The first scientific study into the devastating floods in Nepal and Tibet last month indicates that climate breakdown likely weakened the glacier responsible for the catastrophe. The collapse, which occurred on 26 August, sent an avalanche of 110 million cubic metres of snow and ice into the valley below, triggering flash floods that hit communities downstream without warning.
More than 1,300 people were killed and over 5,000 remain missing after a massive section of glacier and rock, approximately 200,000 square metres, fell from Langtang Lirung mountain. The impact registered as an earthquake, liquidising ice and creating a freezing flood that travelled at speeds exceeding 110 mph.
Researchers from Imperial College London, part of the World Weather Attribution (WWA) project, identified unusually warm conditions prior to the collapse. July and August 2026 were the warmest on record locally, reaching 5C above the 30-year average in the days before the event. Dr Friederike Otto, a climate science professor at Imperial College London, stated that "communities in Nepal are paying with their lives for a crisis driven by fossil fuel emissions thousands of miles away."
The study found that climate breakdown has caused about 2C of warming in the region since pre-industrial times, and about 1.5C specifically in July and August. The freezing threshold in the Himalayas has risen by approximately 100 metres per decade since the 1980s, leading to higher and longer thaw temperatures that weaken mountain slopes. While a 7.8 magnitude earthquake in 2015 also contributed to slope failure, its specific role in the August disaster could not be confirmed.
Dr Ben Clarke, who researches extreme weather and climate change at Imperial, noted that the "fingerprints of climate change" were clear in the long-term changes around the glacier before its collapse. The study describes the disaster as a compound crisis, with multiple factors exacerbated by decades of atmospheric heating from greenhouse gas pollution. The researchers clarified that their study did not directly attribute climate breakdown as the fundamental cause but rather as a destabilising factor on the existing geology.