High temperatures are are making drought conditions worse in the American West
During times of drought, it might rain and even pour, but drought could persist and climate change can still create water scarcity. Despite some recent precipitation, higher than average seasonal temperatures in the American West are wiping out the water stored in soil and mountain snowpack due to greater evaporation, prolonging and even worsening drought conditions. Whether it’s in Arizona, California, Utah, Idaho or Montana, drought has socked it to almost all regions of the American West.
As of April 12, 2022, 90 percent of western US land coverage is in moderate drought or worse, according to the US Drought Monitor, holding steady from the previous week. Only the western parts of Oregon, Washington and Montana, and an eastern sliver of Idaho remain drought-free.
As the US Drought Monitor explained in the previous April 5 installment, some precipitation fell, but it wasn’t enough to change the drought status, which remains true today.
Across much of the West, higher than normal temperatures last week caused premature snow melt, with snowpack values plummeting over just a few days. The California Department of Water Resources noted that about one-third of the water equivalency disappeared in a week. Extreme drought (D3) expanded in northern California, parts of Utah, and New Mexico. In these locations, the warm weather has led to increased evaporative demand and stress on vegetation.
In addition, abnormally warm temperatures are a unique and unsettling factor exacerbating the current Western drought. According to NOAA, for the month of March, the average monthly temperature across the United States’ lower 48 was 44.1 degrees F (2.6 degrees above the 20th-century average), making it the warmest one-third of years of the 128-year climate record. The March temperatures were particularly warm around the West.
These “hot droughts” have severe consequences for places like California and the Colorado River Basin that rely on runoff from mountain snowpack for water supplies. In the Golden State’s Sierra Nevada mountains, for instance, snowpack is abysmal from dry weather, but also from warming and thus greater evaporation of the snow (called sublimation). Similar problems occur when hotter temperatures increase evaporation of reservoirs, soils and vegetation, leaving less water in the system and altering the water cycle as compared to what was once expected for a given region. Lower water levels can prove harmful on many levels, including decreased hydropower generation, reduced water deliveries for farmers, and ecological collapse, as is the case with threatened salmon in California-Oregon’s Klamath Basin.
Last week UCLA climate scientist, Daniel Swain, described the worrisome outlook for California’s snowpack—and thus its negative impact on water supplies—because record heat was causing the snowpack to disappear much more quickly than is typical.
Even though the West appears to be drying out, in part due to hotter than average temperatures, there are many untapped opportunities to decrease water use. In addition to enhanced real-time water data and science, many other actions can be taken, such as improved crop productivity, removal of ornamental turf grass, water leak fixes, as Pacific Institute recently outlined. There are smart and effective ways to build resilience into the changing water situation for the American West, but it requires attention and action by public officials and leaders of agriculture, industry, the power sector, utilities and more to find solutions towards a common goal of sustainable water use. People must also learn to change their mindset and the behavior in response to conditions on the ground. Taking personal action through water-saving measures that cut water use—both direct use and virtual water use—not only cumulatively add up, but can also help drive larger-scale political and systems change.
By Kai Olson-Sawyer