Marine Heat Waves Threaten Intensified Storm Season
The Mediterranean Sea is warming twice as fast as the global average, and scientists warn that warm surface temperatures provide extra energy for storms and increase the lethality of heat waves.
The Mediterranean Sea is warming twice as fast as the global average, and scientists warn that warm surface temperatures provide extra energy for storms and increase the lethality of heat waves.
Rising ocean temperatures now have the potential to trigger powerful storms in Europe later this year, according to new research published on August 19, 2026. Scientists from the World Weather Attribution group, which uses peer-reviewed methods for rapid studies of climate change impacts on weather patterns, analyzed sea temperatures during the last two weeks of July and compared them with past marine heat waves and historical averages.
Particularly concerning is the fact that the Mediterranean Sea is warming twice as fast as the average of the world's oceans. Parts of the Mediterranean and the European Atlantic coast in June 2026 recorded surface temperatures more than 6 degrees Celsius above normal, according to the study reported by the Japan Times.
"When we have very warm sea surface temperatures, it gives extra energy to storms so they can last much longer," explained Catherine Gregory, a researcher at the University of Bern and co-author of the report, to the Japan Times. She also warned of the deadly combination of humidity and heat.
"During land heat waves, moisture coming from the ocean can be incredibly deadly. We've seen this in Southeast Asia or in India during monsoon seasons, but we also see it in southern Europe," Gregory said. She added that this is a new area of research, but probably one of the most important impacts when talking about how marine heat waves affect people.
"The heat dome that sat over much of western Europe for much of the summer caused heat waves on land and ocean. They are definitely linked," said Friederike Otto, a scientist at the Centre for Environmental Policy at Imperial College London and co-author of the report, to the Japan Times.
Otto also explained the feedback loop: warm seas contribute to heat on land, seawater retains heat longer, which prolongs marine heat waves, increases humidity in coastal areas, and prevents cooling, especially at night.
Thomas Frölicher, a scientist at the University of Bern and one of the study's authors, told Le Figaro: "From the Atlantic off Ireland to the Mediterranean, European seas are recording an alarming rise in temperatures."
The researchers found that temperatures in the Bay of Biscay and the western Iberian Peninsula rose by 1.5°C, while the eastern Mediterranean warmed by 2.6°C and the western Mediterranean by 3.1°C. The main driver of the record-high sea temperatures recorded in July around the Iberian Peninsula and the western and eastern Mediterranean is human-induced climate change.
Europe, the fastest-warming continent in the world, is struggling with continuous heat waves that this summer have already resulted in an estimated 25,000 deaths. At the current rate of warming, the extreme marine heat waves observed this summer are expected to be 1.3°C to 1.9°C warmer by the end of the century.
The report also notes that European summers are now associated with more extreme marine heat waves, with rapid warming starting earlier and lasting longer.
