HKH glaciers melting rapidly; ice loss rates doubled since 2000: ICIMOD reports

Guwahati: Glaciers across the Hindu Kush Himalaya (HKH) are melting at an accelerating rate, with ice loss rates doubling since 2000, according to two landmark reports released on Saturday by the International Centre for Integrated Mountain Development (ICIMOD) to mark World Glacier Day.

The reports — Changing Dynamics of Glaciers in the Hindu Kush Himalaya Region from 1990 to 2020 and HKH Glacier Outlook 2026: Insights from 50 Years of Himalayan Glacier Monitoring — present the most comprehensive evidence yet of glacier change in the region. They indicate a total loss of up to 27 metres of ice thickness since 1975, raising serious concerns for nearly two billion people downstream who depend on meltwater from the “Water Towers of Asia.”

The HKH region contains the largest volume of ice outside the polar regions, with more than 63,700 glaciers covering nearly 55,782 square kilometres. These glaciers feed at least ten major Asian river systems, underpinning food, water, energy, and livelihood security for billions. However, about 78% of this glacier area, located between 4,500 and 6,000 metres above sea level, is highly vulnerable to elevation-dependent warming.

“This isn’t a distant problem; it’s a crisis unfolding in real time, with new disasters every summer and monsoon. The fact that ice loss rates have doubled this century should shock us all into action,” said ICIMOD Director General Pema Gyamtsho. “The Hindu Kush Himalaya is at a crossroads. The rapidly escalating impacts, from water uncertainty to catastrophic floods, show we are in a critical decade for the cryosphere.”

The analysis shows that between 1990 and 2020, HKH glaciers lost about 12% of their total area and 9% of their estimated ice reserves. Sudan Bikash Maharjan, lead author of the glacier dynamics report, said the most immediate threat comes from smaller glaciers.

“Glaciers smaller than 0.5 sq km are shrinking the fastest, posing risks of localised water shortages and increasing hazards such as glacial lake outburst floods,” he said, noting that nearly three-quarters of the region’s glaciers fall within this vulnerable category.

The HKH Glacier Outlook 2026, based on data from 38 monitored glaciers, shows that glacier wastage has doubled after 2000, suggesting that parts of the Himalayan cryosphere may be nearing irreversible tipping points.

However, the reports flag a major data gap, only seven of these glaciers meet global monitoring standards set by the World Glacier Monitoring Service (WGMS), leaving vast regions such as the Karakoram, Sikkim, Zanskar, and Bhutan largely unmonitored.

“We are trying to navigate a rapidly changing future with an incomplete map,” said ICIMOD cryosphere specialist Mohd Farooq Azam. “Without expanding monitoring networks and standardising methods, critical changes in water flows and glacier risks may go undetected until it is too late.”

The findings also show uneven glacier loss across the region. The highest percentage loss has occurred in the eastern Hengduan Shan mountains, where some areas lost up to 33% of glacier cover in three decades. Meanwhile, the largest absolute losses are concentrated in the Indus, Ganges, and Brahmaputra basins, which together host over 74% of the region’s glaciers.

Large glaciers, those exceeding 10 sq km, hold nearly 40% of the region’s natural water reserves. The Karakoram range, home to 18 of the 25 largest glaciers, remains particularly critical, with implications for long-term water, food, and disaster risks across the region.

With 2025 designated as the International Year of Glacier Preservation and the launch of the Decade of Action for Cryospheric Sciences (2025–2034), the reports underline the urgent need for expanded glacier monitoring, improved data standardisation, and stronger investment in climate-resilient adaptation strategies to address the rapidly changing cryosphere.