Billions of beetles, wildfire spread imperil the northern forests of a warmer world

In this Aug. 6, 2009 photo, spruce bark beetle infested forest are shown in the thick woods of the Alsek River valley, near Haines Junction, Yukon Territory. Spruce bark beetles have destroyed 400,000 hectares (1 million acres) of forest in southwest Yukon, including the woodlands of the Alsek River valley, beneath the peaks of the St. Elias Mountains. Scientists warn that global warming will spur insect infestations and wildfires in the world's northern forests. (AP Photo / Rick Bowmer) By CHARLES J. HANLEY,  AP Special Correspondent
HAINES JUNCTION, Yukon Territory A veil of smoke settled over the forest in the shadow of the St. Elias Mountains, in a wilderness whose spruce trees stood tall and gray, a deathly gray even in the greenest heart of a Yukon summer. “As far as the eye can see, it’s all infested,” forester Rob Legare said, looking out over the thick woods of the Alsek River valley. Beetles and fire, twin plagues, are consuming northern forests in what scientists say is a preview of the future, in a century growing warmer, as the land grows drier, trees grow weaker and pests, abetted by milder winters, grow stronger. Dying, burning forests would then only add to the warming. It’s here in the sub-Arctic and Arctic — in Alaska, across Siberia, in northernmost Europe, and in the Yukon and elsewhere in northern Canada — that Earth’s climate is changing most rapidly. While average temperatures globally rose 0.74 degrees Celsius (1.3 degrees Fahrenheit) in the past century, the far north experienced warming at twice that rate or greater. In Russia’s frigid east, some average temperatures have risen more than 2 degrees Celsius (3.6 degrees Fahrenheit), with midwinter mercury spiking even higher. And “eight of the last 10 summers have been extreme wildfire seasons in Siberia,” American researcher Amber J. Soja pointed out by telephone from central Siberia. …

Beetles, Wildfire: Double Threat in Warming World