Western states fighting for each other’s water may be missing the big picture. As climate change continues, many regions of the U.S. will get hotter and drier, so much so that some of the nation’s most important reservoirs could dry up, according to a new study by researchers at Colorado State University, Princeton, and the U.S. Forest Service. From the study:

Although precipitation is projected to increase in much of the United States with future climate change, in most locations that additional precipitation will merely accommodate rising evapotranspiration demand in response to temperature increases. Where the effect of rising evapotranspiration exceeds the effect of increasing precipitation, and where precipitation actually declines, as is likely in parts of the Southwest, water yields are projected to decline. For the United States as a whole, the declines are substantial, exceeding 30% of current levels by 2080 for some scenarios examined.

The study includes a number of maps showing how water might dry up under different scenarios. Here are ones showing projected changes in water yields in 2020, 2040, 2060, and 2080 under a somewhat middle-of-the-road scenario:

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More dramatic scenarios see reservoirs such as Lake Mead and Lake Powell drying up completely.

Think Progress points out that this is consistent with earlier research into coming water troubles. By 2050, one-third of U.S. counties may be at “high or extreme risk” of water shortages thanks to climate change.

“We were surprised to find that climate change is likely to have a much greater effect on future water demands than population growth,” Forest Service research economist Tom Brown told the Summit County Citizens Voice. “The combined effects of climate change on water supply and demand could lead to serious water shortages in some regions.”

You hear that, future dust-bowl states? Y’all might consider teaming up against climate change instead of fighting amongst yourselves for the last scraps here.