Jul 8, 2016

Ravaged woodlands

Yosemite National Park, Tioga Pass Rd, California
The Economist
Photo: Agence France-Presse
Photo: Agence France-Presse

Much of the West is still parched. This is largely a result of the combined effects of La Niña—a cyclical series of weather events that produces drier conditions in the southern forests of the West—and man-made warming. Climate change is estimated to have made California’s drought 15-20% more severe; in Alaska, where the average winter temperature has risen by over 3°C in the past six decades—over twice the average for the rest of America—its impact is greater. By accelerating the melting of winter snow, for example, in Alaska and the mountains of the West—the Rockies, Cascades, Sierra Nevada—hotter temperatures have made the fire season longer. Since 1970 the average duration has increased from 50 to around 125 days; in Alaska, which had its second-biggest year for fires on record in 2015, some of last year’s blazes are still alight