We all agree that the wind-driven surface flow of the Atlantic Multidecadal Overturning Circulation (AMOC) brings precious warmth from the tropics towards the Arctic & enables a milder climate in Europe and North America. We all agree it’s the oceans that tremendously effect climate and create temperature changes that cannot be explained by a CO2 greenhouse effect.
The AMOC is unique because 1) it carries tropical heat from the south Atlantic, across the equator into the north Atlantic and Arctic Ocean (red currents, graphic A). 2) it creates a reservoir of warm Atlantic water at 100 to 900 meters depth in the Arctic Ocean capable of melting all sea ice 4 times over (graphic C). 3) Because the Atlantic is saltier than the Pacific, it becomes dense enough to sink to the ocean floor when it cools, creating the pressure that drives a deep return current back to the Antarctic (blue currents, graphic A).
When the AMOC slows down, it delivers less heat to the Arctic. Now a growing ocean cold spot south of Greenland suggests the AMOC is indeed slowing down again. To protect global warming narratives, climate alarmists like Stefan Rahmstorf and Michel Mann push the idea that global warming is causing the cooling and that rising CO2 will soon cause a catastrophic AMOC collapse that freezes Europe and disrupts global climates. But the variations in the AMOC’s heat transport have been happening for millennia and do not correlate with changing CO2 concentrations.
Most scientists believe varying AMOC heat transport causes the global see-saw effect contributing to the Atlantic Multidecadal Variability (AMV) (graphic B). When the AMOC strengthens it also pirates more warmth from the south Atlantic. The north Atlantic then warms while the south Atlantic cools. During the 1930s & 40s, the north Atlantic warmed and Arctic sea-ice retreated similar to what is observed today. During the 1970s and 80s, the AMV cycled to cooling the north Atlantic and Norwegian glaciers grew prompting several scientists to warn we were headed for a new ice age. In the 1990s as the AMV cycled and the Atlantic warmed again, the new fear was global warming. Blinkered scientists blamed rising CO2 for the AMOC’s effects. Most ignored the fact that Arctic sea-ice was melting mostly where warm Atlantic water entered the Arctic and downplayed the AMOC see-saw effect that was redistributing heat and causing Antarctic sea-ice to simultaneously increase (graphic D).
Nonetheless those changes provided the ammunition for drama queens and eco-loons like Roger Hallam to create the Extinction Rebellion and Just Stop Oil movements. Ignorant politicians offered government grants to grifting alarmist scientists to demonize CO2 and blame fossil fuels for the warming that they soon hyped as a crisis. To manipulate our fears, alarmist scientists like Katharine Hayhoe falsely claimed the world is warming faster than ever before, rising 1.1°C (2°F) since 1850. But such claims dishonestly ignored climate history and the effects of the AMOC.
During the last glacial period CO2 concentrations were around 180-200 parts per million (ppm) and temperatures were approximately 11 degrees Fahrenheit (6 degrees Celsius) cooler than today. Yet associated with the AMOC effects, the Arctic experienced 25 Dansgaard-Oeschger (D-O) events, raising Greenland temperatures by 18 to 27 degrees Fahrenheit (10 to 15 degrees Celsius) in just a few decades (graphic E, red numbers mark each D-O event in most recent half of glacial period). Such rapid warming can only be explained by the sudden ventilation of Atlantic heat transported via the AMOC and stored in the Arctic Ocean.
As is the case today, the warm salty Atlantic water is insulated from the surface ice and the atmosphere by a layer of fresh water that prevents the heat of the warm Atlantic water from rising to the surface. As the glaciers grew the air dried and the flow of fresh river water into the Arctic was reduced, enabling the warm Atlantic water to rise closer to the surface. Coupled with an increased AMOC bringing more heat, Arctic sea-ice melted, and its stored heat was released, rapidly raising air temperatures.
The ebb and flow of the AMOC today similarly, but less dramatically than during D-O events, contributed to Arctic sea-ice melt, which enabled stored heat to be released. The Arctic temperatures then rose 2 to 4 times faster than anywhere else. The current slowing of the AMOC is simply part of a natural oscillating dynamic. Its current slowdown will soon increase Arctic sea-ice and lower temperatures naturally without crazy Net Zero mandates or Gate’s sun blocking. The slowdown doesn’t mean we are all going to die like the eco-loons and alarmist scientists push with their catastrophic story telling. Whether we burn more or less fossil fuels, it will not change the AMOC. And perhaps it will then be realized that life-giving CO2 is not our enemy!
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We’re going to be needing fossil fuels even more if there is a cooling period. All the more reason to “drill baby, drill” frack baby, frack” and “dig baby, dig”.
Interesting looking at different historical accounts indicating the effect of phases of the AMO on Arctic sea ice….
Also the link between Arctic sea ice and the AMO (sea ice anomaly inverted on these graphs).
Obviously, starting the Arctic sea ice measurements right at bottom of the AMO gives an AGW-cultist view of Arctic sea ice.
Interesting –A century ago (1922) “whitefish and seals” were replaced by “herring and shoals of smelt” according to the Monthly Weather Review. However, in Climate Change extinctions, actually replacements, no are projections, not predictions, 2.7 F wipes out a third of species. https://www.science.org/doi/10.1126/science.adp4461
Actually, the slight drop in Arctic sea ice since the LIA and the 1979 peak, is allowing the return of many species that sediment bone records etc show were prevalent in the MWP and before.
There is nothing new about such changes, small sample, just a compensatory adjustment difficult to compare with varying conditions
Drinkwater, K. F. 2006. The regime shift of the 1920s and 30s in the North Atlantic. Progress in Oceanography. 68(2-4):134-151.
Mountain, D. G. and J. Kane. 2010. Major changes in the Georges Bank ecosystem, 1980s to the 1990s. Marine Ecology Progress Series. 98:81-91. https://doi.org/10.3354/meps08323 Cod down, Haddock up.
Cabilio, P., D. L. DeWolfe and G. R. Daborn.1987. Fish catches and long-term tidal cycles in northwest Atlantic fisheries: A nonlinear regression approach. Canadian Journal Fisheries Aquatic. Science. 44:1891-1897.
There was a huge 1880s mortality of tilefish and cod during an exceptional ice condition, wait until that happens again, not so compensatory.
Collins, J. W. 1884. History of the tilefish. Report Commissioner. U. S. Fish and Fisheries. 10(1882):237-292.
According to current scientific research, the Atlantic Meridional Overturning Circulation (AMOC) has shown signs of weakening over the past 50 years, with studies indicating a potential decline of around 15% since the mid-20th century;
I would like an analysis of the accuracy of these data supporting the claimed AMOC decline.
The AMO and PDO cycles between warm and cool phases, meaning that over a long period, its overall effect on global temperature is close to neutral as it simply shifts heat within the Pacific Ocean.
Why would the AMO, PDO and ENSO cycles be temperature neutral in the long run of 30 to 50 years, but the AMOC is different?
While the AMOC (Atlantic Meridional Overturning Circulation) is widely considered to be the primary driver of the AMO (Atlantic Multidecadal Oscillation), the relationship is complex and not entirely one-directional; most scientists believe that changes in AMOC significantly influence the AMO.
If the AMOC is really declining, then why is there no effect on the AMO?
And why would the AMOC show a long term trend while AMO, PDO an ENSO do not?
Assuming the AMOC trend is real, there is a debate on whether global warming caused the AMOC trend, or whether AMOC trend caused changes in the global average temperature.
The IPCC obviously does not know.
Their position tries to obscure that fact:
The latest, sixth IPCC report found that, even for a low emissions scenario, the AMOC will weaken between 4% and 46% by the year 2100, depending on the model. In the high emissions scenario, the reduction ranges between 17% and 55% (IPCC, 2021). Apr 10, 2024
Good question. Looking forward to the explanation 🙂
According to Rahmstorf the AMV (aka AMO) is responding as the southern Atlantic’s heat content has increased
The AMOC is the integration of many factors. What most data shows is there is a see-saw effect. One determinant of the see-saw is how tropical water gets diverted around the eastern most point of Brazil. Shifts in the pressure systems and the ITCZ can drive more tropical heat northward and cool the southern Atlantic as illustrated in upper graphs.
One metric that sheds light on that dynamics is measurements of the amount of flow in the North Brazil Current which when its flow increases more heat is carried into the North Atlantic
Zhang (2011) Multidecadal variability of the North Brazil Current and its connection to the Atlantic meridional overturning circulation
“The NBC transport time series is coherent with the Atlantic Multidecadal Oscillation
in sea surface temperature, which also has been widely linked to AMOC fluctuations
in previous modeling studies.”
“Concerning the debate about whether a slowdown of AMOC has already occurred under global warming, the observed NBC transport time series suggests strong multidecadal variability but no significant trend.”
I saw this webpage last month, some good info there:
https://rclutz.com/2024/10/30/manns-amoc-collapse-hoax/
This is bs. The beginning is a good indication for the overall quality, it kinda sets the tone.
No, you idiot, this is Atlantic Meridional Overturning Circulation.
No. The reason for this is known well, it was aerosol pollution from sulfur. And this is the whole premise of his bs, and it invalidates his whole argument.
For that matter, why ignorant politicians offered grants to this very “scam” among thousands of other scams (that are, accidentally, real scams as opposed to this one)? I have never ever heard one single good reason for that. This whole thing doesn’t make sense at all.
This is bs
The so-called climate crisis is complete, total and utter bs. Ignorant politicians waste billions on it.
It makes perfect sense to some.
The AMO cycle has been around for a long time and is obvious in Icelandic sea ice records going back centuries.
The aerosol pollution by sulphur meme is just a fake excuse.
Your whole post is BS. !
The AMO profile looks just like the U.S. regional chart temperature profile with high points in the 1880’s, the 1930’s, and today, and low points in the 1910’s and the 1970’s.
This is the true temperature profile of the Earth. I don’t know that the AMO causes this profile, but this is the profile we have.
The AMO does not show a Hockey Stick profile.
The Hockey Stick profile is a BIG LIE and the AMO and numerous regional temperature charts from around the world showing the same temperature profile as the AMO and the U.S. regional chart demonstrate that it is a BIG LIE.
The match with raw Reykjavik temperature data is very close.
Also Ireland temperatures
And if you turn the AMO upside down , you get a good match to Mt Baker USA glacier response.
Flip the NH sea ice data, and put it against the AMO…
NYOLCI,
You are correct it should have been the Atlantic Meridional Overturning Circulation.. I conflated it with the Multidecadal Oscillation. But that is all you got right.
Blaming aerosols the cooling has been disputed and appears to be a desperate attempt to keep the climate crisis narrative intact.
Exactly, just like blaming acceleration on forces. Newton is still (or again) a controversial figure. 😉
Yet again proving your abject ignorance in attempting a totally irrelevant analogy !
Let’s look at SO2 data over the USA
From 1980.. 174ppb to 1998… 89ppb , (a decrease of 14.7 million tons)
UAH USA48 shows no warming or cooling
.
SO2 dropped from 79ppb in 2005 to 24ppb in 2015..( a decrease of 8.1 million tons)
so to less than 1/3.
According to USCRN and UAH USA48 there was no warming or cooling.
Actual data contradicts your fantasy.. time to give up !
And then you have to explain why GISP shows a huge increase in atmospheric sulphates starting around 1850, and the Earth, apparently, got warmer.
Actual data contradicts your fantasy.. time to give up !
Show us the aerosol data. The best paper or review. No models.
A good starting point is IPCC AR6 WG1 3.5.4.1 (and some other chapters referenced here).
And what other arbitrary constraint does your highness set for science? Can we only use abacus? 😉
Model output isn’t data of actual observations, therefore the constraint is not arbitrary.
You can use an abacus if you want. They still work just fine.
Nikky still thinks model output is real data…. pretty dumb, hey !!
See above. This is not even model output.
“in all CMIP5 and CMIP6 models”
They are talking about models, I see that this fact confuses you.
This is not even model output, to be correct. But that’s beside the point. It could’ve been model output, that wouldn’t invalidate it. You have some kinda superstition here about a thing you haven’t the faintest clue about.
So, unable to produce it
Of course you can’t. !
As shown above, aerosol data does NOT support your baseless conjecture.
Jim, why isn’t your name on this article?
dont know
“why ignorant politicians offered grants to this very “scam” among thousands of other scams…”
1) Politicians give to multiple scams, this is far from the only one. 2) This scam is flexible and multifaceted, allowing politicians to get kickbacks in multiple ways. 3) Politicians are more drawn to this scam because the ‘solutions’ involve giving vastly more power to them. 4) The global nature of the supposed problem lets the scammers claim that local observations can’t disprove it.
Bs. According to the prevalent denier mythology, it all started in 1988 (of course it didn’t, I myself remember reading about this in the mid 80s in popular scientific journals). What the hell was the incentive for politicians at that time? The green industry was in its infancy in the early-mid 2000s, at least 15 years later. All the while the extremely large scale Middle Eastern US involvement in the last cc one century is commonly described to oil. Including the Gulf War and Iraq, both preceding any serious green industry.
Yeah, except no. Starting wars for oil is a thing, well documented. Anything that is large scale and green related is more like incentives for EVs and solar panels, and they pale in comparison to investment in fossils (this latter is USD 1T per annum).
Investment by fossil fuel companies is ABSOLUTELY ESSENTIAL for the continued survival of western civilisation.
Even an ignorant cretin like you is totally dependent on them.
EVs and solar panels are more a fetish, are totally unnecessary to the running of modern society.. often causing more problems than they are worth
So called “green” energy is neither green, (highly polluting actually), nor can it be classed as reliable energy.
So you agree with my assessment. Then what’s the reason for your denier belief of a large scale scientific conspiracy about climate change?
Author?
I think this is Jim Steele
Yes I wrote this article
Thanks, Jim, interesting. But why does it take an old rocket scientist to remind folks that the Earth is a big, round, rotating body? The 70% of the surface that is liquid would be free to slosh around the continents and islands in response to the various gravity fields, were it not for rotation. As with the atmosphere, the oceans must maintain contact with the solid surface as it turns, and therefore “still” ocean water must contain the intrinsic kinetic energy determined by its latitude. All well and good as long as it stays in place, but, again as with the atmosphere, because the sun’s energy is most focused on the tropics, this area of the oceans warms more/faster than at higher latitudes, which means that surface water spreads to higher latitudes, replaced by descending cooler water. This process is amplified (some might say overwhelmed) by the water cycle, which takes enormous quantities of water from the tropical oceans. Thus, we have the beginnings of latitudinal displacement that must account for the kinetic energy differential. It is this differential which forces pole-bound surface currents to bend to the East.
Lest you think that this intrinsic energy differential can be ignored, let me remind you that a man standing on the Equator has traveled 24,000 miles in a day, while his friend at the Pole has merely turned around. And kinetic energy has this V-squared thing.
I agree with the final point however the anonymous author’s meaning is opaque, are they claiming that fossil fuel use since the mid-1800s has not contributed to the observed increase in the atmospheric concentration of CO2 and that has not in turn contributed to the observed moderate and mostly beneficial global warming?
The meaning is pretty clear: whatever slight warming effect our CO2 may have had, it certainly isn’t going to affect the AMOC in any noticeable way (if at all).
The cycle goes on but the Atlantic Ocean SST has risen since the mid-1800s:
Mean annual sea surface temperature, 1854-2012, averaged across the North Atlantic Ocean (15°N-55°N, 80°W-0°E). Cool and warm phases of the Atlantic Multidecadal Oscillation are highlighted. Extended Reconstructed Sea Surface Temperature (ERSST) version 3b data provided by the NOAA/OAR/Earth System Research Laboratory Physical Sciences Division, Boulder, CO
Chris, do you have any details about the probity of the sea surface temperature measurements that were used as the basis for a Mean annual sea surface temperature, 1854-2012, averaged across the North Atlantic Ocean (15°N-55°N, 80°W-0°E) construct?
I’d be interested to follow the provenance of the inputs as well.
The diagram comes from a University of Maine publication “Maine’s Climate Future 2015 Update” Fernandez, Stancioff & Schmitt although I have seen similar reconstructions but can’t find them just now.
Yep, that graph looks about right to me. Especially, the N Atlantic seems to have warmed since mid 1990s. The reason we have so many mild winters since that time I believe relates directly to the extra heat being transported onto our shores on the western flank of the Azores/Euro high pressure system. This feature has become more dominant in recent decades during winter months, and represents a subtle climate shift. I have logged all winters since 1980 in terms of mountain snow in Scotland and this graph matches pretty closely what I’ve observed becoming a constant feature on UK weather forecasts. Prior to about 1988 in fact, often warm air from the Azores meeting cold air over the UK would form a classic battle ground scenario. With the Polar front often straddling the UK, the battle of the airmasses would last for long periods, creating ideal conditions for long lasting snow storms on high ground.
Since about the mid to late 1990s however, whenever Scottish mountain regions receive a blast of cold air, it tends not to last. As soon as the Azores air arrives, the battle ground doesn’t last long. Instead, the warm SW airstream tends to just invade, virtually unapposed, and then establishes itself for long periods. As a result, mountain snowfalls rarely get the chance to go through partial thaw, followed by several, freeze/cycles, with gradual net gain over winter months. Instead, what we’ve observed in recent decades, is snowfall followed by complete thaw to ground level for at least 70-80% of cover. Poor ski seasons and winter sports have generally declined in that period.
Storm Daragh has in fact just produced one of the more significant falls for some years over the Cairngorms. My suspicion is that sooner or later in the next few weeks, we’ll be inundated by warm air from the Azores for several days, which will leave a patchwork cover.
The bottom line is that the oceans constitute the Earth’s main heat sink, and it is the oceans that affect the atmosphere, not the other way around. All due to simple physics in terms of specific heat contents of liquid water vs. air and solid earth, and the humongous difference in masses of the oceans vs. the atmosphere. All of the energy the Earth gets from the sun gets absorbed by the Earth’s surface, whether solid or liquid. It gets stored there, some is released to space, and due to a variety of cyclic processes affected by numerous characteristics (physical barriers between continents and ocean bottom topography, relative salinity, etc.) the heat gets transported to varying locations of the Earth at varying intensities.
The warmunist “CO2 is THE temperature control knob” BS is completely divorced from the reality of even current knowledge of how our Earthian system functions, which increases continually, let alone any future improvements in understanding. The warmunists demand that science stop, no more learning, no more data, no more models, and no more understanding. All of their scientific efforts are focused on proving their simplistic notion is what controls. That is not science.
Warmunism is religion – whereby the underlying assumption is that all truth worth knowing is already known, and the imperative action is to suppress any dissent which is “heresy”. They even use that historical religious term openly in describing the “non-believers”.
Science is the admission that we don’t already know all the truth of how stuff works, so we must keep searching for better understanding using advancing technology to better acquire data and develop new models.
AMOC shuts down every so often-around 6,000 years. This is before humans and their evil, CO2. Needless to say, WHEN this happens, it will be humans to blame. The solution will be more taxes and more control over our lives.
I’m sure that whenever this may have happened before (is there a cite for the 6k years?) humans were blaming themselves as well.
“Now a growing ocean cold spot south of Greenland…..”
Where exactly is this growing ocean cold spot south of Greenland? Looking at the latest SST anomalies, I just don’t see it. Obviously, I can see it clearly on the image shown at the top of the article but where does this image come from and why is it in contradiction to SST data on the ENSO page?
Ah, challenging the probity, provenance and presentation of climate “data”.
A man after my own heart 🙂
Aye, but nobody has got back to me yet to explain the difference between the ENSO page and the image used here. Certainly, there was a bit of a cold pool emerging south of Greenland a few years back but for some time now, it seems to have disappeared from the ENSO N. Atlantic SSTs.
Very nice.
Out of curiosity, who is our “guest blogger”?
I am
When and why did people start using the term AMV (Atlantic Multidecadal Variability) instead of AMO (… Oscillation)?
IIRC, Michael Mann named it AMO on the spot during an interview, it may have been essentially the term “Thermohaline Circulation” Dr. Bill Gray used.
I see in the 2021 paper https://journals.ametsoc.org/view/journals/clim/34/13/JCLI-D-20-0983.1.xml
https://climatedataguide.ucar.edu/climate-data/atlantic-multi-decadal-oscillation-amo refers to AMO 55 times and AMV 6 times, each of the latter linking the two, e.g.
For a good time, play around with https://trends.google.com/trends/explore?date=all&q=Atlantic%20Multidecadal%20Variability&hl=en and variants.
Interest in the phenomenon peaked around the last time it flipped, which matches my informal observation that people aren’t referring to the next flip as much as they should be. It’s been “a few years away” for several years now. At an ICCC, I asked Dr. Gray after lunch if there were any precursors to a flip. (I had already known flips were hard to forecast.)
“That’s an interesting question,” he started to reply. Then someone came to drag him of to talk with one of the upcoming speakers. Sigh.
More on Mann’s naming. From https://michaelmann.net/content/rise-and-fall-atlantic-multidecadal-oscillation in 2021 he says:
Sigh. Or Yow. Or something. 🙂 The trekkie in me suggests maybe it’s “Amok Time” for the AMOC.
It’s the Hockey Stick temperature profile that doesn’t exist, Michael.
The AMO profile matches the temperature profiles of all the written, historic, regional temperature charts from around the world: Equally warm in the 1880’s, and the 1930’s, and today, and equally cool in the 1910’s and the 1970’s. What came after the warmings in the 1880;s and the 1930’s? Answer: Cooling happened to the tune of a reduction in temperatures of about 2.0C from warmest to coolest. So what happens after the current warming of today? Well, if the pattern of the past continues, then we can expect a period of cooling.
Oh, that’s right, Michael dismisses regional surface temperature charts, too.
There’s a pattern here from Michael: Dismiss and downplay anything that calls the Hockey Stick lie into question.
What else can he do? He can’t admit to this lie, so he continues to distort the facts.
AMO is also noticeable in the Icelandic sea ice record going back through the LIA.
Varies between 60 years to 80 years.
Low sections are marked on this chart
Yes, you find this same temperature profile everywhere you look.
The only place you don’t find this temperature profile is in the Bogus Hockey Stick, computer-generated chart.
The written, historic temperature records tell a different story. A story that tells us we are not experiencing unprecedented warming today, as the Climate Alarmists claim. A story that tells us we have nothing to fear from CO2, because although there is more CO2 in the air today than in the past, it is no warmer today than in the past, therefore CO2 has had no discernible effect on atmospheric temperatures.
Thank you, Jim, for another well illustrated and written article!
It’s well past time to start calling out the charlatans of the Climastrology Hoax movement for the liars and ideologues that they truly are! Even more than the opportunistic politicians who are happily wasting trillions of dollars on this scam, the self-proclaimed scientists, who alter and/or hide their data, should bear some financial responsibility for their crimes against humanity!
Just as the push to outlaw meat is largely coming from the Seventh Day Adventists, vegans, and other religious fanatics; the NutZero movement is merely another in the long line of doomsday cults decrying the liberty and prosperity of our modern, fossil fueled civilization! The adherents spend their time and money frightening children and gullible adults with scary stories; while proving that they don’t actually believe their dogma because they refuse to call for more nuclear power! Anyone who pushed this malarkey should be disconnected from the grid until they repay their fair share of the waste and fraud they have perpetrated on Mankind!
Just a couple of days ago I described one possible cause of the ~60 year cycle was natural melting/freezing of Arctic sea ice. I also indicated this could be the driver of the AMO. Essentially, my description and Jim’s differ in terms of cause and effect. He has the AMOC as the driver whereas I theorized the Arctic itself is the driver and the AMO the effect.
I would suggest my view provides a very distinct cause, the natural insulating effect of sea ice within a fairly fixed volume of water. Jim mentions “the ebb and flow” of the AMOC but does not have a specific cause. Maybe that is the effect.
“When the AMOC slows down, it delivers less heat to the Arctic.”
The MOC slowed down during negative the NAO regimes of 1995-1999 and 2005-2012, which warmed the AMO and the Arctic.