Guest Post by Willis Eschenbach
I must admit to being greatly bemused by Michael Mann’s new (and sadly, paywalled) opus magnum about the Atlantic Multidecadal Oscillation (AMO), sometimes called Atlantic Multidecadal Variability (AMV). Here are a couple of quotes from our boy on the subject, emphasis mine:
“The AMO, defined as a 40-60 year timescale oscillation originating in coupled North Atlantic ocean-atmosphere processes, is almost certainly real“
and
“This is a key finding of Knight et al (2005) (of which I was a co-author) as well as Delworth and Mann (2000) [the origin of the term ‘Atlantic Multidecadal Oscillation’ (AMO) which I coined in a 2000 interview about Delworth and Mann w/ Dick Kerr of Science].”
followed by Mann 2021
“Two decades ago, in an interview with science journalist Richard Kerr for the journal Science, I coined the term the “Atlantic Multidecadal Oscillation” (AMO) to describe an internal oscillation in the climate system resulting from interactions between North Atlantic ocean currents and wind patterns. … Today, in a research article published in the same journal Science, my colleagues and I have provided what we consider to be the most definitive evidence yet that the AMO doesn’t actually exist.”
I do enjoy Mann’s implication that he was the discoverer of the AMO phenomenon, when in fact it had been described in detail in 1994 by Schlesinger and Ramankutty, six years before the publication of Delworth and Mann. Also, in the linked Kerr article in Science that Mann refers to above, despite discussing the name “Atlantic Multidecadal Oscillation” in detail, Kerr never says that Mann named the phenomenon … but I digress.
First, what is the AMO? It is a slow temperature swing of the Atlantic, most visible in the North Atlantic. Here’s a graphic of the oscillation.
Figure 1. Long AMO, from NOAA. This shows a period of about 65 years. There are various instrumental versions of the AMO data. This is the longest instrumental version of the AMO held by NOAA, starting in 1856.
Since the first description of the AMO in 1994, the phenomenon has been extensively studied by any number of scientists. A search on Google Scholar shows 31,300 web pages discussing the AMO. So why does Michael Mann now claim it’s not a natural variation of the Atlantic?
Because “state-of-the-art” climate models say so … his study starts like this:
An analysis of state-of-the-art climate model simulations spanning the past millennium provides no evidence for an internally generated, multidecadal oscillatory Atlantic Multidecadal Oscillation (AMO) signal in the climate system and instead suggests the presence of a 50- to 70-year “AMO-like” signal driven by episodes of high-amplitude explosive volcanism with multidecadal pacing
(Protip—any time someone starts out by talking about “state-of-the-art climate models” you can safely ignore their claims … but again I digress.)
Mann’s claim in his new paper, “Multidecadal climate oscillations during the past millennium driven by volcanic forcing“ (paywalled), is that in preindustrial times what people have been calling the “AMO” was actually a stable Atlantic that was being forced by sporadic volcanic eruptions that just happen to have the same frequency as the AMO. But then that volcanic forcing has died out in modern times, and just in the nick of time volcanic forcing has been replaced by anthropogenic forcing … funny how that works. In M. Mann’s world, it’s always the humans who are to blame.
In any case, I thought I’d see what I could learn from the data in both the instrumental and proxy AMO records, along with the volcanic records discussed by Mann. To start with, here’s the Amman et al. dataset that Mann et al. used of 61 tropical eruptions that they say drove the AMO before modern times. I’ve shown the eruptions as vertical lines. On top of these volcano lines, I’ve overlaid several of the empirical modes of a Complete Ensemble Empirical Mode Decomposition (CEEMD) analysis of the eruptions, showing the various longer-term cycles in the data.
Figure 2. Tropical volcanic eruptions, and various CEEMD modes.
Here’s the thing about signals. As the brilliant mathematician Joe Fourier showed way back a couple of centuries ago, any signal can be decomposed as the sum of underlying signals of various periods. CEEMD is like Fourier analysis, except it doesn’t break a signal down into regular sine waves. It breaks a signal down into underlying signals that can change over time, as you can see above.
Now, is there a cycle in the eruption data similar to the ~ 65 year period of the AMO? Well … kinda. But since each and every signal can be broken down into underlying signals, it may just be by chance. The underlying signals have to have some period, and it might just be fifty to sixty years, as in the volcanos.
So that’s the volcanos. How about the proxy records of the AMO? The main one that is discussed by Mann is the Wang et al study, “Internal and external forcing of multidecadal Atlantic climate variability over the past 1,200 years“. The data is available here. It’s based on “a network of annually resolved terrestrial proxy records from the circum-North Atlantic region.” In that study, Wang et al. distinguished between what they called “AMV”, Atlantic Multidecadal Variability”, and the AMO. They said that something like 30% of the variability of the AMV was from volcanoes, and when that’s taken out we’re left with the AMO. Me, I doubt that, because modern volcanoes show little effect on the AMO. I also wanted to see how well the eruptions matched up with their data, so I’ve used their raw “AMV” data.
First I looked at how well the Wang proxy records matched the instrumental records shown in Figure 1. I’ve also added in the 50-60 year empirical mode of the CEEMD analysis of the Amman eruption records shown above in Figure 2.
Figure 3. Two AMO records and one eruption record, 1856 to present.
We see a couple of things in Figure 3. First, the Wang paleo proxy AMV (red) is very close to the modern instrumental AMO (blue).
However, the Amman eruption data is a quite poor match to the modern AMO data. This is no surprise. Look at Figure 1. If you don’t know which year the huge Pinatubo eruption occurred, you couldn’t tell it from Figure 1.
Next, I looked at the longer term view of that same data. Figure 4 shows that result.
Figure 4. Two AMO records and one eruption record, 800 to present.
Again, some interesting things in Figure 4. First, the average length of the cycles in the Wang paleo AMV is 65 years, which matches the modern data.
However, as in the modern period, there’s a very poor fit between the Amman eruption data and Wang paleo data. Among other things, the period of the eruption data averages 55 years, not the 65 years of either the Wang paleo data or the modern instrumental data. So although at times it matches up with the Wang data, it goes into and out of sync with both the instrumental AMO and the Wang AMV data.
So … how did Mann et al. come to their conclusions? As mentioned above, computer models …
The CMIP5 Last Millennium multimodel experiments provide a pseudo-ensemble of N = 16 simulations driven with estimated natural forcing (volcanic and solar, with minor additional contributions from astronomical, greenhouse gases, and land-use change) over the preindustrial period (the interval 1000 to 1835 CE is common to all simulations). We estimate the forced-only component of temperature variation by averaging over the ensemble, based on the principle that independent noise realizations cancel in an ensemble mean.
(In passing, let me note that it is certainly not always true that averaging a number of model outputs means that the “noise realizations cancel”. But again I digress …)
I rather did like the idea of a “pseudo-ensemble”, however … is that a bunch of random computer models hanging out on a street corner smoking cigarettes and pretending to be an ensemble? But I digress …
And what were their conclusions (emphasis mine)?
The collective available evidence from instrumental and proxy observations and control and forced historical and Last Millennium climate model simulations points toward the existence of externally forced multidecadal oscillations that are a consequence of competing anthropogenic forcings during the historical era and the coincidental multidecadal pacing of explosive tropical volcanic activity in past centuries. There is no compelling evidence for a purely internal multidecadal AMO-like cycle.
His claim is that for about eleven centuries, “explosive tropical volcanic activity” made it look like there is an AMO. And coincidentally, just when the volcanic forces left off, a competition between CO2 and sulfate forcings caused the AMO swings.
You’ll forgive me if, given what I see in the Figures above, I don’t find that argument even slightly compelling.
Finally, this is what I love about studying the climate. The science is far from settled, and that gives me the opportunity to learn something new from every paper that comes out.
Here on our dry northern California coastal hillside, rain is forecast starting tomorrow morning and lasting two days. However, around here, rain forecasts even twelve hours out are sometimes way wrong, and it’s generally true for rain forecasts three or four days out. Funny thing about chaotic systems. They tend to be … well … chaotic.
[NOTE: It’s now “tomorrow morning” when the rain was supposed to start … bright sunlight and not a cloud in the sky. Gotta love chaotic systems.]
Seems like out here in the real world, the modelers don’t have that whole “noise realizations cancel” deal completely worked out … but I digress.
My best regards to all, skeptics and mainstream folks alike,
w.
PS—I sign everything I write with my initial, “w.”, and for the same reason I choose my words very carefully—because I wrote them, I take ownership of them, and I know that it is always possible I will be called upon to defend them. However, I can’t defend your interpretation of my words. So when you comment, please quote the exact words that you are discussing. This avoids endless misunderstandings.
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In this corner we have the coral reefs and in that corner we have Mann models. You can place your bets but I think the poor corals have no chance in the denier camp in a rigged fight.
An honest broker (or objective scientist) would at least entertain the idea that possibly the models are not trustworthy, or fit for purpose, particularly since they are known to run warm and have a poor reputation for regional forecasts.
The moment manniacal claimed the models provided real data and real predictions, their credibility plummeted.
Perhaps manniacal will provide Mark Steyn will more data to support his writing another “disgrace to the profession” book using quotes and complaints from manniacal’s confederates… Most of whom do not really want detailed investigations into their models.
…and can’t hindcast if the start date of the model run is changed from the one “tuned” for.
AGW
That I didn’t know! Thank you. Can you supply me a reference off the top of your head?
I can’t, I’m afraid. Guess I should catalogue all the stuff I read…
Don’t the Alarmists always tell us volcanoes have no effect on climate? I guess unless it serves their purpose?
Something that I don’t think Mann appreciates is that volcanic eruptions, like temperatures, become less reliable as one goes back in time. In particular, until the modern period of satellite observations, scientists were often unaware of small eruptions in remote countries, and even when they were aware that a major eruption took place, they were often not sure just where. Therefore, the veracity of the historical record of eruptions should be taken with a grain of ice.
Geologists have been looking for periodicity in earthquakes and volcanic eruptions for generations, and have been unsuccessful in demonstrating a correlation. About the best that has been done is to assert that there have been periods in the past when volcanic eruptions were so frequent and violent that they caused the extinctions of biota. It is generally accepted that we live in a time when volcanic activity is mild, allowing civilization to flourish.
I think that the barrier Mann has to surmount is to convince volcanologists that not only are eruptions periodic, but that in relatively recent times (geologically speaking) that the period has been about 65 years. If he presents his speculations to actual experts, I think he will have a very difficult time convincing them that he has discovered something that they haven’t.
Ha ha ha, I kinda guessed he was lying about coining the AMO terminology.
From lying about his Nobel Prize to lying about the AMO. Oh how the mighty have fallen.
I didn’t say he’s lying. I said we only have his word for evidence, and “Nullius In Verba” applies triple to him.
w.
Of course, the fact that, “Nullius In Verba” is the motto Of The Royal Society, was coincidental … right?
Just re-reading Admiral Morrison’s “The European Discovery of America” and the part that stuck out at me is how many fake islands there were in the Atlantic. they were…almost certainly real at the time, of course.
I mean, they’d go on the maps because on one hand, the mapmakers needed them to be there. That, and they just copied each other of course. Kinda like peer review these days, I guess.
Not much different hundreds of years later, really.
Thanks Willis, great work in a short time.
Climate data is not in Latin, it can be accessed and tested.
And found to fail, like this latest Mann-ism.
The volcano data don’t fit the AMO, hypothesis rejected, next.
What fits the AMO (red) much better is the surface (150m) ocean temperatures in the Barents sea (black), as shown by Levitus et al 2009:
https://agupubs.onlinelibrary.wiley.com/doi/epdf/10.1029/2009GL039847
This supports the AMO being a pulsed alternation in the strength of the AMOC bringing warm water to the Arctic.
Mr Eschenbach,
You do not need to find this paper compelling. That is not what it is for. It is much nearer to the mediaeval Church’s explanation for the existence of HUGE volumes of the ‘true cross’ – miraculous multiplication.
We are not dealing with science here – we are dealing with religion and politics. Any variation in climate forcing before 1900 needs to be abolished – this will do it. End of problem.
If you point out any deficiencies in the explanation you are a heretic and must be ignored.
WUWT is losing this battle because it is bringing science to a politico/religious fight…..
There seems to be some significant confusion, on this website and others, about what Mann’s paper is actually arguing.
The paper is not arguing that the AMO is not a real feature seen in observational datasets. Rather, it is arguing that the AMO is not the result of internal variability within the system – it is a response to external forcings. Mann is also not arguing that volcanism exhibits a regular periodicity, but that there is an apparent quasi-periodic nature to several major eruptions that leads to the appearance of a periodic cycle in SSTs that has been interpreted as an internal oscillation. Mann’s argument to this point seems extremely compelling to me, and despite the generally dismissive attitudes I’m finding in the skeptical blogosphere, nobody seems to actually be addressing the fundamental argument.
You are not alone having read what Mann is arguing. And what you may find compelling isn’t science, but science denying.
That’s because you are gullible, non-thinking, carbon-deranged, brain-hosed moron.
Arguments using climate models are TOTALLY INVALID
Mann’s arguments are VAPID and EMPTY, and hold ZERO scientific worth.
Climate models will always be a straight line without external forcing,
IGNORANCE OF NATURAL CYCLES is built into them.
There is no such thing as the “deniersphere” it is fantasy or those incapable of rational scientific thought.
Tell us what we “deny” that you have real scientific proof for.
Next you will be saying we “deny” Grimm Bros fairy-tales.
Hi Fred, I did not introduce the term “denier,” you did. I referenced the “skeptical blogosphere,” which is simply the collection of blogs that discuss and endorse scientific skepticism related to AGW.
Your personal attacks are not productive, and are not appreciated. If you have a substantive response to anything I wrote in my comment above, I’d be happy to engage you in good-faith discussion based on mutual respect.
What is strange is that you give Mann any benefit of the doubt. Mann is a known liar and huckster. Very scorn worthy.
There is no benefit of the doubt here – Mann has published his work in a refereed journal and it is available for anyone to evaluate. I’ve read the research paper and found it convincing, and have not seen anyone adequately rebut the arguments it presents. That is not to say that the arguments are indisputably true, but that no one is doing a thorough job of disputing them.
And that is EXACTLY the problem, your idiotic GULLIBILITY. !
You are too brain-washed to even look rationally about this mickey mann’s farce.
Using the climate models as a “control” is just utter and complete NON-SCIENCE. !
All Mann has shown is the utter lack of skill of the climate models.
Why are you SO DUMB and willfully blind that you cannot see that.
You repeat your error, addressing exactly zero of the cogent criticisms, merely stating an opinion based on ignoring those very criticisms that are well articulated by Willis.
Of course you find it convincing, you want to be convinced.
Anyone who thinks that climate models are proof of anything, has given up all claim to being a rational thinker. Fred’s insults may be a tad over the top, however you unthinking support of Mann and other alarmists has left you open to it.
Now watch as you squirm and slither trying to avoid answering the simple question.
Tell us what we “deny” that you have real scientific proof for.
NONE of your comment are productive
You are a wasted space.
The fundamental argument HAS been address, by many people.
Using climate models as a “control” is total and absolute ANTI-SCIENCE NONSENSE.
Sorry your competence level does not rise to basic comprehension.
Fred, do please try to mind your manners, your disrespectful tone is unwarranted and brings down the quality of discussion for everyone. The word “deny” was not introduced into this thread until you typed it out – I have never accused anyone of denying anything.
“Using climate models as a “control” is total and absolute ANTI-SCIENCE NONSENSE.”
Argument by declaration is not compelling. Why are climate models inappropriate to use in this context? What is anti-science about it? Please be specific in your criticisms.
You poor petal !!
I will decide if my tone toward an AGW suckophant is warranted or not. You have to earn respect… and you are FAR from it, going the opposite way, in fact..
Sorry you are so DEVOID of scientific understanding as to not know that MODELS ARE NEVER PROOF OF ANYTHING
Especially not climate model.
The fact you find mann’s arguments “convincing” tells us all we need to know about your scientific understanding.
You are OUTING yourself as a zero-science, brain-hosed, empty sock.
“Why are climate models inappropriate to use in this context?”.
.
Your utter gullibility shines through like a putrid sickly green light.
Climate models are UN-VALIDATED against reality.
They are TOTALLY SKILL-LESS when it comes to basically EVERY facet of climate, having ranges so large that anything could be a “prediction”
They cannot predict basic cycles in the Earth system, such as ENSO, AMO, PDO,
…… so why the **** would you consider them as a “contorl” for those features of Earth’s climate !!
They can’t even get temperature projections correct against REALITY.
They are totally worthless for ANYTHING except propaganda.
They are build for contemptible, gullible, brain-washed scientifically-ignorant fools like you to worship.
Grovel on your knees before the almighty MANN ! suckophant !!
Fred
I’m no supporter of claims generally made by weekly_rise. However, I do think that you owe him the courtesy of addressing specifically what he says, rather than just insulting him. Insults are generally behavior unbecoming of a gentleman, and certainly don’t advance the understanding of either side.
I’m not suggesting that you should be non-committal, just stick to the facts and point out where and how he is wrong. Anything less, and people are liable to think that you don’t know why he is wrong.
Because they are work of fiction
Hi, “Weekly_rise”. Your question is justified. Let’s have a look on the spatial correlation between the observed SST ( Nasa) and the modelled ones:
It’s well known that GCM and ESM do not a brilliant job ( aka a bad one) in the “pattern”. As you can see there is a zero-correlation in the area in question: the extratropical Northern Atlantic. So it seems to be a bad idea to follow from climate models when it comes to this area in the real world.
I hope this satifies your curiosity.
Thanks for this response, FrankClimate. Can you provide more details about what the map is showing? What model experiments/ensemble are being used?
From Mann’s paper he is arguing that models show the spatial and temporal variability associated with the purported AMO when they are externally forced, but that the patterns do not arise in control runs. See, e.g., his Figure 1 and 2 in this RC post.
The map shows what is mentioned in the headline: It compares the observed SST (ERSSTv5, also used by GISS) with the modeled SST ( it’s called “tos” in the model world) of the CMIP5 mean under the RCP 4.5 scenario. All the models are fighting with the modes of the internal variability (iv), e.g. ENSO and AMV and also with the observed pattern of warming which is negligible influenced by the iv. It’s well known that in some relationship the GCM/ESM world has not too much to do with the real world. They also struggle ( if the ECS is too high) with the Temperature contrast NH vs. SH, see https://judithcurry.com/2021/03/05/compensation-between-cloud-feedback-ecs-and-aerosol-cloud-forcing-in-cmip6-models/ . So it seems to be a little overoptimistic to conclude that the AMV is not a result of the iv because GCM/ESM don’t replicate it. They do not replicate so much either.
Wouldn’t a multimodel mean lose a lot of the internal variability unless all of the models are perfectly in phase? That is, the individual models could capture ENSO quite well, but if they don’t all have the same phase for ENSO, the differences would cancel in the mean.
Re: ENSO: there is no one model that replicates the ENSO-phases and it’s origin. Otherwise we would have a working model for ENSO forecasts more than a few month ahead. We don’t.
PS: And yes, the multi model mean shows the response to the forcing, not the internal variability. The conclusion is: in areas where the long term change of the SST doesen’t follow the forcings there mus be iv involved. If the AMO would be a forcing product one would await a better correlation than zero in the area in question.
best
Would we not also expect a low correlation for multidecadal cycles if they are present in the modeled SSTs but simply out of phase? I think a more appropriate approach to identifying the multidecadal signals in model results would be performing some kind of spectral analysis on the models, and looking for correlations between the mean model spectral peaks and observations, as Mann does e.g. here.
It is you that needs a substantial response to this Willis post. As he directly addressed that which you claim to have been ignored.
Instead you ignored every relevant bit of the main post, and of Judith Curry’s cogent critical post.
You are “defending the indefensible” by ignoring the direct criticisms and creating a strawman of skeptical misunderstanding that is simply not there.
According to weekly_rise, it makes sense to him. Therefore, by standard alarmist logic, there is no need to address the criticism that other raise.
Weekly, you stated:
Mann stated:
Is the AMO a real feature that doesn’t actually exist?
Asking for a friend…
The patterns associated with the AMO are real patterns in SSTs, but the AMO as an internal oscillation is not a real phenomenon – the patterns arise from external forcing. That is what Mann’s paper argues. Is this clearer for you?
The paper’s “argument” says it is not a real phenomenon because the models, which contain no information regarding natural climate forces whatsoever, since they wrongfully assume CO2 to be the driver, don’t show it.
Kind of like arguing that there’s no evidence of a 1965 Camaro having an internal combustion engine because a 1965 Camaro matchbox car doesn’t have one in it.
The models do show the patterns associated with the purported AMO when externally forced, they do not show the patterns arising from internal variability. A successful rebuttal of the paper needs to focus on this point, but it seems that everyone is getting caught up in whether volcanic activity is cyclic or not, which is not really the point.
So, are you saying that a non-periodic forcing creates an apparent or pseudo-periodicity? Just how does that come about? Coincidence?
I think coincidence is certainly a valid option, here. We are talking about a roughly 40-60ish year pattern in SSTs, so there’s a lot of wiggle room. From Mann’s RC post (bolding mine):
“A spectral analysis of a simple “energy balance” climate model driven with volcanic-only, solar-only, and volcanic+solar forcing (see article) shows that there is indeed a multidecadal spectral peak in the response of surface temperatures to natural radiative forcing and that peak arises from the volcanic forcing alone. We conclude that the apparent AMO-like signal during the last millennium is a consequence of the coincidental multidecadal pacing by episodes of explosive volcanic forcing.“
It is a “model” that assumes things for which there is no empirical support, and is therefore as good at providing “evidence,” or the lack thereof, about ANYTHING as is examining the cracks in cow pies.
The models have yet to be validated, or to provide any correct predictions. Using them as proof is something only someone with no familiarity with how science works, would say.
Again, Mann’s paper shows absolutely NOTHING.
His conclusions are based on farcical climate models.. NOT EVIDENCE
He manufactures volcano correlations that are meaningless.
The whole paper is an absolute farce from start to finish, like most of his papers.
But… ….. enough to “convince” a low-science person like you.
And you haven’t read it, of course.
Poor rusty nail, hanging on by a threads of corroded thought
MODELS CAN NEVER BE EVIDENCE..
Basic science deludes you !
LMFAO!
What tangled webs they weave…
Weekly_rise March 8, 2021 2:19 pm
I have no idea why you bring this up. Here’s what I said.
… which is just what you are saying.
You continue:
No, that’s not his argument. “Several major eruptions” won’t lead to an AMO type cycle. Mann et al. say that there is a:
He also says there is:
So your claim that Mann is “not arguing that volcanism exhibits a regular periodicity” is contradicted by the words of the study itself. They specifically say the volcanism has a “pronounced multidecadal periodicity”
Finally, you say:
I addressed their “fundamental argument”, which you have totally misrepresented, as demonstrated by the quotes above from the study itself. And call me crazy, but I don’t find the results of “state-of-the-art” climate models “extremely compelling” in the slightest.
Regards,
w.
Willis, my comment was not directed at you specifically, although I do feel that you have not addressed the primary argument Mann is making – all you have done is breezily dismissed it because it is based on climate models. You might not find the results compelling, but the results are what they are, and cannot be dismissed by mere derision; you cannot replicate the observed oscillations associated with the AMO without invoking external forcing.
A second significant point is that the spatial and temporal patterns of the signal reflect response to tropical volcanic forcing. I cannot find the specific quotation you cite in the text of the study itself, but it is clear in context that Mann is not arguing that the pattern of volcanism is necessarily anything more than happenstance. In a post on RC he says:
“The temporal pattern (Figure 3BC) shows that the major cooling excursions coincide with several of the largest explosive tropical eruptions of the last millennium (e.g. the 1258 CE, 1331CE, and 1453 CE eruptions), which happen to be paced in a manner that projects onto an apparent multidecadal (60-70 year period) “oscillation”.
Weekly_rise March 8, 2021 7:18 pm
I did a CEEMD analysis of the eruptions used by Mann and compared it to both the modern and the preindustrial AMO. I did not find the correlation Mann claimed, either in the form or the period of the eruptions. Claiming I dismissed it because of models just means you didn’t read what I wrote.
Learn to read. I did nothing of the sort.
I’m under no obligation to “replicate the observed oscillations”. They are what they are, and they have existed for hundreds of years. My own feeling is that this represents some unknown shift in the oceanic currents that either speeds up or slows down the rate of transfer of energy from the tropics to the Arctic. But I don’t have to prove that.
I couldn’t find any sign of the claimed response. Nor have you.
All we have is some vague handwaving by Mann that claims that by happenstance, the eruptions “project onto anapparent multidecadal (60-70 year period) oscillation.
Please point out to us the 60-70 year oscillation in Figure 2. If you can’t find it there, please do the homework and you point out to us where it is.
w.
Either Mann is wrong in his original paper declaring the existence of the AMO andEVERY subsequent paper written on the back of his AMO paper is equally baseless
OR
His latest paper is Wrong and any future papers building off of it are equally baseless
OR
Mann is wrong about being wrong and so can’t be trusted to be right and no one in the scientific community should utilize his research as a foundation for their own papers
Willis, by “you” I mean the general “you,” not you specifically.
Your analysis of volcanic activity comes to the conclusion that, “Now, is there a cycle in the eruption data similar to the ~ 65 year period of the AMO? Well … kinda. But since each and every signal can be broken down into underlying signals, it may just be by chance.” Which I think Mann would almost certainly agree with. The idea is simply that the ~60 year cycle is just an apparent one because of the spacing of volcanic events.
But more importantly, your post focuses on examining whether there is a cyclic pattern in volcanic activity (and comes away inconclusive), but that is not the focus of Mann’s paper. The main thrust is that model control runs do not show the temporal patterns associated with the purported AMO, while externally forced model runs do. This is the piece I am saying you haven’t adequately addressed, because your only discussion of it is to pish posh it away because it’s based on models, but it’s by far and away the most interesting part of the paper.
Models can only show the result of what input ever. As there is no input “natural variability”, you can’t find any in the results.
As long as CS has no idea about the sources of that variability, you will have wrong results, or you draw wrong conclusions, as Mann did once more.
” all you have done is breezily dismissed it because it is based on climate models”
What’s wrong with you? Is it that you can’t read or just refuse to?
ROFLMAO
The very fact you you accept anything from climate models , shows just how willfully GULLIBLE you really are.
Models are NEVER proof of anything…
…. especially not UN-VALIDATE suppository, and PROVABLY WRONG climate models that have nothing of natural variability and cycles built into them.
Next you will be saying your “believe” Grimm Bros fairy tales or the screen-play in Warcraft.
They are not results
Only someone who knows nothing about science would use models to prove anything.
Using a model, you can’t replicate …
Your mistake is your belief that not being able to find something in a model, is proof that it doesn’t exist.
I could create a model that shows AMO happening without external forcings. Would that be sufficient to prove it?
The “paper” assumes “models” are a realistic representation of the real world, which is the highest order of nonsense. Mann thinks “evidence” or lack thereof, can be drawn from them. He is a snake oil salesman.
Mann’s “proof” is what is being ridiculed. Mann actually believes that since his model is not able to create an AMO without using external forcings, is proof that the AMO must be from external forces is laughable, and only those who are drunk on the kool-aid would accept it.
Excellent dissection of manniacal’s latest assault on science, Willis!
As Feynman stated:
Manniacal and his magical mystical “analysis of state-of-the-art climate model simulations” fantasies.
They are wrong. That’s all there is to mannical’s AMO fantasies.
“An analysis of state-of-the-art climate model simulations spanning the past millennium provides no evidence…”
You can stop right there, Mikey. Climate models don’t provide evidence of anything except excessive government grants.
Wait! Do you mean to say that Science isn’t Settled? How many more things will that guy turn out to be wrong about?
Sorry I can’t help it but this is one for Josh
Hi Willis,
i came across a great quotation from Michael Crichton today. I am reading his novel “Next” talking about scientists:
Page 95:
“The cost of such fraud is enormous,” McKeown said, “estimated at thirty billion dollars annually, probably three times that. Fraud in science is not rare, and it’s not limited to fringe players. The most respected researchers and institutions have been caught with faked data. Even Francis Collins, the head of NIH’s Human Genome Project, was listed as co-author on five faked papers that had to be withdrawn.
“The ultimate lesson is that science isn’t special—at least not anymore. Maybe back when Einstein talked to Niels Bohr, and there were only a few dozen important workers in every field. But there are now three million researchers in America. It’s no longer a calling, it’s a career. Science is as corruptible a human activity as any other. Its practitioners aren’t saints, they’re human beings, and they do what human beings do—lie, cheat, steal from one another, sue, hide data, fake data, overstate their own importance, and denigrate opposing views unfairly. That’s human nature. It isn’t going to change.”
Excerpt From
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Michael Crichton
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So true!
I saw this: Figure 1. Long AMO, from NOAA. This shows a period of about 65 years. There are various instrumental versions of the AMO data. This is the longest instrumental version of the AMO held by NOAA, starting in 1856.
And then, owing to Mr. Mann’s prior claims of knowing Everything About Everything (which is completely not true) and discarding what has not suited his notions of stuff happening, I had to avoid falling off my chair and laughing myself silly. It’s quite apparent now that Mr. Mann lives in his own little world, where everything obeys the diktat of “It is if I say it is”, which I have run into in the work world, uttered by people whose egos were threatened when someone tried to correct them.
And to think that he had so much going for him…..
Oh, well. Moving on.
Wow, Mann is good! I am sure with little effort he could statistically validate the butterflies in Brazil causing Tornados in Texas conundrum!
Raise your hand if you’re surprised the person responsible for trying to fake himself a Nobel prize is trying to take credit for naming the AMO. Anyone? Anyone? Bueller?
Nothing in that statement is “scientifically justified.” See what I did there? Tee-hee!
News flash for “DOCTOR” Mann. No “climate model simulation” (even the vaunted “state of the art” (ROTFLMFAO) ones) provides “evidence” of anything. Evidence is what you get by observation of the real world. A “model” is nothing but a really expensive circle jerk. All it does is reflect the input assumptions of the “programmers.” “Models” provide no evidence. They provide no data. They provide no facts. They provide no insight. They make no revelations. They do not advance human understanding of the natural world one iota. They may occasionally be useful as a “thought experiment” in a strictly academic sense when they are used in a manner that recognizes their limitations, but clearly these morons think the stupid “models” are some kind of “climate oracle.”
I can’t imagine that the fields of “science” have ever seen such an arrogant, conceited, pompous, deluded ass that could even come close to Michael Mann.
Some think that volcanism is prompted by unrecognized forces, so ..
I propose these same unknown variables stimulate the water and air to the extent that both the AMO and the volcanoes are synchronized.
All will be clear, in time. {invoking Poe’s law}
– – – –
Thanks, Willis
An approximation with double amplitude 0.3 K and period 64 yr for the net effect of all ocean cycles contributed 16% of planet temperature trajectory. AMO is a major contributor to the net of all ocean cycles. Analysis shows a 96+% match of average global temperature with measured 1895-2020 with only 2 additional contributing factors and no effect from CO2. Most, if not all, of the increase contributed by human activity is from water vapor increase. The analysis is at https://www.researchgate.net/publication/316885439_Climate_Change_Drivers
Dan, I tried to read that Word doc and it made no sense. I got to this sentence and I quit:
In addition, when I find a 96+% match between climate datasets, I don’t think “Eureka”.
I think “I’ve done something wrong”.
What might be useful is your “elevator speech” about your theory. For those not aware of the concept, imagine you get into an elevator with someone and you have the length of the elevator ride to explain your theory. What would you say?
For example, I think emergent phenomena serve as a global thermostat. Here’s my elevator speech for that theory.
So … what’s your elevator speech?
w.
W,
Thanks for your comments. Sorry the word doc didn’t make any sense to you. Unfortunately that doesn’t help. I was hoping for something specific. You know, like you usually request “So when you comment, please quote the exact words that you are discussing. This avoids endless misunderstandings.” If something doesn’t make sense to me and I truly want to understand it, I read it again…and pay closer attention.
I don’t understand what your point is with this: “…when I find a 96+% match between climate datasets…” I only compared to the HadCRUT4 reported temperatures. It should be the least controversial of the three agencies that report back to before 1900. I expect any of them would give a similar match because the coefficients are adjusted to produce the best match to the measured temperatures. The accompanying graph which shows recent reported temperatures indicates that the main coefficient change would be offset, D. The projections, of course, would apply to the specific trajectory being matched.
Your statement at https://wattsupwiththat.com/2016/07/25/precipitable-water/ “This leads us to a curious position where we have had a larger change in forcing from water vapor since 1988 than from all the other IPCC-listed forcings since 1750 … so where is the corresponding warming?” is what opened the door for me on this issue. I had ruled out non-condensable ghg more than a decade ago from examining Vostok data. http://www.middlebury.net/op-ed/pangburn.html and was looking for what could cause the warming instead of CO2.
As to an elevator speech, I might try this:
Water vapor inhibited the cooling of the planet so that it stayed warm enough for life as we know it to have evolved. Increasing WV, mostly from increasing irrigation, has caused more inhibition to cooling which exhibits as Global Warming/Climate Change. Slight warming from increased CO2 at ground level is countered by increased cooling in the stratosphere with the result that CO2 has no significant net effect on climate.
Dan, the problem I had was with this sentence:
I had and still have no clue just what you are matching to what. It can’t be water vapor, because we don’t have water vapor data going anywhere near that far back. And your document provides no clue as to what is matching what, nor what procedure you used to get the match.
What am I missing here?
w.
W, The algorithm that produced the results is described in Section 17 (page 32). It does indeed use TPW. (I often simply say water vapor to avoid needing to explain what TPW stands for) The other two factors are an approximation of the net effect of ocean cycles and solar. The 96+% is simply the Coefficient of Determination when the results of the calculation are compared to the reported HadCRUT4 temperatures. The numerical integration step size is one year.
Of course you are right about there not being any useful early TPW data. The first worldwide data started in Jan 1988 by NASA/RSS which I found out about from your WUWT article in 2016. I extrapolated the known TPW data back to 1600 using CO2 as a proxy. The proxy function I came up with results in a match of the slope and magnitude of the known TPW trend in 1988. The resulting curve (Fig 3) looks OK to me given a farm-boy-cum-engineer’s general understanding of the development of irrigation in the world over the years and the increase in rate around 1960 as reported by Aquastat (ref 37). The emphasis on irrigation results from the discovery of its importance in Sect 9. An additional consideration is that the method of calculation places less importance on earlier estimates of TPW.
From the Mann:
The CMIP5 Last Millennium multimodel experiments provide a pseudo-ensemble of N = 16 simulations driven with estimated natural forcing (volcanic and solar, with minor additional contributions from astronomical, greenhouse gases, and land-use change) over the preindustrial period (the interval 1000 to 1835 CE is common to all simulations). We estimate the forced-only component of temperature variation by averaging over the ensemble, based on the principle that independent noise realizations cancel in an ensemble mean.
This trick reveals the study to be a worthless empty tautology. A circular argument just making a prior assumption to “prove” the prior assumption.
Mann assumes that all variation is only two things: forced change and noise. Right from the start. Actual internally generated intrinsic variation was excluded by design. It would have been easy to model that as Ed Lorenz had done in 1963 as “deterministic non periodic flow”. But they didn’t of course.
So the study then finds – unsurprisingly – that all variation is only forced change and noise.
Yes – that was the prior assumption and the study found the prior assumption.
In the same way computer models that are coded to make CO2 cause warming, “discover” that CO2 causes warming.
This study and others like it are circular conjuring tricks having no relevance to the real world.
The study was prevented by design from finding internal dynamic oscillation. It’s hilarious how scared MM and his cronies are of chaotic-nonlinear pattern formation. This paper stinks of that fear.
” It’s hilarious how scared MM and his cronies are of chaotic-nonlinear pattern formation. This paper stinks of that fear.”
100%
Absolutely agree, I commented similarly below. The climate models are simply input forcings (W/m^2) converted to temperature. Yes, they have some temperature distributions over the globe via latitude, land/ocean etc but that could be done in a spreadsheet.
This is why the “signal” matching the temp series is only revealed when you average multiple climate model outputs. The simple model explaining this is that a climate model result over time (t) is no more than:
GCM(t) = forcings(t) * scaling factors + noise
So by averaging many GCM(t) the noise cancels and we get:
Average GCM(t) = forcings(t) * scaling factors
This average output approximates the temperature series observed because the priors already do that by construction.
The proof of this is that the Average (GCM(t)) (and also the temperature obs.) can be reconstructed very, very closely just from the input forcings by linear regression (which calibrates the scaling factors). Therefore the climate models do not add anything to the predicted temperature series output that cannot already be determined from the input priors.
Piltdown MAAN at it again eh?
Isn’t it amazing that all discussion about AMO and its climate impact on the climate takes place without regard on its dimension, temperature and salinity values and structure? More here: https://1ocean-1climate.com/the-gulf-stream-is-weakening-says-science/
The NA is very cold:
Following the same argument also the ENSO, the La Nina – El Nino cycles does not exist because there is no ‘state of the art’ climate model that provides evidence that such phenomonons are internally generated.
The guy is either delusional or a charlatan. In both cases: why is he in the job he’s in?
The new reality: In M. Mann’s world, it’s always the humans who are to blame. As climate models are human made, we have the perfect circular reasoning.