Three new studies show that the West is running low on water, and that much of that decline is a result of climate change, says High Country News.
According to a study in the journal Water Resources Research, the average annual Colorado River flow was nearly 20 percent lower between 2000 and 2014 than the average for most of the previous century. Warmer temperatures—not just less rain and snow—are responsible for about a third of that drop, said the study. Farmers and ranchers, as well as city dwellers, rely on the river, which supplies 40 million people in the United States and Mexico. But current allocations don’t reflect today’s drought conditions or climate change’s future impact on the river.
In a report published in Nature Communications, researchers found that the average western snowpack level fell 10 to 20 percent between the 1980s and the 2000s due to climate change. It’s thought that figure could reach 60 percent in the next 30 years—a jarring prediction given that snow “provides about two-thirds of the region’s water,” says High Country News.
Finally, a study in Nature Geoscience discovered that “aquifer levels declined in about half of the deep groundwater wells monitored nationwide between 1940 and 2015,” says High Country News. While about 20 percent of wells saw some recovery, that could be due to the fact that monitoring occurred only during especially wet years and didn’t indicate an overall positive trend.