Up to 13 million people in the United Kingdom could face the long-term risk of coastal flooding driven by climate change, according to recent scientific research. The study highlights the potential for large-scale population displacement along a significantly altered coastline in the coming centuries if global warming continues unchecked.
Current projections indicate that even if the world meets existing carbon reduction pledges under the Paris Agreement, the number of people exposed to coastal flooding in the UK will increase. By the year 2200, approximately 1.4 million additional individuals could be at risk, rising to around 1.7 million by 2300. These increases stem from ongoing sea level rise linked to melting ice sheets and warming oceans.
Over the past century, sea levels around the UK have risen by roughly 20 centimeters (8 inches), with this rate accelerating. Models estimate a further rise of 40 to 60 centimeters by 2100, which would put an additional half million people at risk beyond the 2.5 million already living in vulnerable coastal areas. Regions such as Lincolnshire and the Humber estuary have been identified as particularly exposed.
The study cautions that gradual sea level rise observed so far could accelerate sharply if major ice sheets undergo rapid disintegration rather than slow melting. Such a scenario could result in sea levels rising by as much as 15 meters by 2300, threatening extensive parts of London and numerous other coastal locations.
Researchers emphasize that focusing only on risks within the next century may underestimate the true long-term challenge. They argue that a combined approach involving strengthened flood defenses and managed retreat—planned population moves away from high-risk areas—will be necessary to address flood risks beyond 2100.
“The oceans and ice-covered parts of the world respond very slowly to global warming, which makes sea level rise the sleeping giant of climate change,” said Professor Matt Palmer of the University of Bristol, who led the study. “This means sea level rise is locked in for centuries to come.”
Marine geophysicist Dr. Rob Larter, not involved in the research, described the findings as a sobering reminder of the scale of adaptation required. He noted that scenarios involving several meters of sea level rise should be regarded as plausible outcomes rather than exaggerated forecasts.
This analysis represents the first effort to quantify the UK population at risk under long-term sea level projections, incorporating detailed flood modeling developed by the company Fathom. It does not account for the potential amplification of coastal flooding from storm surges intensified by climate change, nor does it factor in future demographic shifts or changes to flood defense infrastructure, given their uncertainties.
Dr. Joanne Williams from the National Oceanography Centre in Southampton underscored the difficulty and cost of preparing for worst-case outcomes. “Upgrading existing flood defense lines to the levels required by these high-end scenarios would be extremely challenging,” she said, stressing the importance of prompt climate action to mitigate these risks.