A devastating flash flood in Nepal’s Rasuwa area near the Nepal-Tibet border on 26 August has renewed concern over climate change impacts on the Himalayas. Scientists say rapidly melting glaciers and permafrost are weakening mountain slopes, increasing the risk of glacier collapses, landslides and sudden floods. Hundreds of people were killed and many others went missing in the border-area disaster.

The US Geological Survey said a 5.2-magnitude tremor recorded during the event was not an earthquake, but resulted from a glacier collapse and a massive movement of ice and rock downhill. Scientists said the debris entered a river, creating a powerful flow of water, ice, mud and rocks. River levels rose by about nine metres within 30 minutes, submerging nearby settlements, roads, bridges, power facilities and other infrastructure.

Scientists cautioned that further research is needed to determine the disaster’s direct link to climate change. They urged regular monitoring of glaciers and river levels, satellite surveillance, stronger early-warning systems and faster information-sharing among Nepal, China and downstream countries. Rivers originating in the Hindu Kush-Himalaya region support the lives and economies of about 2.1 billion people.