Climate change adds 2C to Mediterranean warming, study says

Climate change added about 2C of warming to the Mediterranean this summer and was the main driver of rising sea temperatures around Europe, according to a study by scientists from the World Weather Attribution group.

The group said climate change also added more than 1.3C to 1.4C of warming to Western European seas. The scientists reached the estimates by combining observational data with climate model simulations.

Thomas Frolicher, an environmental physicist at the University of Bern and a co-author of the study, said European seas from waters off Ireland to the Mediterranean were seeing an “alarming surge” in temperatures. He said the research showed the warming was driven by climate change, especially the continued burning of fossil fuels.

World Weather Attribution said there was evidence of severe ecological impacts, including species moving north to cooler waters and disruption to food chains, coastal fisheries and aquaculture. It also said higher sea surface temperatures can increase humidity in coastal areas and raise the risk of extreme heat.

The group said some Mediterranean areas recorded sea surface temperatures more than 6C above normal during the hottest two weeks of July. It said marine heatwaves affected 90 percent of the Bay of Biscay and Iberian coast region and 80 percent of the Western Mediterranean this year. Without the current 1.4C of human-caused warming, it predicted only about 40 percent of those areas would have been affected.

The European Union’s Copernicus Climate Change Service said the world’s oceans hit record-high temperatures for a second straight month in July.

Marine ecologist John Bruno said it was surprising how little warming can push organisms beyond lethal thresholds, citing about 1C for coral reefs. He said some organisms can benefit from heatwaves, while others lose out, reshaping marine communities.