1188. Ocean-surface Warming Four Times Faster Now than Late-1980s

Recently, a paper was published stating that global sea surface temperature (SST) and ocean heat content (OHC) in the upper 2000 meters reached record highs in 2024.

A study by the University of Reading, published on January 28, revealed that global ocean temperatures hit a record high for 450 consecutive days from 2023 to early 2024, and that the rate of ocean warming has more than quadrupled in the past 40 years. Specifically, ocean temperatures rose by about 0.06°C per decade in the late 1980s, but are now rising at a pace of 0.27°C per decade.

Accelerating ocean warming is caused by a growing Earth energy imbalance, where energy from the sun is being absorbed by the Earth system rather than escaping into space. Due to the increase in greenhouse gas concentrations, the global energy imbalance has almost doubled since 2010. According to the paper, part of the warming is due to El Niño, a natural phenomenon in the Pacific Ocean, but 44% of the record-breaking high temperatures were attributed to the ocean's accelerated absorption of heat over the past decade.

Accelerating ocean warming highlights the urgency of reducing the burning of fossil fuels and stabilizing the climate.

Reference
Merchant, C. J., Allan, R. P., & Embury, O. (2025). Quantifying the acceleration of multidecadal global sea surface warming driven by Earth's energy imbalance. Environmental Research Letters, 20(2), 024037. https://doi.org/10.1088/1748-9326/adaa8a

Contributor: IIYAMA Miyuki, Information Program