What Will A Global Warming ‘Megadrought’ Mean For America’s Future?

Global Warming May Cause More Droughts

NASA scientists released a report saying the U.S. is likely in for a “megadrought” thanks to global warming. One American state, California, is already struggling with the worst drought in 1,200 years, which gives us a view of how a sustained drought could cost and affect the larger Southwest.

Americans are no stranger to drought. The Dustbowl and its iconic, desolate imagery defined a generation of Midwestern farmers struggling to survive. NASA scientists believe that droughts will become far more likely as global warming worsens. The only difference is the Dustbowls of the future will last over 30 years, instead of less than a decade.

Ben Cook, NASA climate scientist, says the probability of a megadrought — a drought lasting over 30 years — happening right now is 12 percent. If gas emissions completely stop by about 2050, the chances will still increase to about 60 percent by the end of the century. If emissions and global warming continue on the current trajectory, there will be an 80 percent chance of a megadrought.

With the world’s biggest CO2 producer, China, still intent on increasing emissions through to 2030, the 80 percent figure seems more probable.

NASA found the last megadrought event occurred in medieval times, between 1100 C.E and 1300 C.E., long before man-made global warming.

“Those droughts had profound ramifications for societies living in North America at the time. These findings require us to think about how we would adapt if even more severe droughts lasting over a decade were to occur in our future,” according to climate scientist Kevin Anchukaitis.

For California, the severe drought conditions are not an academic global warming study or archaeological topic, they’re a reality. The drought in 2014 was the worst in 1,200 years according to NBC News. Although the NOAA says California’s drought is from natural conditions and not global warming, the state is planning long-term water use strategies. State agencies are required to cut usage 20 percent by 2020, eventually stopping growth of per capita water usage, setting it at the same level as in the year 2000 according to the Sacramento Bee.

The goal is ambitious. With the stress of a growing population and worsening global warming, the innovations and policies coming out of the state might be the future for the entire American Southwest.

Elmer Avenue, a working-class neighborhood in Los Angeles, is the front line. The city spent millions to turn the street into a mini “sponge-city,” complete with permeable driveways, drought-tolerant landscaping, and “bioswales.” Bioswales are gullies filled with resilient plant species that funnel water into underground cisterns during rare rainstorms.

The problem with Elmer Avenue is that it’s expensive — costing $2.7 million for just a small neighborhood. According to one resident, it does not seem realistic for the entire city.

“I’d like all the blocks to look like this. I can’t imagine they would spend this kind of money for the whole city.”

If NASA’s global warming study is accurate, Los Angeles and other Southwest communities might have to dedicate large sums to make use out of every drop of rain.

[Image Credit: Getty Images]