The Hindukush Himalaya (HKH) lost 12 per cent of its overall area from 1990 to 2020, according to a new analysis by the International Centre for Integrated Mountain Development (ICIMOD).
In terms of ice concentration, it lost 9 per cent of its total ice reserve at the same time.
“The rate of loss accelerated markedly after 2010, particularly in the eastern and central HKH, where smaller glaciers have been most affected. The most substantial losses occurred in these eastern and central parts of the region,” the report Changing Dynamics of Glaciers in the Hindu Kush Himalayan Region from 1990 to 2020 said.
Outside the polar regions, HKH — often called the Third Pole — holds the largest concentration of snow ice and is the source for multiple river basins, thereby playing the most critical role in sustaining river ecosystems.
More worryingly, the report observed that the Ganga and the Brahmpautra river basin “experienced the greatest total area loss over the past three decades, with reductions of approximately 21 per cent and 16 per cent, respectively”.
Rivers east of the HKH region have done far worse — The Yellow, Yangtze, and Salween river basins lost approximately 22 per cent, 23 per cent, and 33 per cent of their glacier area over the past three decades, respectively.
“The changes documented here translate directly into growing uncertainty for water availability, increasing exposure to hazards such as glacial lake outburst floods (GLOFs), avalanches, landslides, and debris flows, and mounting risks for downstream communities and infrastructure, thereby reinforcing the inextricably linked future of food, water, energy and livelihood security in the overall region with the future of the glaciers in the high mountains,” the report warned.
The HKH, according to ICIMOD, is a high topographical region with an area of over 55,000 square kilometers and spanning across eight countries. The region is also the source of 10 large river basins.
The region is dotted with over 60,000 glaciers, holding close to 6,000 cubic kilometers of ice reserves.
Overall, the Himalayas, the largest of the mountain ranges in the region in terms of overall area and also holding the highest glacial area, lost over 17 per cent of its overall glacial area from 1990 to 2020.
The central part of the Himalayan region, spanning roughly from Shimla in India to the eastern edge of Nepal, reported the biggest overall loss in total area — over 20 per cent.
Apart from the central region, the Himalayas, which are divided into three different regions — based on elevation — also consist of the western flank, running from Kashmir to Shimla, and the eastern flank, spanning from Bhutan and Eastern India and parts of China and Myanmar.
The western and the eastern region reported overall glacial area loss of 12 and 17 per cent respectively.
On a brighter note, the Karakoram range, which is the second biggest in terms of overall area, reported a loss of close to 2 per cent of glacial area, one of the lowest in the region, which consists of 16 other distinct mountain ranges.