The Threat of Melting Himalayan Glaciers and Rising Glacial Lakes
Melting glaciers in the Himalayas are a growing concern for communities and river systems in India. This issue gains attention each year on March 14, which is celebrated as the International Day of Action for Rivers.
Recent studies show that the number of glacial lakes is increasing significantly. Satellite data from the Indian Space Research Organization (ISRO) has tracked 676 glacial lakes larger than 10 hectares in the Himalayas since 1984, with 130 of those located in India. Alarmingly, around 601 of these lakes have more than doubled in size over four decades, raising fears of flooding.
From 2011 to 2025, the area covered by glacial lakes in India grew from 1,995 hectares to 2,445 hectares—a 22.56% increase. This trend points to the risk of more Glacial Lake Outburst Floods (GLOFs), which occur when water behind natural dams (moraines) becomes too heavy, causing a sudden release and downstream flooding.
Professor Bindya Vasini Pandey from the University of Delhi highlights the growing number of new lakes forming in areas like Yamunotri due to climate change. As temperatures rise, glaciers melt, leading to increased risks for nearby communities. To better understand these risks, his team is studying the lakes in the upper Yamunotri catchment area, using satellite data and local observations.
The impact of these changes was evident during the flash flood in Uttarakhand on August 25, 2025. ISRO’s investigation determined that a massive ice mass from the Srikanta Glacier collapsed, resulting in widespread flooding rather than a cloud burst, which was initially thought to be the cause.
Government reports reveal the extent of the challenge. The Glacial Lake Atlas mapped over 28,000 glacial lakes across the Himalayan region, with 7,570 lakes in India, and 428 lakes in need of close monitoring. Most of these lakes are located in Arunachal Pradesh (181 lakes), followed by Ladakh and Jammu and Kashmir.
67 of these lakes have expanded by more than 40%, placing them in a high-risk category. Additionally, moraine-dammed lakes are vulnerable to collapse, especially those above 5,000 meters, making monitoring and warning systems challenging.
Scientists warn that glacier melting has accelerated sharply in recent years, with estimated losses of around 8 billion tonnes of ice annually. Snow levels have also declined, which affects future water supplies for rivers like the Ganga, Indus, and Brahmaputra. If trends continue, these perennial rivers could become seasonal, impacting drinking water, agriculture, and hydropower generation.
The effects of glacial floods extend beyond immediate damage. Hridyesh Joshi, founder of Eco N Energy Talk, points out that floods not only erase crops and destroy homes but also lead to long-term economic issues. High sediment levels can impair dams, reducing their efficiency and posing risks to surrounding infrastructure.
In response to these threats, the Indian government launched the National GLOF Risk Mitigation Programme (2021–2026). This initiative aims to monitor vulnerable lakes with satellite technology and field surveys. Agencies now track 902 glacial lakes monthly and are installing early warning systems in high-risk areas like Arunachal Pradesh.
As scientists continue their research, it’s clear that understanding and mitigating these risks is essential to protect both communities and the fragile Himalayan ecosystem.
For further reading on the impact of climate change on Himalayan glaciers, you can visit the IPCC report.
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GLACIERS, LAKES, MORAINES, DAMS, RIVERS, MELTING HIMALAYAN GLACIERS, INCREASING GLACIAL LAKES THREAT TO INDIAN RIVER SYSTEMS
