The report, Impacts of Climate Change on Biodiversity, Ecoystems and Ecosystem Services, was peer-reviewed by the U.S. Geological Survey and drew on the expertise of 60 contributors from government agencies, universities and private, non-profit organizations such as The Nature Conservancy.
I live in Washington state where one sees such images all over this area, and it's worse north of here in British Columbia. This effect is caused by bark beetles that are allowed to proliferate due to warmer winter temperatures.