Scientists identify factor raising disaster risks in the Himalayas

An international team of scientists examined the factors behind the disaster that struck Nepal’s Rasuwa district on the border with China on August 26, 2026. The collapse of a rock mass and part of a glacier on Mount Langtang Lirung triggered an avalanche that developed into a destructive flow of water, rocks and debris. According to figures cited in the study, 1,386 people had been confirmed dead and another 5,130 remained missing as of September 12.

The collapsing material fell approximately 1,400 meters. The energy released generated seismic waves initially mistaken for an earthquake signal. As the flow travelled downstream, it picked up ice, water and rock, destroying settlements, roads and bridges. Near the Rasuwagadhi border crossing, the flood wave reached an average speed of 188 kilometers per hour.

The researchers found that human-induced climate change had significantly increased temperatures both around the collapse site and across the wider Himalayas. Across the indicators studied, warming has been comparable to the global average or up to approximately 1.5 times greater. The elevation at which air temperature reaches zero degrees Celsius is rising by around 50 to 100 meters per decade during the monsoon and post-monsoon seasons.

Rising temperatures contribute to permafrost thaw and the melting of ice within rock fractures. This weakens the rock, while water entering the fractures can further destabilize slopes. At the same time, glacier thinning and retreat reduce the natural support at the base of adjacent slopes.

The scientists also identified the possible lingering effects of the magnitude 7.8 earthquake that struck the region in 2015. It may have weakened mountain slopes long before the latest disaster. Melting accumulated snow and unusually high temperatures before the collapse may also have contributed.

However, the authors stress that the study does not establish whether this particular avalanche would have occurred without human-induced climate change.

“They support a physically plausible contribution of climatic conditions to progressive destabilisation, but do not establish the magnitude of that contribution or identify a unique trigger,” the study states, referring to its findings.

Such an assessment requires additional evidence on temperatures within the rock, water pressure in fractures and changes in slope stability.

According to the researchers, the magnitude and speed of the flow exceeded the parameters typically used to design protective infrastructure. Efforts to reduce risk are also constrained by the limited availability of habitable land, with settlements, transport routes and hydropower facilities concentrated in river valleys.

“This event shows that limits to adaptation are already being reached and transformative actions are needed at local and global levels to avert, minimize and address losses and damages,” the authors note.

The scientists recommend expanding monitoring in high mountain areas, strengthening cross-border data sharing and accounting for interconnected natural hazards when planning construction.

Earlier Qazinform News Agency reported that the death toll from the devastating August 26 flood in Nepal has risen to 1,403.