Scientists link the Nepal glacier collapse to a warming climate

KATHMANDU: A warming climate most likely contributed to the conditions behind the glacier and rock collapse in Nepal on August 26, according to an analysis by the World Weather Attribution group published on Wednesday.

The disaster on Langtang Lirung, near the border between Nepal and China, killed at least 1,300 people and left about 5,000 missing. Losses are estimated at US$5 billion.

Researchers put the initial failure at roughly 116 million cubic metres of rock and ice. The debris moved at speeds of up to 160 kilometres an hour and rose some 90 metres as it swept through the valley below, making the event about five times the size of the 2021 Chamoli disaster in India.

Rising temperatures are pushing the freezing line upward by about 100 metres a decade, the report said. That shift exposes mountain rock to longer thaws and eats away at the permafrost that has held these walls together.

Glaciers in the area have thinned by more than half a metre a year, and Langtang Lirung itself has retreated about half a kilometre since the 1990s. July and August this year were the warmest on record locally, following unusually heavy snowfall in late 2025.

"When you combine high-elevation permafrost degradation with glacier retreat and record summer heat, the structural integrity of these mountain walls is compromised," said Walter Immerzeel, a mountain hydrologist at Utrecht University.

He described what is happening across the Himalayan mountain environment as fundamental and irreversible.

Ben Clarke, a climate scientist at Imperial College London, said the disaster was not an extreme weather event, but that the fingerprints of climate change on it are still clear.

The report does not treat climate change as the sole cause. The 2015 earthquake is believed to have weakened the rock beforehand, and the destabilising processes played out over decades.

The Hindu Kush Himalaya holds more than 63,000 glaciers, feeding 10 major Asian river systems on which billions of people depend. Between 2000 and 2019, the region's glaciers lost about 267 billion tonnes of ice a year.