Snow Flake Out

The Sierra Nevada’s snowpack hasn’t been this scant in 500 years.

September 15, 2015

Images from NASA's Earth Observatory show snowpack in the Sierra Nevadas in 2010 (left) versus 2015 (right).

When it comes to California’s massive four-year drought, no snow goes along with no rain, and earlier this week, scientists reported that this year's snowpack in the Sierra Nevada was the lowest it's been in half a millennium.

To get a sense of the region’s wintertime weather history, the researchers measured the tree-ring widths of blue oaks for each year going back to the early 1500s. Recent record-breaking temperatures and dry conditions led to this year’s pitiful snowfall. As shown below in a map from National Geographic's report, the state's snowpack on April 1 was 95 percent below average. The lack of white stuff isn’t just a bummer for skiers and snowboarders. In spring, meltwater from the mountains provides about 30 percent of California’s water supply as well as habitat for fish and other wildlife.

Unfortunately, something else can be seen in tree rings: An earlier study going back even further to the Middles Ages found that mega-droughts—like the ones that possibly dried out the Southwest’s Pueblo civilization—are not so uncommon for this part of the country. And what California's in for in the coming decades, the researchers concluded, could be even worse. 

Map courtesy National Geographic

onEarth provides reporting and analysis about environmental science, policy, and culture. All opinions expressed are those of the authors and do not necessarily reflect the policies or positions of NRDC. Learn more or follow us on Facebook and Twitter.

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