Warming could spur water crisis

Colorado River water users will experience frequent shortages in the coming years as warmer, drier conditions squeeze an already overburdened resource, scientists said Monday. Even without the effects of climate change, the scientists warned that the river may not produce as much water from mountain snowmelt as it did when the flow was divided among seven states in the early 1900s, some of the wettest years in centuries. The result in either case would be tough choices among water agencies about who gets water and who gives it up. In the new study, researchers found that if climate change reduces runoff into the river by as little as 10 percent, promised water deliveries to users, mostly water providers who then distribute supplies to consumers, could be missed 60 percent of the time by 2050, a failure rate that climbs to 80 percent if runoff falls further. The study was intended to provoke action among the seven states, not simply paint a doom-and-gloom scenario, said Tim Barnett, a marine physicist at the Scripps Institution of Oceanography in San Diego and co-author of the report...Arizona Republic