|
Climate Facts Hotter and Drier: The West’s Changed Climate Human activities are already changing the climate of the American West. A new report by the Rocky Mountain Climate Organization (RMCO) and the Natural Resources Defense Council (NRDC), drawn from 50 scientific studies, 125 other government and scientific sources, and our own new analyses, documents that the West is being affected more by a changed climate than any other part of the United States outside of Alaska. When compared to the 20th century average, the West has experienced an increase in average temperature during the last five years that is 70 percent greater than the world as a whole. Responding quickly at all levels of government by embracing available solutions is critical to minimizing further disruption of this region’s climate and economy. To read the full report on the impacts of global warming in the West, visit www.nrdc.org/policy. For more information, please contact: Theo Spencer at NRDC (212) 727-2700 Stephen Saunders at RMCO (303) 880-4598 www.nrdc.org/policy March 2008 © Natural Resources Defense Council The West Is Getting Hotter The planetary warming that scientists predict will result from human emissions of heat-trapping gases is already underway. In February 2007, the Intergovernmental Panel on Climate Change (IPCC) declared, “Warming of the climate system is unequivocal,” and it is “very likely” that most of the warming since the middle of the 20th century is the result of human pollutants. The American West has heated up even more than the world as a whole. For the last five years (2003 through 2007), the global climate has averaged 1.0 degree Fahrenheit warmer than its 20th century average. RMCO found that during the 2003 through 2007 period, the 11 western states averaged 1.7 degrees Fahrenheit warmer than the region's 20th century average—which represents 70 percent more warming than for the world as a whole. The West has also experienced more frequent and severe heat waves, with the number of extremely hot days increasing by up to four days per decade since 1950. Planet +1.0°F Western United States +1.7°F Colorado River Basin +2.2°F Arizona +2.2°F California +1.1°F Colorado +1.9°F Idaho +1.8°F Montana +2.1°F Nevada +1.7°F New Mexico +1.3°F Oregon +1.4°F Utah +2.1°F Washington +1.4°F Wyoming +2.0°F More Rapid Warming in the West 2003 to 2007 5-Year Average Temperatures Compared to 20th Century Averages White “bathtub rings” show the pre-drought water level of Lake Powell in Arizona.
|
