Kathmandu, May 30 -- While Nepal was hosting the Sagarmatha Sambaad international climate conference in Kathmandu this month, on Mt Everest it was pretty much business as usual.

The signs of climate breakdown are all there: a river now runs through Base Camp in summer, the Khumbu Icefall is more unstable, and there are more frequent avalanches. When expeditions arrived in March, the mountains were bare: it had not snowed since September, but then blizzards dumped unseasonal snow in May.

And despite climate worries, such is the pull of Himalayan mountaineering that the Everest Industry showed no signs of slowdown. More than 600 international climbers and their Nepali guides had made it to the summit of the world's highest mountain. At o...