Scientists sound alarm as ocean temps hit new record

PARIS: The world’s oceans, which have absorbed most of the excess heat caused by humanity’s carbon pollution, continued to see record-breaking temperatures last year, a study published on Wednesday said.

Oceans absorb about 90% of the excess heat from greenhouse gas emissions, shielding land surfaces but generating huge, long-lasting marine heatwaves that are already having devastating effects on underwater life. The study, by researchers in China, US, Italy and New Zealand, said 2022 was “the hottest year ever recorded in the world’s oceans” . Heat content in the oceans exceeded the previous year’s levels by about 10 Zetta joules — equivalent to 100 times the electricity generation worldwide in 2021, the authors said. “The oceans are absorbing most of the heating from human carbon emissions,” the study noted.

Increasing water temperatures and ocean salinity — also at an all-time high — contribute to a process of “stratification”, where water separates into layers that don’t mix. This has wide-ranging implications because it affects the exchange of heat, oxygen and carbon between the ocean and atmosphere, with effects including a loss of oxygen in the ocean.