The rate of ocean warming more than quadrupled over the past four decades and roughly doubled since 2010, partly due to increasing greenhouse gas concentrations, and because the Earth now reflects less sunlight to space. Global ocean temperatures hit record highs for 450 days straight in 2023 and early 2024. Some of this warmth came from El Niño, the rest explained by sea surface warming up faster in the past 10 years than before. The ocean temperature increase seen over the past 40 years may well be exceeded in just the next 20 years. Because surface oceans set the pace for global warming, this matters.
www.reading.ac.uk/news/2025/Research-News/Ocean-surface-warming-four-times-faster-now-than-late-1980s#:~:text=Ocean%20temperatures%20were%20rising%20at,2024%20saw%20unprecedented%20ocean%20temperatures.