Europe: Climate change has raised sea temperatures by about 2°C — mounting ecological and economic risks

Human-caused climate change has driven a dangerous rise in sea temperatures across Europe this summer, according to a new assessment by the World Weather Attribution (WWA) group. Observational records compared with climate models show roughly a 2°C increase in parts of the Mediterranean and about 1.3–1.4°C higher temperatures in western European waters.
Scientists warn the warming is more than a heat statistic — it is already disrupting marine ecosystems and could place heavy pressure on fisheries and coastal livelihoods. WWA reports clear evidence of ecological impacts, including species shifting north toward colder waters and changes in food webs. Thomas Frölicher, an environmental physicist at the University of Bern and a co-author of the study, said: “From Irish Atlantic coasts to the Mediterranean, Europe’s seas are facing dangerous warming.”
Marine ecologist John Bruno cautioned that even a small increase — for example, one degree Celsius — can cause severe biological damage, such as to coral reefs. WWA noted that during the hottest two weeks of July, some Mediterranean areas recorded sea surface temperatures more than 6°C above normal. Marine heatwaves have affected large parts of Europe’s seas: roughly 90% of the Bay of Biscay and Iberian coasts and 80% of the western Mediterranean experienced marine heatwaves this year.
WWA estimates that, without the roughly 1.4°C of human-caused global warming to date, only about 40% of these areas would have been affected. Researchers warn that warmer seas can increase coastal humidity and amplify heat risk on land, impacting human health and economic activities. Co-author Claire Bergin said warm seas “may look attractive to swimmers, but their subsurface impacts on marine life are far more severe.”
Scientists stress that without deep cuts to human greenhouse gas emissions, such events will become more frequent and intense — posing a growing environmental and social threat across Europe.