The study found that climate change contributed to the melting of glaciers, which caused devastating floods along the Nepal-Tibet border.
The August 26 flood left more than 1,400 people dead and thousands missing.
“There was absolutely no doubt that human-caused climate change played a role in the preconditions for the disaster here,” said Friederike Otto, a climate scientist at Imperial College London and one of the study’s authors.
A World Weather Attribution study released Thursday said the disaster was the result of a “complex event” caused by rising temperatures, thinning glaciers, thawing permafrost and pre-existing geological weaknesses.
Massive floods and landslides have ripped through border towns and villages in Nepal and Tibet, destroying thousands of homes, destroying energy infrastructure and leaving thousands of people dead or missing.
Scientists had previously said the floods were caused by the collapse of a glacier slope near the summit of Langtang Lirung, a mountain on the Nepalese side of the Himalayas.
A large piece of glacier struck the valley floor with such force that it was recorded as a magnitude 5.2 earthquake, according to the United States Geological Survey (USGS).
The World Weather Attribution study says climate change is a “destabilizing factor acting on a pre-existing geological predisposition,” but it is not the only cause of the disaster.
Temperatures in July and August in the area were about 1.5C (34.7F) warmer “due to human influence on the climate,” according to the study.
Meanwhile, glaciers in the region are also thinning by about half a meter (1.6 feet) per year, which could weaken existing cracks and increase instability.
Heavy snowfall in October and November last year also increased the amount of meltwater earlier this year.
This combination of actions “may have interacted to enhance the complex event,” the study said.
