The receding snow line of the Himalayas is perhaps the best indicator of the ill effects of global warming.

I flew over the world's highest mountain range twice, in February and November, this year. The towering peaks of the range, including its highest, Mount Qomolangma, were hardly covered by snow.

I dread to think of the day when the little snow that is left completely vanishes. If the "Roof of the World" turned into arid desert, river sources would run dry, and millions of lives would be at stake.