Photo by Uriel Soberanes
Every part of the global ocean is now affected by the triple planetary crisis of climate change, biodiversity loss, and pollution, according to the ninth Copernicus Ocean State Report published on 30 September 2025.
“No part of the ocean is untouched by the triple planetary crisis, as pollution, biodiversity loss, and climate change are putting pressure on the ocean worldwide,” the report states.
Record warming and heatwaves
Global sea surface temperatures reached 21°C in spring 2024, the highest since satellite records began in 1982. The northeastern Atlantic has been warming nearly twice the global rate at 0.27°C per decade since 1982, whilst the tropical North Atlantic experienced record-breaking heatwaves affecting some areas for up to 300 days in 2023.
Arctic sea ice recorded four all-time lows between December 2024 and March 2025, with ice lost in March 2025 covering an area four times the size of Poland.
Ecosystem and economic impacts
Over 8% of marine biodiversity hotspots are exposed to warming beyond global rates, whilst 10% face acidification exceeding the global average. Warmer waters are facilitating invasive species, with Atlantic Blue Crabs causing 75-100% collapse in clam production in northeastern Italy’s Po River delta.
Global mean sea level rise has reached 4.1 ± 0.1 mm per year (2016–2024), threatening approximately 200 million coastal residents in Europe. In 2024, extreme marine heatwaves occurred in countries where 40-80% of blue economy employment relies on coastal tourism.
“The science is unequivocal: The ocean is changing fast, with record extremes and mounting impacts,” said Karina von Schuckmann, Senior Adviser at Mercator Ocean International and Chair of Copernicus Ocean State Report activities.
Monitoring and tools
The report introduces the Starfish Barometer—an annual assessment of global ocean health, human pressures, and societal impacts—launched at the third United Nations Ocean Conference in Nice. The Copernicus Marine Service, EMODnet, and Digital Twin of the Ocean enable scientists to simulate invasive species spread and forecast heatwave impacts on fish stocks.
The report is compiled annually by more than 100 experts using observation-based data from remote sensing, in situ measurements, and ocean reanalysis. Full details are available at marine.copernicus.eu.