Scientists with the National Oceanic and Atmospheric Administration (NOAA) and independent researchers are reporting that not only is the drought in the southwestern U.S. the worst on record but its severity is connected to climate change.
In a comprehensive report published this week, the researchers detailed the widespread drought that emerged in early 2020 in the U.S. Southwest, which for this report included the four corners states (Arizona, Utah, Colorado, and New Mexico), and Nevada, and California.
Over a period of 20 months, from January 2020 through August 2021, the Southwest U.S. received the lowest total precipitation and had the third-highest daily average temperatures since 1895. This drought has been so severe, it has led to unprecedented water shortages in western reservoirs.
Over 94 percent of the west is in drought conditions this week, while the six states listed in the report are entirely in drought conditions, according to the US Drought Monitor. Two of the country’s largest reservoirs, Lake Mead and Lake Powell on the Colorado River, are draining at alarming rates, threatening the West’s water supply and hydropower generation in coming years.
Not only has the drought impacted Lake Mead and Lake Powell, but countless smaller reservoirs across the west are impacted, leading to unprecedented water shortages that threaten drinking, agricultural, and tribal water supplies; electricity supply generated from hydroelectric plants; and fishing and recreational activities.
La Nina expected to make an appearance
To make matters worse, David DeWitt, director at NOAA’s Climate Prediction Center, says the unrelenting drought there is about to get worse with La Niña on the horizon.
“As we move into fall, from October on, the Southwest US, based on all the best information that we have, they’re going to see persistent intensification and development of drought,” DeWitt told CNN. “There’s, at this point, not any indication that they’ll see drought relief.”
La Niña is a natural phenomenon marked by cooler-than-average sea surface temperatures across the central and eastern Pacific Ocean near the equator, which causes shifts in weather across the globe.
In the Southwest, La Niña typically causes the jet stream — those upper-level winds that carry storms around the globe — to shift northward. That means less rainfall for a region that desperately needs it.
According to WLFI.com, NOAA is predicting a 70 to 80 percent chance of La Nina conditions emerging during the Northern Hemisphere winter season. With La Niña conditions coupled with warming temperatures, the Southwest will see enhanced evaporation that will intensify drought in certain places.
La Nina won’t help the western wildfires. The 2020 and 2021 wildfire seasons have been fueled by the lack of precipitation and surface moisture associated with the drought. Immediate economic losses are in the billions of dollars, with the actual total liability not known until the event ends. The losses will likely be in the tens of billions of dollars based on the costs of similar significant droughts in the past.
Looking into the immediate future
According to Justin Mankin, assistant professor of geography at Dartmouth College and co-lead of NOAA’s Drought Task Force, the longer-term fate of the Western drought remains bleak. What’s needed now, he said, is several years of rain and mountain snow to replenish the draining reservoirs and rivers.
That becomes more unlikely as the climate crisis worsens. Experts say the West will only continue to see more droughts like the present one in the years to come – and they warn that only rapid, immediate cuts to fossil fuels can halt this harsh trend.
“Global warming is making the atmosphere over the West warmer and thirstier, such that even the rain and snow that was once normal may be too little to quench it,” Mankin said. “The only way to stop the kind of atmospheric demand increases that have made this drought so impactful is to stop combusting fossil fuels.”