Parched California: Severe water shortages loom

Over 1,100 U.S. counties— more than one-third of all counties in the lower 48 states — now face higher risks of water shortages by mid-century as the result of global warming and more than 400 of these counties – many within the Central Valley -- will be at extremely high risk for water shortages, based on estimates from a new report by Tetra Tech for the Natural Resources Defense Council.

The report uses publicly available water use data across the United States and climate projections from a set of models used in recent Intergovernmental Panel on Climate Change (IPCC) 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 United States, 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.

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