- Rapidly shrinking glaciers and unstable mountain slopes in Nepal are increasing risks of floods, landslides, and devastating debris flows downstream.
- The Rasuwa disaster demonstrates that mountain hazards are interconnected, necessitating comprehensive monitoring of glaciers, lakes, and slopes.
- Nepal advocates for international climate finance and justice to address increasing environmental losses despite having minimal global carbon emissions.
- Strengthening disaster resilience requires integrating advanced warning technology with community preparedness and building infrastructure that accounts for upstream environmental changes.
Kathmandu: Nepal’s Himalayan environment is changing. Glaciers are shrinking, glacial lakes are forming and expanding, and mountain slopes are becoming increasingly unstable. Avalanches, landslides, floods and changing weather patterns are increasing risks for communities, infrastructure and settlements downstream.
The disaster in Rasuwa on August 26 highlighted the risks associated with these changes. A sudden event in the high mountains affected areas downstream, damaging homes, roads, bridges and livelihoods.
By August 29, at least 669 people had been reported dead in Nepal and seven in Tibet, while around 3,000 people remained missing. More than 3,700 people had been rescued. Rescue operations have been complicated by damaged roads and bridges, disrupted communications and unstable mountain slopes.
Beyond Glacial Lake Outburst Floods
Nepal has focused considerable attention on glacial lake outburst floods (GLOFs), particularly because of the increasing number and size of glacial lakes.
The Rasuwa disaster, however, indicates that mountain hazards can develop through other processes as well.
Preliminary assessments indicate that the event involved the collapse of a large mass of glacier ice and rock, producing a powerful downstream flow of water and debris. Scientists are still examining the precise sequence of events.
It would be premature to conclude that climate change directly caused the Rasuwa disaster. However, the Himalayan environment is changing rapidly, affecting the conditions under which geological, hydrological and climatic hazards occur.
According to ICIMOD, glaciers across the Hindu Kush Himalaya lost ice at a rate 65 percent faster during 2011–2020 than during the previous decade.
Individual disasters can result from several interacting factors. Glacier retreat, unstable slopes, heavy rainfall, avalanches, landslides and changes in water systems can combine to produce complex events.
Interconnected Mountain Hazards
The August 2024 disaster in Thame in the Everest region also demonstrated the interaction between different mountain hazards.
The event was initially viewed mainly as a glacial lake outburst flood. A later ICIMOD study found that a large rock avalanche struck a glacial lake, generating a displacement wave that contributed to the lake’s breach. The resulting flood then affected another lake, increasing the scale of the event.
About 459,000 cubic metres of water and debris were released, destroying much of Thame settlement and displacing 135 people.
These events indicate that disaster assessments cannot focus on individual glacial lakes alone. The condition of glaciers, surrounding slopes, rivers, snow and ice, and possible natural dams also needs to be considered.
Glacial Lakes Remain a Major Risk
A joint assessment by ICIMOD and UNDP identified 3,624 glacial lakes across the Koshi, Gandaki and Karnali river basins in Nepal, Tibet and India. Of these, 47 were classified as potentially dangerous, including 21 in Nepal.
The classification does not mean that all 21 lakes are expected to burst. It indicates that their characteristics require continued monitoring and risk-reduction measures.
The risk can increase when a glacial lake expands rapidly, when its natural dam becomes unstable, or when an avalanche or landslide enters the lake and displaces a large volume of water.
Nepal’s experience with Tsho Rolpa and other glacial lakes shows that preventive measures can reduce risks. Continued monitoring remains necessary because mountain conditions can change.
Climate Risks Across Nepal
Climate-related risks extend beyond the Himalayas.
The Chure and Madhesh regions face drought, extreme heat, forest fires, water shortages, flash floods and land degradation. Farmers can face both water shortages and intense rainfall that damages crops, fields and homes.
Climate-related risks are therefore linked to agriculture, water resources, public health, infrastructure, tourism, employment and the wider economy.
Government figures cited in the source material show that Nepal recorded 32,375 disaster events between 2018 and 2024. These events caused 2,996 deaths and left 446 people missing. Direct economic losses were estimated at around NPR 23.6 billion.
Nepal’s Climate Justice Position
Nepal contributes only a small share of global greenhouse gas emissions but faces significant climate and disaster risks.
Nepal has raised the issue of climate vulnerability and climate finance in international forums. Former Prime Minister Pushpa Kamal Dahal ‘Prachanda’ raised Nepal’s vulnerability at the United Nations General Assembly in 2023 and called for greater international climate finance and support for climate-related losses.
UN Secretary-General António Guterres visited Nepal in October 2023, including the Himalayan region, drawing international attention to changes in the mountains.
Nepal had raised similar concerns earlier. In 2009, then-Prime Minister Madhav Kumar Nepal held a Cabinet meeting at Kalapatthar to highlight glacier melting. At COP26 in Glasgow in 2021, then-Prime Minister Sher Bahadur Deuba raised climate vulnerability and loss and damage. Former Prime Minister KP Sharma Oli also discussed melting glaciers, changing monsoon patterns, floods and landslides at the UN General Assembly in 2024.
Climate Finance and Risk Reduction
Nepal requires greater access to climate finance, technology and scientific expertise to address growing climate and disaster risks.
In July 2025, the Green Climate Fund approved a US$36.1 million grant for a programme aimed at reducing the risk of glacial lake outburst floods in Nepal. The programme covers four lakes—Thulagi, Lower Barun, Lumding Tsho and Hongu-2—and is expected to benefit more than 2.2 million people.
The Rasuwa disaster indicates that risk reduction should extend beyond individual glacial lakes. Monitoring should cover glaciers, slopes, rivers, snow and ice, and other potential sources of sudden water and debris flows.
Early Warning and Community Preparedness
Nepal can use satellites, remote sensing, weather stations, river gauges, glacier monitoring and ground sensors to monitor mountain conditions.
However, monitoring systems need to be connected to effective warning and evacuation mechanisms. Communities in vulnerable areas should have clearly identified evacuation routes and safe locations.
Local residents can also receive training in first aid, emergency communication and basic search and rescue. In remote mountain areas, local communities may be among the first groups able to respond when roads and communication systems are disrupted.
Safer Infrastructure
The Rasuwa disaster also raises questions about infrastructure development in mountain areas.
Roads, bridges and hydropower projects need risk assessments that account for hazards originating upstream. Infrastructure designed mainly around historical flood levels may not be adequate for large debris flows, landslides or other extreme events.
Reconstruction after disasters should therefore consider stronger designs and, where necessary, relocation of highly vulnerable facilities to safer locations. Risk assessments should include changing environmental conditions and events that may not have occurred frequently in historical records.
Regional Cooperation
The Himalayan river systems cross national borders. Changes in glaciers, lakes and rivers can affect communities in neighbouring countries.
Nepal and China have common interests in exchanging scientific information, monitoring high-risk areas and improving emergency communication.
Greater cooperation could improve the flow of information about rapidly developing mountain hazards and provide downstream communities with more time to prepare.
Rethinking Nepal’s Disaster Planning
Nepal’s climate and disaster policy needs to consider the interaction between different mountain hazards rather than focusing on individual threats separately.
A glacier collapse can trigger a rock avalanche or debris flow. An avalanche or landslide can affect a glacial lake. A sudden flood can damage bridges and roads and isolate settlements.
Disaster planning therefore needs stronger scientific monitoring, early-warning systems, safer infrastructure, community preparedness and coordination among government agencies.
Nepal also needs to continue documenting disaster-related losses and presenting evidence of its climate vulnerability in international climate negotiations.
The Rasuwa disaster demonstrates the need for a broader approach to Himalayan risk management. Nepal cannot prevent every glacier collapse, avalanche, landslide or flood, but it can improve monitoring, preparedness, infrastructure standards and emergency response.
Climate change and mountain hazards should therefore be addressed as issues of disaster management, infrastructure planning, scientific research and international cooperation.
