Climate change played role in Nepal-Tibet flood, study finds

A study has found that climate change had contributed to the glacier collapse that unleashed devastating floods on the Nepal-Tibet border.

More than 1,400 people were killed and thousands are missing following the deluge on 26 August.

There was "absolutely no doubt that human-induced climate change played a role here in the preconditioning of the disaster", said Friederike Otto, a climatologist at Imperial College London and one of the study's authors.

The World Weather Attribution study, published on Thursday, said the disaster was the result of a "compound event" caused by rising temperatures, thinning glaciers, thawing permafrost and pre-existing geological weaknesses.

Massive floods and landslides swept through border towns and villages in Nepal and Tibet, wiping out thousands of houses, destroying energy infrastructure and leaving thousands dead or missing.

Scientists had previously said that the floods were caused by the collapse of a glacier slope near the peak of Langtang Lirung, a mountain on Nepal's side of the Himalayas.

The large chunk of glacier hit the bottom of a valley with such force that it registered as a magnitude 5.2 earthquake, according to United States Geological Survey (USGS) data.

The World Weather Attribution study said climate change was a "destabilising factor acting on a pre-existing geological predisposition", but it was not the only cause of the disaster.

According to the study, July and August temperatures in the area were around 1.5C (34.7F) warmer "due to human influence on the climate".

Meanwhile, glaciers in the region had also been thinning by about half a metre (1.6ft) a year, which could weaken existing fractures and increase instability.

Heavy snowfall last October and November also added to a large amount of meltwater early this year.

This combination of activities "may have interacted to amplify the compound event," the study said.

A magnitude 7.8 earthquake that struck the area in 2015 and triggered a rock-ice avalanche, could have also weakened the underlying rock mass, according to the study.

However, authorities said they could not confirm that earthquake's exact impact on the glacier collapse last month.

Another co-author of the report, Utrecht University mountain hydrologist Walter Immerzeel, told reporters that the area was a "geologically vulnerable slope".

Immerzeel said it was "potentially weakened by the 2015 earthquake" and "destabilised further" by glacier and permafrost retreat.

In the wake of the disaster, Nepali authorities have called for global efforts to tackle climate change, saying the country is one of the lowest contributors to greenhouse emissions yet one of the most vulnerable places to the effects of global warming.

In his first foreign trip as Nepali Prime Minister, Balendra Shah is set to appear at United Nations General Assembly in New York next week to talk about the recent disaster and climate justice.