A single summer stole more than 200 feet (60 meters) of ice from the snout of Sólheimajökull, a glacier in Iceland, seen in April 2006.
What a difference a few months made for Sólheimajökull, seen from the same vantage in October 2006. The glacier has withdrawn a third of a mile (0.5 kilometer) over the past decade, in step with rising temperatures.
Years ago, says a veteran skier, "conditions were fantastic" at the world's highest ski area, on 17,250-foot (5,260 meters) Chacaltaya Glacier near La Paz, Bolivia.
Today, few attempt the ski run down Bolivia's Chacaltaya Glacier, even after a snowfall. The glacier has shriveled in the past decade, turning much of the slope into a boulder field.
As icons such as Montana's once well-formed Grinnell Glacier vanish, "people feel a sense of loss," says Dan Fagre of the USGS.
Montana's Grinnell Glacier, a robust body of ice decades ago, is melting.
Mount Everest's East Rongbuk Glacier lost some 350 vertical feet of ice between August 1921 (above) and October 2008 (next).
Mount Everest's East Rongbuk Glacier lost some 350 vertical feet of ice between August 1921 (previous) and October 2008 (above).
Columbia Glacier in Alaska has retreated 11 miles since 1980. Since then, it has diminished vertically an amount equal to the height of New York's Empire State Building.
Columbia Glacier in 2012.
The November 2015 issue of National Geographic magazine.