Face-To-Face
Arup Rajouria has more than twenty-five years of experience in senior management, having served as CEO of the largest semi-governmental natural and cultural heritage conservation organisation in Nepal. He was instrumental in mobilising resources for programme implementation and in developing partnerships with national and international organisations. He has also served as chief technical advisor on climate change at the Prime Minister's Office in the Laos People's Democratic Republic and at the Ministry of Natural Resources and Environmental Conservation in Myanmar, assisting governments in strategising at the political and inter-governmental level, mobilising resources, and developing national strategies on climate change, climate finance, and capacity building.
Following the catastrophic August 26 Bhote Koshi disaster, which has left over 1,377 dead and 5,000 missing, Bal Krishna Sah of The Himalayan Times sat down with climate and conservation expert Arup Rajouria to examine its causes and aftermath. Excerpts:
How have you been observing the Bhote Koshi disaster, which struck on August 26?
This was not simply a flood. It was a cascading mountain disaster-and a warning that the Himalaya is entering a much more dangerous phase.
For years, we have spoken mainly about glacial lake outburst floods. But what happened in Rasuwa appears to be different. Preliminary scientific assessments indicate that it involved a glacier–rock collapse, or ice–rock avalanche, in the upper Lhende Khola catchment. The collapse temporarily blocked the river, and the release that followed sent water, ice, boulders and sediment down the Bhote Koshi and Trishuli systems with devastating force.
The distinction matters. A glacial lake can be identified, monitored and, in some cases, drained. But when warming destabilizes frozen rock, glacier margins and steep mountain slopes, the risk becomes far more difficult to predict. Permafrost is, in simple terms, the frozen material that helps bind rock and boulders together at high altitude. As temperatures rise, that binding weakens. When it fails, an entire mountainside can collapse.
Researchers have identified more than 260 potentially dangerous glacial lakes across the Hindu Kush Himalaya-sites I call ticking time bombs. Nepal has dozens of such high-risk lakes. But the most alarming fact about Rasuwa is that it was not even on that list. This was not a known lake waiting to burst. It was a mountain failing. That tells us the danger may be much wider than the maps we have relied on so far.
Preliminary analysis indicates that the initial debris surge travelled around 20 kilometers in about seven minutes-at an estimated speed of roughly 193 kilometers per hour. At that speed, you are not dealing with an ordinary flood. You are facing a moving wall of ice, water, rock, mud and sediment. It is like wet concrete racing down a narrow valley.
What can survive that? Roads, bridges, border infrastructure and hydropower facilities are simply not designed for that kind of force. The preliminary government assessment indicates that 55 kilometers of roads, 37 motorable bridges, 68 suspension bridges, 13 hydropower projects and 783 MW of generating capacity were affected.
That is why I call this the tip of the iceberg. We are no longer dealing only with dangerous glacial lakes. We are increasingly dealing with unstable mountains.
Some have questioned whether this originated on the Chinese side.
The honest answer is that this occurred in a transboundary mountain catchment, and the exact initiation sequence should be settled through a joint, independent scientific assessment.
The Lhende Khola catchment lies close to the Nepal–China border. Early reports differ on the exact location and sequence, but the broad scientific picture is clear: a major ice–rock mass movement occurred in the upper catchment, temporarily blocked the river and triggered a catastrophic downstream flood.
That is exactly why Nepal and China need real-time data sharing, satellite analysis and joint monitoring of mountain hazards. A collapsing slope does not recognize a political border. A river does not need a visa.
But we should not turn this into a narrow argument over which side of the border the initial collapse took place. The deeper issue is a warming Himalaya. India has suffered devastating mountain disasters in Kedarnath, Chamoli and Sikkim. Those were not China-border incidents. They show the same wider pattern: retreating glaciers, weakening slopes, erratic rainfall and rising exposure of people and infrastructure in fragile mountain valleys.
The Himalaya is telling us that the old assumptions no longer hold.
You have also pointed to black carbon as a factor.
Black carbon is one of the least discussed but most serious threats to the Himalaya. It comes from incomplete combustion-diesel vehicles, brick kilns, coal, biomass burning, household fuels, industry and agricultural-residue burning. When black carbon settles on snow and ice, it darkens the surface. The darker surface absorbs more heat and melts faster.
The southern slopes of the Himalaya are especially exposed because pollution from the Indo-Gangetic Plain can travel north and settle on snow and glaciers. Agricultural-residue burning in India and Pakistan, together with industrial, transport and biomass emissions across the region, adds to the problem.
I would not claim that black carbon alone caused the Rasuwa collapse. That needs a detailed forensic investigation. But it is undoubtedly part of the wider risk environment. We cannot have a serious conversation about glacier loss while avoiding the pollution that settles on Himalayan snow and ice every year.
The wider science is already alarming. Glacier ice loss across the Hindu Kush Himalaya has doubled since 2000. That should concern every government in the region.
What does losing these glaciers actually mean for the region?
The Himalaya is not simply a beautiful landscape. It is one of the world's great water towers-and Nepal sits at the center of that system.
The Hindu Kush Himalaya is the source of 10 major Asian river systems: the Amu Darya, Indus, Ganges, Brahmaputra, Irrawaddy, Salween, Mekong, Yangtze, Yellow River and Tarim. Together, those river systems sustain over 2 billion people across Asia.
Nepal's role is much greater than many realize. Nepal's rivers-particularly the Koshi, Gandaki and Karnali systems-contribute roughly 70 percent of the Ganges' dry-season flow and around 40 percent of its annual flow. That water supports irrigation, food production, ecosystems, culture, drinking-water supply and livelihoods across the Gangetic plains.
So when Nepal loses glaciers, when slopes become unstable and rivers become more unpredictable, this is not only Nepal's problem. It affects food security in South Asia, hydropower in Nepal and Bhutan, agriculture in northern India, downstream ecosystems, trade, migration and regional stability and security.
The danger is not simply that glaciers melt and there is less water. The transition itself is dangerous. In the short term, accelerated melting can increase flood risk, destabilize slopes and enlarge glacial lakes. In the longer term, shrinking glaciers and changing snowfall patterns can make dry-season river flows less reliable.
We are heading towards a double crisis: too much water at the wrong time, and too little water when people need it most.
Under high-emissions pathways, the Hindu Kush Himalaya could lose up to 80 percent of its present glacier volume by the end of this century. That is not just an environmental number. It is a warning about the future of water, food, energy and security for over 2 billion people.
Nepal contributes little to global emissions but bears a heavy cost. What are your thoughts?
That is the central injustice of climate change.
Nepal has contributed very little to global emissions, yet it is already living with glacier retreat, flash floods, landslides, unstable slopes, erratic rainfall, hydropower losses and growing pressure on agriculture and water security.
But Nepal should not go to the world only as a victim with anger asking for sympathy. Sympathy does not build early-warning systems. Sympathy does not protect bridges. Sympathy does not make mountain communities safe.
Nepal needs to make a stronger case: we are custodians of a mountain system that sustains over 2 billion people. If the Himalaya becomes unstable, the consequences will not remain inside Nepal. They will travel through rivers, farms, hydropower projects, cities and economies across Asia.
This is not a case for charity. It is a case for shared responsibility.
What should Nepal's next steps be?
The first priority is a rigorous scientific assessment of the Rasuwa disaster. We need to establish exactly what failed, why it failed, what role warming and permafrost degradation may have played, how the river was blocked, how the flood wave formed and why downstream infrastructure was so vulnerable.
We cannot build policy on rumors, social-media videos or political arguments. We need evidence.
But Rasuwa also shows that Nepal's response cannot be limited to glacial lakes. We already know there are more than 260 potentially dangerous glacial lakes across the Hindu Kush Himalaya-ticking time bombs that require monitoring, early warning and risk reduction. But Rasuwa was not one of them. The next disaster may not come from a lake we have identified. It may come from an unstable slope, a weakening glacier margin, thawing permafrost or a mountain we have not yet understood well enough.
Nepal needs integrated monitoring of glaciers, glacial lakes, permafrost, unstable slopes, rainfall, river flows and downstream settlements. These hazards are connected. A glacier–rock collapse can block a river. The blockage can fail. The resulting debris surge can destroy roads, bridges, hydropower projects and entire communities.
Early-warning systems are essential, but we must be honest about their limits. If debris travels 20 kilometers in seven minutes at around 193 kilometers per hour, there is almost no time to react. You cannot evacuate a town, close a highway or save a bridge in a few minutes. Protection must begin before the event-through safer land-use planning, stronger roads and bridges, resilient hydropower development, evacuation routes, communication systems and community preparedness.
We must stop building as if mountains are fixed and rivers are predictable. They are not.
Are similar events happening elsewhere?
Yes. Similar glacier- and slope-related hazards are being seen in the Himalaya, Karakoram, Caucasus, Central Asia, Andes, Alaska and the European Alps.
The difference is often not whether hazards exist. The difference is exposure and preparedness. In some parts of Alaska or the Alps, an avalanche or outburst may occur in a remote valley with fewer people and stronger warning systems. In the Hindu Kush Himalaya, people, roads, hydropower projects, tourism facilities, markets and border-trade infrastructure are often concentrated in narrow valleys directly below unstable slopes.
That makes our region especially vulnerable. We have faster-changing mountain hazards and a far higher concentration of people and infrastructure in more vumerable way.
Rasuwa was not a remote incident. It disrupted lives, roads, bridges, trade, hydropower and local economies. It showed how one collapse high in the mountains can paralyze an entire valley within hours.
Should Nepal, India and China be coordinating on this?
Absolutely. But it should not be limited to Nepal, India and China. Pakistan and Bangladesh should also be part of the conversation.
The Hindu Kush Himalaya is one ecological system divided by political borders. Rivers cross borders. Pollution crosses borders. Floods cross borders. The consequences of glacier loss cross borders.
Nepal should push for a standing regional framework on mountain risk. That should include real-time weather and hydrological data sharing, satellite access, joint monitoring of glaciers and unstable slopes, transboundary early-warning systems, black-carbon reduction, disaster preparedness and stronger infrastructure standards.
India should see this not only as a climate issue but as a dry-season water-security issue. Nepal's rivers provide around 70 percent of the Ganges' dry-season flow. If glacier retreat, erratic rainfall, sediment surges and slope failures destabilize Nepal's river systems, the consequences will be felt far downstream-in Uttar Pradesh, Bihar, West Bengal and eventually Bangladesh.
This is not charity. It is not even only geopolitics. It is self-interest.
The discussion should not be framed as Nepal blaming India or China. Blame alone does not deliver results. The more practical message is that the risks are shared, even if responsibility for emissions is not equal.
India and China are among the world's largest emitters. But they are also home to vast downstream populations and major economies dependent on Himalayan water systems. It is in their own interest to invest in a safer Himalaya.
So where has Nepal fallen short on climate change?
Our biggest failure has been strategic imagination.
Nepal sits at the heart of a globally important mountain-water system, yet we have often approached climate diplomacy as if we are only a victim seeking assistance. We need to move from a narrative of helplessness to one of stewardship.
Nepal has a credible record. Our community-forestry movement is recognized internationally. Our conservation models, the buffer zone systems, including the Annapurna Conservation Area, show that community-led environmental governance can work. We have expanded forest cover over recent decades and kept our emissions low.
We should say to the world: we are not asking others to do what we refuse to do ourselves. We are protecting forests, conserving biodiversity and trying to follow a lower-emissions pathway. But the scale of Himalayan risk is now beyond what Nepal can finance or manage alone.
That requires stronger institutions, better science, greater technical capacity, credible climate-finance proposals and far more serious climate diplomacy.
What does the future look like if this trend continues?
The future is not simply drier. It is more unpredictable.
We are likely to see more intense rainfall over shorter periods, more flash floods, landslides, debris flows, unstable rivers and pressure on groundwater. Rain that once fell gradually over several days can now fall in a few hours. The ground cannot absorb it. Rivers rise rapidly, slopes become saturated and landslides follow.
At the same time, longer dry spells can reduce groundwater recharge and make agriculture more uncertain. This combination-violent downpours and longer dry periods-is one of the most damaging outcomes of climate disruption.
For Nepal, hydropower planning must change. We can no longer assume that historical river flows are a reliable guide to the future. Energy security will depend not only on building more projects, but on building projects that can withstand sediment surges, floods, unstable slopes and unpredictable water flows.
Agriculture will also have to adjust. Crop zones, planting seasons, water use and livestock systems may all need to change. These are not distant problems. Nepal must start planning for them now.
Prime Minister Balendra Shah is set to address the UN General Assembly soon. What should he say?
The Prime Minister should make a clear and credible case for mountain resilience, climate justice and regional cooperation.
He should say that Rasuwa was not an isolated flood. It was a cascading mountain disaster, showing how glacier change, thawing permafrost, unstable slopes, extreme rainfall and exposed infrastructure can combine into catastrophe with very little warning.
He should remind the world that the Hindu Kush Himalaya is the source of 10 major Asian river systems and sustains over 2 billion people. Nepal's rivers contribute around 70 percent of the Ganges' dry-season flow. Nepal may be on the front line, but the consequences of Himalayan instability will be felt across South Asia, Central Asia, China and Southeast Asia.
The Prime Minister should ask for practical support: better access to satellite data, stronger high-mountain monitoring, modern early-warning systems, climate-resilient roads and bridges, post-disaster recovery, technical capacity and faster climate finance for highly vulnerable countries.
He should also call for structured regional cooperation among Nepal, India, China, Pakistan and Bangladesh. That should include joint monitoring, real-time data sharing, transboundary warning systems, black-carbon reduction and coordinated disaster preparedness.
The message should be firm but constructive: Nepal did not create this crisis, but Nepal is ready to do its part. The world must now move beyond statements of concern and invest in prevention, preparedness and resilience.
What should Nepal actually be asking for?
Nepal needs to go with proposals, not only appeals.
The first requirement is a professional post-disaster damage and needs assessment. The government must present a credible account of losses to lives, homes, roads, bridges, hydropower, trade, tourism, livelihoods and public infrastructure. It must also quantify what is needed to reduce future risks.
Vague figures will not persuade international partners. A detailed, independently verified and costed plan will.
Nepal should seek support for integrated high-mountain monitoring, stronger flood and landslide warning networks, resilient reconstruction of roads and bridges, technical capacity, satellite-data access, community preparedness and risk-sensitive infrastructure standards.
For the past several years, I have been developing the concept of an International Centre for Glaciers, or ICG. I originated this concept as a proposed intergovernmental organization of glaciated countries-not as a Nepal project and not as an institution owned by any one government. The purpose is to create a collective international mechanism for countries facing glacier retreat, thawing permafrost, unstable slopes, glacial-lake hazards and changing mountain-water systems.
The ICG would be laser-focused on closing the gap between science and action. Scientists may detect glacier retreat, unstable slopes or thawing permafrost; communities and governments need that knowledge translated into early warning, risk maps, safer infrastructure, preparedness, technical capacity and financeable resilience programs. That practical gap is where lives are lost, and that is where the ICG is intended to make a difference.
I subsequently served as Team Leader for a concept-level study for the Asian Development Bank covering glaciated countries across the Caucasus, Central Asia and the Hindu Kush Himalaya. The study examined common risks, institutional gaps and potential avenues for cooperation across the Caucasus, Central Asia, the Pamir, Tian Shan, Karakoram and Hindu Kush Himalayan systems. It reinforced why it is urgently needed. It showed that, despite very different political contexts, countries across these regions face the same accelerating threats: shrinking glaciers, thawing permafrost, unstable rock slopes, glacial-lake hazards, volatile river systems and greater exposure for communities downstream
The Finance Minister and Agriculture Minister jointly wrote to the Loss and Damage Fund. What is your assessment?
A formal request is necessary. Nepal must register the disaster and its climate-related losses within the international system.
But a letter is not a strategy.
It must be followed by a scientifically grounded account of the disaster, a professionally verified damage assessment, a precise funding request, a transparent implementation plan and a credible system for showing how funds will be used.
The Fund for Responding to Loss and Damage is politically significant because it recognizes a principle Nepal has argued for years: vulnerable countries face climate impacts that cannot be addressed through adaptation or ordinary development assistance alone. But the fund's available resources remain very limited compared with global need. It should be seen as one avenue, not the answer in itself.
Nepal must pursue multiple channels: the Loss and Damage Fund, multilateral development banks, bilateral partners, climate funds, disaster-recovery mechanisms and regional cooperation. Above all, it must arrive with evidence, credibility and a plan.
Nepal must protect its credibility. Climate finance requires trust. If governments circulate inconsistent figures or make poorly evidenced claims, they weaken their own case. The country needs one transparent assessment, one coherent strategy and one clear voice.
What should Nepal emphasize now?
Nepal should emphasize that Rasuwa is not a one-off tragedy. It is a warning from the Himalaya.
The Hindu Kush Himalaya is the source of 10 major Asian river systems and sustains nearly over 2 billion people. Nepal's rivers contribute around 70 percent of the Ganges' dry-season flow. Glacier ice loss across the region has doubled since 2000, while high-emissions pathways could result in the loss of up to 80 percent of its glacier volume by the end of this century.
Researchers have identified more than 260 potentially dangerous glacial lakes across the Hindu Kush Himalaya-ticking time bombs that could threaten communities downstream. But Rasuwa was not even on that list. That is the real warning. The next disaster may not come from a lake we have already mapped. It may come from a slope, a glacier margin, thawing permafrost or a mountain we do not yet understand well enough.
This is not simply about ice disappearing from remote peaks. It is about water, food, hydropower, biodiversity, trade, livelihoods and security for vast downstream populations.
Nepal should speak with confidence. It should push for a serious regional framework involving Nepal, India, China, Pakistan and Bangladesh-linking glacier and slope monitoring, black-carbon reduction, scientific data sharing, early warning, resilient infrastructure and climate finance.
It should make the case with evidence, not entitlement; with partnership, not confrontation; and with the confidence of a country whose mountains sustain much of Asia.
What happens in the Himalayas does not stay in the Himalayas.
