On March 21, 2025, the world will mark the first-ever World Day for Glaciers, alongside the International Year of Glaciers' Preservation (IYGP) 2025 and the Decade of Action for Cryospheric Sciences (2025-2034). This initiative by the UN General Assembly highlights the urgency of preserving our planet's cryosphere. Glaciers worldwide are retreating at an alarming rate, with their melting waters often creating new glacial lakes or expanding existing ones. These changes significantly increase the risk of “Glacial Lake Outburst Floods”, so-called GLOFs. The danger of GLOFs are often unknown to local communities, but when unstable glacial lake dams collapse, the consequences can be catastrophic – destroying lives, livelihoods and infrastructure, with impacts reaching far downstream.
The Third Pole: A hotspot for GLOF risks
The Hindu Kush Himalaya (HKH) region, comprising the mountains of Afghanistan, Pakistan, India, China, Nepal, Bhutan, Bangladesh and Myanmar, contains the largest concentration of snow and glaciers outside the Polar regions and is therefore called the "Third Pole". This region is a global hotspot for GLOF risks. Between the mountains themselves and the valleys downstream, around 2 billion people are exposed to these risks. Due to widespread poverty, significant development deficits and limited adaptive capacity, many of these communities are particularly vulnerable to these potential sudden floods.
Data indicates that the current average number of GLOF events per decade in the Himalayas is nearly five times higher than before 1950. This surge is likely driven by climate change-related processes, mainly the formation and expansion of glacial lakes and an increase in potential GLOF triggering factors such as avalanches, landslides and ice collapses. Over 9,000 lives have been lost in the region due to these floods, with India, Pakistan, Nepal and Bhutan among the most affected.
GLOFs do not only threaten communities directly, they can leave lasting socioeconomic and ecological consequences by destroying critical infrastructures, including roads, bridges, hydropower plants and irrigation systems. The 2013 Chorabari GLOF, which caused the Kedarnath flood in India, and the 2021 Melamchi flood in Nepal are recent examples of the scale of destruction these events can cause. Economic losses from past GLOFs have been substantial, with long-term impacts on tourism, agriculture and energy sectors. Erosion, landslides and altered river flows degrade habitats, impacting ecosystem and biodiversity. Alarmingly, over 400 potentially dangerous glacial lakes have been identified in the Hindu Kush Himalaya region, many of them located in transboundary regions, posing risks to multiple countries.
The Adaptation Challenge: Gaps in Action and Funding
Despite the high and increasing risks of GLOFs, adaptation efforts remain inadequate. Countries in the Hindu Kush Himalaya region have acknowledged GLOFs as a major hazard in their domestic plans – specifically in National Adaptation Plans (NAPs) and Nationally Determined Contributions (NDCs). Yet, only five countries have initiated any GLOF-specific adaptation measures. Even where adaptation actions are planned, they tend to focus on short-term solutions, leaving a significant gap in long-term adaptation strategies. A major challenge is the lack of transboundary coordination which would be required to address appropriately the cross-border nature of many GLOFs.
In addition, funding remains a critical roadblock. The overall cost of GLOF adaptation in the Himalayas remains unknown, but individual country estimates suggest a significant finance gap. For instance, the costs of implementing GLOF risk reduction and early warning systems in glaciated river basins in Nepal is assessed to be $1 billion by 2030. Yet, to date, Nepal has received only around $7 million in international climate finance for this purpose – far below what is required. Most of the other countries in the region face similar shortfalls, making it difficult to implement essential adaptation projects.
Moving from recognition to action
The fact that current level of actions is insufficient to address the scale and complexity of GLOF risks is not limited to the Himalayas; it is also valid for other glaciated regions such as the Andes, Central Asia, North America and the Alps. A shift from simply recognizing the problem to proactive planning and implementation is essential.
There are several necessary measures to be taken. The transboundary nature of GLOFs asks for strengthening regional cooperation. Hence, governments should invest in shared glacial lake monitoring, transnational early warning systems and open data-sharing to improve preparedness. The focus of adaptation strategies should integrate long-term perspectives and emphasize socioeconomic impact assessments.
In addition, bridging the adaptation finance gap requires a combination of substantial increase in international climate finance, South-South cooperation and engagement with the private sector. Industries such as hydropower and tourism, which face significant risks from GLOFs, can play a crucial role in financing adaptation measures. Making proactive investments in risk reduction can limit the tremendous costs linked with post-disaster recovery.
While structural solutions such as lake drainage and dam construction can be effective, they are often costly due to high-altitude and remote locations. Institutional measures, such as continuous monitoring, early warning systems, awareness campaigns and research and innovations, may offer cost-effective and sustainable alternatives.
Leveraging global initiatives, such as World Day for Glaciers, International Year of Glaciers' Preservation and the Decade of Action for Cryospheric Sciences, presents an opportunity to amplify awareness, drive scientific advancements and accelerate the implementation of effective adaptation strategies worldwide.
