Southwest United States May Face 'Megadroughts' This Century

Droughts can impact the environment and agricultural industry to a massive extent. Unfortunately, there's some bad news on the horizon for the United States. Researchers have found that the chance of the southwestern U.S. experiencing a decade-long drought is at least 50 percent due to global warming. Not only that, but the chances of a megadrought, one that lasts over 30 years, ranges from 20 to 50 percent over the next century.

Currently, most of California is suffering from an "exceptional drought," which is the most severe category. In addition, Oregon, Arizona, New Mexico, Oklahoma and Texas are all suffering from moderate and exceptional drought. As these droughts continue, it's more important than ever to understand exactly how long they will persist.

"For the southwestern U.S., I'm not optimistic about avoiding real megadroughts," said Toby Ault, lead author of the new paper, in a news release. "As we add greenhouse gases into the atmosphere-and we haven't put the brakes on stopping this-we are weighting the dice for megadrought conditions."

In order to assess drought conditions in the future, the researchers used computer models to assess the southwest region. They found that while California, Arizona and New Mexico will likely face drought, parts of Washington, Montana and Idaho may see a decrease in drought conditions. In addition, the scientists found that beyond the United States, southern Africa, Australia and the Amazon basin are also vulnerable to the possibility of a megadrought.

"With ongoing climate change, this is a glimpse of things to come," said Ault. "It's a preview of our future."

The findings reveal the importance of looking for mitigation strategies in the face of long-drought scenarios. These droughts could pose unprecedented challenges to water resources in the region, which means it's crucial to develop new strategies.

The findings are published in the American Meteorological Society's Journal of Climate.