Scientists Say U.S. Needs Plan to Deal With Climate Change-induced Summer Droughts in Western States

The western United States has experienced increasing drought conditions in recent years -- and conditions may worsen if global climate change models are accurate -- yet little has been done to prepare for potential catastrophe, according to a group of scientists.

The United States should consider a national drought policy to help achieve sustainable water for drinking, agriculture and fisheries, said the scientists at the annual meeting of the American Association for the Advancement of Science (AAAS), which was held on Feb. 15-19.

The researchers also pointed out the need to manage water supplies to protect environmental values and to protect urban property from sea level rise and extreme weather events.

Though many climate change models predict warmer and wetter weather for parts of the Earth, the potential for drought in regions like the southwestern United States is actually greater, said Jim Coakley, a professor of atmospheric sciences at Oregon State University and a co-organizer of the AAAS symposium.

Most western rivers and streams are more dependent on snowmelt for sustained flows than regular rainfall. Declining snow packs have already become an issue throughout much of the West, Coakley stated.

"We're already seeing snow packs dwindle and spring runoffs coming earlier and earlier," Coakley said. "The dry summers that we've experienced recently may pale in comparison to what could happen in the near future. There is a kind of domino effect as temperatures warm. Precipitation that would have fallen as snow will come as rain and run off more quickly. Spring runoffs begin earlier. Summers lengthen and evaporation increases."

During the last three decades, temperatures have risen 1 degrees to 2 degrees Fahrenheit, and many scientists believe the pace of that warming is accelerating. Drought is a reality facing many western states, yet the governmental and societal response is through ad hoc crisis management, said Shaun McGrath of the Western Governors' Association.

"Providing adequate supplies of clean water is a challenge when there is normal precipitation," McGrath said, "and extended times of drought and water shortages create further stresses for our water systems. Yet in marked contrast to the myriad federal programs that report, prevent and mitigate the damage of other extreme events -- like floods, hurricanes and tornadoes -- we accept drought's effects as an unavoidable natural hardship."

One purpose of the AAAS symposium was to draw attention to the increases in water stress associated with climate change in the western United States and what needs to be done about it, Coakley said.

"To achieve sustainable water supplies, we'll need a combination of sound science, new technologies, creative management and a coherent policy that weaves all the elements together," Coakley said. "And it won't come without a price -- both economic and social. But given our future, it is a must."

Jim Coakley: http://stratus.oce.orst.edu/coakley

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