By P Gosselin on 30. April 2022
How close is the tipping point?
New studies on the Atlantic current system assess the threshold between natural fluctuations and a climate change-driven evolution
25 April, 2022/Kiel, Germany. With a new publication in the scientific journal Nature Climate Change, researchers from Kiel once again contribute to the understanding of changes in the Atlantic Meridional Overturning Circulation (AMOC) – also known as the “Gulf Stream System”. It is important both for the global climate as well as for climate events in Europe. The authors focus on the question whether human-induced climate change is already slowing down this oceanic circulation. According to the new study, natural variations are still dominant. Improved observation systems could help detect human influences on the current system at an early stage.
Is the Atlantic Meridional Overturning Circulation (AMOC) slowing down? Is this system of ocean currents, which is so important for our climate, likely to come to a halt in the future? Are the observed variations a natural phenomenon or are they already caused by human-induced climate change? Researchers from various scientific disciplines use a wide range of methods to better understand the gigantic oceanic circulation.
“The AMOC provides Europe with a mild climate and determines seasonal rainfall patterns in many countries around the Atlantic. If it weakens over the long term, this will also affect our weather and climate. Other consequences could be a faster rise in sea levels at some coasts or a reduction in the ocean’s ability to take up carbon dioxide and mitigate climate change”, Professor Dr. Mojib Latif, Head of the Research Unit: Marine Meteorology at GEOMAR Helmholtz Centre for Ocean Research Kiel, explains. “We depend on the AMOC in many ways – but so far, we can only guess how it will develop, and whether and how strongly we humans ourselves will push it towards a tipping point where an unstoppable collapse will take its course.”
Using observational data, statistical analyses and model calculations, a team led by Professor Latif has therefore examined changes in the current system over the past one hundred years in greater detail. The results have now been published in the scientific journal Nature Climate Change. According to the researchers, part of the North Atlantic is cooling – a striking contrast to the majority of ocean regions. All evaluations indicate that since the beginning of the 20th century, natural fluctuations have been the primary reason for this cooling. Nonetheless, the studies indicate that the AMOC has started to slow down in recent decades.
Climate models consistently predict a significant slowing of the current system in the future as carbon dioxide emissions continue to rise, the ocean continues to warm, and the melting of the Greenland ice sheet accelerates. “Our results confirm earlier scientific findings. But the question remains how long we will remain in the realm of natural variability and when climate change will take control of the AMOC. Then the trend would only be in the direction of weakening and risks could increase significantly”, co-author and GEOMAR meteorologist Dr. Jing Sun points out.
Better observational data are needed to determine the critical limit, the authors conclude. “Systematic and sustained measurements of the changes already taking place across the Atlantic also allows us to say with greater certainty what influence climate change has on the AMOC current system today and in the future”, says Professor Dr. Martin Visbeck. The head of the Research Unit Physical Oceanography at GEOMAR is also co-author of the new publication. “At the moment, we do not see any clear signs that the system is slowing down dramatically – rather, it is fluctuating. But since the latest climate models agree that a significant reduction will occur, we should know how much longer we are on the relatively safe side of natural change.”
Original publication:
Latif, M., Sun, J., Visbeck, M., Bordbar M.H. (2022): Natural variability dominates Atlantic meridional overturning since 1900. Nature Climate Change, doi 10.1038/s41558-022-01342-4.
Hmm, I got two useful bits of info out of this…
1) “we do not see any clear signs that the system is slowing down dramatically”
2) “the question remains how long we will remain in the realm of natural variability”. So it’s natural.
Most of the rest of the article tries to give the impression something else is going on though (Yes, I do note that they admit natural forces are dominant in other places as well)
Do they get special training on how to twist their words?
There are a few pretty good scams going and climate change is certainly in the top two or three. No matter what happens, blame it on climate change and no one is the wiser.
You are correct Chris, this is more publish or perish nonsense, whereby their models predict a slowdown in the conveyor system of moving warm water to Europe, but they don’t yet see it in the data! End of story, so the models are wrong and the AGW supposition is likely to be wrong as all their data points to natural variations being in control as a normal thinking scientist should conclude. This article is just more mental wanking from alarmist dupes.
Agree. AMOC is a bit obscure altho UK metoffice worries about it a lot.
Other simpler big things climate models have predicted that we don’t see in observational data:
Yes, and no.
And
Supposedly, the Atlantic is cooling. The reality is that these folks have all of their science eggs bet on climate models.
Bad researchers. No cookie!
So someone with a better understanding of the AMOC help me out here…
Isn’t the “Anthropogenic Climate Change ” hypothesis that the AMOC will slow down due to the oceans warming and therefore reducing the stratification that causes circulation?
If it is currently “cooling” and slowing down, isn’t that the opposite of what the models say is the cause?
Basically the entire paper reports a couple of pertinent observations then flies off into a fantasy make-believe world where nothing makes sense. I don’t think I left anything out of that summary.
Yes, reminds me of a Basket Case.
Richard, I couldn’t find the reference for the following and reflects my memory alone, so take it for what its worth: The study lead is Dr. Mojib Latif. In response to public attacks on him relating to some perceived transgressions from CliSciFi orthodoxy he is reported to have said “If my name wasn’t Mojib Latif it would be Climate Change.” So it appears he is pretty set in his beliefs about the whole thing being dangerous and that could be reflected in the conclusions of the study.
The story says part of it is cooling but doesn’t specify where. It matters.
Like any other convection, the AMOC is driven by a difference in temperature. As long as the arctic is cooler than the equator, there will be circulation between the two. The world is not a vampire, it is a heat pump.
the trade winds are the primary driver of the circular gyres of all the oceans ; combined with the oceans being blocked by the continents and steered by coriolis forces .
Logic was not the object of this paper. That fact that they keep saying “natural” climate change indicates they believe “man” controls the weather and climate. It’s all part of the “scare us” scam.
Looks like they think man (including the entire LGBTQIU spectrum of persons) only control heating, cooling is natural.
What the idiot warmunists don’t get at all is that the atmosphere doesn’t warm or cool the oceans. The oceans warm or cool the atmosphere. Atmospheric carbon dioxide concentrations simply do not matter when oceans cover 70% of the planet’s surface.
The oceans store and release vastly more solar energy than the atmosphere, regardless of the makeup of the atmosphere. Oceans are both vastly more massive than the atmosphere, and liquid water has vastly lower specific heat than air – meaning it takes far more energy input or loss to change the temperature of liquid water than the equivalent mass of air.
Duane
You are absolutely correct.
Ah but what is being warmed in the atmosphere – the water content, the air itself or both at the same time?
UK Met Office has a whole web section devoted to this if you want to go deep.
The idea that cool water descending to depth in the north Atlantic is what causes the ocean currents in the Atlantic and Gulf of Mexico is pure nonsense.
The wind currents drive the ocean currents, with other forces such as Coriolis playing important roles.
Vertical motions of water ascending and descending are small scale effects superimposed upon the wind driven surface currents.
There is no huge amount of water from any surface current plunging into the depths, riverlike, anywhere on Earth.
If this was the case, we would see it in stratigraphy of the ocean water column.
A16 transect of Atlantic Ocean showing temp:
These are the major wind flows and the corresponding wind driven ocean currents in the maps below.
For one thing, the amount of inertia in the ocean gyres is stupendously huge.
It may be that installing millions upon millions of wind turbines will at some point begin to affect the amount of wind energy which drives the ocean currents.
Or it may be that the forces driving winds will simply become more powerful if large amounts of wind energy are drawn out of the atmosphere.
As far as I know, no one is studying this subject…what will happen to wind in the atmosphere as ever greater amounts of energy are extracted from it?
At some level, we can look at how wind differs over land and over oceans, where friction is far lower over the oceans than over land, and consequently, there is more wind and the boundary layer of the geostrophic winds is at a lower altitude over ocean than over continental areas.
Global ocean currents pattern:
No need to be a physical geographer to see how closely winds and currents correspond to each other:
And global wind currents:
Source for ocean transects:
eWOCE Gallery Tables (DVD)
“With a new publication in the scientific journal Nature Climate Change ”
Did they forget the “un” before scientific ?
That’s the only way you can slip in cooling truth–wrap in other speculation… Carefully
The AMO 60+ year cycle is about to turn on downward slope, so no surprise there
I had not seen this unsmoothed version of the data before. From this data it sure does look like the AMO could be ready to crash. Could even be this year.
An argument can be made for the last few phase changes to be 1902, 1932, 1962, 1992 and ????. The 1992 phase change could have been masked by the Pinatubo eruption which is why it doesn’t show up directly in the data.
OTOH, this seems extremely regular which would be unusual. I guess we will find out soon.
Might just be wishful thinking on my part. Yes, I realize that colder is not a good change but the sooner the climate scare falls on its face, the sooner the far left propaganda machine is exposed.
Vuk, have you got a link to the source of that graph? It definitely looks like it’s on the turn and I’d love to keep tracking it over the coming years. Many thanks in advance.
Graph source:
https://notalotofpeopleknowthat.wordpress.com/2021/08/30/has-bob-ward-heard-of-the-amo/
Also reproduced here:
https://wattsupwiththat.com/2021/08/31/has-bob-ward-heard-of-the-amo/
Data is here:
https://psl.noaa.gov/data/correlation//amon.us.long.data
Brilliant – much thanks
Also at Wood for Trees.
I made this graph which splices the complete UAH data set onto unadjusted HADCRUT, and superimposed the AMO time series onto it.
Wood for Trees: Interactive Graphs
No correlation there, eh? 😉
Brilliant work – thank you!
I know, right?
I think the AMO matching up with both of the others provides some confidence that the splice has validity.
We can look at graphs of individual coastal cities at many latitudes and in the NH and SH going back over 100 years and see this same general pattern in the shape of the graph.
It matches the pattern seen in pre CAGW era graphs of sea level, sea ice, every graph of long term temps for globe and for NH, and furthermore, there are no discrepancies with any of the historical records and observations of sea ice and alpine glaciers melting and increasing, and with events such as the dust bowl, etc.
And it matches up with what every relevent authority and organization believed was the proper record of variations in global temperatures…right up until the era of global warming alarmism and data manipulation.
On the other hand, adjusted data sets make no sense whatsoever when compared to accounts of rapidly melting sea ice and receding alpine glaciers at various points in the 20th century, the first IPCC report, or any data set of recorded temperatures that are unadjusted.
Mickey Mann won’t like this. He thinks that AMOC doesn’t exist because it doesn’t appear in his models.
Mean while the AMO and various other oscillations are in control. As the AMO moves towards neutral and then into negative territory the lies will become unsustainable. I await the time when that happens.
The AMO and AMOC are different things. I believe you are referring to the AMO. Mann is actually the one who coined the name AMO and then later argued against it. He has a good history of its inception and demise on his blog here.
WRONG as usual! The AMO was first recognized by Folland and colleagues and then studied by and described by Schlesinger and Ramankutty in 1994, all Mann did was give it the name it currently holds.
Even Wikipedia admits the above.
It’s sounds like everyone is on the same page including you, me, Mann, and Wikipedia. So what’s the problem? Are you challenging the fact that the AMO and AMOC are different things?
Bdgwx didn’t say Mann discovered the AMO, just that he coined the term – which you also stated. Just because a poster is usually wrong doesn’t meant there’s a need to reflexively downvote.
rah or anyone should reflexively challenge statements especially those from me. That’s the best way to ensure that my posts are accurate and helpful. I don’t fear being wrong. I will be the first to admit that I make more than my fair share of mistakes. However, I do fear misinforming others. It is important that all of us (me included) understand what the abundance and consilience of evidence says and the best way to do that is to get the facts right.
On that link you gave to Mikey Mann’s blog, he says:
He’s still peddling the busted hockey stick, self-massaging his ego by labelling his own work “iconic”, linking to the zealots at Skeptical Science (haha!), and blathering on about his “climate change den13rs” conspiracy theories. The man’s a pompous wally.
Let me make sure I understand your argument. Are you arguing that because Mann is “a pompous wally” that necessarily means he does not think the AMOC exists?
Let me help you:
He’s a pompous and ego-centric little man who lies about anything ( his refusal to release his data being a case in point). Hence I believe not a single word he says.
Happy to clear that up for you.
If you are referring to MBH98 and MBH99 the data is available here and here.
Ask Mann about the decline he decided to hide. In my book, hiding things is refusing to release all the data.
Just for fun, pop by Mann’s Twitter account and ask him why he lied about receiving a Nobel Prize. See how long it takes before the little weasel blocks you.
Anyway, this conversation is boring me now. We’ll leave it there.
Toodles!
Here’s what Mr. Wilkins response channels. Quite common in these fora…
“- Angela de Marco: God, you people work just like the mob! There’s no difference.
– Regional Director Franklin: Oh, there’s a big difference, Mrs. de Marco. The mob is run by murdering, thieving, lying, cheating psychopaths. We work for the President of the United States of America.”
Eh?
I notice on Mann’s blog you linked to that the vain little man has got a page full of hi-res photos of himself. I couldn’t help posting one of his photos with a similar one for comparison.
#1–it is all models
#2–in the real world there aren’t any indications of human impacts
#3–it is the AMOC, if it changes, there is nothing that could be done to change it back.
These people are not scientists.
This retired beancounter will never understand how supposedly educated rational scientists rely on computer models that cannot replicate the past (today I will ignore all the ‘fudging’ of current & past temperature data)
I’ll help you out. Lots of folks thought Bernie Madoff’s split strike option conversion strategy was brilliant as he told them they were getting rich off their investments in him. Climate change academia is fundamentally no different.
It’s difficult to get a man to understand something when his salary depends on his not understanding it.
-Upton Sinclair (probably)
The study (as far as I could read without throwing stuff at the dogs), simplified: As far as we can tell observationally the speed of the AMOC varies naturally, with some current slowing along with cooling NA SSTs. Invalidated CliSciFi UN IPCC models, driven by the wildly improbable SSP5-8.5 scary scenario, however, tell us that the AMOC will slow down with future warming, screwing up the Earth’s global climate.
The AMOC no longer runs amuk.
Prompted by this paper, I got to thinking what I’d make of my doctor telling me that I had no signs of cancer at the moment, but sometime in the future it COULD happen, so let’s book you in for radiation treatment right now.
This is a skillful example of saying nothing and creating panic. Useless unless you need something to keep your kids from going to sleep.
hum yeah.
from the little reading I’ve done, I’ve learned that the global oceanic conveyor belt is a function of cold deep waters that are more/less saline (I forget which).
about 11,000 BC (?) supposedly the massive lake the remnant of which is today’s Lake Winnipeg broke an ice dam and flooshed all the way to the east coast, into the Atlantic, and stopped the conveyor belt for a century or two (?).
(I don’t remember technicals, and it maddens me.)
and I read that the North Atlantic Oscillation can shift north or south a bit, but that either causes warm moist air to wash over Europe and make good centuries or it causes cold dry air from the steppes to wash over Europe, creating those famines and little ice ages.
it is good to monitor temperatures, but taking man-made global warming as your launching pad is like the Moslems approaching scientific study wherein all results and discoveries must align with the Koran.
hueta es ist kalt, mein shatz!
Jawohl, heute ist es kalt!
How do so-called experts get away with writing sentences like that last one?
The obvious cooling of the Gulf Stream is evidence of the AMO reentering its 30-year cool cycle, not from CAGW…
The PDO index shows the PDO 30-year cool cycle has likely already started.
When the PDO/AMO/NAO ocean cycles all concurrently renter their respective cool cycles, we’ll have 30+ years of flat/falling global temperature anomalies as occurred when this phenomenon occurred from 1880~1913 and from 1945~1979.
in about 8 years, CAGW’s CMIP 6.0 computer model global temp anomalies will be so devoid from reality, CAGW will be laughed at.
Confusion in the study of the AMOC is caused by claims in several different alarmist papers that both speeding up and slowing down of the AMOC cause warming to NH climate. Whatever it does – it’s us and it’s bad.
First principles of course support that the AMOC is one of many current systems moving ocean heat from equator to pole. So reducing its strength will move less heat leading to high latitude cooling.
The AMOC has been shown to be associated with the spectacular and extreme warming-cooling excursions known as Dansgaard-Oeschger (DO) events – “micro-interglacials” happening from 50-15 kya during the last glacial interval. In these events, warming excursions of 10C or more were clearly associated with weakening of the AMOC:
https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2020PA004068
As I’ve heard it, AMOC is driven by thermohaline circulation. (Heat/salt).
I would expect the predicted (freshwater) ice melting at the poles to increase the cold water at the poles and reduce the salinity there. Likewise, the forecast increased temperature at the equator and equatorial regions would be expected to evaporate more water, increasing salinity near the equator.
Given these things, Global Warming ought to increase the AMOC, not slow it.
I’m happy to accept I must be misunderstanding this, but I don’t see my mistake.
I know many posters here are of the opinion that models are mistaken in forecasting a slowdown in the AMOC. I’m not addressing that point, I’m asking if anyone can explain why the models “think” this is a thing.
You are correct that since AMOC is an oceanic poleward heat transfer mechanism, then it would be expected to increase with more CO2 warming with more equatorial heat to redistribute. But one looks in vain for any such logical consistency in alarmist arguments. Instead they take whatever happens and say – “look it’s because of anthropogenic warming”.
AMOC has always varied under its own internal dynamic and also influenced by weak astrophysical forcing. It is probably the strongest source of north hemisphere climate variability, and also causes the big difference in climate between the north and south hemispheres: namely, that on long timescales, NH climate is relatively more variable while that of the SH changes more slowly and less often. For instance the DO events with acute and rapid climate change in the last glacial period characterised the NH only, not the SH. They were driven by the AMOC.
It is a positive feedback within the AMOC that accounts for its spontaneous nonlinear oscillation resulting in the AMO. Downwelling highly saline deep water in the Norwegian Sea draws up more surface water from the Caribbean, self-reinforcing the circulation of the AMOC. But in complex systems like climate positive feedbacks are not runaway “tipping points” as naively believed by alarmists. Instead they are self-terminating. Increased warm water transport to the Arctic melts more fresh water from Greenland which chokes off the Norwegian Sea downwelling. So the cycle returns to the start and continues.
Often the claim is that CO2 will (and has) warmed the poles more quickly than the equator, so there will be less temperature differential and thus less convection.
Don’t know about tipping but North-Atlantic temperature peaked and started cooling around 2018. (2016 was the warmest year.) Warming has slowed down in average since 1995. Attached diagram shows yearly changes of sea surface temperatures between latitudes 0-70N. Previously this happened around 1950, and cooling continued until 1975.
Another ” Stay with the narrative to remain on the gravy train regardless of the results” paper. There are two clear unequivocal conclusions from this study: More research is required. Give me more munny.
You have to consider the viscosity of water when thinking about the Gulf Stream. It flows faster when it is warmer and slower when it is colder. It is one of the few systems that has a positive feedback. When warmer, it makes Europe warmer and when cooler, Europe gets cooler.
So, slowing down means cooling for New England and Europe.
Silly me – I’m confused – if the oceanic circulation, i.e. the Atlantic ‘conveyor belt’ current, is causing a cooling in the North Atlantic what are the ramifications for Europe? These authors don’t say what the reality is only what their models predict – so are we to believe that these models are correct because models are never wrong (sarcasm here)? If this is true about the fluctuations in temperatures will this destabilize Europe’s climate? Questions, questions, so many questions …
as a resident of the National Capital Region, I’m so relieved! its been horribly hot for the last 30 years, and now I know that that’s just my imagination!
The land for the National Capital Region has always been horribly hot and humid in the summer, there’s good reason most of the land for DC was still available, and it’s the reason Congress has a recess in the summer. The record high temp in DC was reached in 1918 and 1930.
“The AMOC provides Europe with a mild climate “ – this sounds reasonable, but I suspect it’s more of an old wive’s tale. Seattle and Lorient, France are at nearly the same latitude. Seattle has the cold Alaska current just offshore while France has the warm Gulf Stream, yet they have nearly identical monthly weather averages.
Europe’s moderate climate is more likely due to the proximity of open ocean and the lack of mountains in the northern half so the trade winds can bring the moderation farther inland.