Researchers say the impact of California’s historic drought on the Sierra Nevada Mountains snowpack is worse than previously believed.
Scientists, writing in the journal Nature Climate Change, estimate the snowpack hit a 500-year low this past winter. By examining tree rings on blue oak trees, scientists were able to determine the lack of sierra snowpack is the most severe in five centuries.
"Our study really points to the extreme character of the 2014-15 winter. This is not just unprecedented over 80 years -- it's unprecedented over 500 years," Valerie Trouet, associate professor in the Laboratory of Tree-Ring Research at the University of Arizona told NBC News "We should be prepared for this type of snow drought to occur much more frequently because of rising temperatures."
Snowpack plays a big role in the state’s water supply, providing about one-third of the California’s water in a normal year. The reduction in the amount of snow covering California mountains will in turn reduce the state’s available water.
Back in April, California Gov. Jerry Brown took part in a snowpack survey and ordered unprecedented water restrictions as he stood in a snowless Sierra Nevada.
Even with a powerful El Niño that could result in a wet fall and winter looming, those potential storms are not likely to contribute to a large snowpack.
"In this study we didn't look into the future, we didn't model anything toward the future, but given what we know, it is likely that this kind of extreme low snowpack is going to be seen more frequently in the future," Trouet said.