Europe's seas hit record heat as climate change threatens marine life
Scientists said Wednesday that human-caused climate change was the main driver behind record-breaking sea temperatures around Europe this summer, warning of severe consequences for marine ecosystems and coastal communities. The Mediterranean saw its hottest July on record, with extreme heat also affecting other European waters.
An analysis by the World Weather Attribution (WWA) group found that human-caused climate change added about 2 degrees Celsius of warming to the Mediterranean this year, and roughly 1.4 degrees to Western European seas. The Mediterranean's average July temperature reached 27 degrees Celsius, the highest on record for that month, while an offshore buoy near Mallorca measured 33 degrees in early August.
Claire Bergin, a climate scientist at Ireland's Maynooth University and study co-author, said such shifts could completely reshape ecosystems that coastal communities depend on for food and income, and could also fuel damaging extreme weather on land.
Records across multiple regions
The analysis concluded that peak sea temperatures recorded this year in the eastern and western Mediterranean, as well as in the Bay of Biscay and along the Iberian coast, would have been virtually impossible without human-caused climate change. In the Celtic Sea, off Britain and Ireland, the extreme temperatures observed would otherwise be expected only about once a century.
Warmer seas raise humidity and overnight temperatures in coastal areas and can help fuel more intense storms later in the year. The World Meteorological Organisation notes that greenhouse gas emissions have pushed the planet's average temperature about 1.4 degrees above pre-industrial levels.
Impact on marine life
John Bruno, a marine ecologist at the University of North Carolina, said some species are moving north in search of cooler waters, but not all can adapt — many are approaching the absolute biological limits of adaptation. Temperature spikes can trigger mass die-offs among corals and other species, disrupting food chains for birds and mammals.
According to the WWA analysis, marine heatwave conditions affected about 90% of the Bay of Biscay and 80% of the western Mediterranean this year, compared with roughly 40% in a world without global warming.
