A new U.S. Forest Service report predicts that most of the Southwest, parts of California and the southern and central Great Plains will be the most vulnerable areas in the nation to water shortages during the next 60 years.
Climate change will substantially increase water demand and cause decreases in water supply in those regions of the United States, even as cities, farms and thermoelectric facilities become more efficient in their water usage.
Scientists from the U.S. Forest Service Rocky Mountain Research Station, Colorado State University and Princeton University used global climate modelsalong with socio-economic scenarios to determine future water supply and demand, and the likelihood of future water shortages.
The research team, led by Tom Brown, Research Economist at the Rocky Mountain Research Station, and Jorge A. Ramirez of Colorado State University, attempted to show where and to what extent water shortages would occur if populations grew and climates changed—but water-allocation rules, infrastructure, laws and use trends remained as they are currently. The report shows where adaptation measures will be most needed.
Brown stated that “we were surprised to find that climate change is likely to have a much greater effect on future water demands than population growth. The combined effects of climate change on water supply and demand could lead to serious water shortages in some regions.”
The report, “Vulnerability of U.S. Water Supply to Shortage: A Technical Document Supporting the Forest Service 2010 RPA Assessment,” affirmed that of 98 river basin assessments across the U.S., the arid and semi-arid regions of the nation are the most vulnerable areas to future water shortages. Although the detailed results differ depending on which scenario is simulated and which climate model is used, the general finding of increasing and substantial vulnerability in the Southwest holds true in all cases.
To download or read the report online, go to: www.treesearch.fs.fed.us/pubs/42363.