Snowfall In The California Mountains Expected To Decline
June 15, 2013

California Mountains Will See Less Snowfall In The Future

April Flowers for - Your Universe Online

A new study from UCLA reveals snowfall in the Los Angeles-area mountains will be 30 to 40 percent lower by mid-century than it was at the end of the 20th century.

Depending on how the world reacts, the projected snow loss, which is a result of climate change, might be even worse by the end of the 21st century. Climate expert Alex Hall, who led the study, said that sustained action to reduce global greenhouse gas emissions has the potential to keep annual average snowfall steady after mid-century. If emissions continue unabated, however, the study predicts snowfall in the Southern California Mountains will be two-thirds less in 2100 than it was before 2000.

"Climate change has become inevitable, and we're going to lose a substantial amount of snow by midcentury," said Hall, a professor in UCLA's Department of Atmospheric and Oceanic Sciences and UCLA's Institute of the Environment and Sustainability. "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."

"This science is clear and compelling: Los Angeles must begin today to prepare for climate change," said Los Angeles Mayor Antonio Villaraigosa. "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."

Snow enthusiasts who enjoy skiing and sledding in the local mountains won´t be the only ones affected by less snowfall in general and a complete loss of snow at some lower elevations. Such loss could also mean changes in the seasonal timing of local water resources, greater difficulty controlling floods and damage to mountain and river ecosystems.

Hall, whose previous research found the region will warm 4 to 5 degrees by mid-century, said the impact to actual snow on the ground could be even greater because the researchers quantified snowfall but not snow melt. The team estimates the snowpack could melt an average of 16 days sooner than it did in 2000.

"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," Hall said. "Increased flooding is possible from the more frequent rains, and springtime runoff from melting snowpack will happen sooner."

"As a California resident, I spend my winters snowboarding in mountains throughout our amazing state," said Jeremy Jones, founder of Protect Our Winters, an environmental nonprofit composed of winter sports enthusiasts. "It breaks my heart to see America's great natural resources harmed by climate change. We must, immediately, begin to reduce greenhouse gas emissions. There is no choice."

The study, entitled "Mid- and End-of-Century Snowfall in the Los Angeles Region," is the most detailed research to date, examining the effects of climate change on snowfall in the Southern California mountains. The complete text of the report, along with maps and graphics, is available online at C-CHANGE.LA/snowfall. This study is the second part of UCLA´s ongoing research project, “Climate Change in the Los Angeles Region.”

The research team studied snowfall in the San Gabriel Mountains, San Bernardino Mountains, San Emigdio/Tehachapi Mountains and San Jacinto Mountains. Low-resolution global climate models were scaled down to create high-resolution models with data specific to towns such as Lake Arrowhead, Big Bear, Wrightwood and Idyllwild.

Baseline snowfall amounts from 1981 to 2000 were used to predict snow amounts for mid-century (2041 to 2060) and the end of the century (2081 to 2100) under a “business-as-usual” scenario, in which the greenhouse gas emissions increase unchecked. They also used a “mitigation” scenario, in which the world significantly reduces emissions. The contrast between the scenarios would be dramatic by the end of the century.

Mid-century snow levels would be 31 percent lower than baseline in the mitigation scenario, but would remain relatively steady at only 33 percent below baseline by the end of the century. On the other hand, in the “business-as-usual” scenario, 42 percent of the snow is expected to disappear by mid-century before decreasing dramatically to a 67 percent loss by the end of the 21st century.

"The mountains won't receive nearly as much snow as they used to, and the snow they do get will not last as long," Hall said.