In 2025, the amount of energy absorbed by the world’s oceans as additional heat will be equivalent to 365 million atomic bombs the size of Hiroshima, according to a new report published in Advances in Atmospheric Sciences. This marks the ninth consecutive year of record ocean warming, driven primarily by rising greenhouse gas emissions. The report, contributed to by 55 scientists, warns of worsening extreme weather, rising sea levels, and destabilizing marine ecosystems.
Consequences of ocean warming are already evident, contributing to severe storms and flooding globally. Notable events predicted for 2025 include devastating floods in Southeast Asia and Texas. Researchers note that ocean temperatures have surged by about 23 zettajoules compared to 2024, marking 2025 as the hottest year for ocean heat content. Around 14% of the oceans reached record-high temperatures last year, particularly in regions like the Southern Ocean and the Mediterranean.
Ocean warming accelerates storm intensity and the melting of glaciers, with Arctic ice extent at its lowest since satellite measurements began. Both the Greenland and Antarctic ice sheets are also experiencing record low mass levels, contributing to global sea level rise. Coral reefs are facing significant threats, with ongoing mass bleaching events affecting approximately 84% of coral reef areas worldwide since January 2023.
The report emphasizes that ocean heat content will continue to rise until global emissions reach net zero. While the situation is dire, rapid emissions reductions can still mitigate future impacts. The authors stress the importance of improving ocean monitoring to help communities adapt to these new climate realities.
