U.S. Great Plains, Southwest at ‘extreme risk’ of water shortage, report says

More than one-third of all counties in the continental United States face higher risks of water shortages by mid-century, according to a new report.

The reason? Global warming, according to the nonprofit Natural Resources Defense Council.

According to the report (.pdf), 14 states face an “extreme or high risk to water sustainability,” with limitations on use expected as demand exceeds supply by 2050.

Those states:

• Arizona
• Arkansas
• California
• Colorado
• Florida
• Idaho
• Kansas
• Mississippi
• Montana
• Nebraska
• Nevada
• New Mexico
• Oklahoma
• Texas

“The more than 400 counties identified as being at greatest risk in the report reflects a 14-times increase from previous estimates,” the NRDC said in a statement.

The findings — by consulting firm Tetra Tech for the NRDC — come from the combination of publicly available water-use data and climate projections based on models used by the Intergovernmental Panel on Climate Change, or IPCC.

Specifically, researchers looked at water withdrawal data for different sectors of the economy, such as irrigation, cooling for power generation, and municipal supply, as well as estimated future demands using business-as-usual scenarios of growth.

Then they compared the future withdrawals to projected renewable water supply levels for 2050, based on a set of 16 global climate model projections of temperature and precipitation.

The NRDC made its data available and arranged it by state, so you can look up your area. That information can be found on the NRDC’s site and also on Tetra Tech’s site.

But the scope of impact goes beyond your ability to take a shower in the morning. In the 1,100 at-risk counties are crops worth more than $105 billion, posing a threat to the nation’s agricultural economy.

Here’s what NRDC Climate Center director Dan Lashof said, in a statement:

Water shortages can strangle economic development and agricultural production and affected communities. As a result, cities and states will bear real and significant costs if Congress fails to take the steps necessary to slow down and reverse the warming trend.

Water management and climate change adaptation plans will be essential to lessen the impacts, but they cannot be expected to counter the effects of a warming climate.

The only way to truly manage the risks exposed by this report is for Congress to pass meaningful legislation that cuts global warming pollution and allows the U.S. to exercise global leadership on the issue.

According to the report, water withdrawal will grow by 25 percent in many areas of the U.S., including obvious areas such as Arizona and New Mexico, but also the Deep South — Florida, Louisiana, Mississippi, Alabama, etc. — and as far north as the nation’s capital, Washington, D.C.

[via National Geographic]