People and Planet: A new study led by the US Geological Survey and other research institutes indicates tree deaths in the US West’s old-growth forests have more than doubled in recent decades, probably from regional warming and related drought conditions. The study, published in Science, documented tree deaths in all tree sizes in the West located at varying elevations, including tree types such as pine, fir and hemlock. Significant die-offs also were documented in the interior West – including Colorado …