Overview
- A coordinated analysis by more than 50 scientists from 31 institutions confirms record-high ocean heat content using three observational datasets and an ocean reanalysis.
- 2025 marked the ninth consecutive year of record upper‑2000 m ocean heat content, signaling persistent long‑term warming.
- Warming was uneven, with about 16% of ocean area at record highs and roughly 33% in their top‑three warmest, including hotspots in the tropical and South Atlantic, North Pacific and the Southern Ocean.
- Global mean sea‑surface temperature ranked third warmest on record in 2025, easing slightly from 2023–24 as conditions shifted from El Niño to La Niña.
- Scientists warn the added heat is raising sea levels, fueling extreme weather and stressing marine ecosystems, and that records will keep falling as long as the planet retains excess energy.