Lake Tahoe warming at unprecedented rate, scientists say
Friday, July 28, 2017, 12:56 - Things are heating up at an unprecedented rate at Lake Tahoe, according to a new report.
In the last four years, the average surface temperature of Lake Tahoe has risen 0.5 degrees per year — 14 times faster than the long-term warming rate, according to an annual report issued Thursday by the UC Davis Tahoe Environmental Research Center.
“It's going up on average,” Geoff Schladow, director of the UC Davis Tahoe Environmental Research Center, and author of the State of Lake Tahoe, tracking the lake's health and temperature told CBS Sacramento . “But year to year there are lots of extreme variations."
The report, released on July 27, 2017, summarizes data collected in 2016 as part of the center’s ongoing, decades-long measurement programs, while also presenting research driven by important questions of the day.
Over the years, summer weather has been persisting longer, leading to earlier spring snowmelt. Last year’s first snowmelt was on March 29 – 19 days earlier than 1961, according to scientists. The report says these vast atmospheric changes are having a profound impact to Lake Tahoe’s ecosystems and the plants and animals they support.
“It’s making conditions less ideal for the species that are native to the lake that are adapted to the very high UV conditions and cold water temperature conditions,” Schladow tells The Sacramento Bee.
Besides dramatic temperature changes, the report found that an alarming number of trees were dying in the Tahoe Basin. The number of dead trees more than doubled from 35,000 in 2015 to 72,000 last year, according to the report.
“The numbers of dead and dying trees throughout Tahoe and the Sierra Nevada are increasing due to a combination of drought stress, insect attack and disease,” says Kat Kerlin, Environmental content provider at UC Davis. “This carries direct implications for fire safety, biological diversity and carbon sequestration.”
The research center says a new NASA instrument on the International Space Station will likely provide further data to help understand these changes.
Despite these changes, the report found that water clarity is improving over the years. In 2016, the average annual clarity level was 69.2 feet, which was a 3.9-foot decrease from 2015, and more than 5 feet greater than the lowest recorded average of 64.1 feet in 1997.
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