The world's oceans absorbed more heat in 2025 than in any previous year since modern record-keeping began, according to a landmark study published in Advances in Atmospheric Sciences. The upper 2,000 meters of seawater stored an unprecedented 23 Zetta Joules of energy—equivalent to 37 years of global energy consumption at 2023 levels—intensifying storms, marine heatwaves, and sea-level rise.
Conducted by over 50 scientists across 31 institutions, the research highlights regional disparities: 16% of ocean areas experienced record-breaking heat, while 33% ranked among their top three warmest years. The tropical and South Atlantic, North Pacific, and Southern Ocean warmed fastest, threatening marine biodiversity and coastal communities.
Although 2025’s global sea-surface temperatures ranked third-highest behind 2023 and 2024, they still drove extreme weather events. Scientists link last year’s severe Southeast Asian floods, Mexican downpours, and Middle Eastern droughts to elevated evaporation rates caused by warmer oceans.
Researchers warn that continued planetary heat accumulation will break more ocean records, urging accelerated climate action to mitigate long-term ecological and economic risks.
