Ocean temperatures were at “record-high values” last year, according to an international academic study published this month.
The warning comes after 2024 saw month-by-month reports of ocean heat reaching levels both worrying and hard to explain, with concomitant impacts on coral and other animals. Olive Heffernan wrote about this issue in December for Dialogue Earth: Why ocean temperatures are a growing concern.
Now researchers led by Lijing Cheng of the Chinese Academy of Sciences say that both global sea surface temperature and the “ocean heat content” of the upper 2,000 metres of the ocean “reached unprecedented highs in the historical record”. (See Olive’s piece for more on these two measurements.)
This continues a worrying run of temperature records. Witness these Washington Post headlines from years past:
2024 – Scientists fear planetary shift as record ocean heat enters second year
2023 – Oceans surged to another record-high temperature in 2022
2022 – Ocean warmth sets record high in 2021 as a result of greenhouse gas emissions.
And there’s Cheng’s own paper: Record-Setting Ocean Warmth Continued in 2019.
“The broken records in the ocean have become a broken record,” as Cheng pithily notes this January.
January also saw confirmation of record temperatures on land and globally too. Both Nasa and the European Union’s Copernicus Earth observation service have confirmed 2024 to be the warmest year on record.