Key Takeaways:
– South Asia’s climate disasters and risks are transboundary but the governance systems to respond to them are not.
– National Determined Contributions/ Climate recognizes shared climate risks, yet to foster cross-border commitments.
– South Asia’s ageing water treaties are up for renewal as climate pressures peak. They offer opportunity to institutionalize climate governance.
– With SAARC largely inactive, bilateral treaties and national climate plans are effectively the entire regional architecture.
– A bioregional framework offers the reset South Asia needs to govern the shared mountains, rivers and deltas.
In the last two weeks of August, a colossal block of ice and rock debris dislodged from a slope above the Langtang valley in the Himalayas. This catastrophic event caused the Bhote Koshi and Trishul river systems to collapse, obliterating villages, bridges, and a border crossing between Nepal and China, killing a thousand, with thousands more missing on both sides of the frontier. The event termed as landslide-dammed lake outburst flood (LaDLOF) is distinct from the glacial lake outburst floods (GLOFs). It’s a landslide blocking a river, damming a lake and then unleashing it downstream with minimal warning. Scientists are still debating the exact mechanism behind this event with theories ranging from glacial lake outburst to ice-rock avalanches and landslide-dam failure. The flood began close to the Nepal-China border, caused its greatest devastation in Nepal and around Gyirong in the Tibet Autonomous Region of China, and then travelled down the Bhote Koshi–Trishuli–Narayani/Gandak system towards Bihar (India), where authorities were already issuing flood alerts as the surge moved downstream.
A hazard born in one country and becoming another country’s emergency within hours is not an isolated case, especially in South Asia. In August 2025, heavy rains swelled three rivers in the same border region further west. Leading to unprecedented floodingover 1,400 villages each in Indian and Pakistani Punjab. Around 300,000 people were displaced in India and over a million in Pakistan. The two consecutive monsoons with two different river systems offers the same lesson – no border checkpoint can slowdown a flood.
Year-on-year, repeated events in South Asia are compelling the argument for rethinking how the region governs climate and infrastructural risks. The region’s hazards are relentlessly transboundary, be it glacier retreat, glacial lake outbursts, monsoon variability, river flows, cyclones, coastal salinity, heat waves, and air pollution. However, the instruments meant to manage these risks stop hard at the border.
Currently, there are two functional frameworks for climate and environmental governance in South Asia. The first is the set of Nationally Determined Contributions each country files under the Paris Agreement. The region’s individual NDCs acknowledge the transboundary nature of their exposure and several of them mention Himalayan glacier melt, cross-border flooding and shared river basins as core areas for adaptation. However, while the risk is understood to be transboundary, the remedies are confined nationally. Bangladesh is the partial exception with having built river-basin cooperation into its climate planning as a matter of survival, where more than ninety percent of its rivers drain from outside its borders. Its NDC explicitly commits to strengthen regional cooperation and transboundary river basin management. Nepal’s NDC gestures in the same direction, pledging transboundary data-sharing on glacial lake risk where possible. But India, Pakistan and Sri Lanka largely treat glaciers, coastlines and river basins as domestic concerns, adapting nationally to risks that are manufactured regionally.
The second framework is the region’s handful of bilateral river treaties that have played an important role in managing shared waters and creating channels of cooperation between countries even in politically difficult circumstances. But they were negotiated for a different set of challenges in a different era. The principal agreements, all bilateral, are the Kosi, Gandak and Mahakali treaty between India and Nepal, the Ganges Water Sharing Treaty between India and Bangladesh, and the Indus Waters Treaty between India and Pakistan. Across these frameworks, the emphasis has been on water sharing, irrigation, hydropower, flood management and infrastructure. Most of these agreements were negotiated and signed in the 1950s and 60s before climate change entered the diplomatic vocabulary at all. These existing arrangements provide a grounded foundation for the next phase of cooperation that can extend beyond water sharing and infrastructure to address the changing ecological and climatic conditions of shared river basins.
The timing presents an unusual opportunity to rethink how South Asia governs its shared rivers. The Ganga Water Treaty of 1996, which set out a formula for dry-season sharing at the Farakka Barrage, expires this December after thirty years. India and Bangladesh have begun the technical exchanges that might precede a renewal. Bangladesh has already hedged its bets by becoming the first South Asian state to join the UN Convention on the Protection and Use of Transboundary Watercourses and International Lakes last year. Meanwhile the Indus Waters Treaty, held in abeyance by India since the Pahalgam terror attack of April 2025, has just been declared by the treaty’s own Court of Arbitration to remain fully in force. A ruling that India has rejected. Whatever the eventual outcome, the present dispute coming after an earlier formal request to modify the Treaty points to a deeper institutional question of redesigning to absorb changing hydrology and climate uncertainty. With the region’s principal intergovernmental platform – SAARC being largely dormant, the more immediate opportunity lies in using NDCs and existing bilateral agreements more deliberately to address the shared hydro-ecological and climate systems that transcend national borders.
Need for a Bioregional Reset
There is, encouragingly, one recent sign of a different instinct. In December 2025, the UNFCCC and the ICIMOD launched the Hindu Kush Himalaya Regional Climate Action and Transparency Hub. This initiative brought together Afghanistan, Bangladesh, Bhutan, China, India, Myanmar, Nepal, and Pakistan to strengthen regional collaboration and knowledge sharing. The aim is to advance solutions and financing among the Himalayan countries. While it is a modest transparency mechanism, not a treaty, it is one of the few structures in the region organized around a bioregion rather than a national boundary. This points toward a more useful way of thinking about the whole problem – Bioregionalism.
Bioregionalism stems from a simple premise that ecological systems and political borders rarely coincide, and governance works better when it reflects the landscapes and communities that hold a region together. A mountain range, river basin, monsoon system or airshed is a lived space, shaped by livelihoods, culture, mobility, local knowledge and long associations with the landscape. When such systems are disrupted, the consequences travel across administrative and national boundaries. A bioregional approach integrates governance on cross-border cooperation by centering communities as holders of knowledge, stewards of local ecosystems and participants in decisions that shape their bioregion. The Lake Victoria Basin, Bioregional Plan 2030 for the Amazon Sacred Headwaters and the Alpine Convention offer different examples of intergovernmental basin governance, community-led bioregional planning and a binding landscape-scale treaty. South Asia, with its deeply connected mountains, rivers, deltas, coasts and monsoon systems urgently needs similar systems.
Building cooperation around a bioregion doesn’t need to compromise sovereignty, just climate-proofing shared systems. The national NDCs can add a layer/annex of bioregional adaptation contributions within them. A mutually binding minimum agreement to share datasets including rainfall, glacier mass, river discharge, reservoir operations, groundwater, and coastal salinity could be agreed as shared regional infrastructure. Sharing early warnings beyond diplomatic goodwill and building on the community-level systems that already operate faster than official channels across borderlands. The renegotiated Ganges Treaty can be the template for joint climate modelling, ecological flows, sediment and ecosystem health, coordinated flood and drought planning, and regular review as hydrological conditions change.
Water braids together South Asia, its communities, and cultures, and hydro-climate systems with the monsoon, the rivers, glaciers, the aquifers, and the deltas. The Langtang disaster did not begin as a diplomatic problem. It became one within hours as rivers reclaimed their own boundaries. Until South Asia’s institutions are built to respond holistically, its climate governance will continue to discover, disaster by disaster, what its rivers have always known.
About the Author
Namrata Kabra is a legal researcher working at the intersection of climate security, governance, and justice, with a focus on gender, water, and bioregional perspectives. She is a Visiting Fellow with Kubernein Initiative and Facilitator of the South Asia Bioregionalism Working Group.
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