Another new heat record, for the oceans this time: they have never been so hot since their heat content was measured. They massively absorb our greenhouse gas emissions.
Another new record that we wouldn’t want to reach: a study published on January 11, 2023 shows that in 2022, the oceans reached the warmest temperatures in all of human history… surpassing the previous record set in 2021. These results were obtained using 24 scientists around the world, 16 institutes, and two data sets. In question, unsurprisingly: human activities at the origin of climate change.
The measurement is made in particular in terms of joules – which corresponds to a quantity of energy, and therefore also of absorbed heat. Oceanic waters, that is to say those reaching a depth of up to 2,000 meters, have absorbed around ten zettajoules (1 zettajoule = 1021 joules = 1,000,000,000,000,000,000,000 joules) in 2022.
With such heat, we could boil about 700 million 1.5 liter kettles per second for a year. This also corresponds to 100 times the world’s electricity production in 2021, 325 times the electricity production of China, 634 times that of the United States.
The oceans absorb our polluting emissions
The increase in heat absorbed by the oceans also leads to:
- An increase in salinity (salt level);
- A stratification of water: it is distributed in piled up layers, with specific properties for each one, instead of mixing correctly, which can, for example, lead to anoxia – absence of oxygen.
These metamorphoses are obviously not good for living organisms: biodiversity risks suffering from them… and is already suffering from them. A typical example is found in coral bleaching – notably threatening the famous Great Barrier Reef. Fauna and flora must be able to adapt quickly enough to face the warming of the ocean, which is increasing too quickly.
This can therefore result in a reduction in ocean biodiversity, or population displacements disrupting the food chain. More broadly: climate change is modifying the hydrological cycle of the planet. The interaction between the ocean and the atmosphere is delicate. Global warming makes waters warmer, more saline, which contributes to the effects of climate change.
” Oceans absorb most of the warming from human carbon emissions “Adds Michael Mann, lead author of this work, in a press release. ” Until we reach net zero emissions, this warming will continue and we will continue to set records for ocean heat content, like this year. Better knowledge and better understanding of the oceans constitute a basis for actions to combat climate change. »
Listen to the podcast The 6th Extinction
What are the threats that weigh on the living today? To understand it and keep hope, discover our podcast The 6th Extinction, carried by science popularizer Marie Treibert. The series is made up of six episodes available on all listening platforms (Spotify, Deezer, Apple, etc.).