Washington Post: Trees in old-growth forests in the Western United States are dying at twice the rate they were a few decades ago, and experts suspect regional warming is to blame. The report, led by the U.S. Geological Survey (USGS), found that the increase in tree deaths has included trees in a variety of forests, elevations and sizes. Species have included pine, fir, hemlock and other coniferous trees. In addition, the rate of new tree growth has not changed, according to the report in the Jan. 23 …