Climate Change Main Driver of European Ocean Warming: Study
Climate change is the main driver of rising ocean temperatures across Europe, adding around 2 degrees Celsius of warming to the Mediterranean this summer and causing serious disruption to marine ecosystems, according to a new study.
“From the Atlantic waters off Ireland to the Mediterranean Sea, Europe’s seas are experiencing an alarming surge in temperatures,” said Thomas Frolicher, an environmental physicist at the University of Bern in Switzerland and a co-author of the study.
“Our research shows clearly that this is being driven by climate change, in particular by the continued burning of fossil fuels,” he added.
Scientists from the World Weather Attribution group estimated that human-caused climate change contributed around 2C of warming to the Mediterranean and more than 1.3C to 1.4C to Western European seas.
The researchers reached their conclusions by combining observational data with climate model simulations.
The study found evidence of severe ecological consequences, with marine species moving northward in search of cooler waters. Such changes could disrupt food chains as well as coastal fisheries and aquaculture.
The impacts could also extend to coastal communities on land. Higher sea surface temperatures can increase humidity in coastal areas, raising the risk of extreme heat, the World Weather Attribution group said.
Marine ecologist John Bruno said even relatively small increases in temperature can push some marine organisms beyond their survival thresholds.
He noted that coral reefs, for example, can suffer severe impacts from warming of only about 1C.
However, not every species is negatively affected by higher temperatures. Some organisms can benefit from warmer conditions or from the disappearance of natural predators.
“There is a kind of reshuffling, reorganisation of communities. So we have what we call winners and losers,” Bruno said.
The findings come as global ocean temperatures continue to reach record levels. According to the European Union’s Copernicus Climate Change Service, global oceans recorded their highest-ever temperatures for a second consecutive month in July.
The World Weather Attribution group said some parts of the Mediterranean experienced sea surface temperatures more than 6C above normal during the hottest two weeks of July.
Marine heatwaves have also affected large parts of European waters. About 90 percent of the Bay of Biscay and Iberian coast region and 80 percent of the Western Mediterranean experienced marine heatwaves this year, according to the group.
Without the current level of around 1.4C of human-caused global warming, only about 40 percent of those areas would have been affected by such heatwaves, the researchers estimated.
Claire Bergin, a co-author of the study and researcher at Maynooth University in Ireland, said warmer seas might appear attractive to beachgoers in traditionally cooler countries.
“However, the impacts on marine life beneath the surface are more serious,” she said.
