Flash floods in Nepal have caused widespread devastation, destroying buildings and bridges along the Nepal-Tibet border and resulting in at least 177 deaths. Officials have described the event as "devastation beyond imagination."
While details are still emerging, a key question is whether climate change contributed to the disaster. A study released in the journal Frontiers in Climate just one month before the floods warned that global warming could trigger glacial collapses in the region, increasing the risk of glacial lake outburst floods (GLOFs).
The study, led by researchers at Kathmandu University, noted that warming rates in the Himalayan region exceed the global average, intensifying climate-related hazards. "The risk of floods, glacier melt, GLOFs and droughts would significantly increase" with temperatures exceeding 1.5°C, the researchers cautioned.
GLOFs are caused by the sudden release of water from a reservoir that has formed at the site of a glacier. As glaciers melt and recede, water can become trapped behind natural dams. When these dams breach, a large volume of water, often carrying mud and debris, can be released downstream, leading to catastrophic flooding.
Dr. Adrian McCallum, a glaciologist and polar engineer at the University of the Sunshine Coast, stated that GLOFs are becoming increasingly common globally due to climate change. He explained that in steep mountain valleys, a landslide or avalanche can block a river, allowing water to build up. If this natural dam fails, it can cause a sudden, devastating release of water.
Nepal is particularly vulnerable to climate change due to its mountainous terrain, fragile ecosystem, and limited capacity to adapt to growing climate impacts. The study highlighted that Nepal is already experiencing significant climate-induced loss and damage. According to the study, at least 45 GLOF events have occurred across 39 lakes in Nepal in recent years, with several resulting in loss of life.
Scientists emphasize that while it is too early to definitively link this specific event to climate change without further attribution studies, rising global temperatures are expected to increase the frequency and intensity of such floods. An event-specific study on extreme rainfall in central Nepal in September 2024 indicated that in a 1.3°C warmer world, the rainfall was approximately 10% more intense and about 70% more probable.
Experts hope that this disaster will spur the development of future warning systems. Dr. Nader Naderpajouh, an expert in risk and resilience at the University of Sydney, suggested that implementing warning systems, similar to those for tsunamis, is feasible with current technology and could save lives and mitigate the impact of future events. Such systems could provide early warnings to downstream communities, allowing for preparation and reducing the scale of damage.