Climate Change May Drastically Decrease Snowfall in Southern California Mountains

Get your skiing and snowboarding done while you can. It turns out that by midcentury, snowfall on Los Angeles-area mountains will be 30 to 40 percent less than it was at the end of the 20^th century. That could mean some extra work for snow machines at ski resorts.

So why are scientists predicting this loss of snow cover? Good question. Climate change is having a huge effect on levels of precipitation and temperature. Because of the warmer temperatures, more snow is falling as rain. This means that there may be less of a snowpack in the region which could, in turn, affect water availability at certain points in the season.

In order to see how exactly our changing climate is affecting snowfall in California, the researchers examined snowfall in the San Gabriel Mountains, San Bernardino Mountains, San Emigdio/Tehachapi Mountains and San Jacinto Mountains. More specifically, they used scaled down low-resolution global climate models in order to create high-resolution models with data that was specific to towns such as Lake Arrowhead, Big Bear and Wrightwood.

Using baseline snowfall amounts from 1981 to 2000, the scientists predicted snow amounts for the years 2041 to 2060 and then for the years 2081 to 2100 under a "business as usual" scenario. This particular outcome assumed that greenhouse gas emissions increased unchecked. They also predicted snow amounts for the same years under a "mitigation" scenario where the world significantly reduced emissions.

In the end, the scientists found that under a business as usual scenario, 42 percent of the snow is expected to disappear by mid-century. That percentage increases dramatically to 67 percent at the end of the century.

"The science is clear and compelling: Los Angeles must begin today to prepare for climate change," said Los Angeles Mayor Antonio Villaraigosa in a news release.

The loss of snow won't just affect skiers and snowboards, though. It could also mean more flooding in the region. Since the area will warm a projected four to five degrees by midcentury, the snowpack will melt an average of 16 days sooner than it did in 2000. It also means that more rain rather than snow will hit the area, which will add to the melting snow and could cause flooding in low lying areas.

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

The findings are published online here.