Expansion of Himalayan glacial lakes is happening due to climate change, posing risk to community and biodiversity because of increased chances of Glacial Lake Outburst Floods (GLOFs).   

Key findings of report:

• Glacial lakes expansion: Himalayan region witnessed a 10.8% increase in surface area of glacial lakes from 2011-24.
  • India: With a 34% expansion in surface area, glacial lakes experienced an even more substantial rise. 
• High risk lakes: 67 lakes in India witnessed an over 40% increase in surface area, placing them under high-risk category for potential GLOFs. 
• Transboundary risks: There exist transboundary risks of these expanding glacial lakes in Bhutan, Nepal and China.   
• Monitoring:  Precise monitoring was done using ‘Sentinel-1’ - Synthetic Aperture Radar and ‘Sentinel-2’ - satellite.

What are glacial lakes?

• These are water bodies originating from a glacier, formed when a glacier erodes land and then melts, filling depression created by it.

About GLOFs:   

• Sudden release of water retained in a glacial lake that can be located in front, at side, underneath, within, or on top of a glacier, causing large amounts of water to flow into nearby rivers.
  • E.g., GLOF in Sikkim (Oct 2023) triggered by bursting of South Lhonak Lake.