Record-breaking sea temperatures in the Mediterranean spark fresh warnings from scientists

Published on 01/07/2025 - 15:22 GMT+2

Sea aboveground temperatures successful nan Mediterranean person reached their highest level ever recorded for June. 

On 29 June, oversea aboveground temperatures deed 26.01°C, according to information collected by Copernicus and analysed by Météo-France. Overall temperatures are presently 3°C higher than average, pinch spikes exceeding 4°C successful immoderate places astir nan French and Spanish coasts.

The astir aggravated warming was observed successful nan occidental Mediterranean basin, including nan Balearic Sea and nan Tyrrhenian Sea. With nan current upwind conditions, scientists opportunity temperatures are improbable to driblet anytime soon. 

The Mediterranean is considered 1 of nan world’s astir susceptible ‘climate alteration hotspots’, warming overmuch faster than nan world average. Without action to curb ambiance change, experts pass that persistent marine heatwaves - prolonged periods of abnormally precocious water temperatures - could alteration nan region beyond recognition. 

Marine heatwaves could devastate life successful nan Mediterranean Sea

A persistent and increasing marine heatwave is gripping nan region, pinch “severe” and “extreme” conditions emerging disconnected southeastern Spain and bluish Morocco. 

Marine scientists pass that nan unfolding business could bring devastating impacts for biodiversity, fisheries, aquaculture, and moreover upwind patterns crossed confederate Europe and North Africa.

“Marine heatwaves of this magnitude successful nan Mediterranean Sea person had awesome effects connected marine life,” says Dr Kathryn Smith from nan Marine Biological Association of nan UK. 

“In nan past, we person seen impacts for illustration wide mortalities of invertebrate species, die-offs of seagrass beds and illness outbreaks successful mussel farms. It's apt that we'll spot akin impacts from this event.”

These events person already driven coral populations down by 90 per cent and pushed nan noble instrumentality mussel to nan brink of extinction. 

Warmer waters clasp little oxygen, starring to wide food die-offs specified arsenic those seen in Tuscany successful 2024. And, arsenic food dive deeper to flight nan power connected nan surface, they can’t beryllium reached by seabirds, which past dice disconnected successful their masses, too. 

The ripple effects of marine heatwaves widen onto land, too. Warm seas substance utmost weather, arsenic seen during Storm Daniel successful 2023 which killed astir 6,000 people. It was made 50 times much apt and 50 per cent much aggravated by precocious oversea aboveground temperatures successful nan Mediterranean. 

Floods successful Valencia successful 2024, which claimed complete 200 lives, person besides been linked successful portion to precocious oversea aboveground temperatures.

Marine heatwaves are becoming much aggravated and lasting longer

Marine heatwaves are now 10 times much aggravated than successful pre-industrial times and past 3 times arsenic long. 

“Climate alteration is responsible for nan world summation successful nan frequency, long and strength of marine heatwaves,” says Dr Alistair Hobday, investigation head for nan Commonwealth Scientific and Industrial Research Organisation’s (CSIRO) Sustainable Marine Futures Programme.

The Mediterranean Sea has been steadily warming since nan 1980s, pinch a crisp acceleration complete nan past decade. Over nan past 40 years, it has gone from experiencing 1 marine heatwave per twelvemonth successful defined areas to an mean of 4 per year, which screen almost nan full sea. Temperatures person been perpetually supra mean for nan past 5 years. 

“The unfolding, wide-reaching heatwave successful nan occidental Mediterranean now demands adjacent attention,” says Dr Karina von Schuckmann, a elder advisor astatine Mercator Ocean International. 

Scientists accent that only accelerated world emanation cuts tin halt this trend. Without urgent action, this ambiance hotspot could beryllium permanently transformed.