Washington State Governor Jay Inslee expanded the state's drought emergency declaration on Monday. It now covers nearly half of Washington as the state's water supply diminishes, and warming weather is expected to continue throughout the summer. Areas in the Southeast United States, including parts of Georgia and South Carolina, are also experiencing abnormally dry weather this spring.
Meanwhile, earlier this year, California officials declared the state to be drought-free after more than seven years. And this week, California is expected to get 150 to 200 percent of its normal monthly rainfall through May 22nd, according to CNN. The Midwest has also experienced extreme weather this spring: Major flooding has claimed lives, closed roads, and devastated infrastructure.
To find out if these conditions are normal (or possibly, the new normal), Pacific Standard spoke to Benjamin Cook, an adjunct research scientist at the Earth Institute's Lamont-Dougherty Earth Observatory and a research physical scientist at the NASA Goddard Institute for Space Studies in New York, where he researches drought.
Are These Droughts Caused by Climate Change?
Washington's drought emergency has occurred amid a pattern of record-setting temperatures in recent years (the five hottest years on record have occurred since 2014). And Washington isn't alone: California, Arizona, New Mexico, and Texas have all experienced severe droughts in recent years.
Increased warming as a result of climate change is only partially to blame, Cook says. "In a lot of places, we are starting to see a kind of fingerprint of climate change on recent drought events, where climate change appears to be intensifying and making many of these events worse than they normally would be in places like the [American] West," he says.
For example, climate change and global warming reduce snowpack and lead to earlier snowmelt, and rising temperatures also increase evaporation—all of which depletes water resources.
Drought will be a problem in the West either way, Cook says, because aridity is just part of the region's natural climate system. But while climate change didn't cause the droughts, it may have worsened them.
Should the Pacific Northwest Expect More Droughts?
Yes, Cook says: In the Pacific Northwest, the climate change projections indicate overall drier conditions. Again, this is related to warming, evaporation, and snowpack, as well as reductions in rainfall.
Think back to the 2015 drought in the Pacific Northwest, Cook advises: Precipitation was rain rather than snow, and the summer heat dried everything out. This is what the region might look like at the end of the 21st century if warming continues, he says.
What About Areas With Record Rainfall (and Flooding)?
While Washington struggles with drought, in California and elsewhere, it has been a very wet spring (and, in some places, a record-setting spring).
This is to be expected. "Sometimes you just get wet years, even in a world that might be drying up because of climate change," Cook says. "That's just because of the normal variability of the climate system."
Normal winter storms that usually hit the Pacific Northwest have been coming in further South this year, although it's hard to explain exactly why, Cook explains. The severity and location of these storms could be caused in part by the very weak El Niño event that's happening right now, he says.
Is Climate Change Still Playing a Role?
Yes, but a subtle one. What we're seeing right now is both extreme and exceptional, according to Cook, but "it's not outside of our expectations for what the natural climate system can do."