In 1921, while climbing the north face of Mount Everest, George Mallory took a few photographs of the white sweep of the Rongbuk glacier.
On 14 July 2010, the Asia Society released images of the glacier taken by mountaineer David Breashears from exactly the same spots (and in the same season) as Mallory. The comparison is stark: rock faces where once there was only snow, and a glacier that looks withered, having lost 320 vertical feet. The IPCC controversy on the melting of Himalayan glaciers might be behind us, but glacial melting is not. Climate change sceptics should look twice.