Working to keep the West special

Climate Disruption in the West: More Heat

More heat is not just a projection, it is a fact. The Intergovernmental Panel on Climate Change reported in 2007, "Warming of the climate system is unequivocal," and that most of the warming since the middle of the 20th century very likely is caused by manmade pollution. Without the effect of heat-trapping gases, natural factors would have led to the planet getting cooler in the last several decades.


  The American West has warmed more than the most of the rest of the United States outside of Alaska. The greatest western warming has been in the Colorado River basin, where it affects the snow-fed river that is the most important water source of the interior West.

Temperatures in 2001-2010, Compared to 1895-2000:
More Heat in the West, Most in the Colorado River Basin

Temperature changes from the National Climatic Data Center (NCDC), National Oceanic and Atmospheric Administration, from its newly revised climate division dataset, adjusted to remove effects of various distortions such as changes in the time of day in which temperatures have been recorded. Data are preliminary; this otherwise unpublished image was provided to RMCO by NCDC. Other NCDC data show that areas shown above where temperatures have not increased are mostly areas where heavy precipitation has markedly increased; when days with heavy storms (and their cooling effect) are removed from the dataset, the remaining days show temperature increases similar to the rest of the country. For more on increases in heavy storms, see the RMCO report Doubled Trouble: More Midwestern Extreme Storms. Conversely, most areas that have become drier have also become particularly hotter.