Climate change threatens water shortage

More than 1,100 U.S. counties face higher risks of water shortage by 2050 as a result of global warming. A new report, “Climate Change, Water, and Risk: Current Water Demands Are Not Sustainable”, by Tetra Tech for the National Resources Defense Council, claims one-third of all counties in the lower 48 states will face higher risks of water shortages. More than 400 of these counties will be extremely high risk.

The report uses publicly available water-use data across the U.S. and climate projections from a set of models used in recent Intergovernmental Panel on Climate Change work to evaluate withdrawals related to renewable water supply. The report finds that 14 states face an extreme or high risk to water sustainability, or are likely to see limitations on water availability as demand exceeds supply by 2050. These areas include parts of Arizona, Arkansas, California, Colorado, Florida, Idaho, Kansas, Mississippi, Montana, Nebraska, Nevada, New Mexico, Oklahoma and Texas. In particular, in the Great Plains and Southwest U.S., water sustainability is at extreme risk. The more than 400 counties identified as being at greatest risk in the report reflects a 14-times increase from previous estimates.

Water withdrawal is estimated to grow by 25% in many areas of the U.S. including the Arizona/New Mexico area, the South Atlantic region, Florida, the Mississippi River basin, and Washington, D.C. and surrounding regions.

The report said estimated water withdrawal as a percentage of available precipitation is generally less than 5% for the majority of the Eastern U.S., and less than 30% for the majority of the Western U.S. But in some arid regions (such as Texas, the Southwest and California) and agricultural areas, water withdrawal is greater than 100% of the available precipitation so that water is already used in quantities that exceed supply. 

 

Pictured: A new report released by the National Resources Defense Council indicates more than 1,100 U.S. counties face higher risks of water shortage by 2050 as a result of global warming.