Nepal has experienced unprecedented devastation from the August 26 flood, dubbed the “Himalayan Tsunami,” marking one of the most severe disasters recorded in the region’s history. Experts characterize the event as a combination of an ice-and-rock avalanche and a glacial surge flood. While glacial lake outburst floods (GLOFs) have occurred in Nepal and neighboring countries before, the scale and impact of this recent disaster are far greater.

Rising temperatures and rapidly melting glaciers across the Hindu Kush Himalayan (HKH) region have heightened vulnerability to such events. According to scientific assessments, warming in this mountainous region is occurring at two to five times the global average, with consequences including shrinking snow cover, advancing glacier retreat, thawing permafrost, and an increase in the number of glacial lakes. The International Centre for Integrated Mountain Development (ICIMOD) has identified over 25,000 glacial lakes spanning more than 1,400 square kilometers across the HKH area, underscoring the escalating risk.

The catastrophe has prompted calls from Nepal for stronger regional cooperation, particularly involving neighboring China and India. Observers argue that these countries, which share the Himalayan ecosystem, must move beyond providing emergency aid to take a leadership role in addressing the ongoing climate crisis. Proposals include establishing legally binding agreements for the protection and sustainable development of the Himalayan environment, similar to frameworks governing other major mountain ranges such as the Alps and the Andes.

Customary international law obliges states to prevent significant environmental harm and to cooperate in environmental protection, principles reinforced by recent judgments from the International Court of Justice (ICJ). The court’s 2025 advisory opinion emphasized the “duty of due diligence,” which requires states to adopt precautionary measures, conduct risk assessments, and engage in consultation with other affected nations to mitigate cross-border environmental risks.

Proponents of a regional legal framework underscore the critical ecosystem services the Himalayas provide, including water, energy, and livelihoods for over a billion people. They stress that the current scientific evidence of biodiversity loss and climate change demands urgent action and that all countries in the region are already bound by international agreements such as the United Nations Framework Convention on Climate Change (UNFCCC), the 1992 Biodiversity Convention, and the 2015 Paris Agreement. Under the Paris Agreement, countries must submit nationally determined contributions (NDCs) that are sufficiently ambitious to limit global temperature rise, a responsibility taken seriously by the ICJ as both an obligation of conduct and result.

In addition to greenhouse gases, black carbon emissions pose a significant threat by accelerating glacial melt through reduced surface albedo. While industrial activity across the region contributes to this problem, experts cite political inertia as a barrier to coordinated, effective responses.

Despite current challenges, some regional cooperation initiatives exist. For example, China and India agreed in 2009 to establish a joint working group for climate policy coordination, and in 2019, China and Nepal signed an agreement on disaster risk reduction and emergency response. These arrangements could serve as foundations for a broader regional treaty addressing the climate and biodiversity crisis in the Himalayas.

Such a treaty would ideally be grounded in the best available science and include provisions for prevention, mitigation, adaptation, and reparations for climate impacts. It would also promote cooperation on finance, technology sharing, joint risk assessments, real-time data exchange, capacity building, and infrastructure development, fostering unified regional positions while discouraging environmentally harmful domestic actions.

Given the existential risks posed to the Himalayan system and the intertwined ecological, social, and economic challenges, Nepal’s appeal highlights the urgent need for its neighbors to engage in meaningful, legally binding climate action. This would advance just climate governance and safeguard a clean, healthy, and sustainable environment as a fundamental right for the people of the Himalayan region.