Lake Tahoe and the community around it are increasingly battered by climate change and drought, with the lake’s temperature climbing 10 times faster than the historic average in the past four years and algae threatening the Sierra Nevada gem’s famous emerald and blue clarity. Intense seasonal changes in 2016 — hallmarks of climate change — killed huge swaths of forest around the lake and nourished invasive species, according to the annual Tahoe State of the Lake Report released Thursday by the UC Davis Tahoe Environmental Research Center. The beloved vacation spot, researchers said, now sees summer conditions for 26 more days than it did in 1968, boosting the danger of devastating wildfires, while the spring snowmelt has moved up 19 days since 1961. The report was based on conditions measured throughout last year. “People come to Tahoe for the trees and because the beaches are clean,” said report author Geoffrey Schladow, the director of the UC Davis center. “The lake is nestled in the mountains and surrounded by a beautiful forest. If it is increasingly dominated by dead and dying trees and stringy algae washing up on the beach, it will change the way people experience the environment here.” Noting efforts to preserve the lake, which have been embraced by lawmakers in Sacramento and Washington, he added, “But I am optimistic because, at Lake Tahoe, most people are pretty much on the same page of where they want the lake to go.” The report called climate change an overarching factor in many of the area’s challenges. Insects, disease and stress — combined with the transition from a historic drought to unprecedented rainfall last year — felled tens of thousands of trees….