New Metrics
Sierra Nevada Snowpack Reaches 500-Year Low

California’s record-low snowpack this year actually may be far more historic than previously thought — at its lowest in more than 500 years, according to a paper published Monday in the journal Nature Climate Change, The Los Angeles Times reports.

To reconstruct centuries-old snow conditions, researchers analyzed data from snowpack measuring stations in the Sierra Nevada, as well as two tree-ring studies. The first study used measurements from 1,500 living and dead blue oak trees to estimate rainfall back to the year 1400. The second included tree-ring data from a different group of trees to model temperatures for the same period.

After researchers put all the data into a chronology, they concluded that the chance a “snow drought” of this intensity would affect the entire Sierra Nevada more than once every 500 years was less than 5 percent.

California’s total precipitation in 2015 fell within the bounds of natural variability, the researchers noted, but winter temperatures were among the highest ever recorded. This leads to less snow and more rain, which the state is ill-equipped to collect and store, according to The Los Angeles Times.

And global warming threatens to make these conditions more frequent, the researchers say.

The report is the latest in a series of studies seeking to characterize the depth of California’s four-year drought and place it in a broader historic context.

Although many Californians have pitted their hopes on promises of an imminent El Niño season to bring relief from the state’s years-long drought, researchers say that rising temperatures mean there will be much less snow and more rain.

Unless California can figure out a way to capture rainwater quickly, much of it will just go into the ocean, the researchers warn. Snowpack is the most important part of California’s water supply — in a normal year melting mountain snow provides the state with one-third of its water. An additional third is pumped from underground aquifers, and the remainder comes from rivers and reservoirs.

Speaking of lack of snowpack, last week a group of stakeholders from the outdoor and snow sports industry calling itself Protect Our Winters — made up of 92 brands, 53 U.S. resorts, 50 professional athletes and 13 snow sports trade groups — signed a letter to President Obama about the urgency of climate change and encouraging him to bargain hard for a tough agreement at COP21.

“The snow sports industry views climate change as an economic opportunity as well as an environmental issue. Our businesses support $62 billion in tourist-related revenue, 964,000 jobs and $4.6 billion in annual retail sales. We are united in our desire to reduce carbon emissions and transition to a clean energy future“2014 was the warmest year in the temperature record, and 2015 is on track to surpass it,” they say in the letter. "Failure to act now on climate is unacceptable, and will result in damage to the environment, tourism and the economy. This is the greatest opportunity of our time. We need meaningful action from all, and it is time to act."