Overview

• The assessment identifies a new global record for mean sea-surface temperature at 21°C in spring 2024.
• Marine heatwaves in 2023–2024 were exceptionally intense and persistent, harming food production, marine ecosystems and coastal economies, including a Mediterranean event that favored invasive blue crabs over traditional clams in Italy.
• Sea level rise is accelerating at an unprecedented rate, elevating flood and erosion risks for coastal zones and affecting more than 200 million Europeans.
• Sea ice continues to decline, with surface minima at new lows and March 2025 extent diverging from the winter average by nearly 2 million square kilometers, according to Copernicus.
• Produced by Copernicus Marine and implemented by Mercator Ocean for the European Commission, the report consolidates evidence of climate change, biodiversity loss and pollution to inform urgent policy action.