Clues from another dry spell 6,000 years ago are helping scientists understand what’s driving the latest one, and why it’s been so unrelenting.
A megadrought has sapped water supplies, ravaged farms and ranches, and fueled wildfires across the American Southwest for going on 25 years. Not in 12 centuries has the region been so dry for so long.
Now comes worse news: Relief might still be decades away.
According to new findings published in the journal Nature Geoscience, the dry spell is no mere bout of bad luck, no rough patch that could end anytime soon.
Instead, it seems to be the result of a pattern of Pacific Ocean temperatures that is “stuck” because of global warming, said Victoria Todd, a doctoral student in paleoclimatology at the University of Texas at Austin who led the new research.
That means the drought could continue through 2050, perhaps even 2100 and beyond — effectively, Ms. Todd said, for as long as humans keep heating up the planet.
Even in the arid Southwest, the long, chronic deficit of moisture since the turn of the millennium has exacted a heavy toll. The possibility of more parched decades ahead raises big concerns in a fast-growing region where agriculture and other industries, including computer-chip manufacturing, use lots of water.