Climate change may increase risk of water shortages in hundreds of US counties by 2050

February 15, 2012
Climate change may increase risk of water shortages in hundreds of US counties by 2050

More than 1 in 3 counties in the United States could face a "high" or "extreme" risk of water shortages due to climate change by the middle of the 21st century, according to a new study in ACS's Journal of Environmental Science & Technology. The new report concluded that 7 in 10 of the more than 3,100 U.S. counties could face "some" risk of shortages of fresh water for drinking, farming and other uses. It includes maps that identify the counties at risk of shortages.

In the analysis, Sujoy B. Roy, Ph.D., and colleagues explain that population growth is expected to increase the demand for water for municipal use and for electricity generation beyond existing levels. Global threatens to reduce water supplies due to decreased rainfall and other factors compared to levels in the 20th century. Roy's group developed a "water supply sustainability risk index" that takes into account water withdrawal, projected growth, susceptibility to drought, projected climate change and other factors in individual U.S. counties for the year 2050. It takes into account renewable water supply through precipitation using the most recent downscaled climate change projections and estimates future withdrawals for various human uses.

Roy's team used the index to conclude that climate change could foster an "extreme" risk of water shortages that may develop in 412 counties in southern and southwestern states and in southern Great Plains states. "This is not intended as a prediction that will occur, but rather where they are more likely to occur, and where there might be greater pressure on public officials and water users to better characterize, and creatively manage demand and supply," Roy said.

Explore further: Study: Human activity produces drought

More information: Projecting Water Withdrawal and Supply for Future Decades in the U.S. under Climate Change Scenarios, Environ. Sci. Technol., Article ASAP. DOI: 10.1021/es2030774

The sustainability of water resources in future decades is likely to be affected by increases in water demand due to population growth, increases in power generation, and climate change. This study presents water withdrawal projections in the United States (U.S.) in 2050 as a result of projected population increases and power generation at the county level as well as the availability of local renewable water supplies. The growth scenario assumes the per capita water use rate for municipal withdrawals to remain at 2005 levels and the water use rates for new thermoelectric plants at levels in modern closed-loop cooling systems. In projecting renewable water supply in future years, median projected monthly precipitation and temperature by sixteen climate models were used to derive available precipitation in 2050 (averaged over 2040–2059). Withdrawals and available precipitation were compared to identify regions that use a large fraction of their renewable local water supply. A water supply sustainability risk index that takes into account additional attributes such as susceptibility to drought, growth in water withdrawal, increased need for storage, and groundwater use was developed to evaluate areas at greater risk. Based on the ranking by the index, high risk areas can be assessed in more mechanistic detail in future work.

Related Stories

New model to assess urban water security

December 2, 2010

University of Adelaide water engineering researchers have developed a model to estimate potential urban water supply shortfalls under a range of climate change scenarios.

Australia needs better plan for variable water future

September 29, 2010

The delivery of sustainable water supplies in Australia will require water managers and engineers to factor in a range of predicted variations in climate and long-term demand for water resources, according to a CSIRO climate ...

A positive step in the face of uncertainty

December 14, 2010

Enormous uncertainty. These two words describe the condition of Phoenix's climate and water supply in the 21st century. Reservoirs have dipped to their lowest levels, continuous drought has plagued the state and forecasts ...

Recommended for you

East Antarctic Ice Sheet has history of instability

December 13, 2017

The East Antarctic Ice Sheet locks away enough water to raise sea level an estimated 53 meters (174 feet), more than any other ice sheet on the planet. It's also thought to be among the most stable, not gaining or losing ...


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.