The oceans just keep getting hotter. According to new research from dozens of international scientists published in Advances in Atmospheric Sciences early on Friday, the world’s oceans stored more heat in 2025 than any other year on record.
In 2025 the upper 2,000 meters of the ocean absorbed a record-setting 23 zettajoules more energy than in 2024. This amount is some 37 times as much as the word’s energy consumption in 2023, according to scientists at the U.S. National Oceanic and Atmospheric Administration, the Institute of Atmospheric Physics at the Chinese Academy of Sciences, and the E.U.’s Copernicus Marine Service.
Average sea surface temperatures—a key metric that can affect weather patterns—were the third-highest on record, at about 0.5 degree Celsius (or about one degree Fahrenheit) above the average from 1981 to 2010.
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These hot surface temperatures are a factor in Earth’s overall annual surface temperature; 2025 is expected to be the second- or third-hottest year on record.
The oceans are like the climatic version of soundproofing in a music studio; they absorb about 90 percent of the excess heat captured by the rising levels of greenhouse gases in the atmosphere. Hotter oceans contribute to rising sea levels, disrupt fragile marine ecosystems and fuel extreme weather. Without urgent action to address the climate crisis, scientists warn, the oceans will only continue getting hotter.
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