World’s oceans absorbed record heat equal to 40 times annual global energy use

The world's oceans absorbed a record 23 zettajoules of heat in the past year—nearly 40 times global human energy consumption—driving rising sea levels, increasing acidification, and widespread coral bleaching, according to the Copernicus ocean state report. Sea levels have risen 3.8mm annually since 1999, accelerating to 4.2mm yearly between 2012 and 2025, while the global ocean has become 17% more acidic over four decades. Between January 2023 and September 2025, 84% of global coral reefs experienced bleaching-level heat stress, with the Mediterranean and Black Seas experiencing record marine heatwaves and the Mediterranean warming 0.32°C per decade.