China’s Everest obsession: following Mallory’s footsteps a century on, I saw how tourism and climate change are transforming the mountain

Chinese tourists at Everest's northern base camp, Rongbuk in Tibet, photograph the world's highest mountain. Carl Cater, CC BY-NC-ND

To the discerning eye, other mountains are visible – giants between 23,000 and 26,000 feet high. Not one of their slenderer heads even reaches their chief’s shoulder. Beside Everest they escape notice, such is the pre-eminence of the greatest. (George Mallory, 1922)

The climbing season on Mount Everest peaks in late May and early June every year. Extreme weather patterns at this location and altitude mean the main climbing season is remarkably short, perhaps only a few weeks between the winter freeze and monsoon storms.