Scientists are predicting a devastating megadrought to hit the southwestern US states, which will be far worse than the 20th century Dust Bowl and last for decades. The previously rare phenomenon is certain to become business as usual if we fail to correct the trajectory of climate change.
A study published in Science Advances documents the findings of researchers from Cornell University, the Lamont-Doherty Earth Observatory of Columbia University and the NASA Goddard Institute for Space Studies. What they found is nothing short of terrifying. If we can somehow stay within the 2 degrees Celsius threshold outlined in the Paris climate agreement, the chance of a megadrought ranges from 30 to 60 percent. At 4 degrees of warming – where we are headed now – megadroughts are practically a certainty.
“Historically, megadroughts were extremely rare phenomena occurring only once or twice per millennium,” according to the study. “A megadrought occurring again in the Southwest in the coming decades would impose unprecedented stresses on water resources of the region, and recent studies have shown that they are far more likely to occur this century because of climate change compared to past centuries.”
California alone is entering its sixth consecutive year of drought conditions. The 4 degree scenario highlighted in the study shows the entire state, save for an itty bitty portion of the southeastern corner, will face a 90-100 percent chance of megadrought. This is mostly due to the reliance on the Colorado River and its tributaries for water. Given that the US isn’t even close to its emissions reduction goals outlined at COP21, the country needs to make drastic cuts in greenhouse gas emissions and improve water efficiency to slow down this life-destroying process.