Experts link Nepal floods to climate change, extreme topography

Deadly flash floods and landslides in Nepal, which claimed at least 165 lives and destroyed entire villages, are being analyzed by experts who point to a combination of the region's extreme topography and the escalating impacts of climate change. Videos from the affected areas depicted a terrifying surge of mud engulfing buildings and tossing vehicles.

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We do know what climate change trends look like in the Himalayas. There is high confidence of more heat waves, glacial retreat, permafrost reduction, these sorts of things that can drive things like landslides and glacial outburst floods.

Initial theories suggested an earthquake triggered a landslide that dammed a river, leading to the catastrophic flood. However, the U.S. Geological Survey later indicated that seismic waves were generated by a glacial collapse and debris flow, not an earthquake. Researchers highlight that glacial lake outburst floods (GLOFs) are a growing hazard in the Himalayas due to global warming, which contributes to glacial retreat and permafrost reduction.

Scientists are undertaking attribution studies to definitively link such events to climate change. These studies compare the likelihood of an event occurring in the current climate versus a pre-industrial era. A similar glacial outburst flood occurred in July 2025, originating in China and affecting Nepal's Rasuwa District. Preliminary assessments found no anomalies on the Chinese side, suggesting a rock-ice avalanche in Nepal may have caused the river blockage and subsequent flood.

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We believe a rock-ice avalanche occurred in Nepal, blocking the Lhende river and causing the cascading flood event.

Hydrologists noted the absence of prior rainfall, a factor that bypasses conventional flood warning systems. By the time the mudflow is visible, it is often too late to escape, rendering traditional flight or vehicle-based evacuation methods ineffective.

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That defeats essentially every operational flood warning system in the world. By the time you see the mud flow coming, it’s too late. Running will not help.