Overview
- The peer‑reviewed synthesis in Advances in Atmospheric Sciences combines multiple datasets and reanalyses from more than 50 scientists across roughly 30–31 institutions, including Copernicus Marine, NOAA/NCEI and China’s Institute of Atmospheric Physics.
- Ocean heat content increased by 23 zettajoules compared with 2024, a jump reported as roughly equivalent to 37 years of global energy use.
- About 16% of the global ocean surface registered record heat content in 2025 and roughly 33% ranked within the three warmest, with hot spots in the South and tropical Atlantic, the North Pacific, the Southern Ocean, the Mediterranean and the northern Indian Ocean.
- The stored heat is linked to stronger marine heatwaves, heavier rainfall and more powerful storms, and it is driving sea‑level rise through thermal expansion.
- While 2025’s average sea‑surface temperature ranked third warmest due to a shift from El Niño to La Niña, the long‑term ocean heat content trend continues upward with signs of slight acceleration since the 1990s.