Scientists from the International Centre for Integrated Mountain Development (ICIMOD) have identified a concerning increase in glacier-lake floods in the Hindu Kush Himalayas. When water from a lake fed by a melting glacier is abruptly released, it is known as a glacial lake outburst flood (GLOF). These floods were earlier predicted to occur in the region once every five to ten years in the 2000s. Glacier-lake floods in the Hindu Kush Himalayas are now being observed with greater frequency, raising serious concerns about the changing hydrology of the mountains.

However, ICIMOD documented three GLOF incidents in May and June 2025 across Pakistan (Chitral, Hunza), Afghanistan (Andorab Valley), and Nepal (Limi). Researchers emphasize the urgency of examining the underlying triggers, as the speed of these events can produce cascading impacts.

Climate-Driven Causes and New Trends

Temperature is crucial for glacial flooding as glacial lakes evolve and expand in size due to sustained warming and melting processes. Temperature can shift on a short timescale, in some cases leading to unanticipated consequences, such as ice calving, avalanches, or slope failures, which generally result from melting permafrost or a surface material that has been or was frozen for two or more consecutive years.

According to ICIMOD, newly formed supraglacial ice-dammed lakes were responsible for recent GLOF events, including the June 2025 flood in the Bhotekoshi Nadi of Rasuwa, Nepal. These lakes start as small meltwater ponds that enlarge or merge on the surface of glaciers, often in debris-covered areas. By June 2025, the lake that caused the flooding in Nepal had further grown in area since it was imaged in December 2024.

Also Read: Melting Ice Caps May Trigger More Explosive Volcanic Eruptions

Challenges in Detection and Possible Future Risks

The low resolution of free and publicly available satellite data from programs such as Landsat and Sentinel-2 makes it challenging to detect supraglacial lakes, notably smaller or short-lived ones. Historically, the study of supraglacial lakes has concentrated mainly on moraine-dammed lakes, and even then, only those larger than 0.02 km² were recognized as a hazard. There are currently 25 lakes classified as ‘potentially dangerous‘ in Nepal, 21 in China’s Tibet Autonomous Region, and a single lake classified as potentially dangerous in India.

To enhance hazard assessments, the researchers advocate for increased mapping and monitoring, up-to-date lake inventories, and a more thorough analysis of smaller ice-dammed lakes. They indicate that there is currently a significant difference between what is being monitored and the present rate of change.

According to ICIMOD, the risk of GLOF is projected to triple by 2100 in the Hindu Kush Himalayas, a region spanning eight countries that supports the food, water, and energy needs of approximately two billion people. Glacier-lake floods in the Hindu Kush Himalayas thus represent not just a regional issue, but a broader environmental and humanitarian challenge.

Also Read: Europe’s Heatwave Claimed 2300 Lives In 10 days: New Study