The floods that swept through Nepal’s Rasuwa district in late August 2026 have renewed debate over how prepared the Hindu Kush-Himalaya region is for a rapidly warming climate.
For Devendra Kumar Sharma, president of the International Commission on Large Dams and a member of India’s National Security Advisory Board, the disaster is not only a Nepali tragedy. It is a warning for the wider Himalayan arc, from Ladakh and Himachal Pradesh to Uttarakhand, Sikkim and beyond.
Sharma, who was in the region when the disaster struck, says the event exposed a growing mismatch between older engineering assumptions, outdated flood records and the new reality of glacier loss, permafrost thaw and more frequent extreme events.
His message is direct: the Himalaya can no longer be managed using 20th-century data and design standards.
According to Sharma, the day of the Nepal disaster began with apparently normal weather. Conditions had been stable for two days, with no obvious sign of an impending extreme event. Yet within hours, a high-altitude failure, likely involving ice, rock and moraine, triggered a cascade that became a deadly flash flood downstream.
Residents at higher elevations reportedly sensed danger and warned communities below to move to safer ground. But many dismissed the alerts because the sky was clear and the weather had been calm.
“If those warnings had been taken seriously and people had moved in time, the loss could have been significantly reduced,” Sharma said.
The episode, he said, highlights a critical gap in Himalayan disaster management: issuing scientific warnings is not enough. Alerts must reach last-mile communities in clear, usable forms, and people must know where to go when alarms sound.
Clear skies, Sharma warned, are no guarantee of safety in a landscape where glaciers, permafrost, slopes and river systems can fail suddenly.
Investigations are still under way behind the cause of the ice-rock avalanche. Scientists and officials initially suspected a Glacial Lake Outburst Flood, or a related glacial-moraine failure, may have played a role in the Rasuwa disaster.
Moraine-dammed glacial lakes are common across the Hindu Kush-Himalaya. When such natural dams fail, a lake can drain rapidly, releasing a torrent of water, ice, rock and mud that can devastate settlements, hydropower plants, bridges, roads and border infrastructure downstream.
The Nepal floods have brought these risks back into policy focus across the region. Sharma said rising temperatures, retreating glaciers and weakening mountain slopes mean that GLOFs, debris flows, landslides and sudden floods are likely to become more frequent and severe.
He stressed that Nepal’s disaster must not be viewed in isolation. The Hindu Kush-Himalaya is a connected system, where glaciers, rivers, rainfall patterns and disaster risks cross national borders. An event in an upper catchment in Tibet or Nepal can rapidly translate into floods, sediment surges and infrastructure damage downstream in India and Bangladesh.
“India and Nepal are not just geographical neighbours,” Sharma said. “Their rivers, Himalayan ecology, water resources and disaster risks are interconnected.”
In March 2025, Sharma led a study, Proposed Cooperation: India-Nepal Collaboration in the Context of Climate Change, which was later shared with the Nepal government. The report outlined climate-driven risks in the Hindu Kush-Himalaya, particularly GLOFs and other mountain hazards, and called for risk monitoring, data exchange, early warning and adaptation measures. It also flagged August as a month requiring heightened vigilance for glacier-related risks.
The wider scientific context is troubling. Recent ICIMOD reports released in March 2026 show that glacier ice loss across the Hindu Kush-Himalaya has doubled since 2000, with the most recent decade recording more frequent extreme melt years.
Two studies, Changing Dynamics of Glaciers in the Hindu Kush Himalaya Region from 1990 to 2020 and HKH Glacier Outlook 2026, document a 12 per cent reduction in glacier area and a steep decline in ice reserves. About 89 per cent of recorded years show negative glacier mass balance, indicating persistent retreat.
The implications go beyond the environment. Accelerating glacier loss increases GLOF risks, disrupts water availability for high-mountain communities and threatens the long-term flow regimes of the Indus, Ganga and Brahmaputra river systems, which support nearly two billion people.
ICIMOD’s 2018 report, The Status of Glacial Lakes in the Hindu Kush Himalaya, mapped more than 25,000 glacial lakes across five major river basins. The study remains an important reference for identifying potentially dangerous lakes and planning risk-reduction measures.
Sharma said the warnings were especially relevant for India’s western Himalaya. A recent study, Vulnerability of the Himalayan region under the climate change analysed 120 years of temperature records and eight global climate models. It found that the western Himalaya, covering Ladakh, Jammu and Kashmir and Himachal Pradesh, is warming faster than the central and eastern Himalaya, with rising temperatures in every season.
Under high-emission scenarios, winter temperatures in the western Himalaya could rise by more than 7 degrees Celisus by the end of the century compared with the early 20th century. The study also warned of severe future snow loss, with implications for snowpack, glaciers, spring-fed streams and river flows.
For states such as Himachal Pradesh, which has seen deadly cloudbursts and flash floods in recent years, these findings are a policy warning. Sharma said the dynamics seen in Uttarakhand’s Chamoli disaster in 2021 and Nepal’s Rasuwa floods were increasingly relevant across the western Himalaya.
Sharma argues that Himalayan disaster policy can no longer remain centred on relief and rehabilitation.
“We must move from reacting after disasters to acting before they happen,” he said.
That means systematic risk assessment, continuous monitoring of glaciers and glacial lakes, and early-warning systems that connect science to communities.
He called for a layered approach: satellite monitoring to track glacier change, new lake formation and slope instability; ground-based instruments and local observation networks to validate data; and last-mile communication systems, including mobile alerts, community radio and local sirens.
Technology alone, however, will not be enough. Sharma said every settlement in hazard-prone zones should have identified safe sites and evacuation routes.
“Telling people to ‘evacuate’ is meaningless if they don’t know where to go,” he said.
Community drills, local-language risk maps and the integration of indigenous knowledge with scientific data should be part of disaster planning, he added.
Sharma also warned against unchecked construction along Himalayan rivers.
Across several mountain states, hotels, homes and infrastructure have expanded into floodplains and river corridors, often in the name of tourism and “scenic” development.
Himalayan rivers descend steeply and can change course rapidly during extreme rainfall, landslides or glacial events. Building in natural river pathways without proper hazard mapping increases future losses, he said.
He called for strict regulation of construction near riverbanks, flood-prone areas and natural river corridors, along with enforceable no-build buffers.
For policymakers, Sharma said, the challenge is not whether to develop, but how to develop safely in a climate-stressed mountain environment.
Hydropower projects are often blamed after Himalayan disasters, but Sharma cautioned against simplistic conclusions.
“It is not scientifically correct to hold hydropower projects solely responsible for every Himalayan disaster,” he said.
Climate change, rising temperatures and shifting geo-hydrological conditions are central drivers, he added.
Even so, he said the design and safety standards of dams and hydropower infrastructure must be urgently reviewed. Many large dams in the region were designed using historical flood and sediment data from a cooler and more stable climate.
“Just because a certain flood magnitude was the maximum in the last 100 years does not mean a larger flood cannot occur in the future,” Sharma said.
ICOLD, under his leadership, is discussing how new dams should be designed for future climate scenarios and how existing dams can be retrofitted with additional safety measures. This includes reassessing spillway capacities, sediment management, extreme flood routing and seismic resilience in light of new climate projections.
After the Nepal floods, Sharma held discussions with Nepali hydropower engineers, laboratory experts and academics on adapting infrastructure design to changing risks. The broad conclusion, he said, was that future projects cannot rely on past climate normals. They must account for more intense rainfall, higher sediment loads, debris flows and compound hazards.
Sharma also emphasised the equity dimension of Himalayan climate risk. Mountain communities in countries such as Nepal and India are facing the consequences of glacier loss, GLOFs and water insecurity, even though historical emissions have largely come from industrialised nations.
Countries with stronger technology, scientific capacity and financial resources must support vulnerable Himalayan states with modern monitoring systems, satellite data, early-warning platforms and risk-assessment tools, he said.
“Developed nations must help,” Sharma said. “This is not charity; it is climate justice.”
For India and Nepal, cooperation is also a matter of security. Shared glacier and glacial-lake databases, joint satellite monitoring, co-developed risk maps and harmonised early-warning protocols could save lives on both sides of the border.
The Rasuwa disaster is a reminder that a warming climate is rewriting the rules of mountain safety. Sharma said the Himalaya is entering a new risk regime, where old experience and older design codes are no longer enough.
“The strategy for the Himalaya in this era of climate change must be based on science, technology, local experience, international cooperation and new-generation safe infrastructure standards,” he said.