Opinion | Escalating climate change impacts 

The Hindu Kush Himalayan (HKH) region is one of the world’s most fragile and hazard-prone regions. Shifting snowfall and rainfall patterns due to climate change increase the region’s vulnerability. Cloudburst events are becoming more frequent, glaciers are retreating at an accelerated pace, snowfall is declining and permafrost is melting, leading to a cascade of multi-hazard events that cause substantial damage.While significant attention has been given to mapping glacial lakes larger than 0.02 square kilometres and monitoring a few potentially dangerous ones, other critical hazards, such as permafrost degradation and smaller, undocumented glacial lakes, have been overlooked. Additionally, there has been insufficient focus on minimising vulnerability and exposure downstream, which are the key components of disaster risk reduction.Glacial lake outburst floodsGlacial lake outburst floods (GLOFs) occur when meltwater from glaciers accumulates behind an ice or moraine dam, which can fail due to overtopping caused by rising water levels or collapse resulting from melting of the ice core within the moraine dam. This failure often triggers external events such as avalanches or landslides into the lake. The GLOF event in April this year at Birendra Lake in Gorkha, Nepal, highlights the severe impact of glacier ice cascading into the lake. This sudden influx caused a sharp rise in water levels, leading to an overflow that inundated downstream areas. Earthquakes may also trigger the GLOF. The 2015 Gorkha earthquake brought about a GLOF in the Langtang Valley by destabilising the Langtang Glacier. The sudden release of large volumes of water generates catastrophic floods that can overwhelm river channels and pose severe risks to nearby communities and critical infrastructure like hydropower and bridges.On August 16, 2024, a GLOF devastated Thame, a Sherpa village in the Khumbu region, destroying 25 structures, including homes, guesthouses, a school and a hydropower project, while displacing 135 people. Additionally, the Khumbu region was severely impacted by the Dig Tsho GLOF in 1985, which caused widespread destruction, including the loss of lives, property and infrastructure. The 2021 Melamchi debris flow was triggered by monsoon rainfall and landslides and exacerbated by upstream glacial melt, leading to devastating floods and sediment-laden flows. Similarly, the 2012 Seti River flash flood in Pokhara was caused by a landslide-induced dam breach upstream, which released a massive volume of water, highlighting the cascading risks associated with glacial melt and moraine instability linked to GLOF phenomena. All these GLOF-related events underline the need for robust multihazard early warning systems, risk mitigation measures and strong design of critical infrastructures.In the Himalaya, GLOFs can trigger a series of landslide dam outburst floods (LDOFs) by releasing large volumes of water that destabilise slopes or transport debris downstream, causing