My thanks to Jaime Jessop for returning my attention to the subject of this piece, and my apologies to her for going over ground that she has already covered so well.

I first became aware of the return of the Atlantic Meridional Overturning Circulation (AMOC) scare story a few weeks ago when the You Tube algorithm pushed a Sabine Hossfelder video at me. In this she sought to worry viewers about the possibility of temperatures in north west Europe dropping by 5C or even 10C should AMOC shut down.

Around the same time the BBC website published an article with the heading “Could the UK actually get colder with global warming?” That in turn followed hard on the heels of another BBC article which appeared just a few weeks before that, headed “The ocean current vital to regulating our weather”. It’s almost as though the earlier article was setting the scene for the second article, and softening the public up for it.

It’s all rather odd, since it’s seven years or so since a study by Caesar, Rahmstorf, Robinson, Feulner and Saba put the cat among the pigeons. It was titled “Observed fingerprint of a weakening Atlantic Ocean overturning circulation” and it offered evidence of a weakening of AMOC by around 15% since the mid twentieth century. Why, seven or so years later, is the possibility of an AMOC shutdown suddenly once more in the news? This is where it gets even stranger. The renewed interest and claims seem to have been triggered by a study by Terhaar, Vogt and Foukal, which appeared in Nature on 15th January 2025, yet the study headline (“Atlantic overturning inferred from air-sea heat fluxes indicates no decline since the 1960s”) ought on the face of it to defuse, rather than ignite, AMOC scare stories. The core conclusion from the abstract was as follows:

Based on the here identified relationship and observation-based estimates of the past air-sea heat flux in the North Atlantic from reanalysis products, the decadal averaged AMOC at 26.5°N has not weakened from 1963 to 2017 although substantial variability exists at all latitudes.

One might have expected that the BBC article that followed the publication of last month’s study (and to my mind might have been triggered by it), should have talked about its results, and offered a cautious degree of optimism for its readers on the back of the study’s results. Not a bit of it. Instead we were presented with a scare story, which ignored the study altogether, and appeared to cite the results of the 2017 study instead (while not actually referring to the study or its date of publication). The BBC chose to offer us this partial (and not terribly up-to-date) analysis:

But Amoc appears to be getting weaker...

…indirect evidence suggests it could have already slowed by around 15% over the last couple of centuries, although not all scientists agree.

A slowdown in Amoc – meaning less warmer water would be transported to this region – is seen as a possible culprit.

This is “a very clear signature and footprint of a classic Amoc slowdown” says Matthew England, professor of oceanography at the University of New South Wales….

…In 2021, the IPCC said it had “medium confidence” that Amoc would not collapse abruptly this century, although it expected it to weaken.

But some more recent studies have pointed to a growing possibility of Amoc passing a tipping point in the coming decades, beyond which full collapse would be inevitable….

…But many scientists are growing increasingly concerned. Prof Thornalley argues that, whatever the imperfections of individual studies, taken together they “lead to a conclusion that we maybe need to be worried”….

The BBC would no doubt argue that it has presented a report about AMOC which contains a number of appropriate scientific caveats, and that it can’t be criticised for it. Yet, the report is undoubtedly on the alarmist side of things, and a fully balanced report would have included the results of the most recent study. It didn’t, and I find that inexcusable. BBC Science editors will surely be aware of it (it was all over the internet in the few days after its publication) and failure to mention it seems like an unacceptable oversight.

I am still mystified as to why they have suddenly decided to scare us with the prospect of freezing instead of boiling. Is it because although we are bombarded almost daily with stories of a heating world, we in the UK have seen precious little sign of warmer weather over the last few years? Did they need to suggest that January 2025 in the UK, being 0.9C cooler than the long-term average, ushered in a new and scarier climate? Is it because in 2024 Iceland experienced its coldest year since 1998? Is it because in January 2024 Oslo experienced the coldest temperature ever recorded there? Or is it just because we have to be kept in a constant state of fear about climate change?

17 Comments

  2. As I may have said on this channel before, as soon as you measure something twice, you have enough data to make scientists “grow increasingly concerned.” Second reading higher than the first? Look what happens if you join the dots and extrapolate out 50 years! Second reading lower than the first? Ditto.

    I’m sorry, climate scientists, but we have too many of you, and you are not producing a product we need in such high volumes. I recommend cutting your numbers by 99%.

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  4. Jit, 99% ? I’m shocked that you should exaggerate. Surely the ‘settled science’ number is 97%

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  5. This is a continuation of Mann’s claim last Fall, a warning based on fears, not facts.
    1. The AMOC has been stable for the last four decades.
    2. Paleo records show past AMOC changes due to seafloor shifts not climate change.
    3. AMOC alarm presupposes Arctic “Amplification” of Global Warming.
    4. Hypothesis that rising CO2 will collapse the AMOC is flawed.
    5. The “Tipping Point” scare is unscientific.

    https://rclutz.com/2024/10/30/manns-amoc-collapse-hoax/

    Of course, as others have mentioned above, freezing alarmists have a motive to keep CO2 hysteria alive as Earth turns into a cooling phase.

    Liked by 2 people

  7. Less than 6 weeks after the last AMOC study was published, we now have another one (broadly supporting the findings of the last one). I get it that this stuff is important, but I can’t help feeling that this is an enormous gravy train. How many studies do we need?

    “Total collapse of vital Atlantic currents unlikely this century, study finds

    Climate scientists caution, however, that even weakened currents would cause profound harm to humanity”

    https://www.theguardian.com/environment/2025/feb/26/total-collapse-of-vital-atlantic-currents-unlikely-this-century-study-finds

    ...The latest study is important because it uses climate models to reveal the reason that the Amoc is more stable: winds in the Southern Ocean continuing to draw water up to the surface and drive the whole system. The study does not rule out an Amoc collapse after 2100, and other modelling research suggests collapses will occur after that time.

    “We found that the Amoc is very likely to weaken under global warming, but it’s unlikely to collapse this century,” said Dr Jonathan Baker at the UK’s Met Office, who led the latest study. He said it was reassuring that an abrupt Amoc crash was improbable, and that the knowledge could help governments plan better for future climate impacts….

    The usual climate worriers aren’t reassured, naturally…:

    …Prof Niklas Boers at the Potsdam Institute for Climate Impact Research (PIK) in Germany said the study delivered a substantial improvement in the understanding of Amoc. “But even a weakening that is not due to a tipping point could have similarly severe impacts on, for example, tropical rains,” he said. “One could even go as far as saying that, in the short term, it doesn’t really matter if we have a strong weakening, say 80%, or a collapse.”…

    The study can be found here, for those who are interested:

    https://www.nature.com/articles/s41586-024-08544-0

    Liked by 1 person

  8. Mark,

    When is a ‘severe weakening’ a ‘collapse’? As usual, the public are being taken for idiots again and The Day After Tomorrow is still very much on for climate alarmists:

    Prof Stefan Rahmstorf, an Amoc expert at PIK, said the latest study considered a collapse to be the total cessation of the currents in the North Atlantic, while previous studies have termed a greatly weakened Amoc a collapse.

    “But even a weakening that is not due to a tipping point could have similarly severe impacts on, for example, tropical rains,” he said. “One could even go as far as saying that, in the short term, it doesn’t really matter if we have a strong weakening, say 80%, or a collapse.”

    Liked by 2 people

  9. Had a quick look at – About Prof. Stefan Rahmstorf | climate change and warming

    Partial quote –

    “Rahmstorf also addresses the topic of global warming publicly, for example in exciting presentations as a keynote speaker or in the RealClimate blog, which he co-founded. In doing so, he always focuses on the current research situation and the most pressing questions of our time. For example, what happens now that the Paris Climate Agreement has been adopted and the USA has rejoined it? How do we get climate change under control now? What happens if we give in and the world’s great rivers suddenly change their temperature?”

    Bit behind the times our Stefan’s “about” web page. Interesting he co-founded RealClimate blog.

    ps – I must be thinking about someone else when I read his name, the image in my head was an older bearded guy playing the guitar/stringed instrument for his adoring students.

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  10. dfhunter,

    He’s a very clever and well-qualified man. But he is a high-up at the Potsdam Institute for Climate Impact Research, which I regard as being very much on the alarmist side of things. They write reports such as this:

    A new National Interdisciplinary Climate Risk Assessment outlines the risks to Germany’s national security resulting from climate change through 2040. It provides the first comprehensive overview of the many cascading and compounding climate risks. The Assessment will be officially presented at the Munich Security Conference in February 2025. Developed under Germany’s National Security Strategy 2023, it was co-authored by the Potsdam Institute for Climate Impact Research (PIK) in collaboration with various partners.

    https://www.pik-potsdam.de/en/news/latest-news/major-risk-assessment-links-climate-change-with-germany2019s-national-security

    They are very keen on “tipping points” and are so interested in AMOC that they are currently advertising for a PhD to work in this area – with funding guaranteed for three years.

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  11. Not AMOC this time, but it’s the same scare-mongering:

    “Earth’s strongest ocean current could slow down by 20% by 2050 in a high emissions future

    Melting Antarctic ice is releasing cold, fresh water into the ocean, which is projected to cause the slowdown”

    https://www.theguardian.com/environment/2025/mar/03/antarctic-circumpolar-current-slow-down-ice-melting-climate

    But is it or isn’t it?

    ...Co-author and climate scientist Dr Taimoor Sohail said the slowdown could lead to a “vicious cycle”, where more warm water reaches the Antarctic shelf accelerating ice melting and further weakening the current.

    This could also disrupt ecosystems and food webs, he said, as the oceanic current helps to prevent invasive species – such as rafts of southern bull kelp – from reaching the fragile continent, or redistributed them.

    “Concerted efforts to limit global warming – by reducing carbon emissions – will limit Antarctic ice melting, averting the projected slowdown,” Sohail said.

    Dr Edward Doddridge, a physical oceanographer at the University of Tasmania who was not involved with the study, said it was significant and surprising, given previous studies had indicated that the northern parts of the Antarctic Circumpolar Current were accelerating due to ocean warming….

    Is climate science settled?

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  13. “Collapse of critical Atlantic current is no longer low-likelihood, study finds

    Scientists say ‘shocking’ discovery shows rapid cuts in carbon emissions are needed to avoid catastrophic fallout”

    https://www.theguardian.com/environment/2025/aug/28/collapse-critical-atlantic-current-amoc-no-longer-low-likelihood-study

    …The research found that if carbon emissions continued to rise, 70% of the model runs led to collapse, while an intermediate level of emissions resulted in collapse in 37% of the models. Even in the case of low future emissions, an Amoc shutdown happened in 25% of the models.Scientists have warned previously that Amoc collapse must be avoided “at all costs”.

    It would shift the tropical rainfall belt on which many millions of people rely to grow their food, plunge western Europe into extreme cold winters and summer droughts, and add 50cm to already rising sea levels.…

    Liked by 2 people

  15. The EU says AMOC’s in peril too:

    “Gulf Stream ‘could collapse in our lifetime,’ warns EU climate chief

    Key ocean current that keeps Europe warm could start shutting down this century, Dutch studies projects.”

    https://www.politico.eu/article/gulf-stream-could-collapse-lifetime-warn-eu-wopke-hoekstra/

     The European Union’s climate chief has warned that the Gulf Stream could collapse in a few decades after Dutch scientists found key ocean currents are weakening faster than thought.

    The Atlantic Meridional Overturning Circulation (AMOC), the system that forms part of the Gulf Stream — an Atlantic Ocean current that keeps Europe from becoming frigid — could start shutting down in the 2060s as a result of climate change, according to a study by Utrecht University researchers published this week. 

    European Climate Commissioner Wopke Hoekstra described the findings in a social media post as a “wake-up call.” ...

    Liked by 2 people

  16. Groan.

    “. . . . science has spoken, yet again . . . . . a big thanks to these scientists for giving us another serious climate wake-up call.”

    So why do I feel like nodding off? This AMOC shutdown scare regurgitated every couple of months is becoming very, very boring.

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