An alarming claim from from the University of Exeter, based entirely on modeling.
Study finds early warning signals of abrupt climate change
A new study by researchers at the University of Exeter has found early warning signals of a reorganisation of the Atlantic oceans’ circulation which could have a profound impact on the global climate system.
The research, published today in the journal Nature Communications, used a simulation from a highly complex model to analyse the Atlantic Meridional Overturning Circulation (AMOC), an important component of the Earth’s climate system.
It showed that early warning signals are present up to 250 years before it collapses, suggesting that scientists could monitor the real world overturning circulation for the same signals.
The AMOC is like a conveyor belt in the ocean, driven by the salinity and temperature of the water. The system transports heat energy from the tropics and Southern Hemisphere to the North Atlantic, where it is transferred to the atmosphere.
Experiments suggest that if the AMOC is ‘switched off’ by extra freshwater entering the North Atlantic, surface air temperature in the North Atlantic region would cool by around 1-3°C, with enhanced cooling of up to 8°C in the worst affected regions.
The collapse would also encourage drought in the Sahel – the area just south of the Sahara desert – and dynamic changes in sea level of up to 80cm along the coasts of Europe and North America.
“We found that natural fluctuations in the circulation were getting longer-lived as the collapse was approached, a phenomenon known as critical slowing down,” said lead author Chris Boulton.
“We don’t know how close we are to a collapse of the circulation, but a real world early warning could help us prevent it, or at least prepare for the consequences” adds co-author Professor Tim Lenton.
The study is the most realistic simulation of the climate system in which this type of early warning signal has been tested.
“The best early warning signals in the model world are in places where major efforts are going into monitoring the circulation in the real world – so these efforts could have unexpected added value’ adds Professor Lenton.
###
‘Early warning signals of Atlantic Meridional Overturning Circulation collapse in a fully coupled climate model’ by Chris Boulton, Lesley Allison and Timothy Lenton is published today in the journal Nature Communications.
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“Experiments suggest that if the AMOC is ‘switched off’ by extra freshwater entering the North Atlantic, surface air temperature in the North Atlantic region would cool by around 1-3°C, with enhanced cooling of up to 8°C in the worst affected regions.”
By George, are they finally catching on to the real danger, cooling, instead of warming?
Everybody know climate is not chaotic, so no such surprises are possible in the settled science.
Yeah, climate is not weather. Or a double pendulum. Or any other complex non-linear system. /sarc
Experiments? What experiments?
This is modeling run AMOK.
Don’t get you knickers in a twist. This one is a “highly complex” model.
Same apocalyptic scenario – different al – gore – ithm.
But they do say that persistence is directly related to success. Have another try.
“Experiments suggest …”
Computer games ARE NOT experiments.
End of.
This stuff would be funny if it wasn’t the equivalent of falsely yelling fire in a crowded theater.
I was thinking these are the type who would have pulled the fire alarm in school just to watch the reaction.
(Conclusion based on a psychological model, of course.)
Stephen Schneider would have been proud of them!!
BTW Anthony, why all if the secrecy about who is involved in your “Open Climatic Society” venture? The claims made about the organisation’s objectives and the lack of transparency remind me too much of out-of-work high-school art teacher John O’Sullivan’s “Principia Scientific International” blog for my liking. “Wattsupwithtransparencywatts”
Best regards, Pete
“Experiments suggest that if the AMOC is ‘switched off’ by extra freshwater entering the North Atlantic, surface air temperature in the North Atlantic region would cool by around 1-3°C, with enhanced cooling of up to 8°C in the worst affected regions.”
I’m assuming “extra freshwater” is melt water, but wouldn’t the cooling tend to counteract that?
Partly, Paul.
But more likely extra rain
More Faux science:
‘experiments suggest …..’
Dickering with models does NOT constitute an experiment.
‘a phenomenon known as critical slowing down’
Wow, that does sound frightening – job done.
“Dickering with models does NOT constitute an experiment.”
Sure it does.
Suppose I want to understand the effect of a large asteroid hitting the earth off the coast of NYC.
I might be able to learn some things from history, but to gain a deeper understanding, I build a model.
I run experiments with the model. I get results that show what kind of wave height I might see with increasing sizes of asteroids.
The models suggest that for a certain size of asteroid, building a wall to protect the city is futile.
The model is never tested against real world data. It’s derived form physics as best we can. It probably misses a lot of detail. But I dont need to know the exact wave heights, I just need something that is
in the ball park.
I want to know if a crew protection system will work to protect astronauts if their rocket blows up.
Hmm. I dont build a rocket , put people in it, and then blow it up to see if my design works.
I build the the best model I can. A lot of detail gets simplified and parameterized.
Many designs fail in simulation. When a design fails in simulation, we usually dont argue that the simulation is flawed and the design might work, so throw Johnny in the cockpit to see for sure.
Models are used to conduct experiments where you cannot afford to do a real experiment. Or where the
experiment is too big to fit in the lab.
Its best if I can validate my model against reality. But sometimes that is hard or impossible.
Example: In building the F/A-18 there was a requirement that the plane be able to survive hits from
Air to Air gunfire without a catostrophic fire. basically, you needed to take hits to the fuel tanks and survive
say 95% of the time.
How do you test that?
Simple: you run a model.
https://www.dsiac.org/resources/models/covart
How good is COVART? That’s hard to say. I once worked on a proposal to destroy 50 million dollars worth of airplanes to validate one small part of the model.
Bottom line, we use models all the time to run experiments. They are called simulations.
Nobody mistakes these experiments for experiments with the real world.
In short, IF you are ignorant of how a field uses a term (‘experiment or simulation) then you wont understand what they write.
“In short, IF you are ignorant of how a field uses a term (‘experiment or simulation) then you wont understand what they write.”
And in the field of climate science do a) those writing the papers actually know/care about the difference and b) do those reporting on it also know?
Then there is the FACT that most people seem to take the simple view…experiment is something done with physical instruments on ‘real’ items/conditions and simulations are done with computers.
Example: In building the F/A-18 there was a requirement that the plane be able to survive hits from
Air to Air gunfire without a catostrophic fire. basically, you needed to take hits to the fuel tanks and survive
say 95% of the time.
How do you test that?
Simple: you run a model.
================================================
Yes
But if a global warming scientist were running this model,. they would add hits on the f-18 by photon torpedoes and phaser fire.
That’s about the same fantasy that current global warming models being run with “An Increase in C02 will destroy the planet.”
Yes, many models work well
Global warming ones don’t
I wonder why Mosher did not use climate models as his examples?
Is it right that governments formulate policy on the back of models that have a poor track record (ask the IPCC).
What do you think of these models Mosher?
As fuel tanks and pilots have been vulnerable since the first air combat in 1914 (1917 for some) there is 100 years of real unadjusted data on building combat aircraft. It does mean you get a decent model, combined with the fear of a huge damages and no more lucrative contracts for screwing up then one imagines the models would be pretty good. I bet a couple of fuel tanks were built and shot at. Could test fuel tank busting bullets and fire extinguishers at the same time.
Mosher
In the examples you note the variables and their interactions are fairly well known. In climate ( or the “AMOC system”), not so much.
Then call them what they are then – simulations.
The use of the word experiment is Press Release spin to add credibility to a typically speculative piece of climate ‘science’. The writers know very well what the normal understanding of this word is.
If you want to know if astronauts can survive an explosion, yes you model, but you don’t put humans in the capsule until you build a couple of them and blow them up. With sensors inside to measure the intensity of the forces.
If you want to know what happens to an airplanes fuel tank when it is hit by anti-aircraft fire, you build one and then you explode an anti-aircraft shell nearby and measure the results.
Your ideas regarding how models are used in the real world are quaint to say the least.
The French refer to experiments (old French) as experiences. Both from the Latin ‘experimentum’ for trial. If models are used to see what will happen IF something changes, then you can refer to them as experiments but I think that it is still misleading because it is like changing a variable in a simple function. You wouldn’t refer to that as an experiment. Is a plot of a sin function an experiment?
When they are used in place of chicken entrails it is wrong to refer to them as experiments as they have not been tested by comparison with the real world.
I’ll use an example from my own field where I tried to understand a complex chemical process using the knowledge derived from models and backed up by experiment.
I found that if you purified the starting material more thoroughly that you got completely different results than what was predicted by the models developed over decades. I got called a fraud for my troubles. The models are still state of the art.
What you describe, Mosh, is not “dickering” with models. It’s dicking with models. And it’s not an experiment, even if the model is perfect, which no climate model has ever been. Calling it an experiment is just another dangerous way for climate scientists to fool themselves.
Oh yes they do.
But some people wilfully use the term to deceive those (possibly a majority of the population) who are not aware of the distinction.
Mosh is right!
But then again only if the model you are working with actually works before you start playing
Before you can use model to perform simulation (not experiment) that you can trust you have to validate it. Unvalidated models are garbage, no matter what.
Only climate scientists use term “experiment” to describe model runs. Everywhere else we call it simulations.
I don’t know how F/A-18 was designed, but I can’t believe that it was “tested” using models with predictive capabilities of current climate models. Somehow I suspect that it was really shot at by real bullets on scale models and on real things, in the air and on the ground, during many different design phases.
If an engineer ran 50 model test runs, and they all performed poorly, say they dramatically overestimated the altitude a plane could fly, and then the engineer recommended that said plane could fly over any mountain at the model mean of his 50 model run, he career would be short lived, to say the least.
I affect this is exactly what the IPCC does.
Actually, Mr Mosher, we took F/A-18 fuselages out into the desert and fired lots of rounds into them. It’s called live-fire testing and is required for new DoD aircraft (although the requirement is often waived). COVART is good, but life-fire testing proves the design objectively. (The engineers involved in ballistic survivability reported to me.)
Models are good, GIGO is bad. Some models are better than others and unfortunately climate models don’t fall into the good category. We’ve had decades to see how the climate models have performed and it isn’t pretty.
When and if a good climate model is constructed, it will be decades before the results can be confirmed with observations. Until that time arrives all climate models will be looked at with disdain and rightfully so.
If they had built a proper model or readily admitted otherwise when it became apparent they were failing, I don’t believe they would in the same position today. Sometimes it seems CAGW alarmist live in Sim City.
“Example: In building the F/A-18 there was a requirement that the plane be able to survive hits from
Air to Air gunfire without a catostrophic fire. basically, you needed to take hits to the fuel tanks and survive
say 95% of the time.
How do you test that?
Simple: you run a model”
###
Wrong. You fire A to A artillery at it. That’s what Test Engineering is all about. Only a leftist idiot would trust a model for this. You ought to do a bit of research before spouting off and making a fool of yourself.
Mosher is the perfect example of why English majors should not be discussing computer science topics,
Space Shuttle Challenger Accident:
http://history.msfc.nasa.gov/book/chptnine.pdf
Boeing 787 Dreamliner Wing Failures:
http://www.designnews.com/document.asp?doc_id=228554
More bullshit from Mosher. Looks like this was live fire tested,
http://www.airspacemag.com/military-aviation/shoot-em-up-35669028/?all&no-ist
Maybe next time you should do some research before posting more bullshit.
Mosher, most of what you say makes sense, but it is still NOT an experiment. It is a simulation. Simulation is NOT an experiment. It doesn’t mean it is useless. It is useful in many cases when experimentation would be extremely costly and the simulator has already proven many times that it closely simulates reality, and therefore experimentation is considered unnecesary. Now tell me who and when testeed the simulator that has been used in this piece of science, I mean, crap.
None of the people that run simulated bullet impacts on F-18 fuel tanks dared to say that they had verified the resistance experimentally. No. Wrong. Simulation does NOT constitute experimentation, Doing simulation instead of experimentation does not allow you to call the simulation an “experimentation”. Curiosity’s landing on Mars was simulated hundreths of times before it actually went to Mars and landed. None of those simulations constitued experimentation, The only experimentation was the actual landing on Mars.
Steven – that’s a calculation, not an experiment.
“Sure it does.”
No it doesn’t.
Stop making stuff up.
If you don’t do a real experiment, do what Einstein did, call it a “Thought experiment”. Running a computer simulation is the same as a theory. It is the embodiment of a theory, put together through the algorithm it runs.
After you have developed your theory, run your simulation, etc, you still need to know if it is real, or just castles in the air. You need to make a prediction and run an experiment (a real experiment) to verify the theory predicted the experimental result. And when the experimental result is different from the theory (model), you don’t blame the experiment, you acknowledge that the theory was wrong and go back to the drawing board. Yes you guys at the University of East Anglia, I am looking at you.
We’ve heard this nonsense before. They do like to recycle their nonsense, so I guess that’s “green” of them.
Could… could… if… would… could… could… Now give those of us who have reached the status of elite complete control of energy so we can protect our families and you can twist in the hot (or cold) wind of climate change.
By all means, we want to avoid this:
Not to worry, paleoclimatologist Dennis Quaid will save as many as he can.
I think his brother Randy Quaid would make a far better climate “scientist.”
I suppose the fresh water pulse would come from where??
Greenland’s ice sheet continuously drains to the sea as it slowly melts into the north Atlantic. Even if it accelerates it’s melting in coming centuries, the fresh water is not pooling in a Lake Agassiz-meltwater lake where it can release as one big freshwater pulse.
From their Results:
From their Discussion:
Consider those two statements. 1 Sverdrup is approx equal to all the annual current annual global freshwater input into the world’s ocean. To get AMOC collapse, they had to steadily increase freshwater input between 20N- 50N at 0.05 Sv/century. Then at the 8 century point, at an additional 0.4 Sverdrup input/century to this part of the N.Atlantic, AMOC collapsed.
Where does this steadily increasing amount of fresh water come from? Not from North America or Europe or Siberia. In early Holocene, the St Lawrence Seaway and the Mississippi River supplied much of the fresh water pulse to the North Atlantic from the melted Laurentian Ice Shield of the LGM. Greenland is north of the 50N point. The dynamics of a southern Greenland ice sheet melt would be completely different, probably taking many thousands of years even in a warming planet to get to those Sv input levels. In short it would not be anything like these modeled inputs or system responses.
This analysis from U Exeter is a fantastical-unrealistic modeling of an input to an AMOC-like system that does not currently exist on 21st Century Planet Earth nor will it again until another Ice Age termination.
Reading their results, they could only get AMOC collapse when they used steadily increasing Sv inputs to keep driving the system away from equilibrium. When they used constant (not increasing) Sv inputs, they could not get AMOC collapse below 0.25 Sv at any time span. Constant Sv inputs above 0.25 Sv/century did lead to collapse, but they didn’t get their cherished “early warning signals.”
Quoting them,
A Joel, it’s inevitable. Here is a thought experiment for you. In two years, President Obama will be back in Chicago. He’ll be walking along the edge of Lake Michigan one day in downtown Chicago, when a gasoline powered car backfires sending a plume of Global Warming into the air, the President is startled and falls into Lake Michigan along with his huge ego. This sends a huge tidal wave north into lake Superior and Huron, setting up a harmonic wave that empties the whole of the Great Lakes into the St. Lawrence River and on out into the Atlantic Ocean, halting the Atlantic Conveyor and initiating a new Ice Age. The crazy squirrel finds all kinds of acorns embedded in the ice, pulls one out and the whole Atlantic drains into the Pacific creating snowball earth.
There, see what models can do. We just demonstrated that Global Warming caused Ice Ages and Snowball Earth. Now we just have to wait two years to verify the model. 😉
(cleaning up the beer from my monitor.) Thanks Wayne for that mental image.
I just hope that tidal wave will wash back over Chicago and then thru Springfield, so that the good people of Illinois could clean out the rats.
Obviously important.
Needs more funds.
Fling funds, no accounting of their use needed.
games engineers understand models (and how to force simulation of wanted behaviors) much better than these idiots!
Are these climate “modellers” really unemployed Games Engineers.
Not only pretend Nobel Laureates, incompetent scientists but also failed Games Engineers – such is climate “science”.
Computer model experiments!
So now it’s gone from “we only have a few years left to act” to “early warning signals are present up to 250 years before it collapses”? So when absolutely nothing happens (like for maybe 18 years or so) they are trying to tell us to give them another 250 years to carry on with the same old fear mongering?
The title of the paper is amusing.
And here is their next grant application right in the abstract itself.
So they try to alarm. Then they demand more money based on the alarm. This whole exercise is complete and utter bollocks.
‘Early warning signals of Atlantic Meridional Overturning Circulation collapse in a fully coupled climate model’ by Chris Boulton, Lesley Allison and Timothy Lenton is published today in the journal Nature Communications.
OK. They found something in the model.
1. Just how good is this model?
b) How many years of observations will it take to verify that what they found in the model actually occurs?
3. If we had the early warning, is there anything that could be done to prevent the collapse of the circulation?
iv) Will Boulten, Allison, and Lenton be retired before we know the answers to questions 1-3?
“How good is this model”?
Guess we won’t know for 250 years.
Now THAT is what I call a very long trough indeed…oink, oink oink.
If they got this idea from the Younger Dryas they are on shakey ground. That period preceded a postglacial warmup with, I believe, a false low temperature signal from O18 depleted meltwater. Lots of meltwater means high inland temperatures, not low.
That is back to the New Ice Age propaganda of the 70th. Does it mean, Club of Rome and Global 2000 were eventually right, after all?
OK, this has happened before. Why the panic?
Wake me up when the early warning alarm bells go off, and then I can go back to sleep for another 250 years.
More natural variation wrongly interpreted as “signs of impending doom”.
Why don’t they just read the signs from entrails like the soothsayers of old. It would have as much credibility, it would cost a lot less and at least there’d be a lamb supper afterwards.
…ya know… I had a leak in my roof this past monsoon season… it worried me, because another rain storm could have made it much worse. The insurance claims adjuster came by last month and asssured me that the rainy season was over, but it would be a good idea to get the roof repaired during this upcoming “dry period” in Vegas.
So, for the past weeks, I have been watching the NOAA weather, the local broadcasters, and the weather- underground for upcoming weather. …Biting my nails, hoping for no new rain to further damage my roof and ceiling. NONE of the forecasters agreed on showers that were coming here (or not) from the storms that hit California last week.
Well, the NOAA, and its super computers got the forecast WRONG (again and again) all week, last week. Every single daily forecast was wrong regarding temperature and rain. A 20% chance of rain turned out to be a 100% chance according to the local forecaster. The weather underground folks were not correct either.
So how the H#LL can some MODEL figure out stuff decades from now? … if the super computers can’t even be as good as the local forecasters looking out the window?
I am an engineer. I have worked with many so-called “model” scientists. The bottom line is that thousands of variables fed into the model, in the wrong way, or with the wrong coefficients (weighting), and other factors can change everything about the model output. In college, I had a hard time solving equations with 2 or three unknown variables…I can’t imagine how to handle thousands.
The summary of super computers and models: Garbage In = Garbage out.
By the way… my roof leaked again…because I believed the NOAA.
I’d go with the Farmer’s Almanac first.
OK here is the full paper. Governments must act now based on the following.
Thank you Jimbo for providing us with a link to the full paper. Very interesting , with many enticing references but densely argued and I suspect that even the acknowledged experts on this site will need some time to assess its relevance. Unfortunately whilst readers elsewhere may examine and digest this over a course of weeks whilst working on comments or collaboration , on a blog site like this the topic will have effectively passed away within a week.
Incidentally , if anyone else is wondering what exactly we should be monitoring , it is the Sverdrup (Sv), a measure of ocean current flow equal to 10^6 m^3/sec (acknowledgements to Wiki).
“Experiments suggest”????? Since when is modelling, experiments?
“The study is the most realistic simulation of the climate system in which this type of early warning signal has been tested.” So they’d like us all to believe!
And it’s probably true, but only because they are comparing it with even greater pieces of shit!
“We found that natural fluctuations in the circulation were getting longer-lived as the collapse was approached, a phenomenon known as critical slowing down,” said lead author Chris Boulton.”
Perhaps they would be better to study a phenomenon known as critical thinking. http://www.early-warning-signals.org/theory/why-should-we-expect-early-warning/
Did anyone let these grubers know that arctic ice is at or near the 30 year mean?
Modeling modeled models once again …….
Well doesn’t this and some other authors predict that global warming will cool Arctic and bring cold winters to e.g. the Great Britain? So more sea ice proves CAGW. And less sea ice does that as well.
Hot is cold and cold is hot. More is less and less is more and if anything happens, it can be blamed on Co2. Now if the dog craps on the neighbors yard, that can be blamed on CACA.
Capital G, as in “Grubers”.
As in the “grubers” continue their lies.
When scientists say that “experiments suggest,” we normally assume that means observations on carefully controlled phenomena in the real world. Obviously that is hard to do with planetary-scale ocean currents. So these ‘climate scientists’ play with computer models instead. But to imply that they are conducting actual experiments in the natural, not virtual, world is seriously misleading, if not actually fraudulent.
/Mr Lynn