This is hardly reported at all...

Southern Ocean current reverses for first time, signalling risk of climate system collapse

A major ocean current in the Southern Hemisphere has reversed direction for the first time in recorded history, in what climatologists are calling a “catastrophic” tipping point in the global climate system.

The development, which was confirmed by Spanish marine scientists at El Institut de Ciències del Mar (ICM-CSIC) in Barcelona, has triggered widespread alarm among climate scientists due to its potential to accelerate global warming and destabilise weather patterns worldwide.

“The stunning reversal of ocean circulation in the Southern Hemisphere confirms the global climate system has entered a catastrophic phase,” said climate activist Ben See in a post on social media.

The collapse involves the deep overturning circulation in the South Atlantic — part of the global conveyor belt of ocean currents — which typically pulls cold, nutrient-rich water up from the ocean floor and drives planetary heat distribution.

The study, published on July 2, identifies a collapse and reversal of the Deep Western Boundary Current (DWBC) in the South Atlantic — a key part of the Atlantic Meridional Overturning Circulation (AMOC).

This current system plays a crucial role in regulating global temperatures and storing atmospheric carbon dioxide in the deep ocean. The ICM’s data show that the flow of the DWBC current reversed from northward to southward for several consecutive months in 2023 — the first such event in 30 years of continuous monitoring.

“This is an unprecedented observation and a potential game-changer,” said physicist and lead author Dr Marilena Oltmanns, who warned the changes could “alter the Southern Ocean’s capacity to sequester heat and carbon.”

According to the ICM-CSIC, the reversal is likely linked to an ongoing weakening of the Antarctic overturning circulation, a deep-ocean process driven by the formation of cold, salty water masses near Antarctica. That system has slowed by up to 40% since the late 1990s, and the new findings suggest it may be destabilising regional ocean dynamics more rapidly than expected.

There has been a lot of speculation that the whole AMOC (otherwise known as the Gulf Stream), could come to a halt. The AMOC brings warm water to Europe from the equator, and when it stops flowing that will lead to a mini-ice age in Europe with winter temperatures dropping by 10-30C. While scientists are 98% certain that the AMOC will stop flowing by 2100, recent studies suggest that the collapse could come as soon as this year, or at least in the next few decades.

The ICM report warns that the reversal of the DWBC could also unleash vast amounts of carbon dioxide currently trapped in deep-ocean reservoirs. The reversal will undermine the ocean’s role as a carbon sink, which currently absorbs about 25% of all anthropogenic CO₂ emissions.

“This could double current atmospheric CO₂ concentrations by releasing carbon that has been stored in the deep ocean for centuries,” the report said. Such a release would likely obliterate existing climate targets, as the additional emissions would overwhelm current carbon budgets and render mitigation strategies based on gradual reductions, obsolete.

“The planet is sending us increasingly clear signals that we are crossing critical thresholds,” the ICM warned, characterising the event as a shift from “chronic climate stress” to “acute systemic breakdown.”

The reversal threatens to weaken the ocean’s crucial role as a carbon sink — one of the Earth’s key natural defences against rising atmospheric CO₂ — and will also dramatically disrupt global weather systems, sea level patterns, and marine ecosystems.

The Mediterranean is as hot as bathwater

The event coincides with an unprecedented marine heatwave in the Mediterranean. A Spanish metrological buoy recorded a sea temperature of 31C on July 4 – as hot as a lukewarm bath. The northwestern Mediterranean Sea has recorded a temperature anomaly of +6.21°C above the 1982–2015 average, part of a pattern of record marine heatwaves that scientists say are reshaping entire ecosystems.

The northwestern Mediterranean Sea is currently 6.21°C above the 1982–2015 average, creating what scientists have called “bathwater” conditions in a historically temperate basin. Warmer surface temperatures could further stall or disrupt ocean currents, feeding a dangerous feedback loop of warming and current instability.

While ocean circulations have shifted in the deep past due to glacial cycles, the current reversal is the first to occur in modern times due to anthropogenic climate change. Researchers now warn of increased risk of abrupt changes in monsoon patterns, fisheries collapse, and a rapid sea-level rise in the Southern Hemisphere. They are calling for immediate global attention and a reassessment of climate adaptation strategies in light of what may be a new and more volatile climate regime.

“The stunning reversal of ocean circulation in the Southern Hemisphere confirms the global climate system has entered a catastrophic phase,” said climatologist Ben See on social media.

The reversal of the current will bring cold water up from the deep in which is trapped CO₂. That means the reversal, “could double current atmospheric CO₂ concentrations by releasing carbon that has been stored in the deep ocean for centuries,” the El Institut de Ciencies del Mar said.

“The planet is sending us increasingly clear signals that we are crossing critical thresholds,” the Institute added.

Southern Ocean current reverses for first time, signaling risk of climate system collapse

"A major ocean current in the Southern Hemisphere has reversed direction for the first time in recorded history, in what climatologists are calling a “catastrophic” tipping point in the global climate system.

“The stunning reversal of ocean circulation in the Southern Hemisphere confirms the global climate system has entered a catastrophic phase,” said climatologist Ben See in a post on social media.

The collapse involves the deep overturning circulation in the South Atlantic — part of the global conveyor belt of ocean currents — which typically pulls cold, nutrient-rich water up from the ocean floor and drives planetary heat distribution.

The study, published on July 2, identifies a collapse and reversal of the Deep Western Boundary Current (DWBC) in the South Atlantic — a key part of the Atlantic Meridional Overturning Circulation (AMOC)....

Here is a rebuttal

Ocean “Reversal” Hysteria: Facts Not Included

Willis Eschenbach

Guest Post by Willis Eschenbach

Every so often, the climate media machine spits out a headline so breathless you’d think the laws of physics had just been accidentally repealed by a badly-worded executive order. Case in point: bne IntelliNews in Germany recently told us that a “major ocean current in the Southern Hemisphere has reversed direction for the first time in recorded history,” and that climatologists are calling it a “catastrophic” tipping point. It also quotes a climatologist as saying “The stunning reversal of ocean circulation in the Southern Hemisphere confirms the global climate system has entered a catastrophic phase.”

And the headline for that hysteria?

Southern Ocean current reverses for first time, signalling risk of climate system collapse

The implication: pack your bags, the climate apocalypse is here, and don’t forget your floaties.

But as is so often the case, the devil isn’t just in the details—it’s in the words they didn’t mention. The article, like a magician with something up both sleeves, never links to the actual scientific study.

So, after a bit of digital spelunking, I dug up the source. It’s an article in PNAS, the Proceedings of the National Academy of Sciences, yclept “Rising surface salinity and declining sea ice: A new Southern Ocean state revealed by satellites.”

To start with, here’s the Southern Ocean Overturning Circulation (SMOC) that they are claiming has “reversed”.

Figure 1. Ocean currents around Antarctica. The Bottom Water descends from the edge of the continent and runs towards the Equator along the ocean floor. Above that, the Deep Water flows towards Antarctica, rises to the surface, and moves back toward the Equator. When it hits the Circumpolar Current it splits into the Intermediate Water and Mode Water. Not sure what a “reversal” of that would look like.

And when I got to the study, what do you know? The study doesn’t mention “tipping point,” “collapse,” “current reversal,” “Southern Ocean current” or even “overturning circulation.” The only “reversal” in the paper refers to satellites detecting a reversal in surface salinity trends from decreasing to increasing, not a reversal in the the direction of the Southern ocean’s most complex circulation shown above.

So what did the study actually say? Here’s the paper’s abstract:

“For decades, the surface of the polar Southern Ocean (south of 50°S) has been freshening—an expected response to a warming climate. This freshening enhanced upper-ocean stratification, reducing the upward transport of subsurface heat and possibly contributing to sea ice expansion. It also limited the formation of open-ocean polynyas. Using satellite observations, we reveal a marked increase in surface salinity across the circumpolar Southern Ocean since 2015. This shift has weakened upper-ocean stratification, coinciding with a dramatic decline in Antarctic sea ice coverage. Additionally, rising salinity facilitated the reemergence of the Maud Rise polynya in the Weddell Sea, a phenomenon last observed in the mid-1970s. Crucially, we demonstrate that satellites can now monitor these changes in real time, providing essential evidence of the Southern Ocean’s potential transition toward persistently reduced sea ice coverage.”

I love how in the very first line, the earlier freshening (decreased salinity) of the polar Southern Ocean is described as “an expected response to a warming climate”. This is to demonstrate how well they understand what happens as the Earth warms, they knew it was going to freshen …

… but then they failed to mention that the increase in salinity post-2015 is an unexpected change that was unforeseen by either climate numerologists or computer haruspicy. But to be sure, they’ll gladly tell us what the climate will be like in 2100 AD.

In any case, let’s translate the actual science: For decades, the surface of the polar Southern Ocean (south of 50°S) was getting fresher—a little less salty—thanks to melting ice and increased precipitation, which the climate modelers assured us was exactly what a warming world would do. But then, around 2015, the trend did a U-turn. Suddenly, the surface started getting saltier, not fresher, and sea ice coverage dropped like a rock. The study’s main points? Satellites are now good enough to watch these swings in real time, and the ocean’s surface salinity is a lot more jumpy than either the models or the scientists predicted.

The media, meanwhile, went straight from “salinity trend reversal” to “ocean current reversal” to “climate system collapse.” It’s like watching a game of telephone played by people who skipped science class and majored in panic. But don’t worry, we’re assured it’s legit because bne IntelliNews said the study “was confirmed by Spanish marine scientists at El Institut de Ciències del Mar (ICM-CSIC) in Barcelona”.

Discouragingly, it’s not just the media. Even the scientists at the aforementioned Spanish Ocean Sciences Institute managed to headline their press release “Major reversal in ocean circulation detected,” despite the fact that the study didn’t detect any such thing. Antonio Turiel, ICM-CSIC researcher and co-author of the study, even said:

“We are witnessing a true reversal of ocean circulation in the Southern Hemisphere—something we’ve never seen before. While the world is debating the potential collapse of the AMOC [Atlantic Meridional Overturning Circulation] in the North Atlantic, we’re seeing that the SMOC [Southern Meridional Overturning Circulation] is not just weakening, but has reversed. This could have unprecedented global climate impacts.”

YIKES! EVERYONE PANIC!

Want to know the kicker? I mean, other than the fact that neither “reversal” nor “SMOC” are even mentioned in the study?

This isn’t even the first time it’s happened. Check out the Abstract again. The study itself notes that the Maud Rise polynya—a big seasonal hole in the sea ice—was visible in the 1970s under similar conditions, and is currently visible again. But you wouldn’t know that from the headlines, which prefer to treat every wiggle in the data as a sign of imminent doom.

The real lesson here is the one my grandmother Dorothy Greene, an amazing woman, handed down to her descendants:

“You can believe half of what you read, a quarter of what you hear …

… and an eighth of what you say.”

Although for popular reports of climate science, you might want to divide by sixteen. The next time you see “catastrophic tipping point” in the news, do yourself a favor—find the actual study, read the abstract, and remember that in climate science, as in life, reality is usually a lot less dramatic than the press release.

My warmest wishes to everyone for crisp mountain mornings, or warm summer evenings, or sunlight far-reaching on the sea, the best of whatever you dream to you all,

w.

Yep. I’ll say it again: When you comment, please quote the exact words you are discussing. I can defend my words. I can’t defend your unclear claims as to what I said.