Record temperatures in the Mediterranean Sea this summer contributed to the freak storm that sank a superyacht off the coast of Sicily, with similar extreme events expected to increase in frequency and intensity as the climate crisis tightens its grip, Italian scientists have said.
One person is confirmed to have died and rescuers are searching for six missing people, including the British tech entrepreneur Mike Lynch and his 18-year-old daughter, Hannah, after the 56-metre Bayesian capsized in the early hours of Monday.
The vessel is thought to have been struck off the coast of Porticello, near Palermo, by a tornadic waterspout, a whirling column of air and water mist that has the same characteristics as a land tornado.
Sea temperatures in the Mediterranean have reached 30C, three degrees higher than average, during two months of consecutive heatwaves, the most recent of which was broken at the weekend by a sudden blast of cold air and heavy storms across Italy.
Sicily had also been grappling with a months-long drought. The sea surface temperature around the southern Italian island on Monday was between 27.3C and 30.5C.
Luca Mercalli, the president of the Italian Meteorological Society, said the high temperatures created a huge amount of energy, which made the storms more intense.
“For example, 30 years ago an event of this kind might have brought winds of 100kmh,” he said. “Today it’s 150kmh because sea temperatures of three degrees higher means an enormous quantity of energy for storms, and when cold air arrives it’s explosive.”
Bayesian left the Sicilian port of Milazzo on 14 August, sailing for a few days around the Aeolian Islands and off the historic coastal village of Cefalù. It moored about 700 metres off the port of Porticello after its journey was disrupted by bad weather.
The powerful waterspout lasted just minutes, hitting a restricted area. A boat moored nearby was unscathed.
“Whoever was in that position at that time would have experienced these conditions,” said Mercalli. “Episodes of such speed and intensity mean that even if you are prepared, it is difficult to react in time.”
Roberto Danavaro, a marine biologist at the University of Ancona, said there was “an absolute direct link” between the anomalous sea temperatures this summer and the storm. Several other tornadoes have occurred recently close to Italy’s coastline, including in the Adriatic and off Liguria, in northern Italy.
In May last year, a similar violent storm killed four people when their tourist boat capsized on Lake Maggiore.
“Occurrences of tornadoes or Mediterranean hurricanes have been increasing in frequency over the last 10 to 15 years,” said Danavaro. “And based on the high temperatures, we are likely to see more in September and October. The heat of this summer will not bring anything good.”
Paolo Sottocorona, a meteorologist, said a waterspout of the intensity that struck Bayesian, built in 2008 and refitted in 2020, was “the extreme of the extreme”.
“This is because the situation in the Mediterranean has reached temperatures that were never reached before, and this brings instability,” he said. “Unfortunately these events, which were once anomalous, in the sense they almost never happened, are now beginning to occur more often. This is a sign of climate change.”
The high sea temperature has also affected the Adriatic, which is part of the Mediterranean, triggering the widespread proliferation of mucillagine, or marine mucilage, a thick, slimy white-yellow substance formed of various microalgae that accumulates on the seabed or the surface. The phenomenon has had a detrimental impact on fishers this summer.
Italy has become known by scientists as one of Europe’s climate risk hotspots owing to a range of vulnerabilities including its geographical location, diverse topography and densely inhabited Mediterranean coastal areas.
Within the last three years, the country has been hit by devastating floods, landslides, wildfires, record-breaking heatwaves and the collapse of a glacier in the Dolomites which killed 11 hikers.
In 2023, there were 378 extreme climate events in Italy, an increase of 22% on 2022, according to a report by the environmental agency, Legambiente, published last December.
“These events are only going to get more frequent and more intense,” said Mercalli.
