ISLE OF SHEPPEY, ENGLAND: Static caravans sit atop rapidly eroding cliffs on 27 May 2026 in Isle of Sheppey, England. The Isle of Sheppey is among the worst affected areas in Britain for coastal erosion with the northern part of the island losing an average of 1 to 2 meters each year. The soft, unstable London Clay cliffs, wave undercutting, and climate change are the primary factors in the rapid erosion of the shoreline. (Photo by Carl Court/Getty Images)

UK Faces Rising Coastal Flooding Risks Due to Climate Change, Research Finds

By Claire Meyer

22 July 2026

Up to 13 million people in the UK face the long-term risk of coastal flooding due to climate change, and the risk might necessitate large-scale movement of populations away from the coast, according to a study published 21 July in Nature Communications.

By 2100, all of the flood models studied by the researchers showed that an additional 500,000 people will be exposed to 1-in-200-year undefended flood events—a 25 percent increase compared to today. Under the most pessimistic model, with significant ice-sheet instability driven by climate change, up to 13 million more people could be exposed to such a flood event. While that model is less likely, it is still within the realm of possibility given current climate change rates.

Even if current global pledges to cut carbon pollution are met, 1.7 million more people in the UK will be exposed to coastal floods in 2300, the study said.

The study’s simulations did not include flood defenses, either new or existing. This decision aimed to identify new populations that could become exposed to flooding in the absence or failure of defenses, infrastructure or land that could become exposed to floods, and locations that could be repurposed for relocated communities to inhabit.

Over the last century, the sea level has risen by around 20 cm in the UK, The Guardian re ported. Another 40 to 60 cm sea-level rise is already assumed by 2100, putting a half-million more people at risk of flooding in the UK, on top of the 2.5 million already in danger near the coasts. If ice sheets suddenly start collapsing into the ocean, though, instead of gradually melting in place, the UK could suffer up to 15 meters of sea level rise, which would swamp large parts of London and many other places.

That increased exposure to flood risk “implies widespread disruption to the economy and society,” the study said. The scenario would require major investments in new and existing flood defenses, potential movement of communities away from coastlines, and put critical infrastructure and national strategic importance sites at high risk of disruption.

“[Planners] who only consider changes over the coming century may have a false impression of the true risk landscape, given the potential for post-2100 acceleration of sea-level rise,” the researchers wrote. “It is therefore inevitable that a combination of additional or enhanced flood defenses and managed retreat will be necessary to mitigate against post-2100 flood risk.”

Coastal flood risk is only one resilience challenge the UK is facing. Winter rainfall in the UK was 20 years ahead of predictions in January 2026, with flooding cutting off communities and closing schools and businesses. Climate change means that winters are getting wetter in the UK, hitting damp areas like the southwest hardest with heavy downpours, The Guardian reported earlier this year.

Those downpours can trigger flash flooding, especially in historically non-flood-prone areas that don’t have robust drainage systems.

Environment Agency data from 2024 estimated that 6.3 million properties in England are currently at risk of flooding. The number will rise to 8 million by 2050.