Understanding Himalayan Glacial Lake Outburst Floods through Ecological, Geomorphological, and Socio-Economic Lenses

Glacial lake outburst floods (GLOFs) are emerging as one of the most consequential climate-driven hazards in high-mountain regions, with the Himalayas at the global epicentre of risk. Accelerated glacier retreat, rapid expansion of moraine- and ice-dammed lakes, and increasing slope instabilities are fundamentally reshaping hazard regimes, exposing millions of people, critical infrastructure, and fragile ecosystems to low-frequency but high-impact disasters. Here, we synthesise current scientific evidence on Himalayan GLOFs through an integrated ecological, geomorphological, and socio-economic lens, linking physical triggering mechanisms to downstream impacts and risk governance challenges. We show that GLOFs not only drive profound geomorphic reorganisation of mountain valleys and long-term ecosystem degradation, but also generate cascading socio-economic consequences that undermine livelihoods, development trajectories, and regional stability. Despite major advances in remote sensing, hydrodynamic modelling, and hazard mapping, a persistent gap remains between scientific knowledge and actionable risk reduction. We identify community-centred, non-structural interventions—early warning systems, land-use planning, local capacity building, and knowledge co-production—as critical yet under-implemented components of effective GLOF risk management. Crucially, we argue that integrating disaster risk reduction into development planning and strengthening transboundary cooperation are essential to address the cross-border nature of Himalayan cryospheric hazards. By bridging physical science, ecology, and social vulnerability, this synthesis provides a holistic framework for managing GLOF risk in a warming world and offers policy-relevant insights for enhancing resilience across high-mountain socio-ecological systems.