Carbon pollution makes Europe’s ocean heatwaves 100 times more likely.

Europe’s seas are burning. This summer, carbon pollution has driven a “massive expansion” of marine heatwaves, with some waters hitting temperatures 6C above normal. A new analysis by World Weather Attribution found that the hottest two-week periods this year would have been “virtually impossible” in a preindustrial climate in three of the four sea regions studied. In the Celtic region, which covers much of the water around the British Isles, the heat reached levels that used to occur only once every 100 years. The study shows that human-caused climate change is not just warming the air—it is fundamentally altering the ocean. The extreme temperatures are now far more likely, and the scientists warn of severe impacts for marine life. In short: what was once a rare, century-scale event is now a regular threat, driven directly by carbon pollution.