Imagine the Dust Bowl of the 1930s. Now make it 20 years longer. That’s the claim from one group of researchers who say the Southwest and Great Plains are at risk of 21st century ‘megadroughts.’
The study was published yesterday in the journal Science Advances. It’s based on projections from several climate models, including one with the backing of NASA. According to the research, increases in human-produced greenhouse gas emissions lead to a jump in risk of severe droughts in southern and western parts of the U.S.
“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.
“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,” Cook added.
Ben Cook was also the lead author of the study.
How at risk is the U.S. for one of these ‘megadroughts?’
Right now, Cook puts the likelihood of a megadrought at 12%. If nothing changes (emission levels stay the same), this risk rises to more than 60%. If greenhouse gas emissions increase along current projections throughout this century, the risk of a megadrought in the Southwest and Central Plains between 2050 and 2099 hits 80%.
Where Did These Numbers Come From?
Researchers compared a thousand years of tree ring data to soil moisture data from 17 different climate models. Then a model was created to determine the soil moisture levels into the future.
The model shows the ground gets drier as temperatures increase. The video below illustrates the researchers’ point. Fast-forward about a minute in to see the model data.
Kevin Anchukaitis, a climate scientist at the Woods Hole Oceanographic Institution who wasn’t involved with the study, talked about the consistency shown in the study.
“What I think really stands out in the paper is the consistency between different metrics of soil moisture and the findings across all the different climate models,” said Anchukaitis.
He added, “It is rare to see all signs pointing so unwaveringly toward the same result, in this case a highly elevated risk of future megadroughts in the United States.”