Copernicus warns El Niño and climate change could drive further temperature records
The world’s oceans recorded their warmest June ever observed, with global sea surface temperatures reaching 21.0 degrees Celsius, according to the European Union’s Copernicus Marine Service.
The agency said June 2026 surpassed previous records set in the same month in 2023 and 2024, marking another sign of sustained ocean warming. It added that the first half of the year was dominated by unusually high sea surface temperatures and widespread marine heatwaves across much of the global ocean.
According to Copernicus, marine heatwaves expanded steadily and eventually affected around 82 percent of the world’s oceans. The Mediterranean, central North Atlantic and equatorial Pacific emerged as major hotspots, reflecting what scientists described as continuing thermal stress across marine systems.
El Niño could push temperatures higher
Scientists warned that the possible arrival of a powerful El Niño weather pattern could further increase ocean and atmospheric temperatures in the coming months.
Carlo Buontempo, director of the Copernicus Climate Change Service, said current conditions may signal the start of another phase of record-breaking heat. He added that with ocean temperatures already at extreme levels, more global temperature records could fall soon.
El Niño develops when parts of the Pacific Ocean become unusually warm, releasing additional heat into the atmosphere and altering weather patterns worldwide.
Warming seas threaten climate stability
The Copernicus report follows recent UN warnings that the world’s oceans face a deepening crisis as seas warm and rise faster.
Oceans absorb about 90 percent of the excess heat produced by greenhouse gas emissions, making them central to regulating Earth’s climate. However, warmer waters increase atmospheric moisture, fuel stronger tropical storms and intensify destructive rainfall.
Hotter seas also contribute directly to sea-level rise as water expands with heat. In addition, prolonged marine heatwaves threaten coral reefs, where extreme temperatures can trigger bleaching and widespread ecosystem damage.
