26 Aug '12, 5am
Pine beetle-ravaged Western forests and raging widlfires combine for an uncertain, but scary, threat. @OnEarthMag
Against the majestic backdrop of the Tetons, dead and dying whitebark pine defines a ridgeline in Wyoming’s Gros Ventre Range. Credit: George Steinmetz In a little over a decade, the largest mountain pine beetle outbreak on record (by a factor of 10) has killed more than 70,000 square miles of Rocky Mountain forests -- an area the size of Washington State. From above, the infested pine trees seem color-coded: green is healthy, red is dead, and after three or four years, the dead red needles fall off, leaving behind a graveyard of bare gray bark -- or, if you’re worried about wildfires, what amounts to a field of 100-foot-tall matchsticks. Colorado, already facing the most destructive wildfire season in state history, has 3.3 million acres of beetle-killed forests to worry about. No one doubts that dead and dying trees are a potential problem, but fears that the beetle infe...