India, March 21 -- Glaciers in many regions will not survive the 21st century if they keep melting at the current rate, potentially jeopardising hundreds of millions of people living downstream, UN climate experts said on the first World Day for Glaciers.

Together with ice sheets in Greenland and Antarctica, glaciers lock up about 70 per cent of the world's freshwater reserves. They are striking indicators of climate change as they typically remain about the same size in a stable climate.

But, with rising temperatures and global warming triggered by human-induced climate change, they are melting at unprecedented speed, said Sulagna Mishra, a scientific officer at the World Meteorological Organization (WMO).

Last year, glaciers in Scand...