The devastating aftermath of the flash floods in Nepal has once again raised concerns over the changing Himalayan environment and the growing risks linked to rapidly melting glaciers. Amid the disaster, it has emerged that experts had already warned about these dangers months before the flash floods struck Nepal.
Five months earlier, two reports by the International Centre for Integrated Mountain Development (ICIMOD) had highlighted the increasing risks posed by rapid glacier melt and glacial lake outburst floods across the Hindu Kush Himalaya region.
The ICIMOD reports, titled “Changing Dynamics of Glaciers in the Hindu Kush Himalaya Region from 1990 to 2020”, published in March 2026, and the “HKH Glacier Outlook 2026”, highlighted the accelerating loss of glaciers and the potential dangers for communities living downstream.
According to the reports, glaciers in the upper Himalayas lost nearly 12 per cent of their total area and around 9 per cent of their estimated ice reserves between 1990 and 2020. ICIMOD Remote Sensing Analyst Sudan Bikash Maharjan said the changes had intensified hazards such as glacial lake outburst floods.
The reports also highlighted the risks faced by nearly two billion people living downstream who depend on meltwater from the region’s “Water Towers of Asia”. The situation becomes even more concerning because around three-quarters of the region’s glaciers fall into a vulnerable size category.
The HKH Glacier Outlook 2026, which studied 38 glaciers, found that the rate of glacier loss had doubled since 2000. The report warned that parts of the Himalayan cryosphere could be approaching critical tipping points that may lead to irreversible retreat.
The report further cautioned that if global climate action fails and greenhouse gas emissions continue to rise rapidly, as much as two-thirds of the region’s glaciers could be lost by 2100.
Meanwhile, scientists and geologists are investigating whether a glacial collapse followed by an ice-rock avalanche triggered the devastating flash floods along the Bhote Koshi River on Wednesday.
Preliminary assessments suggest that the debris may have temporarily blocked the Lhende River, creating a landslide dam. The natural barrier later gave way, sending a large volume of water and debris downstream and affecting Nepal’s Rasuwa district.
Satellite images examined by ISRO’s National Remote Sensing Centre (NRSC) have also provided important clues about the scale of the glacier collapse. The images indicate that nearly two-thirds of the glacier had separated from its original position.
A Sentinel-2 image captured on August 24 showed the glacier still intact. However, a Landsat-9 image taken on Wednesday after the disaster showed a large scar at the site of the collapse.
The satellite images also revealed a wide trail of ice and rock debris descending towards the river, indicating the massive scale of the avalanche and raising further questions about the role of glacier instability in the Nepal flash floods.
