A new analysis has revealed that the catastrophic floods in Nepal in late September, which claimed over 240 lives, were intensified by human-induced climate change.
The study, conducted by World Weather Attribution (WWA), found that rainfall during the three-day deluge was about 10 per cent more intense due to global warming.
The extreme rainfall, which began on 26 September, triggered widespread floods and landslides, particularly in central and eastern Nepal. On 28 September, several weather stations recorded more than 320 mm of rain, setting new records and devastating large swathes of the country.
“Climate change was responsible for making the extreme downpours in Nepal about 10 per cent more intense. Bursts of rainfall will become even heavier, risking more destructive floods until the world replaces fossil fuels with renewable sources of energy,” the WWA analysis noted.
The research also highlighted the urgent need for Nepal to reconsider urban development, especially in low-lying areas along rivers, to protect communities from future disasters. The analysis pointed to Kathmandu, Nepal’s largest city, which lies in a flood-prone area along the Bagmati river.
The capital’s rapid, unchecked growth in recent decades exacerbated the destruction caused by the floods.
Human impact on climate
WWA, a collaborative network of international scientists, assesses the role of climate change in extreme weather events such as storms, floods, and heatwaves.
Their rapid analysis linked the intensity of the Nepal floods to the wider problem of human-induced global warming.
“If the atmosphere wasn’t overloaded with fossil fuel emissions, these floods would have been less intense, less destructive, and less deadly,” said Mariam Zachariah, a researcher at the Centre for Environmental Policy at Imperial College, London.
She emphasised that the floods, which caused the worst flooding Kathmandu has ever seen, were a stark reminder of the consequences of unchecked climate change.
More than 50 people were killed in the Kathmandu valley alone, where properties worth billions of rupees were damaged. Witnesses in the capital described the flooding as unprecedented, and scientists believe that the situation is only set to worsen without urgent action.
Roshan Jha, a researcher from the Indian Institute of Technology, Bombay, warned that Asia, particularly countries like Nepal, is becoming increasingly vulnerable to severe rainfall and floods due to climate change.
“With every fraction of a degree of warming, the atmosphere can potentially hold more moisture, leading to much heavier downpours, and catastrophic floods like these,” Jha explained.
Rebuilding Nepal’s future
The WWA study called on the Nepalese government to implement stricter controls on urban development in flood-prone areas. By limiting construction along rivers and ensuring cities are better prepared for extreme weather, the researchers believe the country could mitigate the risks of future floods.
“Limiting development in flood-prone urban areas will reduce the number of people in harm’s way and save lives when floods occur in the future,” the report said. The scientists also urged Nepal to invest in early warning systems and improve disaster preparedness to minimise the impact of future floods.
Zachariah pointed out that the study of the Nepal floods is part of a broader pattern across Asia. In 2024 alone, WWA studies have revealed the clear impact of climate change on deadly floods in India, China, Taiwan, the UAE, Oman, and now Nepal.
“Clearly, climate change is no longer a distant threat in Asia,” Zachariah said.
With climate change accelerating and leading to ever more frequent extreme weather events, Nepal and other vulnerable nations must act swiftly to protect their people and infrastructure.
The findings of the WWA analysis serve as a stark reminder of the ongoing consequences of climate change, with increasing urgency for global efforts to reduce carbon emissions and build resilience in the face of escalating environmental crises.
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