Introduction

Glacial lake outburst floods (GLOFs) are sudden, high-magnitude and catastrophic flood events triggered by the failure of a natural dam containing a glacial lake, often leading to devastating consequences for downstream communities1. These phenomena are not new, but they have become more frequent and intense in recent years due to climate change leading to rapid glacier melt, extreme precipitation events, permafrost degradation, and glacial lake expansion2. GLOF events have occurred across the globe, including the Himalaya, Andes, Alps, Greenland and Iceland, resulting in loss of life, vital infrastructure damage, and long-term socio-economic disruptions3. A recent study has reported 3151 GLOF events witnessed in 27 countries between 850 and 2022 CE with a 6-fold increase in the documented GLOF events during the 20th century4. These GLOF events have killed thousands of people around the globe5 and 15 million people are at risk6, particularly in countries where socio-economic challenges are already significant. Despite notable progress in hazard mapping and modelling, remote sensing, and monitoring tools and technology, the effective prediction and mitigation of GLOF impacts remain constrained, as reliable and comprehensive early warning systems are still in their infancy and operational only in a few regions worldwide. Many high-risk areas have structural mitigation measures in place, such as artificial drainage systems and check dams, however, they are frequently rendered ineffective due to implementation and maintenance failure. More importantly, there is a major disconnect between scientific research, policy design and implementation, and community preparedness. Mountain communities are often the first, and in some cases, the only ones, to face the impacts of GLOFs, yet they are often the least prepared. Limited resources, lack of awareness, poor risk communication and inadequate emergency response mechanisms leave them highly vulnerable. Government policies and scientific research are highly inclined towards technical aspects, often neglecting the role of community-based adaptation and response strategies. The recent GLOF events, such as the Gya GLOF in Ladakh7 and the South Lhonak in Sikkim8 are both stark reminders of this reality, where a lack of preparedness and weak policy enforcement led to severe destructions.

To build truly GLOF-resilient communities, a paradigm shift is required—one that prioritizes not just technological solutions (structural measures) but also local capacity-building, inclusive governance, and community-driven adaptation and mitigation strategies. Bridging the gap between research, policy, governance, and community action is key to minimizing future losses and ensuring long-term resilience.

GLOFs are mainly triggered by the failure of glacial lakes dammed by moraines or ice, often due to: (i) extreme precipitation events—increasing lake water volume, (ii) landslide or ice avalanches—displacing water and triggering seiche waves, or directly impacting the dam, (iii) seismic activity—weakening natural dam structure and side slopes, or generating tsunami waves, (iv) permafrost degradation—reducing lateral moraine and moraine dam stability, and (v) localised cloud burst event—directly damaging the lake dam. There are over 110,000 glacial lakes worldwide, spanning approximately 15,000 km², with their total area increasing by ~22% per decade from 1990 to 20201. Global glacial lake volume has increased by 48% to 156.5 km³ between 1990 and 2018, with lake numbers and total area rising by 53% and 51%, respectively9. A recent case study by Sattar et al.8 investigated the deadly GLOF event caused by the collapse of the northern part of the lateral moraine into South Lhonak lake in Sikkim Himalaya on October 3, 2023. The catastrophic flood extended up to 385 km downstream, resulting in 55 deaths, 70 missing persons, and widespread infrastructure damage, including hydropower plants, bridges, and highways. As climate change accelerates glacier melt and destabilizes high-altitude ecosystems, the growing size and number of glacial lakes heighten the risk of GLOFs, threatening the downstream communities and infrastructure10.

People living in the GLOF-prone regions, often situated in high-altitude remote valleys, face extreme vulnerabilities due to a combination of environmental, infrastructural, and socio-economic factors11. Many of these communities are located directly downstream of rapidly expanding critical glacial lakes, leaving them highly exposed to sudden, high-magnitude floods with little or no warning. Limited access to crucial resources, early warning systems, and real-time monitoring means that residents often become aware of an impending disaster only when it is too late to evacuate safely. Weak infrastructure, such as poorly designed roads, bridges, and hydropower plants, adds to their vulnerability, as these structures are usually built in the risk areas without consideration for GLOF-resistant design. Poverty, low literacy rates, and inadequate institutional support are the socioeconomic challenges that make preparedness, mitigation, and recovery even more difficult12. In many cases, these communities are unaware of GLOF hazards, evacuation plans, and emergency response procedures, making them extremely susceptible when disaster strikes. Besides that, inadequate policy frameworks and weak governance hinder proactive risk mitigation, while transboundary complexities in regions like the Himalaya make coordinated disaster response efforts even more challenging13. Without urgent intervention, these vulnerable communities remain at the mercy of an escalating threat led by the changing climatic regime.

The current requirement for GLOF risk reduction is to establish a community-driven approach that empowers local residents as first responders. We emphasize the importance of Community-Based Early Warning Systems (CBEWS), which use locally maintained alerts, sirens, and mobile networks to issue timely warnings. Regular workshops, training programs, and mock drills are vital for improving preparedness and ensuring communities understand evacuation procedures, and this responsibility falls upon local administrations, governments, and researchers. Collaboration among local NGOs, village councils, and disaster management agencies can further help bridge the gap between policy and action on the ground. Participatory risk mapping and planning enable locals to actively identify hazards and collaborate on response measures. Strengthening infrastructure resilience through GLOF-resistant designs and combining traditional knowledge with modern advancements can help to protect vulnerable places. A decentralized governance paradigm that empowers local leaders is critical for achieving long-term and successful GLOF risk reduction at the grassroots level.

The ever-increasing threat of GLOFs demands an urgent shift from reactive response to proactive resilience-building14. Addressing the growing threat of GLOFs requires a proactive, multi-dimensional approach that strengthens community resilience alongside advancing science and policy reforms (Fig. 1).

Fig. 1
Fig. 1
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A framework for building GLOF-resilient communities, emphasizing vulnerability assessment, early warning systems, awareness programs, resilient infrastructure, and collective actions.

First, effective early warning systems must be built, which include automated lake monitoring, weather and seismic stations, real-time flood predictions, and community-driven alarm mechanisms. Second, community awareness and preparedness initiatives must be prioritised to ensure that people understand GLOF hazards and risks, evacuation routes, and emergency response processes. Third, infrastructure planning should incorporate climate-resilient designs, ensuring critical facilities like roads, bridges and hydropower plants are constructed outside the high-risk zones and fortified against extreme events. Fourth, governments must bridge institutional gaps by developing specific GLOF risk reduction policies and incorporating climate adaptation into disaster management plans. Finally, regional and transboundary collaboration is critical, as GLOFs frequently affect river basins that cross numerous countries. Data sharing, coordinated monitoring programs, and collaborative response systems can considerably improve preparedness. Without immediate action, the devastation caused by GLOFs will continue to grow. It is critical to bridge the gap between scientific research, policy implementation, and community resilience to protect lives and livelihoods before the next crisis occurs15.

GLOF-WATCH: Watershed Adoption for Continuous Hazard Monitoring

Current research on glacial lakes and GLOF risk assessment is spatially fragmented, with studies undertaken at a variety of geographical scales, including individual lake case studies, basin-wide, regional, and global assessments. This disconnected approach results in methodological discrepancies, data gaps, and challenges in integrating findings for effective risk mitigation. Furthermore, owing to reasons such as funding limitations, researchers frequently perform short-term studies on individual lakes, catchments, or areas, resulting in a lack of temporal consistency in data collecting and interpretation. Given the dynamic character of glacial lakes and the abrupt and unpredictable nature of GLOFs, ongoing, long-term monitoring is both necessary and appropriate for enhancing hazard assessments and early warning systems.

Here, we propose GLOF-WATCH as a structured and systematic approach for addressing these issues (see Fig. 2). This method proposes international collaboration through a single, globally coordinated organization dedicated to glacial lake monitoring and GLOF risk assessment. On a national scale, research groups, organizations, and agencies would be assigned specific watersheds for continuous monitoring, assuring long-term data collection and evaluation uniformity. This watershed-based strategy would encourage standardized methods, seamless data sharing, and the exchange of instruments, skills, and best practices among researchers and institutions. Implementing this model will decrease redundancy, reduce differences in GLOF risk assessments, and considerably improve predictive capabilities.

Fig. 2
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GLOF-WATCH: Watershed Adoption for Continuous Hazard Monitoring.

To ensure the feasibility and practicality of this approach, GLOF-WATCH requires strategic investments in infrastructure, international partnerships and funding mechanisms. GLOF-WATCH can take the shape as a union or consortium of countries, most vulnerable to GLOFs as the core members and funders of this organisation, while other member countries can also contribute through resources, technology, and monetary support. This also translates into rising over geopolitical differences for a common good where the outcomes can transcend boundaries in saving lives, livelihoods, ecosystems, and infrastructures. The time commitment needed for long-term monitoring, the financial viability of setting up watershed-specific observation networks, and the logistical challenges of working in remote, high-altitude settings are important factors to consider. Securing long-term funding and operational support will need coordination among government agencies, academic institutions, and international organisations. Additionally, utilising technical innovations like artificial intelligence (AI)-driven predictive modelling and unmanned aerial vehicle (UAV)-based surveys, along with satellite remote sensing may reduce costs and improve monitoring effectiveness. A structured, long-term monitoring system would enable more consistent hazard monitoring and evaluations, stronger early warning mechanisms, and better integration of climate adaptation plans. However, enhancing early warning systems (EWS) by themselves is not enough; timely communication and community preparedness are essential to EWS’s efficacy. For example, the catastrophe could not be prevented in locations like Chungthang, Sikkim, India, where evacuation processes and disaster preparedness teams were in place prior to the South Lhonak Lake event. GLOF-WATCH must emphasize the importance of not only developing robust EWS but also ensuring that warning messages reach at-risk populations in an understandable and actionable manner. A recent paper15 effectively raises this question of what happens when “the alarm rings” in such disaster situations; we hardly have any mechanism in place. The effectiveness of EWS will be enhanced by integrating local communication networks, such as community radio, mobile alerts in regional languages, and real-time warning dissemination through local authorities. Even though collaboration and data exchange between researchers and institutions are essential, there is still a big gap in how well scientific findings are communicated to local people. For instance, local inhabitants were not adequately informed about the potential damage that hydrodynamic modelling studies had previously predicted in Chungthang. To address this issue, GLOF-WATCH must integrate comprehensive community engagement strategies and effective science communication to public and policymakers. Conducting workshops, public screenings, and presenting risk projections in local languages will enhance accessibility and awareness. Outreach should extend beyond educated or urban populations to include vulnerable and remote communities. NGOs, self-help groups (SHGs), and local organizations are instrumental in disseminating this knowledge effectively. By embedding these community-driven initiatives into its framework, GLOF-WATCH can ensure that scientific research translates into practical risk reduction measures and enhances preparedness for those most exposed to GLOF hazards.

GLOF-WATCH: practicality, challenges, feasibility, and way forward

The idea of establishing a global GLOF-WATCH to address GLOF risks is undeniably practical given the increasing threat due to climate change. The primary goal of such an organization would be to centralize knowledge on GLOFs, promote standardized risk assessments, and create and disseminate best practices for mitigation. The practicality of creating such an organization can be framed by examining the existing global frameworks that have successfully dealt with other environmental challenges. For instance, the Intergovernmental Panel on Climate Change (IPCC) has proven that international collaboration can produce impactful research and policy recommendations on complex climate issues. Similarly, the United Nations Office for Disaster Risk Reduction (UNDRR) has played a key role in standardizing disaster risk reduction efforts across the world. At a more regional level, the efforts of the International Centre for Integrated Mountain Development (ICIMOD) as an intergovernmental organization to improve cooperation and collaboration among the Himalayan countries, are commendable. Given these precedents, it is reasonable to imagine an analogous body focused on GLOFs. The growing body of research on glaciers and hydrology, along with climate change projections, could form the scientific backbone of such an organization. Collaborative research efforts between universities, government agencies, and international bodies could foster a more comprehensive understanding of the underlying mechanisms driving GLOFs and the best strategies for managing them. By establishing a knowledge-sharing platform, the organization could ensure that the latest research is accessible to all regions at risk.

While the practicality of a global GLOF-WATCH is clear, several significant challenges must be addressed to make this vision a reality. One of the most significant challenges would be coordinating among diverse stakeholders across different regions and sectors. A global organization would need to engage not only governments and international agencies but also local communities, scientists, environmentalists, industries, and development organizations. Each stakeholder brings its own priorities, resources, and approaches to the table. For example, local communities may be more focused on immediate flood protection measures and industries might be keen on infrastructure strengthening, while scientists and policy makers might prioritize long-term data collection and climate models. The challenge lies in aligning these priorities and fostering effective collaboration between such diverse groups. To overcome this, the organization would need a clear governance structure that balances the input of local actors with global initiatives. It would also require regular and open communication channels to ensure that the needs and voices of all stakeholders are heard and integrated into decision-making processes.

Another significant barrier to the formation of a global organization would be securing sustainable funding. Addressing GLOF risks requires substantial investment in research, monitoring systems, infrastructure development, and community engagement. In many high-risk areas, especially in low-income countries, the financial resources to tackle such large-scale initiatives may be limited. Even in wealthier nations, the political will to allocate funds for GLOF mitigation may fluctuate depending on the economic climate. A key strategy to overcome this challenge would involve tapping into a variety of funding sources. This could include national governments, international financial institutions such as the World Bank, private sector partnerships, and climate change adaptation funds. Additionally, the organization could work to create a global fund specifically designated for GLOF risk mitigation, similar to existing climate adaptation funds that target disaster resilience. The goal would be to pool resources from both public and private sectors to create a sustainable and equitable funding model.

The risks associated with GLOFs vary significantly across different regions. In the Himalayas, for example, while GLOFs may result from rapid glacier retreat, high-seismicity, extremely complex topography, and high population density, makes GLOFs riskier than many other regions globally. The geological, cultural, and socioeconomic contexts also vary greatly, which means that a one-size-fits-all approach to GLOF mitigation would be ineffective. Thus, GLOF-WATCH would need to be flexible enough to adapt to local conditions while providing universal standards for data collection and risk assessment. This could be achieved by designing regional offices or advisory groups within the organization that specialize in the specific challenges and characteristics of different geographic areas. Moreover, local stakeholders would need to be included in the decision-making process to ensure that interventions are culturally appropriate and contextually relevant.

The political and legal landscape of GLOF mitigation could also present challenges. Many countries have sovereignty concerns, especially regarding the management of natural resources and cross-border water systems that could be affected by GLOF events. There could be resistance to international oversight or cooperation, particularly in regions where national security or economic interests are closely tied to natural resources. Owing to political differences, such countries have extremely stringent laws against UAV-based monitoring along the borders. UAVs are the future of remote sensing16, and relaxation in laws for scientific research and monitoring of glacial lakes can really benefit such efforts. To mitigate these political challenges, the organization could focus on fostering international cooperation through soft diplomacy and shared scientific understanding. By emphasizing the global nature of climate change and the shared risks posed by GLOFs, the organization could create a collaborative environment in which countries view the GLOF issue as a common challenge. Additionally, legal frameworks for transboundary water management could be integrated into GLOF mitigation strategies to address shared risks.

To overcome these challenges and make the GLOF-WATCH a reality, a phased approach would be necessary. The first step would involve establishing a steering committee composed of scientists, governments, and international organizations to define the mission, governance structure, and operational plans. Following this, pilot projects could be launched in key regions to develop best practices and create a proof of concept for the broader initiative. The organization would also need to invest in building capacity at the local level, helping communities become more resilient to GLOF risks through education, early warning systems, and infrastructure development. These efforts could be complemented by global advocacy campaigns to raise awareness about GLOFs and garner international support.

In conclusion, the formation of a global GLOF-WATCH to study, standardize, and mitigate GLOF risks is both a necessary and feasible goal in light of the growing threats posed by climate change. By addressing coordination issues, securing diverse funding sources, accounting for regional disparities, and navigating political challenges, such an organization could significantly reduce the risks associated with GLOFs and improve global disaster resilience.