Warming, 2015 quake 'behind Nepal disaster' after scientists trace glacier thaw

Climatic drivers, especially warming, piggybacking on geological factors, played a key role in triggering the August 26 avalanche that devastated Nepal, according to a rapid scientific analysis released this week by World Weather Attribution scientists and international glaciologists.

Earlier, some researchers had said it was difficult to conclusively link a fast-moving, localised rock-ice avalanche to global warming. The massive rock-and-ice collapse on the country’s northern border swept away communities and localities.

“Scientists identify the role of climate change on possible causal factors of the collapse, which resulted in devastation well in excess of adaptation limits,” reads the report. World Weather Attribution is an international scientific collaboration that analyses and communicates the possible influence of climate change on extreme weather events, such as storms, extreme rainfall, heatwaves and droughts.

“Decades of atmospheric warming — caused primarily by the burning of fossil fuels — have melted the glacier and pushed the freezing threshold line (0°C isotherm) upward by around 100 metres of altitude per decade,” states the report, explaining that “…this has resulted in glacier recession and thawing occurring in permafrost within rock fractures that historically hold high mountain walls together, rendering them unstable”. The report adds that the 2015 earthquake of 7.8 magnitude is likely to have preconditioned the slope for collapse.

“The fingerprints of climate change are clear to see in long-term changes…. We found that climate change is transforming the high mountain environment, influencing many of the possible drivers of this collapse. This increases the risk in a region that is already exposed to high seismic activity,” said Ben Clarke, an extreme weather and climate change researcher from Imperial College London and a member of the research team.

Apart from glacial thinning, permafrost thaw and compound preconditioning because of the massive earthquake in 2015, high locally recorded recent temperatures and increased meltwater were identified as major causes behind the sudden flood that ravaged the area and its people, at a speed of more than 190km per hour in the initial flow, the report suggests.

“July and August 2026 — directly before the collapse — were the warmest on record locally. High snowfall in October and November 2025 added large amounts of meltwater in the months preceding the collapse,” the report says.

Harjeet Singh, global convenor of the Fill the Fund campaign and founding director of Satat Sampada Climate Foundation, said: “The science is now unambiguous: fossil-fuelled warming thinned the glaciers and thawed the permafrost that held the mountain together. Nepal did nothing to cause this, yet its people are paying with their lives. This is climate injustice — and the Loss and Damage Fund must deliver now, not as charity, but as compensation and reparations.” Nepal has urged the Loss and Damage Fund for financial support.

The Fill the Fund campaign is a global climate initiative demanding that wealthy nations and corporate polluters fully finance the United Nations “Fund for Responding to Loss and Damage”.

“The Bhote Koshi catastrophe is a stark warning of the growing risks people are facing with the rapidly warming Himalaya,” added Manjeet Dhakal, director of climate analytics South Asia.