NASA: Carbon Emissions Could Dramatically Increase Risk of U.S. Megadroughts

NASA scientists used tree rings to understand past droughts and climate models incorporating soil moisture data to estimate future drought risk in the 21st century.

Droughts in the U.S. Southwest and Central Plains during the last half of this century could be drier and longer than drought conditions seen in those regions in the last 1,000 years, according to a new NASA study.

The study, published Thursday in the journal Science Advances, is based on projections from several climate models, including one sponsored by NASA. The research found continued increases in human-produced greenhouse gas emissions drives up the risk of severe droughts in these regions.

"Natural droughts like the 1930s Dust Bowl and the current drought in the Southwest have historically lasted maybe a decade or a little less," said Ben Cook, climate scientist at NASA's Goddard Institute for Space Studies and the Lamont-Doherty Earth Observatory at Columbia University in New York City, and lead author of the study. "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."

According to Cook, the current likelihood of a megadrought, a drought lasting more than three decades, is 12 percent. If greenhouse gas emissions stop increasing in the mid-21st century, Cook and his colleagues project the likelihood of megadrought to reach more than 60 percent.

However, if greenhouse gas emissions continue to increase along current trajectories throughout the 21st century, there is an 80 percent likelihood of a decades-long megadrought in the Southwest and Central Plains between the years 2050 and 2099.

(The article is here.)