Climate Change Could Mean Less Snow in the Mountains for Southern California

Climate change could mean the mountains in the Los Angeles area will experience 30 to 40 percent less snowfall by 2050 than they did toward the end of the 20th century, according to a new study led by University of California, Los Angeles' Alex Hall.

What's more, Hall, a professor in the Department of Atmospheric and Oceanic Sciences, warns the projected snow loss could rise to 67 percent by the end of the 21st century, depending on those actions taken to address the issue.

"Climate change has become inevitable, and we're going to lose a substantial amount of snow by midcentury," Hall, said in a press release. "But our choices matter. By the end of the century, there will be stark differences in how much snowfall remains, depending on whether we begin to mitigate greenhouse gas emissions."

Without sustained action, Hall and his colleagues report, sizable economic losses for snow-dependent businesses and communities as well as changes in the seasonal timing of local water resources, greater difficulty controlling floods and damage to mountain and river ecosystems are all likely to occur.

However, this could represent only the beginning, according to Hall, whose previous research showed the region warming by 4 to 5 degrees by 2050, as the researchers qualified snowfall but not snowmelt.

"We won't reach the 32-degree threshold for snow as often, so a greater percentage of precipitation will fall as rain instead of snow, particularly at lower elevations," he said, adding that increased flooding due to more frequent rains as well as sooner runoff from melting snowpack are other possible implications.

The study, which represents the second part of UCLA's ongoing research project, "Climate Change in the Los Angeles Region," was supported in part by the city via a grant it received from the U.S. Department of Energy, and has, along with the first study, inspired action among local government leaders.

"The science is clear and compelling: Los Angeles must begin today to prepare for climate change," Los Angeles Mayor Antonio Villaraigosa said regarding the findings. "We invested in this study and created the AdaptLA framework to craft innovative solutions and preserve our quality of life for the next generation of Angelenos."

Other funding came from the Los Angeles Regional Collaborative for Climate Action and Sustainability and the National Science Foundation with future studies covering elements of climate change including precipitation, Santa Ana winds, soil moisture and streamflow.