Study: Increase in Carbon Emissions Boosts Risk of Megadroughts

Posted on February 14, 2015

A NASA study has found that an increase in carbon emissions could significantly increase the risk of megadroughts in the U.S. These terrible droughts could be similar to the Dust Bowl but last three or four times as long.

The researchers predict that by the end of this century the American Southwest and Great Plains are likely to experience longer and more severe droughts that any in the past 1,000 years. The researchers say the current likelihood of a megadrought is 12%. If greenhouse gases stop by the mid-21st century the chance of a megadrought is 60% according to the researchers. If greenhouse gases continue to rise along current trajectories then the risk of a megadrought rises to 80%.

Ben Cook, a climate scientist at NASA's Goddard Institute for Space Studies nad lead author of the study, says in a statement, "Natural droughts like the 1930s Dust Bowl and the current drought in the Southwest have historically lasted maybe a decade or a little less. What these results are saying is we're going to get a drought similar to those events, but it is probably going to last at least 30 to 35 years."

The scientists analyzed 1,000 years of tree ring data and compared the records to soil moisture data from 17 climate models. The researchers say the computer simulations all show a drier world. The above image shows soil moisture 30 cm below ground for the year 2095 if emissions are kept high. The image below shows the soil moisture for 2095 with more moderate emissions.

NASA Goddard released the following video explaining the findings. Take a look:

The study was reported here in the journal, Science Advances.

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