A new UCLA study has found that by 2050 mountains in the Los Angeles region could be seeing 30 to 40 percent less snowfall than levels seen at the end of the 20th century. Immediate action to reduce greenhouse gas emissions could keep these levels steady, but if emissions continue unabated, snowfall could be reduced to two-thirds by the year 2100.
The message is clear to Los Angeles Mayor Antonio Villaraigosa, who says that the city must begin to prepare for climate change today. In addition to investing in this study, the city has created an “AdaptLA” framework to develop innovative solutions for climate change.
Less snowfall, and, in some cases, a complete loss of snow at lower elevations, could mean sizable economic losses for snow-dependent businesses and communities. Problems include changes in seasonal timing, increased flooding, and damage to mountain and river ecosystems.
The predicted impact may be even greater than anticipated given that the study only quantified snowfall but not snow melt. By mid-century, researchers estimate that snowpack could melt up to 16 days earlier than it did in 2000. Flooding is of particular concern because of increased rainfall, due to higher temperatures, and a shorter timeframe for springtime runoff.
The study examined snowfall in the San Gabriel Mountains, San Bernardino Mountains, San Emigdio/Tehachapi Mountains and San Jacinto Mountains. Using scaled down low-resolution global climate models, the research team created high-resolution models with town specific data. The study used baseline snowfall levels from 1981 to 2000. Snow levels were predicted for midcentury (2041 to 2060) and the end of the century (2081 to 2100) under a “business as usual” scenario, in which greenhouse gas emissions continue unabated, and a “mitigation” scenario, in which emissions are significantly reduced.
The UCLA study is the most detailed research to date examining the impact of climate change on snowfall in Southern California mountains. It is the second part of UCLA’s ongoing research project, “Climate Change in the Los Angeles Region.” The research was conducted in partnership with the Los Angeles Regional Collaborative (LARC) for Climate Action and Sustainability, a regional network that develops science and strategies to address climate change.
LARC was founded by the city of Los Angeles and Los Angeles County in order to bring together leadership from the different sectors to encourage greater coordination and cooperation at the local and regional levels.
Future studies will cover other elements of climate change including precipitation, Santa Ana winds, soil moisture and streamflow. The complete reports are available online at C-CHANGE.LA/snowfall.