Record ocean temperatures show that the seas are warming faster than expected, with significant impacts globally. Oceans absorb over 90% of the heat trapped by greenhouse gases, and since March 2023, daily global ocean surface temperatures have set new records. February 2024 saw a full year of 1.5℃ surface air temperature warming.
This unexpected warming is causing widespread damage. For example, in 2023, the water temperatures off the coast in Florida were warmer than a hot tub, resulting in massive coral bleaching. Other effects include deep sea de-oxygenation and increased rainfall.
Michael McPhaden of National Oceanic and Atmospheric Administration (NOAA) attributes the record heat to rising greenhouse gases and a major 2023 El Niño event. Other factors include the 2022 Tonga volcano eruption and a 2020 mandate reducing sulphur dioxide emissions from shipping, which has lessened heat-reflecting clouds.