American West 'looking down the barrel of a loaded gun' from climate change-driven droughts: scientist

The historic drought plaguing California and other Western states is showing no signs of letting up. Record high temperatures and erratic precipitation patterns have put millions of Americans at risk of running out of fresh water, and the longer that elected leaders stall on curbing the nation's dependence on fossil fuels, the risks to lives and livelihoods increase dramatically with each passing year.

The data is alarming, Dr. Andrew Schwartz, the lead scientist at the Central Sierra Snow Lab's station center at the University of California Berkeley, wrote in Monday's New York Times.

'This past week, I joined teams of other scientists gathering the most important measurements of the Sierra Nevada snowpack from over 265 sites throughout the state. Typically, this measurement marks the transition from snow accumulation season to the melt season and contains the most snow of any measurement throughout the year," Schwartz said in his editorial. "The 2022 results, however, confirmed what those of us monitoring the state’s drought had feared: California’s snowpack is now at 39 percent of its average, or 23 percent lower than at the same point last year. This signals a deepening of the drought — already the worst in the western United States in 1,200 years — and another potentially catastrophic fire season for much of the West."

Normally, Schwartz said, droughts are defined by prolonged periods without rain or snow. But the current situation is different, he noted, because of the impact of human-caused climate change.

"As more frequent and large wildfires and extended dry periods batter the land, our most important tools for managing water are becoming less and less accurate. At the same time, our reliance on these models to try to make the most of the little water we have is becoming more and more problematic," he pointed out.

Those ballooning discrepancies mean that residents of affected regions lack the necessary means to adequately prepare.

"Droughts may last for several years or even over a decade with varying degrees of severity. During these types of extended droughts, soil can become so dry that it soaks up all new water, which reduces runoff to streams and reservoirs. Soil can also become so dry that the surface becomes hard and repels water, which can cause rainwater to pour off the land quickly and cause flooding. This means we no longer can rely on relatively short periods of rain or snow to completely relieve drought conditions the way we did with past droughts," wrote Schwartz.

"Many storms with near record-breaking amounts of rain or snow would be required in a single year to make a significant dent in drought conditions," he continued. "October was the second snowiest and December was the snowiest month on record at the snow lab since 1970 thanks to two atmospheric rivers that hit California. But the exceptionally dry November and January to March periods have left us with another year of below-average snowpack, rain and runoff conditions."

As the planet becomes ever warmer, "this type of feast-or-famine winter with big storms and long, severe dry periods is expected to increase," Schwartz added, noting that "as a result, we’ll need multiple above-average rain and snow years to make up the difference rather than consecutive large events in a single year."

But chronically dry conditions are only half of the equation. Wildfires – which have escalated in frequency, intensity, and size – also have profound effects on the relationship between water and soil.

Those infernos, Schwartz explained, "cause distinct changes in the way that snow melts and that water, including rain, runs off the landscape. The loss of forest canopy from fires can result in greater wind speeds and temperatures, which increase evaporation and decrease the amount of snow water reaching reservoirs."

Fire 'also alters soil properties and can create flash flooding during intense periods of rain. These landscape changes, feast-or-famine precipitation patterns and increased demand on the water supply are making water management in the West a precarious and difficult task," he stressed.

Consequently, the "simplistic" models employed by government agencies "such as the National Weather Service’s Office of Hydrologic Development, the Army Corps of Engineers and the California Department of Water Resources" are perilously outdated and insufficient for tackling today's growing regional weather crises, Schwartz said. "Land surfaces, snowmelt patterns and the climate have all changed since many of these models were developed, which means they’re missing crucial pieces of today’s water puzzle. What’s prevented updates to the models for decades is shrinking funding for science and engineering."

This means that bracing for water shortages will be extremely challenging, calling into question the future habitability of large areas of the United States.

"We are looking down the barrel of a loaded gun with our water resources in the West," warned Schwartz. "Rather than investing in body armor, we’ve been hoping that the trigger won’t be pulled. The current water monitoring and modeling strategies aren’t sufficient to support the increasing number of people that need water. I’m worried about the next week, month, year, and about new problems that we’ll inevitably face as climate change continues and water becomes more unpredictable."

Schwartz then called upon lawmakers to "invest in updating our water models rather than maintaining the status quo and hoping for the best. Large-scale investment in the agencies that maintain and develop these models is paramount to preparing for the future of water in the West."

Like water, time is a precious resource that is quickly diminishing.

"Better water models ultimately mean more accurate management of water, and that will lead to greater water security and availability for the millions of people who now depend on the changing water supply. It is an investment in our future and, further, an investment in our continued ability to inhabit the water-scarce regions in the West," Schwartz concluded. "It’s the only way to ensure that we’re prepared when the trigger is pulled."

Read Schwartz's full editorial here (subscription required).