwest regional office. “Those people who were relying on the mountain snowpack are going to have difficulty later in the year,” Brinton said. …