Image: The Hotlum glacier is seen on the northeast face of Mt. Shasta, Thursday, June 19, 2008. While global warming is causing the retreat in glaciers in the Sierra Nevada, Cascades and the Rocky Mountains, the seven glaciers on Mt. Shasta are growing. (AP Photo/Rich Pedroncelli)
Story: Mount Shasta glaciers growing, despite warming - Global warming is shrinking glaciers all over the world, but the seven tongues of ice creeping down Mount Shasta's flanks are a RARE exception: They are the only long-established glaciers in the continental U.S. that are growing. Mount Shasta is actually benefiting from changing weather patterns over the Pacific Ocean. A warming Pacific Ocean means more moist air. On the mountain, precipitation falls as snow, adding to the glaciers enough to overcome a 1.8 degree Fahrenheit rise in temperature in the last century. By comparison, the glaciers in the Sierra Nevada, more than 500 miles south of Mount Shasta, are exposed to warmer summer temperatures and are retreating. Climate change has cut the number of glaciers at Montana's Glacier National Park from 150 to 26 since 1850, and some scientists project there will be none left within a generation. The storied snows at Africa's Mount Kilimanjaro might disappear by 2015. Although Mount Shasta's glaciers are growing, researchers say the 4.7 billion cubic feet of ice on its flanks could be gone by 2100. For the glaciers to remain their current size, Shasta would have to receive 20 percent more snowfall for every 1.8-degree Fahrenheit increase in temperature. Even without global warming, another threat to Shasta's glaciers could come far more quickly: a volcanic eruption could melt them, creating mud flows that could bury the surrounding small communities. Over the last 4,000 years, Shasta has erupted about every 250 to 300 years, and did so most recently about 200 years ago.