Jake Slobe | May 10, 2017
Less than 5 percent of the U.S. was in some stage of drought as of May 4, the most recent update, compared to the 65 percent in drought in September 2012.
The last time drought levels across the country were this low was in July 2010, when 8 percent of the U.S. was in drought after which came a remarkable period of deep, damaging drought that led to billions in crop and livestock losses, spurred major water restrictions, and helped fuel terrible wildfires.
The ups and downs in drought levels could be linked to some of Earth’s natural climate cycles that can usher in relatively wet and dry periods. But climate change is likely to play a role as higher temperatures lead to increased evaporation and therefore worse drought conditions.
The epicenters of drought were in the central and southern Plains states from 2011 to 2013 and in California from 2012 to this winter. At the peak of its drought, more than half of California was experiencing “exceptional” drought conditions, the highest category of drought. At the end of September 2011, more than 85 percent of Texas was in this category as well.
Both droughts were fueled by a combination of dry weather and repeated, sizzling heat waves. The exceptional heat that blanketed much of the central and eastern portions of the country in 2012 boosted it to the hottest year on record for the U.S., while California experienced back-to-back record-hot years during its drought.
That heat is the clearest link between climate change and droughts, as rising global temperatures fueled by increasing concentrations of greenhouse gasses in the atmosphere tilt the odds in favor of record heat.
Studies have pointed to the role of climate change-fueled heat in California’s drought, and droughts in the future, no matter where they happen in the U.S., are likely to be more intense than those of today because temperatures will be higher on average.