Climate Change Fueled Deadly Nepal-Tibet Glacier Flood, Study Finds

Human-induced climate change played a significant role in the glacier collapse that caused devastating floods on the Nepal-Tibet border, killing more than 1,400 people and leaving thousands missing, according to a new study.

The World Weather Attribution study, published on Thursday, characterized the disaster on August 26 as a "compound event." This involved a combination of rising temperatures, thinning glaciers, thawing permafrost, and pre-existing geological weaknesses.

"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 study found that July and August temperatures in the affected region were approximately 1.5 degrees Celsius (34.7 degrees Fahrenheit) warmer due to human influence on the climate.

The floods were triggered by the collapse of a glacier slope near the peak of Langtang Lirung, a mountain in Nepal. The impact of the collapsing glacier was so immense that it registered as a magnitude 5.2 earthquake, according to data from the United States Geological Survey.

Glaciers in the region have been thinning by about half a meter (1.6 feet) per year, a process that can weaken existing fractures and increase instability. Heavy snowfall in October and November of the previous year also contributed to a large volume of meltwater early this year, the study noted. This confluence of factors "may have interacted to amplify the compound event."

Scientists have also considered the impact of a magnitude 7.8 earthquake that struck the area in 2015. This earthquake triggered a rock-ice avalanche and could have weakened the underlying rock mass, according to the study. However, authorities have not been able to confirm the exact extent to which the 2015 earthquake contributed to the recent glacier collapse.

Walter Immerzeel, a mountain hydrologist at Utrecht University and a co-author of the report, described the area as a "geologically vulnerable slope" that was potentially weakened by the 2015 earthquake and further destabilized by glacier and permafrost retreat.

In the aftermath of the disaster, Nepali authorities have emphasized the country's vulnerability to climate change, despite being one of the lowest contributors to global greenhouse gas emissions. Prime Minister Balendra Shah is scheduled to address the United Nations General Assembly in New York to discuss the recent disaster and the concept of climate justice.