Global ocean temperatures hit record high as El Nino intensifies

Copernicus warns of ‘unprecedented strain’ on world’s oceans as El Nino and climate change drive up sea surface temperatures.

The average global sea surface temperature has reached its highest level on record, a European Union agency said, warning that a rapidly intensifying El Nino and human-caused climate change were putting “unprecedented strain” on the world’s oceans.

In a statement on Monday, the EU’s Copernicus Climate Change Service said sea surface temperatures hit ۲۱.۱ degrees Celsius (۶۹.۹۸ degrees Fahrenheit) on Friday and Saturday, surpassing the previous record of ۲۱.۰۹C (۶۹.۹۶F) set in March ۲۰۲۴.

“This record is another clear signal of an ocean under growing stress,” said Samantha Burgess, the strategic lead for climate at the European Centre for Medium-Range Weather Forecasts (ECMWF). “El Nino is adding heat to the system, but it is doing so on top of decades of human-driven warming.”

Copernicus called the timing of the new record “particularly notable”. It said global ocean temperatures usually peak in March and April, when the summer in the Southern Hemisphere – which is mostly ocean – draws to a close.

But this year, the record was set in August.

Burgess told The Associated Press news agency that the oceans will keep getting hotter until the current El Nino – a natural temporary warming of parts of the Pacific that then warps weather and raises temperatures globally – reaches its peak, which is expected sometime between November and January.

The World Meteorological Organization, too, said it expects El Nino to strengthen in the coming months, and Copernicus said its seasonal forecasting system indicates that the event “could reach levels not seen for several decades”.

The added heat from El Nino comes as long-term fossil-fuel-driven warming has already raised ocean temperatures by ۰.۸C (۱.۴۴F), Burgess noted.

Copernicus also warned that rising ocean temperatures have “far-reaching consequences” for marine ecosystems and coastal communities.

Warmer oceans contribute to sea-level rise through thermal expansion, it said, and increase the likelihood and intensity of marine heatwaves, which can damage coral reefs and seagrass beds. This can in turn disrupt food chains and threaten industries such as fishing and aquaculture.

Warmer oceans are less able to absorb carbon dioxide, too, it said, weakening one of the planet’s key defences against climate change.

Higher ocean temperatures can also supply more heat and moisture to the atmosphere, enhancing the “potential for extreme weather events”.

Jane Lubchenco, an oceanographer and former head of the US National Oceanic and Atmospheric Administration, called the finding “very troubling”.

“An ocean this warm destabilises weather patterns and threatens food security, economic prosperity and marine life,” Lubchenco told the AP. “A warmer ocean is not our friend.”