Key facts
- Climate change likely contributed to a catastrophic glacier collapse in Nepal and Tibet in late August.
- The collapse killed around 1,400 people, with thousands still missing.
- Rising temperatures, thinning glaciers, thawing permafrost, and pre-existing geological weaknesses were cited as contributing factors.
- Mean temperatures in the Himalayan region were around 5 degrees Celsius higher than normal in August, with 1.5 degrees Celsius attributed to climate change.
- Glaciers in the region have been thinning by about half a meter per year since 2000.
- A 2015 earthquake may have also played a role in weakening the bedrock.
Climate change likely contributed to a catastrophic glacier collapse that unleashed devastating floods on the Nepal-Tibet border, killing around 1,400 people and leaving thousands missing, scientists said. The World Weather Attribution (WWA) study cited rising temperatures, thinning glaciers, and thawing permafrost as key factors in the disaster on August 26.
Friederike Otto, a climatologist at Imperial College London and one of the study's authors, stated there was "absolutely no doubt that human-induced climate change played a role here in the preconditioning of the disaster." The study concluded the event was a "compound event" resulting from rising temperatures, thinning glaciers, thawing permafrost, and pre-existing geological weaknesses.
According to the study, mean temperatures in the Himalayan region were around 5 degrees Celsius higher than normal in August, with 1.5 degrees Celsius attributed to human influence on the climate. Glaciers in the region have thinned by about half a meter per year since 2000, potentially weakening existing fractures and increasing instability. Heavy snowfall last October and November also added to meltwater early this year.
Scientists at the United States Geological Survey (USGS) said the floods were caused by the collapse of a glacier slope near the peak of Langtang Lirung. The collapse registered as a magnitude 5.2 earthquake. The WWA study noted that a 2015 earthquake could have also weakened the underlying rock mass, but authorities could not confirm its exact impact on the recent collapse. Walter Immerzeel, a mountain hydrologist from Utrecht University and co-author, described the area as a "geologically vulnerable slope" further destabilized by glacier and permafrost retreat.