These images and excerpt are from the October 125th anniversary issue of National Geographic magazine.
Glaciers are wild beasts. Back in our preindustrial days we feared them like wolves-except glaciers ate whole villages. By the late 19th century they'd become tourist attractions; in Switzerland you could venture into the belly of the Rhône Glacier through a tunnel dug each summer next to the Hotel Belvedere. By then we had also begun creating a world that may one day have no room for glaciers. But for now, beasts they remain.
Ilulissat Ice Fjord, Greenland, 2008. Solid turns to liquid as a 15-story iceberg erodes in the warming seas of the North Atlantic. © James Balog/National Geographic
Photo by Extreme Ice Survey with Matthew Kennedy
2006 Columbia Glacier, Columbia Bay, Alaska. When Balog first photographed the debris-streaked Columbia Glacier, its face had retreated 11 miles since 1980. That pace compelled him to launch the Extreme Ice Survey, installing cameras at 18 glaciers to witness climate change. © Extreme Ice Survey with Matthew Kennedy
2012 Columbia Glacier, Columbia Bay, Alaska. Iceberg-choked Prince William Sound reveals that the retreat of the Columbia Glacier is accelerating: It's lost two more miles of ice in six years. And since 1980 it has diminished vertically an amount equal to the height of New York's Empire State Building. © James Balog/National Geographic