Global warming felt more in Western U.S.

The American West is heating up faster than any other region of the United States, and faster than the Earth as a whole, according to a new analysis of 50 scientific studies.

For the last five years, from 2003 through 2007, the global climate averaged 1 degree Fahrenheit warmer than its 20th century average. During the same period, 11 Western states averaged 1.7 degrees warmer – 70% more than the world as a whole, the analysis reported.

The 54-page study, was released today by the Rocky Mountain Climate Organization – a coalition of local governments, businesses and nonprofits – and the Natural Resources Defense Council.

The report reveals “the growing consensus among scientists who study the West that climate change is no longer an abstraction,” according to Brad Udall, director of Western Water Assessment at the University of Colorado. “The signs are everywhere.”

In fact, Udall noted, data suggest that as time goes on, the West will warm about 1 1/2 times faster than the global average. That is because large, arid areas away from slow-warming oceans will heat up more than other areas.

The Colorado River basin, which spans the Western region from Wyoming to Mexico, is in the throes of drought, and climate scientists predict that the additional warming will accelerate the melting of snowpacks that feed the river, causing worse droughts in the future.

About 30 million people in fast-growing cities such as Los Angeles, San Diego, Phoenix and Las Vegas depend on water from the Colorado and its tributaries.

The federal Environmental Protection Agency is under court orders to address global warming, and Congress is considering legislation to curb greenhouse gases, which scientists say are largely responsible for the heating of the planet. Utilities that operate coal-fired power plants and other industries are battling the legislation, which is expected to be debated in the Senate this spring.

Meanwhile, California is drafting rules to slash its greenhouse gas emissions by 80% by midcentury, and six other Western states – Arizona, Montana, New Mexico, Oregon, Utah and Washington – have joined it in a regional compact to curb global warming pollution.

margot.roosevelt@latimes.com