Photo: Gran Canaria, Canary Islands, Spain. Credit: European Union, Copernicus Sentinel-2 imagery.

Sea level rise will have major consequences for Europe’s Outermost Regions and Overseas Countries and Territories, yet these consequences remain poorly studied. A recent study focused on these overseas territories to fill this gap.

Current situation

At present, between 370 and 900 km2 of land along coastlines of Europe’s overseas territories is expected to be flooded annually. This corresponds to about 0.1% of the total land area of these overseas territories, and affects between 9,000 and 39,000 people, around 0.24% of the population. The resulting expected annual damage of flooding is between 99 and 215 million euros.

Of all these overseas territories, the expected annually flooded area, as a percentage of total land area, is greatest for the Netherlands Antilles Aruba, Bonaire, Sint Eustatius and Saba, at approximately 1%. The Canary Islands and Reunion contribute most to the number of people exposed to flooding.

Flooded area in the future

By the year 2050, the land area that is expected to be flooded annually increases by more than 70% compared to the current situation, reaching between 763 and 1386 km2 under a moderate scenario of climate change. This corresponds to around 0.18% of the total area. This number will keep growing in time, reaching between 0.25 and 0.35% of the total land area by 2100, a 2.5 to 3.5 increase compared to the current situation.

In the long run, between now and 2150, the projected increase in the land area that is flooded annually is especially high for the islands Bonaire, Sint Eustatius and Saba, at between 11.0% and 16.6%. The increase is also high for Aruba (8.8%–15.5%), Guadeloupe (5.0%–8.6%) and Saint-Martin (4.5%–6.7%).

Damage and people affected

For all Europe’s overseas territories, by 2050, the number of people exposed to flooding is projected to increase around 5 times, while the expected annual damage due to flooding is projected to increase at least seven times, compared to the current situation. By 2100, the number of people exposed to flooding and the expected annual damage are projected to increase between 10 and 17 times, and between 14 and 24 times, respectively. The expected annual damage will be less than 1% of GDP by 2050, but probably more than 2% by 2100.

By the end of the century, more than half of the people in Europe’s overseas territories that are annually exposed to flooding are living on the Canary Islands and in Reunion. By then, the expected annual damage is projected to be several percent of GDP for most of these territories.

Source: Vousdoukas et al., 2026. Nature Communications 17: 188.