Europe's seas are warming at an alarming rate, faster than the global climate average, according to a new report from World Weather Attribution. Scientists found that marine heatwaves have affected waters from Ireland to the Mediterranean, with some regions experiencing temperatures up to 6°C (11°F) higher than normal this summer.
The international team of scientists assessed water temperatures across four key regions: the Celtic Sea, the Western Mediterranean, the Eastern Mediterranean, and the Bay of Biscay & Iberian Peninsula. In most areas, the summer warming exceeded the global average increase of 1.4°C (2.5°F). Specifically, the Celtic Sea was about 1.2°C (2.2°F) above average, while Mediterranean waters were up to 3°C (5.4°F) warmer.
Combining observational data with climate models, the research identified human-induced climate change as the primary driver of this warming. The analysis indicates that climate change has directly contributed approximately 2°C (3.6°F) of warming to the Mediterranean, 1.4°C (2.5°F) to the Bay of Biscay and Iberian Peninsula region, and 1.3°C (2.3°F) to the Celtic region.
"Every very extra tonne of carbon we emit pushes Europe's coastal temperatures and ecosystems into uncharted territory," stated Professor Thomas Frölicher from the University of Bern. He emphasized that the continued burning of fossil fuels is a key factor.
These elevated temperatures have significant consequences for marine life and coastal communities. Professor John Bruno from the University of North Carolina at Chapel Hill explained that extreme ocean heat can lead to mass mortality events for vital habitat-building species like corals and sponges, creating cascading impacts throughout marine ecosystems. While some species may shift their ranges northward, others are unable to adapt quickly enough, pushing them towards their biological limits and threatening biodiversity and fisheries.
Professor Friederike Otto from Imperial College London noted that many people and industries depend on stable sea temperatures. "In our oceans and seas there can be very hard limits for adaptation," she said. "The longer we wait with transitioning away from fossil fuels, the higher the price. A price not paid by the rich."
The report highlights the urgency of transitioning away from fossil fuels to mitigate the escalating impacts on marine environments and the communities that rely on them. The findings underscore the challenge of adhering to the goals of the Paris Agreement, which aims to limit global average temperature increase to well below 2°C (3.6°F) and pursue efforts to limit it to 1.5°C (2.7°F) above pre-industrial levels.