Nepal, Jan. 25 -- The pale green ice on the top of the lake gleams in the pale January sunlight. The dark waters beneath are visible through the translucent frozen surface.

This is Thulagi Glacial Lake at the foot of Mt Manaslu in central Nepal, classified as one of the most dangerous lakes to appear in the Himalaya due to climate heating.

The place is breathtaking not just because of its 4,050m altitude, but the scenery all around. The beauty belies the threat this expanding lake poses downstream along the Marsyangdi Valley.

The lake lies at the terminus of the 4.5km long Thulagi Glacier. The local Gurung inhabitants call it Dona Tal. They say it started appearing in the 1960s. Local guide Chandra Bahadur Gurung, 47, has been ferryi...