Ocean 'under unprecedented strain' as El Niño helps supercharge warming to record levels

Global ocean temperatures have reached a record high as El Niño injects extra heat into our already-warming world.

On Saturday (Aug. 22), the daily global average sea surface temperature (SST) was hotter than at any time since records began in 1979, according to the European Union's Copernicus Climate Change Service .

"This record is another clear signal of an ocean under growing stress," Samantha Burgess , the strategic lead for climate at Copernicus, said in a statement . "El Niño is adding heat to the system, but it is doing so on top of decades of human-driven warming. As ocean temperatures continue to rise, the risks to marine ecosystems and coastal communities also increase."

Human activities are driving global warming through the widespread and continued burning of fossil fuels, along with other activities that emit carbon dioxide (CO 2 ) and other greenhouse gases into the atmosphere. These gases trap heat by absorbing radiation.

Now, El Niño, officially underway as of June 11 , is temporarily piling on additional warming. El Niño is the warm phase of a multiyear natural climate pattern, marked by unusually warm waters in the Pacific Ocean. The pattern typically boosts global temperatures and fuels disruptive weather, but this time, the conditions appear to be supercharged.

Researchers have warned that we're on the cusp of a likely historic super El Niño , with the potential to bring about a humanitarian crisis and possibly push an already-stressed climate ecosystem across a critical threshold .

Copernicus estimates global SST using satellites with temperature-measuring sensors. These showed that the SST hit 21.1 degrees Celsius (69.98 degrees Fahrenheit) Saturday, surpassing the previous high of 21.09 C (69.96 F), recorded in 2024 — the hottest overall year on record. The 2024 records were fueled by Earth's last El Niño, which was on the cusp of the "super" threshold, so not as extreme as what's forecast this time.

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