Himalayan glaciers’ ice loss rates doubled since 2000: ICIMOD report

Glaciers across the Hindu Kush Himalaya are melting at an accelerating rate, with ice loss rates doubling since 2000, even as they lost 12 per cent of their area between 1990 and 2020, two reports by ICIMOD said Saturday.

Coinciding with the World Day for Glaciers, observed annually on March 21, the reports were published by the International Centre for Integrated Mountain Development (ICIMOD), a regional intergovernmental body headquartered in Kathmandu, providing the most comprehensive evidence of glacier change in the region.

The reports ‘Changing Dynamics of Glaciers in the Hindu Kush Himalaya (HKH) Region from 1990 to 2020’ and ‘HKH Glacier Outlook 2026: Insights from 50 years of Himalayan Glacier Monitoring’ reveal a total loss of up to 27 metres of ice thickness since 1975, ICIMOD said in a press release here.

The reports call for a massive scale-up in glacier monitoring, better standardisation of methodologies, and robust investment in climate-resilient adaptation planning to mitigate the impacts of a rapidly changing cryosphere.

The Himalayan Mountain range holds the largest volume of ice outside the poles, the report said, adding that these are also the source of at least 10 major Asian river systems, supporting the food, water, energy, and livelihood security of billions of people.

Around 78 per cent of this glacier area, located between 4,500 and 6,000 metres above sea level, is highly exposed to elevation-dependent warming, according to the report.

Pema Gyamtsho, Director General of ICIMOD, termed this a crisis unfolding in real time. “The fact that ice loss rates have doubled this century should shock us all into action,” he said, adding that the Hindu Kush Himalaya is at a crossroads.

“The rapidly escalating impacts we’re seeing from water uncertainty to catastrophic floods underscore that we are in a critical decade for the cryosphere. We must scale up monitoring and invest in adaptation now. They are our new reality,” he said.

The comprehensive analysis reveals that between 1990 and 2020, HKH glaciers lost about 12 per cent of their total area and 9 per cent of their estimated ice reserves, the report highlighted. “But the losses are most acute for the region’s smallest glaciers — those below 0.5 sq km —which are shrinking more rapidly than others,” said Sudan Maharjan, Remote Sensing Analyst at ICIMOD and lead author of the glacier dynamics report.

“This poses immediate risks of localised water shortages for high mountain communities and intensifies hazards like glacial lake outburst floods,” he said.

“The danger is magnified because three-quarters of the region’s glaciers fall into this vulnerable size class.”

“We are not just losing ice; we are facing a rapid escalation of risks,” the report pointed out.

“The HKH Glacier Outlook 2026 synthesises data from 38 monitored glaciers, revealing that widespread wastage has doubled post-2000, signalling that parts of the Himalayan cryosphere may be nearing critical tipping points toward irreversible retreat,” the ICIMOD statement said.

The report also highlighted a critical data gap: of those 38, only seven meet the global benchmark monitoring standards of the World Glacier Monitoring Service (WGMS). Major glacierised regions, including the Karakoram, Sikkim, Zanskar, and Bhutan, remain largely unmonitored, it added.

“Large parts of the Himalaya remain blind spots. Without expanding our monitoring networks and standardising methodologies, accelerated changes in water flows and cryosphere risks could remain undetected until the impacts are severe,” said Mohd Farooq Azam, a cryosphere specialist at ICIMOD and one of the report’s authors.

Sustained monitoring of representative glaciers like Mera and Rikha Samba in Nepal, and Chhota Shigri in India, is critical; they are our early warning indicators for the entire mountain system, he said.

According to the reports, glacier losses are spatially skewed, with the highest percentage of area loss in the eastern Hengduan Shan mountains, where some areas lost up to 33 per cent of their glacier area in just three decades.

However, the largest absolute area losses are concentrated in the Indus, Ganges, and Brahmaputra basins, where over 74 per cent of the region’s glaciers are found, underlining their critical vulnerability.

The larger glaciers above 10 sq kms hold nearly 40 per cent of the region’s natural water reserves. The heavily glaciated Karakoram range, home to 18 of the 25 largest glaciers, remains highly vulnerable to long-term water, food, and disaster risks with ramifications for the entire region, it pointed out.