Major reversal in ocean circulation detected in the Southern Ocean

If deep water is now rising and releasing centuries of stored CO2, we're talking about a major shift in Earth's climate plumbing. Also wild that this only became visible thanks to a novel satellite processor

Why would the deep water have more dissolved CO2 than the surface water?

The high pressure at depth allows it to dissolve more gas.

Exactly the same reason you coke can out-gasses when you open it

The Biological Pump. Organic matter created at the surface (by photoplankton and by consumers) falls into the deep ocean, where other biological processes oxidize it back to CO2.

https://en.wikipedia.org/wiki/Biological_pump

The fact that this was discovered by a novel satellite processor makes an uneducated person like me on this topic wonder if this has happened before and us humans just didn't have any way of observing it. We've only had satellites for a few decades and earth and its oceans have been here a while longer than that.

It’s happened before, and we’ve observed it indirectly.

The last time the northern Atlantic current shut down, parts of Western Europe were covered in glaciers.

The climate models are extremely accurate within certain ranges. When you get outside those ranges, previously unknown tipping points like this will start to manifest themselves.

It’s the difference between predicting what a piece of precision machinery will do when it’s new vs after it’s been dropped and hit with a sledgehammer.

This is why the 1.5C global warming goal was irresponsibly high. We’ll cross it in ~ 18 months, so expect more terrible news like this article’s findings as we get further and further away from well-understood climatology.

"The global annual average for 2024 in our dataset is estimated as 1.62 ± 0.06 °C (2.91 ± 0.11 °F) above the average during the period 1850 to 1900, which is traditionally used a reference for the pre-industrial period. This is first time Berkeley Earth has reported an annual average above 1.6 °C (2.9 °F), and the only second time that Berkeley Earth has reported any year exceeding the key 1.5 °C (2.7 °F) threshold, after slightly doing so in 2023."

https://berkeleyearth.org/global-temperature-report-for-2024...