On 18 September 2026, the Climate Risk and Resilience Lab (CRR Lab), in collaboration with NAXA, Creasion, Nepal Climate Centre, and the Climate Change Management Division (CCMD), Ministry of Agriculture, Forests and Environment (MoAFE), Government of Nepal, organized the first webinar of the three-part flagship webinar series, “Rasuwa Bhotekoshi Climate Catastrophe 2026: From Devastation to Resilience.”
The first session, “Unpacking the Physical Basis, Science & Attribution,” brought together around 200 participants, including government representatives, researchers, mountain scientists, climate experts, practitioners and members of the wider public. The session featured diverse expertise in mountain hazards, cryosphere science, Earth observation, climate attribution, climate policy and long-term climate change, examining the 26 August Rasuwa-Bhotekoshi catastrophe, what happened, the physical processes involved, the role of a changing climate, and what these lessons mean for Nepal’s future mountain risk and resilience.
Watch the full recording of the webinar:
Keynote and Expert Contributors
- Dr. Maheshwor Dhakal: Senior Joint Secretary and Chief, Climate Change Management Division, Ministry of Agriculture, Forests and Environment, Government of Nepal; UNFCCC Focal Person
- Dr. Simon K. Allen: University of Zurich, Switzerland
- Dr. Alton C. Byers: Senior Research Associate, Institute of Arctic and Alpine Research, University of Colorado Boulder
- Amrit Thapa: PhD Candidate, University of Alaska Fairbanks; Founding Member, Cryosphere Society of Nepal
- Prof. Dr. Friederike E. L. Otto: Professor in Climate Science; Co-lead, World Weather Attribution
- Prof. Dr. Detlef van Vuuren: Professor, Faculty of Geosciences, Utrecht University, Netherlands
- Moderator: Binod Prasad Parajuli: Executive Director, Climate Risk and Resilience Lab
Opening the conversation: Dr. Maheshwor Dhakal
The webinar opened with a keynote address by Dr. Maheshwor Dhakal, Senior Joint Secretary and Chief of the Climate Change Management Division (CCMD), Ministry of Agriculture, Forests and Environment, Government of Nepal, and Nepal’s UNFCCC Focal Person. He also serves as an Alternate Board Member of the Fund for Responding to Loss and Damage.
His keynote placed the Rasuwa-Bhotekoshi catastrophe within Nepal’s wider climate policy, mountain agenda and international climate negotiations.
A central message from his intervention was:
“The mountain agenda must be given a stronger place in the UNFCCC negotiation process, with the specific risks & needs of mountain regions reflected in global climate discussions.”
This framing was important for the discussions that followed. While the webinar focused heavily on the physical science of the catastrophe, Dhakal’s opening remarks situated those scientific questions within a much broader policy challenge: how should Nepal’s growing mountain risks be reflected in national planning, adaptation efforts, climate finance, Loss and Damage discussions and international climate negotiations?
In this sense, the keynote established the overarching context for the session: understanding what happened in Rasuwa is not only a scientific exercise, but also has implications for how Nepal prepares for and responds to emerging mountain risks.
Understanding the Physical Cascade: Dr. Simon K. Allen
The technical discussion then started with a presentation on the physical processes underlying the catastrophe, by Dr. Simon K. Allen examining the event as a complex interaction of mountain hazards.
His presentation highlighted the role of rock, ice, water, sediment and unstable mountain terrain, placing the Rasuwa-Bhotekoshi event within the broader context of cascading hazards occurring across the Himalaya.
Rather than viewing the disaster simply as a flood, the presentation demonstrated how an event originating in the high mountains can evolve through multiple interconnected processes before producing devastating downstream consequences.
One of the important messages was that these cascading processes are occurring in a mountain environment experiencing significant cryospheric and climatic change. At the same time, Allen emphasized the continuing need for better risk mapping, monitoring and early warning, particularly as exposure continues to increase along mountain settlements, infrastructure and strategic corridors.
His broader message was that the unprecedented nature of the 26 August event should not obscure the fact that it forms part of a wider pattern of cascading mountain hazards.
Evidence of Instability Before the Catastrophe: Amrit Thapa
Amrit Thapa, PhD Candidate at the University of Alaska Fairbanks and founding member of the Cryosphere Society of Nepal, brought Earth-observation evidence into the discussion through his presentation on periglacial slope instability in the Himalaya.
His analysis provided an important dimension to the question of whether the disaster was truly a sudden event.
Satellite observations showed that the exposed bedrock near the glacier terminus had already experienced more than 30 cm of movement over 34 days before the incident. The presentation also indicated that movement had been detectable earlier, beginning in 2025, and subsequently accelerating.
This was one of the significant lessons from the presentation: catastrophic failure may be preceded by measurable changes that are detectable through Earth-observation technologies.
Thapa also presented evidence of changing movement patterns in rock glaciers and periglacial environments, including observations from Humla showing widespread increases in rock-glacier movement during 2022.
His recommendation was therefore forward-looking: Nepal needs stronger and more continuous use of satellite-based monitoring, InSAR and optical/SAR feature tracking to identify changes in unstable slopes and the cryosphere before they develop into catastrophic events.
Glacier Hazards and the Role of Knowledge: Dr. Alton C. Byers
Dr. Alton C. Byers, Senior Research Associate at the Institute of Arctic and Alpine Research, University of Colorado Boulder, brought decades of experience working on mountain environments to the webinar.
His presentation, “Climate Change and Glacier Hazards in the High Mountains: Integrating Science and Traditional Knowledge for Reduced Impact and Strengthened Adaptive Response,” examined the diversity of hazards associated with changing mountain environments.
He discussed different forms of glacier-related and cascading hazards, demonstrating that high-mountain disasters can emerge through a range of mechanisms rather than a single hazard pathway.
An important aspect of Byers’ contribution was the emphasis on bringing together scientific knowledge and traditional/local knowledge. Understanding mountain hazards requires not only sophisticated scientific observation, but also knowledge of landscapes, historical events and local environmental changes accumulated by communities living in these environments.
This perspective also connected science with preparedness: the ultimate purpose of understanding changing mountain hazards is to reduce their impacts on people and infrastructure.
Climate Attribution: Prof. Dr. Friederike E. L. Otto
The webinar then moved from physical processes to one of its most important questions: what does climate attribution tell us about the conditions surrounding the event?
Prof. Dr. Friederike E. L. Otto, Professor in Climate Science and Co-lead of World Weather Attribution, discussed the role of human-induced climate change in shaping recent temperature conditions around the disaster site.
A key point from her contribution was that July and August temperatures near the disaster site were higher because of human-induced climate change than they would otherwise have been.
She also highlighted physical processes through which a warming climate may contribute to high-mountain instability, including:
“Glacier thinning and debuttressing, increased meltwater infiltration, and permafrost degradation.”
This was particularly relevant to the wider discussion because it connected recent extreme warmth with the longer-term warming trend and the changing conditions of the high-mountain cryosphere.
At the same time, the discussion underscored the importance of distinguishing between establishing the influence of climate change on temperature and fully attributing a complex cascading disaster involving multiple geological and cryospheric processes.
Otto also connected the scientific discussion to the issue of Loss and Damage:
“We need to take Loss and Damage much more seriously.”
Her intervention therefore extended the discussion beyond attribution itself, towards the implications of climate-related impacts for finance and international climate action.
Looking Beyond the Event: Prof. Dr. Detlef van Vuuren
The session also included a contribution from Prof. Dr. Detlef van Vuuren, Professor at the Faculty of Geosciences, Utrecht University, whose work focuses on integrated assessment, climate scenarios and long-term climate pathways.
His contribution brought the discussion from the immediate event towards the long-term implications of climate change for mountain regions.
His message was clear:
“Deep cuts in greenhouse gas emissions are essential to limit warming, but adaptation will still be necessary as glaciers continue to retreat, even under Paris aligned pathways.”
This provided an important connection between mitigation and adaptation. Limiting future warming remains essential, but even under ambitious emissions-reduction pathways, changes already underway in glacier and mountain systems mean that adaptation and risk reduction will remain necessary.
From Attribution to Action: What the Panel Discussion Highlighted
Following the expert contributions, the speakers came together for a panel discussion moderated by Binod Prasad Parajuli, Executive Director of Climate Risk and Resilience Lab.
The discussion brought together the different strands of the webinar: physical processes, cryosphere change, Earth observation, climate attribution, early warning, adaptation and Loss and Damage.
One of the central questions was how different forms of evidence can be brought together to understand the event more comprehensively. Climate data alone cannot explain a complex cascading mountain disaster; it needs to be considered alongside geological evidence, cryosphere observations, remote sensing and information about the evolution of unstable slopes.
The panel also explored lessons from other mountain regions and the potential for Nepal to strengthen its own systems for monitoring, preparedness and early warning.
This reinforced a recurring message throughout the webinar: the objective of science is not simply to reconstruct the disaster after it happens, but to identify signals that can support decisions before the next disaster occurs.
Key Takeaways
1. The Rasuwa-Bhotekoshi disaster was a cascading mountain hazard:
Understanding the event requires looking beyond the flood itself to the interconnected processes involving rock, ice, glaciers, water, sediment and unstable slopes.
2. Mountain instability can develop before catastrophic failure
Earth-observation evidence presented during the webinar showed that measurable movement can occur weeks, months or longer before a major failure, creating opportunities for monitoring and risk reduction.
3. Climate change is altering the physical environment in which mountain hazards occur
Long-term warming and recent temperature anomalies are occurring alongside glacier retreat, permafrost degradation and other cryospheric changes. Understanding how these factors interact with geological processes remains an important area of research.
4. Monitoring needs to become operational
Satellite observations, InSAR, optical imagery and other technologies can provide valuable information but their greatest value comes when they are connected to risk assessment, early warning, preparedness and evacuation decisions.
5. Science needs to inform policy and finance
The opening keynote and subsequent discussion highlighted that mountain risks need stronger recognition in national climate planning, international negotiations, adaptation and Loss and Damage processes.
6. Resilience requires both mitigation and adaptation
As the discussion highlighted, reducing greenhouse gas emissions is essential for limiting future warming, while adaptation remains necessary in response to changes that are already underway.
From Devastation to Resilience
The first webinar did not attempt to provide a single explanation for an extraordinarily complex event. Instead, it brought together different forms of evidence and expertise to begin answering three interconnected questions:
What happened?
What role is a changing climate playing?
And what can Nepal do differently as mountain risks evolve?
The discussion demonstrated that the answers lie at the intersection of mountain science, climate attribution, Earth observation, policy, finance and community preparedness.
The Rasuwa-Bhotekoshi catastrophe has therefore become more than a case study of a single extreme event. It is an important opportunity for Nepal to examine how a rapidly changing mountain environment is being monitored, how emerging risks are communicated, and how scientific evidence can be translated into preparedness and resilience.
The first webinar began by unpacking the science. The next step is to translate that understanding into action.