New research indicates that climate change is giving a boost to the odds of long-term drought across the Southwest.
The research, published in the Journal of Climate, puts the chances of a megadrought lasting 35 years or longer at up to 50 percent in the region. It would be a drought of epic proportions that would wreak havoc on the region’s already tenuous water supply for its growing population.
>“It’s been recognized for awhile now that during climate change, because of rising temperatures, a lot of the Southwest dries out, gets less average precipitation,” said Toby Ault, the study’s lead author and Cornell-based climate researcher. “The novelty of this research was to just try and use those predictions of the future to estimate the risk of prolonged drought, to translate what those predictions of long term drying meant for megadrought.”
If greenhouse gas emissions continue to rise, the odds of a megadrought hitting some parts of the Southwest is a 50-50 proposition. And the odds of a decade-long drought – like the Dust Bowl of the 1930s or Southwest drought of the 1950s – are around 90 percent.
There’s also a 5-10 percent chance that parts of the region could see a state of “permanent” megadrought lasting 50 years or longer.
>“Even without climate change, there would be some risk of megadrought even if we weren’t warming up the planet. But because of climate change and drying predicted from climate change, that weights the dice toward making these things more likely,” Ault said.
Jason Smerdon, a scientist at Lamont-Doherty Earth Observatory also not affiliated with the study, agreed.
>“Such hybridizations of model and observational evidence can thus improve future risk assessments, and in this case, the authors estimate that drought projections informed by paleoclimatic and observational evidence significantly increase the estimated risks of prolonged droughts in the future,” Smerdon said.
>“This (current drought) is kind of worse than the things we looked at in terms of intensity, but it’s not nearly as long as multidecadal or megadrought. I think it’s an important window into what we expect from climate change. What’s happening now, whether or not its driven by global warming, is a glimpse of the shape of things to come,” Ault said
> “I do feel a sense of optimism in the sense that this is a natural hazard in the Southwest – and it appears to be a very important one under climate change – but because we know this and because we’re a very adaptive and sophisticated species, I’m confident we can find ways of managing that risk and even thriving,” he said.