The Arctic is losing sea ice at a rate of roughly 490,000 square kilometres per decade, while parts of Europe's surrounding seas have experienced record marine heatwaves, according to the latest assessment from the European Union's Copernicus Earth observation programme.
The tenth Ocean State Report, released by the Copernicus Marine Environment Monitoring Service, examines ocean conditions using observations extending back to 1960. It found that the average global sea level has risen by approximately 4.2 millimetres per year since 2012 as ocean temperatures continue to increase.
The most dramatic changes are occurring in the Arctic. Between 1979 and 2025, sea-ice extent declined by approximately 490,000 square kilometres every decade, an area almost as large as Spain, exposing Arctic coastlines to stronger winds and waves.
According to the report, approximately 60 per cent of Arctic coastal infrastructure is now vulnerable to erosion and rising sea levels, while the Mediterranean and Black Sea experienced record-breaking marine heatwaves in 2024, with temperatures reaching more than 4.6C above normal levels in affected areas.
Small Island Developing States face another significant threat, with 65 per cent of their combined Exclusive Economic Zones having experienced accelerating sea-level rise since 1999 as the oceans warm.
The European Commission said Copernicus data are intended to provide governments and institutions with reliable information for measures to protect biodiversity, reduce pollution and strengthen resilience to climate change.
