Scientists deliver ‘starkest warning yet’ of profound changes sweeping the planet’s oceans

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🗞️ Driving the news: The 10th Copernicus Ocean State Report, drawing on more than four decades of observations, warns that the world’s oceans are undergoing interconnected and long-term changes
• More than 100 scientists highlight accelerating warming, rising seas, acidification and ecosystem disruption

🔭 The context: Oceans absorb roughly 90% of the excess heat generated by human activity
• In 2025, they absorbed a record 23 zettajoules of additional heat, while global sea levels have risen about 3.8 mm per year since 1999
• The Mediterranean and Black Seas experienced record marine heatwaves in 2024, with some temperatures reaching 4.6°C above average

🌍 Why it matters for the planet: Ocean warming is intensifying marine heatwaves, stressing ecosystems, contributing to sea-level rise and amplifying risks from extreme storms. Ocean acidification has also increased by around 17% since 1985, threatening organisms such as corals and shellfish.

⏭️ What’s next: Scientists are calling for sustained ocean monitoring so governments and communities can better anticipate and prepare for changes already underway
• A powerful El Niño is adding further short-term pressure to an ocean system already experiencing long-term warming

💬 One quote: “The ocean is transforming before our eyes: warming, rising seas and ecosystem degradation are interconnected signs of significant and long-term change,” said Pierre Bahurel of Mercator Ocean International

📈 One stat: 23 zettajoules — the additional heat absorbed by the world’s oceans in 2025, a record for the ninth consecutive year

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