Kathmandu, May 8 -- It is now looking doubtful if countries around the world can cut their greenhouse gas emissions as agreed in Paris six years ago, so that global temperature rise will be limited to 1.5 Celsius by 2050. The earth is going to heat up by more than that.

Even if it is 1.5 Celsius, the average temperature in the Himalaya will go up by 1.8 degrees because of a phenomenon called 'altitude effect'. The best-case scenario is that one-third of all remaining Himalayan glaciers will have melted during this century. However, if greenhouse gas emissions continue to rise at the present rate, two-thirds of Himalayan ice will be gone by 2100.

All this will have a catastrophic effect on water supply for 1 billion people downstream on ...