Kathmandu, 10 July 2025
Nepal is facing increasing threats from glacial lake outburst floods (GLOFs), as warming temperatures linked to climate change accelerate the melting of Himalayan snow and ice. The latest disaster struck on Tuesday morning when a massive flood swept through Nepal’s Rasuwa district, originating from a glacial lake breach high in the Tibet Autonomous Region of China.
According to the National Disaster Risk Reduction and Management Authority (NDRRMA), the flood was triggered by the sudden collapse of a supraglacial lake located 35 kilometers upstream of the Nepal-China border. Dinesh Raj Bhatt, Executive Chief of the Authority, confirmed that the lake was formed from accumulated meltwater due to prolonged snowmelt. When the natural moraine dam failed, the lake drained rapidly, sending torrents of water through the Lhendekhola and Bhotekoshi rivers, eventually surging into the Trishuli River basin.
Satellite imagery from Chinese and international sources has verified that the glacial lake, which held around 638,000 square meters of water earlier this week, was reduced to just 435,000 square meters following the breach. These figures reflect a significant loss in volume and confirm the lake as the flood’s origin point.
“This is a direct impact of climate change,” said Bhatt. “Rising temperatures are intensifying glacial melt, leading to the formation of unstable lakes on the glacier surface. Once these lakes exceed a critical threshold, their sudden failure results in catastrophic flooding downstream.”
The effects of such disasters are not isolated. In recent years, multiple regions in Nepal—including Solukhumbu, Melamchi, Humla, and now Mustang—have experienced similar events. In Mustang's Lo Manthang area, a recent flood is also suspected to have been triggered by the collapse or leakage of a glacial lake. An investigation team has been deployed to assess the situation.
Glaciologists warn that these events are likely to increase in frequency and intensity. Scientist Nitesh Khadka from the Chinese Academy of Sciences explained that the flood in Rasuwa originated from a supraglacial lake covered by sediment and ice. “Such lakes are inherently unstable and form quickly due to fluctuations in temperature. Many of the lakes observed in Tibet today didn’t exist before 2021,” he stated.
Supporting this assessment, researcher Amrit Thapa noted that satellite images showed extensive snowmelt occurring just days before the flood, with large amounts of ice and snow disappearing between Friday and Sunday. This meltwater likely collected in the glacial pond and, unable to be contained by the fragile ground beneath, breached with devastating force.
Adding urgency to the situation, glaciologist Dr. Sudip Thakuri emphasized that the Hindu Kush Himalayan region is experiencing a sharp rise in temperatures, resulting in a dramatic increase in the rate of glacial melting. According to the International Centre for Integrated Mountain Development (ICIMOD), Nepal is home to 21 glacial lakes identified as high-risk. An additional 47 glacial lakes lie along Nepal’s international borders, contributing to the danger of transboundary floods.
Alarmingly, Nepal has not conducted an updated study on glacial lakes since 2015.
Experts are calling for urgent monitoring, research, and early-warning mechanisms to prevent further disasters. “With climate change accelerating, glacial lakes are forming faster than we can study them. Without timely interventions, such disasters will become the new normal,” Bhatt warned.
As Nepal grapples with the growing threats of climate-induced hazards, this latest flood serves as a stark reminder of the global climate emergency unfolding in the world’s highest mountains.
