Rising global emissions of greenhouse gases are expected to intensify the severity of extreme flooding in the Central Himalayan region during this century. A recent study by geographers at Durham University, UK, highlights how flooding on the Karnali River could become significantly more destructive, with critical implications for communities in Nepal and India.
Severe Flooding on Karnali River: A Growing Threat
The Karnali River, flowing through Nepal and China, plays a vital role in regional ecology and livelihoods. Researchers simulated flood risks based on climate models, estimating that extreme floods – those with a 1% annual chance – may increase in size by 22% to 26% between 2020 and 2059 compared to historical data from 1975 to 2014.
Projections for 2060 to 2099 show this could jump to 37%-43% with moderate emissions, and a staggering 73%-84% under high greenhouse gas emission scenarios.
Why the Central Himalayas Face Increasing Flood Hazards
The Central Himalayan foreland is one of the world’s most flood-prone zones. Increased rainfall, rather than glacier or snowmelt, will be the dominant source of floodwater as climate change modifies weather patterns. These floods already cause severe human and economic losses. For example, floods in September 2024 led to 236 fatalities, displaced over 8,400 people, and caused damage equaling 1% of Nepal’s GDP. By 2050, flood damages could cost 2.2% of the country’s annual GDP.
What This Means for People and Ecosystems
Beyond physical destruction, flooding jeopardizes food security and heightens risks of epidemics due to water contamination and displacement. As climate change accelerates, these challenges will grow more severe. Dr. Ivo Pink from Durham University warns that floods with a 1% annual chance today could happen every five to ten years by the century’s end without significant greenhouse gas reductions.
How Researchers Predicted Flood Increases
The Durham team combined climate projections from global centers with hydrological simulations. This hybrid modeling approach accounted for uncertainties in climate and river flow, strengthening the reliability of future flood scenarios. Professor Sim Reaney emphasized that combining multiple data sources enables decision-makers to understand the range of future possibilities and design strategies for resilience.
The Urgent Need for Climate Action
The research underscores that flood hazards will worsen for decades even after greenhouse gas emissions peak. This reality points to an urgent need for global emission reductions alongside local flood management. Without swift action, the Central Himalayas will face increasingly devastating impacts from extreme flooding, threatening millions of lives and livelihoods.
Questions and Answers About Himalayan Flood Risks
Q: What causes the increase in Himalayan floods?
A: Primarily intensified rainfall caused by rising greenhouse gas emissions leads to more severe flooding, rather than melting glaciers or snow.
Q: How often might extreme floods occur by 2100 in the Himalayas?
A: Floods with a 1% annual chance today could occur every five to ten years by the end of this century under high emissions.
Q: What are the economic impacts of floods in Nepal?
A: Flood events already cause damages worth about 1% of Nepal’s GDP, and this could rise to 2.2% by 2050.
Q: Can flood disaster risks be reduced?
A: Yes, through improved flood hazard management, infrastructure adaptation, and by drastically cutting greenhouse gas emissions worldwide.
FAQs on Flooding and Climate Change in Central Himalayas
Q1: What communities are most at risk?
Communities along the Karnali River and the central Himalayan foreland in Nepal and India face the greatest flood hazards due to population density and geographic exposure.
Q2: How reliable are flood projections?
While all forecasts hold uncertainties, combining climate models and river flow simulations allows for better estimation of risks and helps local authorities plan accordingly.
Q3: What role do glaciers play in floods?
Glaciers contribute less to extreme floodwater compared to the increasing rainfall due to climate change in this region.
Q4: How can policymakers use these findings?
This study informs disaster preparedness by highlighting flood risk trends, helping target resources for flood defenses and community resilience.
