Glacial alarm : Expanding lakes demand urgent action

AN IIT-Mandi study identifying nine rapidly expanding glacial lakes in Himachal Pradesh should be read as a warning, not merely another climate-change statistic. The study mapped 2,076 glacial lakes above 3,500 metres in 2025 — around 710 more than a decade earlier — while their cumulative area grew by 28.45%. More than 15 bridges, besides inhabited areas and educational and healthcare facilities, lie within potential hazard zones. The timing could hardly be more sobering. Nepal is still counting the human and economic cost of the August 26 disaster triggered by a glacier collapse. More than 1,300 people have died and thousands remain missing. A huge surge of water, mud, ice and rock swept through valleys, destroying settlements and infrastructure and trapping workers at hydropower projects. There is no suggestion that Himachal is destined to suffer a similar catastrophe. But the Nepal tragedy demonstrates how quickly a high-altitude event can become a downstream disaster. In a warming Himalaya, glacier retreat, expanding lakes, thawing permafrost, landslides and extreme rainfall can interact in ways that conventional disaster planning may fail to anticipate. Himachal cannot afford to wait for a glacial lake to burst before taking preventive action. Satellite monitoring must be supplemented by ground-based surveillance, real-time early-warning systems and clearly marked evacuation routes. Communities downstream need regular drills, while bridges, hydropower projects and other critical infrastructure must be assessed for cascading hazards. Development policy also needs a rethink. Roads, tourism and construction in fragile high-altitude areas cannot be planned as though the mountain environment were stable. The more infrastructure is placed in vulnerable valleys, the greater the potential human cost of a natural hazard. The IIT-Mandi study has provided the map. The next step must be action.