How Climate Change Worsened Nepal's Deadly Mountain Collapse

Nearly 1,400 people lost their lives when a mountain slope collapsed, triggering flash floods that swept through Nepal and Tibet. Over 5,000 others are still missing. Initially believed to be caused by an earthquake, glaciologists and climate scientists have since found that a combination of factors, with climate change playing a significant role, led to the disaster.

Warming temperatures caused the glacier to recede, thaw permafrost, and increase meltwater, destabilizing the slope. The collapse occurred at an elevation of around 5,150 meters, with a series of processes acting over years to decades, not a single trigger. A massive rock avalanche on Langtang Lirung's north face, combined with the collapse of part of the glacier, sent approximately 110 million cubic meters of rock and ice down.

This energy release was comparable to a magnitude 5.2 earthquake. The flood, moving at 170 kilometers per hour, traveled 200 kilometers in under seven hours. Climate change, through rising temperatures and other factors, made this mountain particularly vulnerable, rendering local adaptation efforts ineffective in preventing such a catastrophic event.