Scientists Warn Gulf Stream Slowdown Could Begin as Early as 2025

Yves here. While you were busy paying attention to uncheery news on the Israel-Gaza-and-now-Iran front, uncheery news is moving forward on other fronts. For quite some time, climate change mavens have warned that enough glacial ice melt would slow down the Atlantic Gulf Stream, due to lower saline levels. An article in LiveScience predicted the Gulf Stream could reach an inflection point in 2100. The article below moves the possible onset up considerably.

The LiveScience piece gives a good short treatment of the mechanism:

The Gulf Stream (also known as the Atlantic Meridional Overturning Circulation, or AMOC) is essentially a “giant conveyor belt” along the East coast of the United States, study co-author Stefan Rahmstorf, a researcher at the Potsdam Institute for Climate Impact Research (PIK) in Germany, said in a statement.

The current begins near the Florida Peninsula, carrying warm surface water north toward Newfoundland before meandering east across the Atlantic. By the time it reaches the North Atlantic, that warm surface water becomes cooler, saltier and denser, sinking into the deep sea before being driven south again, where the cycle repeats. According to Rahmstorf, the current moves more than 5.2 billion gallons (20 million cubic meters) of water per second, or “almost 100 times the Amazon [River] flow.”

This wet conveyor belt has myriad climate impacts on both sides of the Atlantic, keeping temperatures in Florida and the U.K. mild, influencing the path and strength of cyclones and helping to regulate sea levels. Since direct measurements began in 2004, however, scientists have detected a troubling pattern: AMOC currents are getting slower and weaker.

To better contextualize this slowdown in their new study — published Feb. 25 in the journal Nature Geoscience — the researchers attempted to extend the history of the AMOC’s flow by nearly 2,000 years. Because no direct measurements of the flow are available before the last two decades, the team turned to proxy data: information from environmental archives, such as tree rings and ice cores, that can help put the AMOC in a long-term perspective.

The team used 11 different proxies — including temperature records, Atlantic silt data, underwater sediment cores and deep-sea coral population records — to create a comprehensive picture of how warm the AMOC was and how fast it was moving over the past 1,600 years.

“We looked for example at the size of the grains in ocean sediment cores, as a faster current can transport larger grains,” Caesar said. “We also looked at the species compositions of corals, because different types of corals prefer different water temperatures, and the Gulf Stream system influences water temperatures in the North Atlantic.”

Together, these proxies told a unified story about the current’s sudden decline, beginning with a small slowdown in about 1850, at the end of the Little Ice Age (a period of global cooling that spanned from roughly 1300 to 1850). A second, more dramatic slowdown began in the mid-20th century; since then, currents have weakened by an additional 15%, the team found.

“We found consistent evidence that the system over the last decades has been weaker than any time before in the last 1,600 years,” Caesar said.

Now to the main event:

By Kurt Cobb, a freelance writer and communications consultant who writes frequently about energy and environment. His work has also appeared in The Christian Science Monitor, Resilience, Le Monde Diplomatique, TalkMarkets,, Business Insider and many other places. He is the author of an oil-themed novel entitled Prelude and has a widely followed blog called Resource Insights. He is currently a fellow of the Arthur Morgan Institute for Community Solutions. Originally published at OilPrice

  • India’s heatwave criteria do not consider humidity, leading to an underestimation of heat danger.
  • Deadly wet-bulb temperatures, where perspiration does not evaporate, are occurring more frequently.
  • Potential slowdown or collapse of the Gulf Stream could plunge Northern Europe into a colder climate.

There were two pieces of recent news which highlight why what was once most often referred to as global warming is now called climate change. Yes, the globe is heating up. But effects vary depending on where you live for various reasons.

First, a report from India calls out problems with the criteria used by the India Meteorological Department (IMD) to issue a heatwave warning: The criteria do NOT consider humidity, only temperature. Anyone who lives in a hot climate or any climate that includes hot summer days knows that humidity can make a huge difference in whether one can stay cool in hot weather. It turns out that the IMD criteria fail to recognize that temperatures below what is considered a heatwave may be just as dangerous to human health when humidity is high and even be downright life-threatening. In short, India is already experiencing conditions that at times are at or near the limits of human suvivability.

The vast majority of humans—even with an unlimited supply of water—would likely die after a few hours in conditions that exceed 95 degrees in very high humidity, what is called wet-bulb temperatures because they represent a wet towel around the bulb of a thermometer.  This web-bulb temperature is supposed to mimic the way that humans cool themselves through perspiration. At very high humidity, it becomes hard to get perspiration on the skin to evaporate which is what allows for cooling of the body. It’s why a handheld or electric fan helps cool the body because it speeds up evaporation.

Scientists have previously believed such extreme conditions currently occur very infrequently anywhere on Earth. Recent studies suggest that 40 years ago such extremes occurred once or twice a year somewhere on the planet. Now models suggest they are occurring 25 to 30 times per year. Without dramatic reductions in greenhouse gases, these extremes will become increasingly common. “Such conditions are unbearable without technology like air conditioning and make outdoor labor near impossible,” according to the ScienceNews article linked above.

A second story this week warns temperatures might go in the opposite direction in one area of the globe as a direct result of the warming of the Greenland ice sheet, increased rainfall attributed to climate change, and dropping salinity in the tropical waters where the Gulf Stream arises.

The Gulf Stream, also known as the Atlantic Meridional Overturning Circulation (AMOC), moves heat from the tropics, along the U.S. coast, then across the Atlantic to the British Isles and turns back and north to Iceland and Greenland. There, having lost much of its heat, it turns downward into the Atlantic depths to between 6,000 to 9,000 feet and begins a journey back to the equator and along South America.

Just how much heat does the Gulf Stream move? Some 50 times the energy used by all of human civilization. This explains why Northern Europe—a branch of the AMOC flows toward Scandanavia as well—and Iceland are much warmer than their high latitudes would suggest. If the energy transfer were to slow dramatically or stop, it would almost certainly plunge these areas into a much colder climate regime, one for which they are not currently prepared.

The basic idea was illustrated in an exaggerated way in the film “The Day After Tomorrow”. The speed of the transformation from moderate climate into frozen wasteland takes one week in the film. It should be concerning, however, that past collapses of the AMOC have taken place in a decade.

Scientists have been tracking the AMOC since 2004 and believe it is slowing. When researchers discovered in their calculations and modeling that the AMOC might start its next collapse as early as 2025, they couldn’t believe it. They rechecked the results, and the conclusion was confirmed. Their model suggests that the current could begin collapsing anywhere from 2025 to 2095. (Some scientists pointed out the considerable uncertainties in the model, a legitimate criticism. My response: Shall those in the path of potential destruction simply wait and do nothing until the model can be better confirmed? If so, how long should they wait?)

The range cited above is not that wide even from a human perspective. And, it suggests once again that the catastrophic effects of climate change aren’t merely going to be someone else’s problem in the distant future. In the coming decades humans could be migrating away from catastrophes which either make life too hot to be bearable…or too cold—both due to climate change.

Print Friendly, PDF & Email


    1. steppenwolf fetchit

      I read somewhere that the Mongol Invasions throughout Asia and some of Europe caused enough farmland to go back to forest to suck enough carbon dioxide out of the air to allow some re-cooling to begin. And then the Explorer Germocaust of the Indian Nations caused forest regrowth over several million square miles of depopulated farm and garden land leading to a rather bigger skycarbon re-suckdown leading to even more global recooling . . . enough to set off a ” Little Ice Age”. And by 1850 modern industrial man had gotten enough groundcarbon back into the sky to reverse the recooling and then begin further warming.

      Sun cycles affect this too. Here is a little text-bit from the search page for Maunder Minimum . . .
      ” The Maunder Minimum occurred within the Little Ice Age, a long period (c. 1300 – c. 1850) of lower-than-average European temperatures. The reduced solar activity may have contributed to the climatic cooling, although the cooling began before the solar minimum and its primary cause is believed to be volcanic activity.”

      In my amateur science-buff opinion, if the earth atmosphere had already been somewhat down-carbonized by tree regrowth caused by the Mongols and then by the Spanish and Portuguese Explorer Germocaust of the Indian Nations, then the earth surfacesphere could cool down real fast if the sunlight dimmed as during a Maunder Minimum. If the sun were to have another Maunder Minimum, we could see if the current skyload of greenhouse gases would prevent the surfacesphere from cooling down as fast as it did during the last Maunder Minimum when skies were less greenhousey. It would be an interesting natural experiment.

  1. James T.

    Very scary propositions but I am very concerned that without resolution of the uncertainties and modeling that reduces the number of years for the range of collapse most will just ignore it. I have discussed with many people and they just seem to think it is way too far out to be a concern for them today. In the end, it will take catastrophe to change their minds and of course then it will be late to stop the cycle. Thank you for the update and excellent information as always.

    1. Polar Socialist

      The very idea of AMOC collapse was conceived in the 1980’s when research found out that AMOC has had several different stable states and a lot of variation since the pleistocene. As in during the last 2.6 million years. During that time it has never collapsed, but suddenly the possibility existed.

      Now, lets remember that AMOC has two main driving forces: the rotation of the Earth itself (resulting coriolis forces cause persistent winds strong enough to push the surface water from south to north, and the high salinity in the North makes water dense and thus forms into cold and salty North Atlantic Deep Water that then returns to South in the deep.

      Since the Earth wont stop rotating, the surface part to the North will not cease to happen, no matter how much Earth will warm. There will be strong perturbations, sure, but the general wind direction will remain as is.

      Thus, as we probably all know, the possible collapse is related to the salinity of the sea water in the North Atlantic. And certainly a flood of freshwater from melting glaciers is likely to dilute the sea water and slow down the circulation – maybe even stop it.

      Except that most recent models show AMOC to be quite persistent like it’s geological record is – remember that 2.6 million years? The glaciers melt, because the North is getting hotter (and much faster than the South is), which creates multiple feedbacks itself: the sea ice is diminished and the surface water is getting warmer, too. In the models, being fresher from the glacier fresh water, it’s also stays on the surface longer getting even warmer. And warm water evaporates faster, which luckily for us means that it gets saltier and thus heavier and, as the physics would have it, it sunks.

      And as we know from the earlier that still cooler and salty, deep water will find it’s way back to the South to resurface and be pushed by the eternal winds to the North again. It’s likely not as strong circulation as what we’ve been used to, but it’s circulating and it’s very likely to overlast the glaciers melting and then return to “normal”.

      Sources (open access):
      Stability of the Atlantic Meridional Overturning Circulation: A Review and Synthesis, Weijer et al., Journal of Geophysical Research: Oceans (2019)
      AMOC decline and recovery in a warmer climate, Nobre et al., Scientific Reports (2023)

      1. hpreddi

        “And warm water evaporates faster”

        what becomes of the evaporated water?
        more cloud cover to cool europe?
        more rain in europe?
        then what?

        1. Polar Socialist

          Then some of the worst consequences of the Climate Change, surely. But that was not the scope of this discussion, was it?

    2. jsn

      Outside of those already concerned, people will continue to ignore this until it is framed in an actionable way that proposes cost sharing with some mechanism approximating fairness. Uncertainty will always be magnified by those who benefit from the status quo and the issue is science which never provides certainty.

      Anyone paying attention knows by now the systemic basis of the issues and that no individual action will even begin to dent the collective problem which hinges on decisions of the very, very rich and the very, very powerful.

      Our vvr & vvp Secretary of Treasury just scolded the Chinese for driving the cost of trying to solve at least part of the problem down because it will crimp some local profit centers in the West. The cranial rectal inversion of our “elite” is so extreme, they look normal, but you can tell by the stench of what comes out of their mouths.

      1. Michael.j

        The cranial rectal inversion of our “elite” is so extreme, they look normal, but you can tell by the stench of what comes out of their mouths.

        Great quote!

        Definitely worth repeating!

      2. Polar Socialist

        proposes cost sharing with some mechanism approximating fairness

        How about progressive electricity cost? First 3 kWh per day is cheap, but then it goes up fast. On the days you stay under the 3 kWh, you might actually get reimbursed.

        That, of course, works only with a very progressive taxation, so that nobody has the money to not care.

  2. Yaiyen

    Humanity is finish. For years scientist dint count aerosol how it affect the planet heat. It was from Guy McPherson i heard it from mostly that humanity is finish even if they stop all polution, there is a bomb in the ocean ready to pop, sure he is wrong about the time but end result is the same

  3. Pudding

    This should be required reading by one of the world’s experts on ocean currents. Key quotes:

    “A full shutdown of the AMOC would have truly devastating consequences for humanity and many marine and land ecosystems. Figure 15 shows the model of Liu et al. (2017) after a doubling of CO2, with an AMOC collapse caused by this CO2 increase. The cold air temperatures then expand to cover Iceland, Britain, and Scandinavia. The temperature contrast between northern and southern Europe increases by a massive 4°C, likely with major impact on weather, such as unprecedented storms.”

    “Apart from a full shutdown of the AMOC, there is still the second type of tipping point to consider, the one where convection shuts down in one region. That happens in a surprising number of climate models, and so far hasn’t gotten the public attention it deserves….What’s more, it typically happens as soon as the year 2040 and for moderate emission scenarios—​even without properly accounting for Greenland melt. Thus, a collapse of convection in the subpolar gyre, resulting in rapid AMOC weakening and abrupt regional cooling, must be considered a high risk urgently requiring attention.”

    “The risk of a critical AMOC transition is real and very serious, even if we cannot confidently predict when and whether this will happen. We have already left behind the stable Holocene climate in which humanity has thrived (Osman et al., 2021), and the latest IPCC report warns us that beyond 1.5°C of global warming, we move into the realm of “high risk” with respect to climate tipping points (IPCC, 2023).”

  4. Alan Sutton

    The Gulf Stream has long been recognised as one of the irreversible tipping points that might come sooner rather than later.

    Another is the reduction in the Albedo effect as the ice melts on both poles.

    Lovelock identified both of these problems I think. He also urged a quick pivot to nuclear energy which is worth considering, if we can divorce it from nuclear weapons.

    Something has to happen pretty bloody quickly!

  5. MFB

    There is clearly something funny going on with the weather. We’ve had nationwide heavy rainfall in South Africa despite being warned of a drought — the rainfall included a 300mm-in-two-hours deluge which washed away the overdeveloped tourist town of Margate, KwaZulu-Natal — and meanwhile Zambia a few hundred kilometres north of us says it needs a billion dollars to save it from the worst drought in its history.

    So perhaps Western Europeans should start buying thick furry hats even if it does make them look like evil Russians with snow on their boots.

  6. timbers

    Only a massive reduction in human population can solve the climate change problem and it is to happen, one way or the other.

    1. mrsyk

      Sadly, I have to agree. Hope I don’t get burned out this fire season (taps left fore knuckle against temple).

    2. Tony Wright

      Diseases, famine, war and other conflicts – the usual ecological constraints on overpopulation, plus the human additions of flood, fire and other climate change effects.

    3. Jams O'Donnell

      Speculation on the future can be found here

      I’m not sure what the authors qualifications are, but the articles do make interesting reading, including the critical comments.

  7. clarky90

    The Sun is 864,400 miles (1,391,000 kilometers) across. This is about 109 times the diameter of Earth. The Sun weighs about 333,000 times as much as Earth. It is so large that about 1,300,000 planet Earths can fit inside of it.

  8. Joker

    Shoulda, woulda, coulda. Scientists say that I could become a millionaire by 2025, if the Nigerian prince keeps his part of the deal.

    The real main event are not words, but actions. What those scientists want to be done in order to fix potential problems? Does it include killing cows, or eating bugs? Maybe some form of “carbon tax”? How about reducing population by pronouncing some people untermenschen and killing them off? There must be some final solution proposed.

    The precise impacts could be “even more severe,” Caesar said, though scientists won’t know for sure until we cross that bridge. Hopefully, by limiting global warming as much as possible in the coming decades, we’ll never have to find out.

    “Limiting global warming as much as possible” sounds pretty vague to me. Almost as vague as “hate speech” in the new Scotland’s hate crime law. Hopefully, it was not made in order to be abused.

    1. Jeremy Grimm

      Scientists have been pushed as far away as possible from making or influencing policy. Their voices are heard at very small volume smothered in noise where our Elites decide policy.

  9. Robert Hahl

    How do we know what the Gulf Stream has done over millions of years? I have never heard a single word about the explanation.of this.

    1. jsn

      Where is the reference to over a million years?

      Did you read the post?

      “The team used 11 different proxies — including temperature records, Atlantic silt data, underwater sediment cores and deep-sea coral population records — to create a comprehensive picture of how warm the AMOC was and how fast it was moving over the past 1,600 years.”

  10. jefemt

    One would think any business tying to insuring human activity, life, or property would have its value going to zero…

    1. ambrit

      Perhaps because the long-term effects of “climate change” do not automatically mean Terran human species extinction. They do, however, mean a severe changing in Terran human civilizational norms.
      The climate has fluctuated mightily over the aeons. Life of some sort or another has carried on despite that. Terran human industrial civilization may not survive, but something will, perhaps even a ‘different’ Terran human civilization.
      Oh, and hot breakfast cereal is a signifier of cognitive dissonance???

  11. The Rev Kev

    Any temperature changes would not be smooth but would be bouncing up and down for decades before it settled into a new norm. Good luck in the UK/Europe trying to grow crops or depending on available sunlight to power solar panels. Chaotic does not begin to describe how it would all play out.

      1. ambrit

        “Watch where you point that point Mister!” he said anxiously as his hand reached slowly for his eraser.

  12. i just don't like the gravy

    So much is written about AMOC collapse affecting Europe. What about other areas, like Nova Scotia? Will they dramatically cool too?

    1. Lefty Godot

      Judging by the maps of the currents after the described collapse, yes, Labrador, eastern Quebec, Nova Scotia, New Brunswick, and Maine will all see very noticeable cooling.

  13. Jonathan Moses

    I wish I could be less cynical. I’ve been hearing predictions of imminent climate catastrophe for 50 years. At this point it’s like the end times cults that keep pushing back the apocalypse. How many times will the climate fanatics cry wolf and still expect to be believed? I’m reminded of the imminent success of fusion energy, it’s been right around the corner since the 1960’s.

    1. Jeremy Grimm

      Where did you come across predictions of imminent climate catastrophe in the mid 1970s? I remember “Silent Spring” and the “Population Bomb”, but I do not recall seeing any predictions of imminent climate catastrophe. Until the 1990s climate change took a back seat to concerns about the environment. Outside of the movies I cannot recall any predictions of imminent climate catastrophe.

      Cults may keep pushing forward the date for their apocalypses. The climate science I am aware of — read papers from the American Geophysical Union [AGU] or Science or Nature — is reluctant to claim apocalypse or assign dates for a moment of apocalypse. Most apocalyptic prognostications I am aware of tend to suggest extremely rapid extremely catastrophic events occurring very near each other — like the AMOC collapse and flash ice age portrayed in the movie “The Day After Tomorrow”. I am not aware of any claims by climate scientists comparable to movie or evangelic predictions of apocalypse. Climate science is often pilloried for not giving precise predictions for the time and place for the impacts of Climate Chaos.

      Crying wolf warns of imminent danger. I am not sure what climate fanatics you are referring to. What climate scientists have warned of imminent danger? The climate science I read warns of future dangers of complex shape quite unlike the presence of a wolf. Your reference to imminent success of fusion power makes me wonder what you regard as imminent. There have been claims for decades that ‘successful’ energy generation through controlled fusion will be accomplished in 30 years, sometimes in 20 years. That is more imminent and precise than the heavily couched predictions of even the most radical “climate fanatics” I am aware of. The “could begin as soon as early as 2025” is just a headline.

      If you are anxious for some ‘proof’ that climate change is real I believe your best bet is watching for the time crops fails in many places because of ‘unusual’ weather. I cannot offer a specific date or precise measure for the extent of the crop failures. Such failure is likely — not imminent to occur — in the next decade. If you want real excitement just wait until the Arctic pole melts some time in the future.

      1. Lefty Godot

        Accusing climate scientists of “the sky is falling” alarmism and guaranteeing dire events that didn’t happen by the predicted date is a tried and true tactic employed by denialists. Usually it works by picking outliers among the scientists who made more aggressive claims, or by referencing popular science headlines rather than actual scientific papers, or by straight out lying about the timelines that scientists were projecting events happening in (or taking the “extremely early” scenario as if that was the consensus midpoint for events). And all you need is a few contrarian scientists, often recipients of largesse from the big corporations whose profits would be hurt by taking the science seriously. Easy!

        And, not only for climate change denial, it has worked the same way for denying all the harms that profit-making corporations inflict on us by “externalizing” the environmental and social costs of their operations.

      2. FamousDrScanlon

        Record heat rots cocoa beans threatening Ivory Coast agriculture

        Last year Georgia orchards lost 95% of their peach crop.

        It’s happening all over. When it hits major grain crops & prices rise, the speculation & fear will begin. It won’t be long.
        This guy does a climate roundup every other day. It’s mostly climate consequences. They are increasing in frequency & scale. I watch. –
        No one knows for certain how much resilience the various, inter-dependant systems have. Oil is the master resource. As long as the oil flows the systems can limp along for a time.
        There’s loads of hurt baked in {when not if} and dozens of positive self reinforcing feedback loops underway – runaway climate change is underway AND Since….

        “We now estimate that global liquid fuels consumption averaged 102.0 million b/d in 2023, a 2.0 million b/d increase from 2022 and about 1.0 million b/d higher than in last month’s STEO.”

        U.S. Energy Information Administration
        AND Since….

        “The global average carbon dioxide set a new record high in 2023: 419.3 parts per million. Atmospheric carbon dioxide is now 50 percent higher than it was before the Industrial Revolution.”

        …..I ignore any & all talk of solutions as sad jokes. That’s like an alcoholic who just added a fentanyl addiction to his daily routine wanting me to listen to his plans for getting clean & sober. Sure thing Mr WrongWay.

  14. FamousDrScanlon

    Talk about myths that won’t die.
    “Little Ice Age (a period of global cooling”

    There was no ‘global cooling’. There was regional cooling. Also little and age is oxymoronic.

    The myth of Europe’s Little Ice Age

    “In recent research we attempt to discover how much European weather actually worsened during the Little Ice Age. Our conclusion – using a variety of standard temperature reconstructions – is that there is little evidence that a European Little Ice Age ever occurred (Kelly and Ó Gráda 2014).”

    I have no idea why it won’t die. Even Wikipedia gets it.

    “The Little Ice Age (LIA) was a period of regional cooling, particularly pronounced in the North Atlantic region.[2] It was not a true ice age of global extent.[3]”

  15. Lefty Godot

    We are by nature mostly short-term thinkers who prefer immediate gratification and fantasy fulfillment, even when it comes to scary fantasies. Every generation believes that the past was basically just like today and that the future will similarly be like today. Totally false, but that’s our default mindset. As each generation also believes its values and social mores are timeless and that all uncertainties about those things have been conclusively decided.

    People don’t tend to worry too much about anything much beyond about three years out. (For example, see the great sighs of relief and dropping of politics as a subject of interest for many of our citizens after a Presidential election has been decided.) And for things not scheduled to happen for decades or, worse, beyond their own individual lifetime, they don’t worry at all, in spite of all the appeals to think of our children or grandchildren. And the less power people have to change the future, the less they think about it (and the less they can afford to think about it, with few material and emotional resources).

    So a few very powerful people make most of the decisions that affect human civilization’s responses to predicted future crises. Unfortunately, few of those people care about the welfare of the less powerful. If they can’t even react to a livestreamed genocide in Gaza right now, why would they care about a billion people dying from heat-related causes in India or millions freezing to death in Scandinavia a couple of decades from now? So we are not going to do anything meaningful about the degradation of climate thanks to human activities, and we (or our descendants) will suffer whatever happens, on its own schedule. In a similar way, we won’t do anything meaningful about microplastics and other pollution until life expectancies and human and animal fertility drop drastically, at which point there will probably be no recovery. What we will do is use denial and dreams of miracle techno-solutions to allay our anxiety and let us continue on our current course of inaction.

    1. Jeremy Grimm

      Mantra for our fearless leaders:
      I’ll be gone. You’ll be gone. So party on!
      Dance, Dance, Dance ’til the music’s done.

  16. southern appalachian

    I read about this in the 1990’s, was one of the effects I was expecting to occur after my death. That sort of thing keeps happening. I’m old but nowhere near abnormally long lived. So to the models, which uncertainty troubles me quite a bit.

    Also discussed in those 1990’s studies, as with any of the more in depth projections, was migration. It is painful to observe our reaction here in the US to migrants. The movement of people is only just begun. We are not handling it well.

Comments are closed.