Disappearing Glaciers

boulder_glacier_combined At the end of the Little Ice Age in 1850, there were 150 glaciers in the mountainous area that would become Glacier National Park. Then the glaciers began a slow retreat. This withdrawal accelerated around 1932 when the older photograph of Boulder Glacier, at above left, was taken. The acceleration is due to rising temperatures from the loading of carbon dioxide in the atmosphere due to the burning of fossil fuels. The carbon dioxide blankets the Earth, allowing sunlight to penetrate but blocking much of the heat from escaping—a condition known as the Greenhouse Effect. As industry, travel, and population increase, this process continues to speed up, affecting alpine glaciers worldwide. Over 50 percent of our water supplies find its source in mountain ice. Much of this may disappear. And nowhere are glaciers more vulnerable than in Glacier National Park. By 1998, Boulder Glacier, at upper right, had all but vanished. Today, only 25 of the original 150 glaciers in the Park remain. They are expected to disappear in the next decade or so. For them, it is too late. But as The Melting World shows, reducing carbon emissions could save other alpine glaciers, such as those in the Himalayas.

For repeat photograph pairs of other Montana glaciers, go to: www.NRMSC.usgs.gov/repeatphoto/overview.html

For images of vanishing Himalayan glaciers, go to: www.GlacierWLisa_Icebergorks.org