An international study published Friday in Advances in Atmospheric Sciences reveals that the world's oceans absorbed more heat in 2025 than in any year since modern record-keeping began. The findings, based on data from 31 research institutions globally, show the upper 2,000 meters of ocean stored 23 zettajoules of energy – equivalent to 37 years of global energy consumption at 2023 levels.
Researchers found 16% of ocean areas experienced record-high temperatures last year, with the fastest warming occurring in the tropical Atlantic, North Pacific, and Southern Ocean. While 2025's global sea-surface temperatures ranked third highest behind 2023 and 2024, they remained 0.5°C above baseline levels, contributing to extreme weather events like Southeast Asia's catastrophic floods and the Middle East's prolonged droughts.
The study underscores ocean warming's role in sea-level rise through thermal expansion and its capacity to intensify storms via increased atmospheric heat and moisture. Scientists warn that continued heat accumulation will break more records, urging accelerated climate action to mitigate cascading ecological and economic risks.
