By Christina Larson
Having just written about the efforts of Chinese and Tibetan observers to grasp the impact of melting glaciers (and drying streams) in the Himalayas, I wanted to add a note about another way to visualize changes underway as the planet warms.
During one of his famed attempts to ascend Mt. Everest in 1921, the British adventurer George Mallory and his entourage took photographs of what they saw. In 2007, American mountaineer David Breashears stood in the same place Mallory had been, and his team took a second high-resolution photograph. Breashears, who now works with GlacierWorks and the Asia Society, wanted to record the changes in the ice sheets.