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."
The team says the drying would surpass in severity any of the decades-long megadroughts that occurred much earlier during the past millennium – one of which has been tied by some scientists to the decline of the Anasazi or Ancient Pueblo Peoples in the 13th century.
Many studies have already predicted that the Southwest could dry due to global warming, but this one, based on projections from several climate models, is the first to say that such drying could exceed the worst conditions of the distant past.
“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,” said study lead author Dr Benjamin Cook of the NASA Goddard Institute for Space Studies and the Lamont-Doherty Earth Observatory.
As bad as recent droughts in California, the Southwest and the Midwest have been, scientists say far worse "megadroughts" are coming — and they're bound to last for decades.
"Unprecedented drought conditions" — the worst in more than 1,000 years — are likely to come to the Southwest and Central Plains after 2050 and stick around because of global warming, according to a new study in the journal Science Advances on Thursday.
"Nearly every year is going to be dry toward the end of the 21st century compared to what we think of as normal conditions now," said study lead author Benjamin Cook, a NASA atmospheric scientist. "We're going to have to think about a much drier future in western North America."
There's more than an 80 percent chance that much of the central and western United States will have a 35-year-or-longer "megadrought" later this century, said study co-author Toby Ault of Cornell University, adding that "water in the Southwest is going to become more precious than it already is."
Megadroughts last for decades instead of just a few years. The 1930s Dust Bowl went on for more than 35 years, Ault said.