Muir Glacier, located in Glacier Bay, Alaska, photographed by W. Field in Aug. 1941 (left) and B. Molnia in Sep. 1976 (middle) and Aug. 2004 (right). Note how the glacier has retreated to expose rock in 1976 that has since become lush vegetation in 2004. The glacier has retreated so much that it is hardly visible in the 2004 photo. Courtesy NSIDC Glacier Photo Collection

Retreating mountain glaciers in Bhutan. This satellite image shows the termini of several glaciers in the Himalayan mountains of Bhutan. The glaciers have been receding over the past few decades, and lakes have formed on the surfaces and near the termini of many of the glaciers. Source: NASA's ASTER (Advanced Spaceborne Thermal Emission and Reflection Radiometer instrument aboard NASA's Terra satellites). Image provided by Jeffrey Kargel, USGS/NASA JPL/AGU, through NASA's Earth Observatory.

Retreating glacier in Nunavut, Canada. The large grey area on the valley floor is freshly exposed till and gravel. Source: Natural Resources Canada. Photograph by Ron DiLabio. Copyright Terrain Sciences Division, Geological Survey of Canada.