Environment & Science

Sierra snow cover could drop 50 percent by the end of the century due to climate change

Mammoth Mountain, in the Eastern Sierra Nevada mountains of California.
Mammoth Mountain, in the Eastern Sierra Nevada mountains of California.
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The all-important Sierra Nevada snowpack could be dramatically cut by the end of the century if greenhouse gas emissions aren't reduced, according to a new analysis from UCLA.

Researcher Alex Hall used a complex computer model to look at what would happen to the Sierra Nevada mountains if these pollutants kept entering our atmosphere at the current rate.

He found that by the end of the century, average temperatures could climb by 7 to 10 degrees Fahrenheit and average land area covered by snow could fall by 50 percent.

Even worse, this reduction in snow would likely fuel more warmth, since as snow melts it exposes land. Since land isn’t as reflective as snow, it absorbs more heat and adds more warmth to the area around it.

Hall said it’s a feedback loop that spells trouble for the snowpack.

"The climate effects of snow and the amplification of warming associated with the retreat of snow has big implications for water resources as well," he said.

That’s because with less snowpack, there’s less water trickling down from the mountains in the spring and summer, when cities and towns need it most.

The analysis was done by using powerful climate models focused just on the Sierra Nevada ranges, rather than the entire globe. That allowed Hall's team to get extremely precise predictions for the region.

In particular, this new study forecasts more warming in the mid-elevation areas between 4,000 and 7,000 feet than previous studies.

Hall said there is hope. His team modeled climate changes under a carbon-cutting plan like the one laid out in the Paris climate accord.

They found that in such a scenario average temperatures would only be 4 to 5 degrees Fahrenheit warmer and the snow-covered areas would be cut by only 20 to 30 percent.

He added that the Earth is "hanging in the balance right now,” depending on how leaders around globe chose to move forward on carbon-cutting goals.

Correction: An earlier version of this story said the study focuses on snowpack. It focuses on snow cover instead.