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.
Willis,
Thank you for taking the trouble to do this analysis, so we don’t have to.
Mann also tried to pin the Little Ice Age on volcanoes, as a regional phenomenon, rather than a global interval caused by repeated solar minima.
Way back in the days of UseNet, I ran into infamous serial Wiki censor William Connolly and he was as adamant that “everyone knows” that the LIA was local, short and not very impressive.
Its the scientific equivalent of denying Ruby shot Oswald…
A long-lived false meme sustained by the Carbonari.
Wait, Ruby shot Oswald? No way! It was some guy named Grasse Noel.
I thought it was Neil deGrasse Tyson.
Well, in reality,Mann refused to acknowledge the existence of the LIA in the early days of his spiels, because it upset his line of blather. That was back when he first began to gain some notoriety.
But he also said that ice masses (similar to icebergs) and ice dams did not form on rivers, and this was right after a massive flow of ice masses had been caught on video flowing south down the Des Plaines River from its northern end. It was so spectacular that it was on the local news.
There is a reason his eyes are brown, you know.
Send him to St.Claire River in Michigan. Ice dams have been causing flooding recently. We could have used a Russian nuclear icebreaker.
…and eliminated the MWP.
Nothing better than friends with time on their hands.
AMO is clearly visible in Icelandic sea ice data even through the LIA.
Iceland…..don’t they have volcanoes too and are slap bang in the middle of the north Atlantic. No there’s a forcing that should leap out the data?
There was a urban legend around UNIVAC that one guy got a patent for a electronic circuit .. followed by second guy who got a patent on the same circuit with a resistor value changed .. followed by third guy who got a patent on the same circuit with the resistor value changed back.
I’m seeing Mann as the second guy.
Resistance is Futile
“Resistance is …. not futile”? 3rd of 5
Love it – thanks
3rd of 5, AKA “Hugh”.
Priceless!
I think the 2nd and 3rd guy are manniacal.
Then manniacal claims he invented the name ‘circuit’.
And although he got a patent on a circuit board, the manniacal says electricity does not exist
Well, someone in the agenda science ranks had to step forward to erase or confuse the AMO cycle. It might as well be the ring leader.
I guess this means the AMO is now seen as the most challenging issue for the Climate Crusades. It must be stopped at all costs. That also means they see it for what it is but don’t want to acknowledge it publicly. Send out the goon squad instead.
Congrats to those who already saw the AMO as a major cyclical cooling force coming into the forefront from this simple concept of cycle turning points. All we need now is some honesty surrounding the problems of detrending it or allowing for cycle differences on peak amplitude.
Better hurry though because Uncle Joe is about to wreck the economy based on not knowing anything about the AMO or its implications. No pressure–just facts
Uncle Joe will have joined the Paris Accord and dropped a whole shedload of dollars into the Green Fund for China (who will NOT thank him).
The AMO will fall and it will get significantly colder – Joe and John Kerry will declare victory over AGW. It will continue to get colder. The obvious way for Joe to stop the freeze is to get a rebate from the Green Fund…….
That is as logical as Mann checking models against the real world and declaring the real world as wrong.
If it gets significantly colder, it will be difficult to claim victory, as there is no way that atmospheric CO2 will stop increasing thanks to emissions from China, India and Third World Countries.
As AMO is cyclic, and following a warm period is a cool period, have we to be aware of coming volcanoe erutions ?
Else, I see no “external forcing” for the coming cooling AMO period.
They will drop nuclear bombs in volcanos, so they have something to blame.
Krugman has apparently convinced Uncle Joe that the reason why Obama’s $800million infrastructure bill didn’t stimulate the economy was because it was too small.
To fix that problem, they are currently discussing a $3Trillion dollar infrastructure bill. No doubt, like the COVID relief bill, most of the money will be directed towards blue states. But there is no politics here.
OK, I live in a blue state (possibly the bluest) and our Governor, by a mere signature, redirected a new tax to fix the roads to another cause. We will look fore=ward to all that infrastructure money flowing out of Our Nation’s Capitol. However, I won’t hold my breath waiting for the roads to get fixed.
…and California can expect little of the magical maniac money to go towards water infrastructure.
It’ll likely to fund the high speed rail. It doesn’t go anywhere but, hey, at least it’s an expensive boondoggle.
I am sorry, but according to The Princess Bride, they are the BRUTE squad.
Max:
Beat it or I’ll call the Brute Squad!
Fezzik:
I’m on the Brute Squad.
Max:
[sees Fezzik’s size] You are the Brute Squad!
Terminology is so important
“Uncle Joe” doesn’t know anything about anything. He’s a stooge. Check for the “radical handlers” behing the curtain.
The most experienced president since the 1960s…
The stooge was the guy who spent his time on the golf course and watching daytime TV
Oh yes,sure, what am I doing here, eh, I’ll have to look at my memory card, uh, eh, experience is a weird thing……
Read a transcript of the other guys speeches, mostly incoherent rambling
Remember the Oval Office speech that cut of americans from returning home…had to be corrected, or the internal blue lights thing , or the tweets that were deleted because they were nonsense
Can you repeat that, this time in English?
Or has hatred caused you to have a stroke?
Being the oldest doesn’t make him the most experienced.
So what if he takes in an occasional round of golf?
Your partisan hatred has rotted your brain. You aren’t even trying to make sense any more.
eck;
What is even worse, the “Joe Biden” that we now see is an imposter. No idea who he is. Compare images of him before 2019, and the present, especially note the different right ear lobe. There are other subtle differences. Sean Hannity ran a piece on this. .,
This “Joe Biden” is the real Paul McCartney.
damp.
No, Paul’s right earlobe is not attached to his cheek, as is the fake Joe’s
Folks, can we please leave the politics to a political blog? This is a SCIENTIFIC blog, so let’s set the politics aside for another time and place.
w.
Manns paper passed peer-review ?
unbelievable….
Believe it, his peers reviewed it – he’ll probably review something of theirs soon. /s
Same comment but no /s
Science (the Journal) is getting worse than the PNAS
It’s more like Pravda at this stage.
It’s Loo Paper and Pee-er review
Lew paper.
It’s good enough for political peer review.
Hey, if they can accept, peer review and publish a paper in TWO DAYS stating that PCR tests are acceptable for COVID19, then, yeah, its believable.
Its 2021 and the word “science” has been post-moderned out of existance…
Unbelievable!! How it passed the peer review! We need the name of the Editor and all reviewers! It is high time to demand disclosing the peer review report. Put all the scientific comments as raised by many scientists and experts in the form of open peer-review. This published paper is so absurd and has no merit.
Can science go like that? Sensible scientists need to step up!
Pal-review.
No. It was a Pierce review. Seymore Peirce. Don’t know him??
Willis has just peer reviewed it and proved it wrong.
Real peer review only occurs when a paper becomes public and, as Einstein said, ‘It only takes one to prove me wrong’.
John in Oz:
“It only takes one to prove me wrong”
Good point.
I offer my paper “A Graphical Explanation of Climate Change”
http://www.skepticmedpublishers.com/article-in-press-journal-of-earth-science-and-climatic-change/
Any takers?
Interesting posting, W. As a geologist with a lot of experience with volcanic activity (OK, especially volcanic activity that produces gold deposits) I cannot imagine what cyclic, or oscillation if you prefer, could possibly control the timing of volcanic eruptions. Let’s e clear here, at least half of volcanic eruptions are on the sea floor, and not many detected. Then you face the issue of how explosive does a volcanic eruption have to be to get aerosols into the atmosphere where they MIGHT modify the weather/climate. The big, explosive, volcanic eruptions are all subduction related, where the melt incorporates crustal material as it ascends to a magma chamber (ascends based on density contrast) then the composite melt sits there and undergoes progressive crystal fractionation, resulting in accumulating volatiles, then the bad tacos event occurs and the magma chamber is emptied in explosive fashion. How can there be a cyclicity to this complex sequence of steps?
I think one can look at the sporadic nature of eruptions, each of which likely has some different impact on climate (more or fewer stratospheric aerosols produced), and see a cyclic pattern if one is needed.
A 2012 study of Pacific sediments did find a correlation with the 41k year Milankovitch obliquity cycle:
https://pubs.geoscienceworld.org/gsa/geology/article-abstract/41/2/227/131209/A-detection-of-Milankovitch-frequencies-in-global?redirectedFrom=fulltext
But that’s a far cry from a multidecadal oceanic oscillation.
“How can there be a cyclicity to this complex sequence of steps?”
Oh, man, where to start… I’ll leave it to better mathemathingy guys. Complexity is the stuff Nature builds the most beautiful cycles upon. Just go look at a cloud…
Does anyone have data on geostorms before and since fracking become a “revolution”? I have serious doubts about that programme.
I define “geostorm” as tectonic events, underground thunder if you like. And geostresses directly influence local weather (Devereaux) and animal behaviour. You know, all the fish run to high ground and the elephants climb trees before the tsunami hits?
More of that sort of thing since fracking came to this part of the world. Volcanoes release a lot of geostress quickly, which can change weather patterns, even enough to start a butterfly effect?
Sorry to ramble, had this on my mind again for some months now. I would not be surprised, should someone show AMO and volcanic activity to be part of the same underlying frequency. What is the life expectancy of your average continent floating on a pool of lava millions of years in the burping?
I’m sorry, but defining “geostorms” as “tectonic events” is meaningless. Until you can tell us exactly what “tectonic events” are, what units are they measured in, and what data sources you are using you’re just waving your hands.
w.
Isn’t the volcanic cycle just an artifact of the data? Things that are not cyclic can have cycles …. random chance.
Tectonic events: Stresses building up in the crust. Stresses releasing in the crust. Volcanoes, earthquakes and tremours. Subsidence and extrusions(?) and plates crushing against each other, you know, “underground weather”? Imagine the mantle to be just another type of atmosphere, Like fish swim and birds fly, earthworms ooze through this medium, solid to us, but then, humans have a rather narrow bandwidth of existence. Do I measure it? As much as I do lightning strikes, which, in my personal life, consists mostly of “hey, dude, that was close by, let’s get off the roof”.
Then I wave my hands at the damage done afterwards, helpless against forces anything bigger than my umbrella can handle. While I invent definitions for terms I use to convey an idea I spend much time pondering, because none of the clever guys bother writing anything on the subject I understand. And from the many downvotes, it seems I failed miserably at stating my question, which remains: how has the underground weather changed since fracking became a financial miracle? From my personal, biased perspective, it seems things have become rather stormy.
I guess someone will try convince me it’s the ‘cancer factor’, where we excuse the horrendous upsurge in cancer caused by the poisoned food chain, to the marvelous advances in medical technology; “we find more because we test more”. We hear of more tremours, quakes and outbursts, because our instruments are better? Maybe, I doubt it.
Fraccing has nada to do with this discussion. It’s earthquake swarms are real and measures to minimize/avoid them should be mandated. I,e, more, better, and better spotted hazardous waste disposal wells.
Yea, we gotta avoid those super damaging 1.0 earthquakes.
There is no evidence that there is anything wrong with the current disposal methods.
“Yea, we gotta avoid those super damaging 1.0 earthquakes.”
Not bad for you. Only off by few logarithms (Richter scale look it up).
https://en.wikipedia.org/wiki/Oklahoma_earthquake_swarms_(2009%E2%80%93present)
School time. Oklahoma and Texas haz waste disposal wells were mostly constructed 50+ years ago, and their standards are awful. Poorly tubed, poorly cemented. And they were meant to dispose of fluids at rates orders of magnitude lower than required by modern shale* development. Additionally, at least in Oklahoma, the Arbuckle shale is increasingly resistant to haz waste injection (injection pressures are increasing). This increased stress, along with the concomitant lubricity from the fluids, causes the damaging quakes.
Just one more external cost of shale development, passed along to the public…
*The linked article is mistaken about the incremental volumes coming from the Mississippi and the Hunton. Most of those produced fluids are reinjected into those intervals,
On the issue of how explosive, I studied that and wrote up the results as part of essay Blowing Smoke in the eponymous ebook while debunking a really bad Colorado University paper.
The answer is almost no VEI 4, but most VEI 5 and 6, throw aerosols into the stratosphere where they only slowly wash out so can (for a couple of years) effect surface temperatures by changing albedo (measured as stratospheric opacity, or the equivalent optical depth). Up through VEI 4, the troposphere volcanic washout is typically at most a few weeks. It depends on the latitude of the volcano and the season. Higher latitudes have a higher troposphere aerosol residence time.
Rud Istvan:
I, too, have studied the effect of volcanic eruptions, and I have found that VEI4 eruptions typically cool the :atmosphere for a year or more, and usually result in the formation of a La Nina. Few, if any, VEI3 eruptions have any climatic effect.
See “A Graphical Explanation of Climate Change”
http://www.skepticmedpublishers.com/article-in-press-journal-of-earth-science-and-climatic-change/
And: “The Definitive Cause of Little Ice Age Temperatures”
https://www.osf.io/bmu69/
Both show that most VEI4 eruptions result in decreases in average anomalous Global temperatures.
Bad tacos event? Oof, that’s why I hold the hot sauce when there is risk of bad taco subduction.
Hi Ron,
You might want to check this lecture out from Willie Soon:
The “Global Blue Sun”: Solar Anomaly during 1450s-1460s?
https://youtu.be/XxiQoanjvLE?t=2379
He is discussing a different topic, but gets into about 20 mins of Solar Perturbation Theory relating that to the historical minimums and warm periods (where I started the video). Then at 44:18 he starts discussing volcanic eruption patterns. This is not relevant to the period Mann is postulating, but since you stated: “I cannot imagine what cyclic, or oscillation if you prefer, could possibly control the timing of volcanic eruptions”, I thought you might be interested. As I am a chemist, I can’t evaluate any of it, but found it fascinating. FYI.
I’ve had some emptying in explosive fashion from some bad tacos, not pleasant at all
Ron Long, when Pinatubo erupted, the debris was a high enough volume to block sunlight and drop the global mean temperature by (I think) ONE degree Fahrenheit. It was brief, but it did happen. That was some time ago, but the records should be somewhere.
Let’s suppose that there really is a volcanic cycle in sync with the AMO. Isn’t it possible that the volcanic cycle could be caused by the AMO, not the other way round? The AMO would change the pressure patterns on Earth’s crust, and that could affect volcanic activity.
Did Michael Mann look at the PDO too? Or is that going to have to be eliminated next?
Mann attempted to get rid of the mwp and the lia with his hockey stick, recently they tried to get rid of the Holocene optimum and now the amo so yes your probably right and the pdo will be next. Wonder what will be deleted after that?
Mann’s First Law: Never consider hypotheses that do not agree with what you are trying to sell.
Well, getting cause and effect backwards is “climate science” stock-in-trade, after all.
Ah yes the ol’ “state-of-the-art” models. Just like Pablo Picasso painted state-of-the-science pieces.
In the definitions of “sciency” terms, “state of the art” means “the latest absolute crap.”
The art must be in a terrible state me thinks.
In just today’s TWTW we find…
It is so unfair that the Pacific has its decadal oscillation, but Mann took away the Atlantic’s. So unfair.
Perhaps the Atlantic should Tsu
Early wanrnig about 6.5 years in advance of a phase shift shouldt be better and more accurate than the Schellnhuber / PIK El Niño warning a year in advance that in reality became a La Niña ;-/
This is a classic case of deciding the answer, and then finding a way to “prove” it.
I was going to say that’s what lawyers do. I realize that comparing Dr. Mann to a lawyer is a serious affront to lawyers everywhere and I am deeply sorry for even thinking such a thing.
Lawyers are officers of the court and they have legal and ethical obligations. For instance, a lawyer may not hide evidence or concoct evidence or present misleading evidence. (That said, a lawyer may have conflicting duties and things can get complicated.) I don’t know any lawyers who aren’t scrupulously honest.
Anyway, it always brings me joy to point out that, because of his conduct in the Ball case, Mann has confessed to being a fraud by way of adverse inference. He has thus admitted that he belongs in the state pen because, if he had evidence otherwise, he should have produced it.
Don’t both of the Clinton’s have law degrees?
Bill’s was revoked, with good cause.
Then there’s Rod Blagojevich and the Obamas, sterling stars of the legal profession in IL.
My bad.
I don’t personally know any lawyers who aren’t scrupulously honest.
And I too would disavow personally knowing any lawyers who were dishonest. 🙂
Scrupulously honest? Politics is overloaded with lying lawyers.
Find or not an answer it still could be part of a useful scientific research. Both Maxwell and Einstein looked for answers to their ‘thought experiments’ and concluded they did found adequate answers, but neither could prove it. Proofs came some years later provided by Heinrich Hertz and the space technology.
Yes, the opposite of what the left typically does, i.e., sees something work in practice but dismiss it because it doesn’t fit the theory.
As is the entire notion of “anthropogenic” global warming/climate change/whatever-they-call-it-next-week.
“There is no compelling evidence for a purely internal multidecadal AMO-like cycle.”
Ah there it is, a non-linear dynamic cycle is not linear and therefore there is no natural cycle. Akin to an area during the LIA that was warmer than today and an area during the MWP that was cooler than today so therefore they do not exist.
There seems to be a lot of hubris from the climate cult about the AMO being completely controlled by man lately, almost like they are expecting global cooling to kick in.
AMO hasn’t to exist as real scientists found out, climate is driven by ocean cycles
Climate is driven by the Whims of Mann and Model Drivel
It is only climate scientists who use language of “internal” and “external” forcing. Earth system scientists understand that everything is related ecologically. Furthermore, the self contained biosphere is a myth – the Earth system is not separate from the solar system. Similarly, what we call “climate” is not separate from geology. We perceive them and label them as separate systems, but in fact they are coupled. You cannot separate one from another, and in doing so leads to false assumptions and invalid conclusions.
To take things a step further, obsession with “forcings” while ignoring “feedbacks” makes the entire exercise little more than mental masturbation.
About 10 or so years ago I compared the N.Atlantic SST ( de-trended data is known as the AMO) to the N. Atlantic tectonic activity, both visual inspection and correlation of just under 0.7 would suggest causal relationship. I suspect it might be related to effect on down-welling in the Icelandic region of the Atlantic.
NAO
data
AMO-NAO oscillate in anti-phase, akin to an LC electric circuit
(p.s. all my graphs are out of date some more than others)
However, there is some co-incidental similarity in the longer term of the N. Atlantic tectonics and solar activity
Sorry, Vuk, but sunspots and earthquakes are NOT related. See my post “Spot The Quakes” for an actual analysis that’s not just squinting at two graphs and saying “co-incidental similarity”.
w.
See my comment to John Tillman below.
So if it were volcanoes before the rise in man-made CO2, it still is volcanoes.
Hi John
At the moment I’m inclined to think it is more to to do with ocean currents than the CO2.
I’m a bit puzzled by the tectonics – sunspot coincidence, unlikely to be be related to the orbital mechanics, possibly geomagnetic lithospheric induction.
“There is strong evidence of electromagnetic processes responsible for earthquake (& volcanoes? -vuk) triggering, that we study extensively. We will focus here on one correlation between power in solar wind compressional fluctuations and power in magnetospheric pulsations and ground H component fluctuations.”
Geophysical Research Abstracts,Vol.8,01705, 2006;Lab for Solar and Space Physics, NASA Goddard Space Flight Center,Greenbelt, MD
http://www.cosis.net/abstracts/EGU06/01705/EGU06-J-01705.pdf
https://earth-planets-space.springeropen.com/articles/10.1186/s40623-015-0213-3)
Does “tectonics” include earthquakes as well as volcaniic eruptions?
Most definitely it does. It’s all part of the same dynamic.
As I recall, tectonics is defined as “forces and movements within the earth’s crust”, circa 1971.
Long term CET data is also co-related to the N. Atlantic tectonics, hence dismissing above relationships as ‘pure coincidence’ it might be premature.
The fact that England’s temperature is related to N. Atlantic temperature is obvious, but it means nothing about “tectonics”, whatever those might be.
w.
Of course England’s temperature is related to N. Atlantic SST, the weather forecasters over-here tell us that daily often more than once. I put that graph there to show longer term (350+years) co-incidence since the AMO data goes back only about 150 yrs.
Whether it has or has not anything to do anything with tectonics (indirectly via N.Atlantic SST) it is a matter of conjecture. My graph makes me think it is more likely than not (of course I’m biased, since I have studied the CET for at least a decade, it affects me on the daily basis). On the other hand anyone is free to take opposite view according to their interpretation of available data and the relevant science .
I think it’s more interesting to look for quantifying tectonics with CO2 outgassing. There are several papers about. 😀
Vuk and Willis
I wonder what role, if any, galactic cosmic rays have on volcanic activity. Low solar activity mean relativity weak solar winds, which help protect the earth from GCRs. GCRs penetrate deep into the earth and I won’t be surprised if the data shows they help set off volcanic activity. I have seen references that point to major volcanic activity being correlated with low sunspot activity. More to the point, I continue to be surprised that more is not being made of the weakening of the earth’s magnetic field, which also helps protect against GCRs. While the earths magnetic field started dropping in the mid 1800s, it has really picked by speed the last few decades. The field is dropping at 5% per decade currently and the drop seems to be accelerating. If this continues, I think the earth could be in for some interesting times. “Ship of Fools” Turney just published a piece about the magnetic excursion 42k years ago, which was not a pleasant time. It seems like the earth experiences magnetic excursions about every 12k years and we are about due if the cycle does exist. If we lose another 5% of the field in the next 10 years and the 25th cycle is as weak as the 24th and the AMO rolls into the negative phase, I think the worry about CO2 will quickly fade.
Been there … studied that. No correlation.
and
See here and here.
w.
Thanks, Vuk. Questions:
a) Just what is it that you are calling “North Atlantic tectonic activity”?
b) What units is it measured in?
c) What is the source of the data?
d) What data source are you using for the North Atlantic SST data?
e) What are the north and south limits that you are using for the “North Atlantic SST”?
Without those, it’s just pretty pictures … and beyond that:
f) What is the physical explanation for the claimed 7-year lag between “tectonic activity” and SST?
w.
Lots of questions there to answer in one go.
In brief, data is collected and cross-referenced from a number of institutions (Smithsonian, BGS, Iceland Geosurvey, BGR, BRGM, etc ) all publicly available. Output calculated according to formula on the graph. If ever complete the paper started some years ago I will have much more to say, and if the WUWT is still around I certainly will make an announcement.
N.A. SST data : https://psl.noaa.gov/data/correlation/amon.us.long.mean.data
The 11 year running mean shows an encrease
Looking at your graph, you don’t have a correlation of 0.7. That is your r^2 value. Your r value is about 0.83.
Yes, thanks Clyde.
The climate changes for the Holocene could be explained by natural salinity changes over time along with natural ocean cycles such as the AMO. The salinity cycle was created by melt pulses at the end of the last ice age. Lots of cold fresh water entered the Arctic and North Atlantic undercutting warmer ocean water.
The Younger Dryas could have been a period when the cool, fresher water returned to the surface.
It is possible the next higher salinity cycle led to the Holocene Optimum with the additional feature where the global MOC slowed. This extended the warm period. However, the current has since gotten back up to speed and we see millennial periods of warming and cooling as the water traverses the globe.
The MWP was the last period of higher salinity. The LIA was created by a drop in salinity. We have been in a time of rising salinity for the past ~500 years.
https://www.nature.com/articles/s41467-018-02846-4/figures/2
Over the past century humans have been adding to the salinity of the oceans via salt usage for water treatment, deicing, farming, etc.
The AMO could also be salinity driven as well, driven by cyclic melting of polar ice to freshen portions of the AMOC.
It all fits together nicely. Now is it true? There’s no money in studying this kind of natural phenomena so chances are it will be ignored for many years to come.
Good point: the role of salinity is usually overlooked. Most deep downwelling is where salinity (in colder seas) is highest: in the northern Atlantic. The warm Gulfstream transports the most saline surface waters from the North Atlantic Gyre (around 30°N) to the higher latitudes of the Atlantic, enabling ‘warmer than normal’ water to sink and/or to enter the Arctic Ocean area as ‘warmer than normal’ subsurface water. It is THIS warmer water that caused the recent decades of ice melt in the Arctic which changed weather patterns etc. etc. That warmer than normal water is progressing along the Siberian coast to the east. More open water in the arctic north of East Siberia (during summertime and autumn) is changing regionally the quantity of water vapor in the air and in this way is changing pressure patterns.
When air pressure patterns change, winds change and by consequence ocean currents will change. And then salinity changes. It will be interesting years to come.
I thought that surface salinity was highest in the tropics, where there is a lot of evaporation taking place.
Note the lowered salinity along the ITCZ above the equator in the Pacific. This is due to the rainfall from the ever-present thunderstorms.
w.
Clyde Spencer: “I thought that surface salinity was highest in the tropics, where there is a lot of evaporation taking place.”
WR: It is the highest in the tropical gyres and more especially in the North Atlantic Tropical Gyre. That’s why I wrote: “where salinity (in colder seas) is highest”.
It is this very saline surface water of the most saline gyre (the North Atlantic Gyre) that is brought to the highest latitudes by the Warm Gulf Stream and (mixed with precipitation and fresher water from ice melt) still has the highest salinity of the cold oceans, resp. the oceans at the highest latitudes. Perfectly shown by Willis’ map below. Compare the North Atlantic with the North Pacific at the same latitude. The Southern Ocean (near Antarctica) is fresher as well.
There’s a lot of evaporation, but there is also a lot of rainfall
It’s almost like somebody besides Mann labeled photo in the way they did.
The “fingerprint of AGW” points to Mann’s fingers in the photo;
Mann’s fingerprint is all over the exaggeration of tree rings (tea leaves, knuckle bones, and chicken guts) with respect to Mann’s anthropocentric climate claims.
Umm … yeah, the person who labeled the photo?
That would be me … and yes, it is satire.
w.
And BRILLIANT
Digressing in a chaotic system is not really digressing.
Ah, very good.
w.
Willis likes to digress. But I think he likes telling us he’s digressing more than the actual digression.
Judith Curry made it pretty clear what Mann’s motivation is to eliminate the AMO as a phenomenon.
Mann has been alarmist’s go-to carnival barker after every hurricane to claim they’ve been made more intense due to CO2 driven AGW. The AMO explanation blows up his fraudulent claims on recent hurricane intensity, so now he goes after the AMO.
Now when goes on some interview and claims this or that hurricane has been made more intense due to AGW, if someone tells him the AMO shift explains it, he can tell them peer-reviewed literature” shows the AMO to be figment of past volcanic forcings.
It’s all very much Orwellian-motives to send inconvenient observations down the memory hole and further the climate scam. But I can assure you somewhere in Mann’s latest attempt to weave a tangled-web of a new narrative on the Atlantic AMO and hurricanes something else comes unraveled in the climate scam as he attempts to deceive.
The list of natural cycles which must be done away with keeps growing. First, the Team had to get rid of the Medieval WP, pounding it into submissin by high sticking, then the LIA and now oceanic oscillations, with possible exception of ENSO, as too well established. The Roman, Minoan and Egyptian WPs and the Holocene Optimum apparently aren’t well enough know to pose sufficient threat as to require cancelling. Yet.
http://www.realclimate.org/index.php/archives/2021/03/the-rise-and-fall-of-the-atlantic-multidecadal-oscillation/
“A scientist has to admit when they are wrong. Unfortunately for all of us, my colleagues and I weren’t wrong about the unprecedented warming revealed by the now iconic “Hockey Stick” curve, despite the unrelenting attacks on it by climate change deniers over the past two decades. But I was wrong about the existence an internal AMO oscillation when I coined the term twenty years ago” But I was right about the stick?
It appears that the deniers need to please do something about the AMO, still cool on the Texas coast. Might start here from a professional observer (went out at night) about the cold kill. “These turtles were left to die because of the bureaucracy of our government. It’s a federal offense to handle a sea turtle without a federal certification. US fish and wildlife prohibited us from rescuing “cold stunned” sea turtles during this event, because we weren’t trained by federal wildlife handling class.”
This post protected by the iconic “right” to be choatic. Am currently innocent because the last time I touched a cold-killed turtle was in 1989. They were rare then, now all over the bays. Hockey Stick! Both turtles and regulations.
Willis comment – “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 … “
Mann’s lies and distortions are perpetual
On Jan 21, 2021 Mann filed a motions for summary judgment in Steyn/NR/CEI/Stimberg law suit.
Virtually every page has 2-3 distortions/lies or misrepresentations.
A partial listing
1) ” the DC court of Appeals sitting enBanc ruled ….
2) he cited 4 court cases claiming all 4 held “x” when only one court even discussed the subject but was not on point so it was inapplicable to the Mann case,
3) filed motion to strike JA curry under the Daubert standard – “as not qualified as an expert”
4) repetitively stated that he was exonerated in all the 8 climategate investigations.
“I do enjoy Mann’s implication that he was the discoverer of the AMO phenomenon…”
Mann can say that, having won the Nobel Prize and stuff.
keep in mind the Oslo-committee awarded Nobel Peace Prize (which Mann claims a part of) was largely debased to irrelevance when the committee gave it to Obama for accomplishing absolutely nothing.
The actual Stockholm Nobel Prizes in Physics, Chemistry, Medicine-biological sciences are still very much coveted and signify discoveries and work that withstood scientific rigors of independent verification.
“…having won the Nobel Prize and stuff”.
————
“keep in mind…”
————-
Your enjoinder might have been better spent, reminding me that some number of the “sarc” challenged do visit these pages.
Maybe it should be re-titled “Nobel Get-A-Piece-of-the-Action Prize.”
Nobel Peace prize become mostly just a meaningless leftist gesture.
You only have to look at some of the most disgusting people who it has been awarded to
eg Yassar Arafat , Al Gore, O-bummer, IPCC
Not “meaningless” to those who receive the money for just being politically correct.
It was debased to irrelevance long before that, when awarded to Yasser “Start the “peace” negotiations, we’re running out of ammo” Arafat.
I guess we can put Mann’s claim to have discovered the AMO right next to his claim to have received a Nobel prize.
… and right next to the single Bristlecone Pine that told him there was no Medieval Warm Period … (roughly equivalent to Briffa’s half dozen Yamal Larches).
Lovely image of psuedo-ensembles on the street corner.
But they aren’t smoking ciggies, they are all playing different instruments that are out of tune both with each other and with the tuning fork
“I do enjoy Mann’s implication that he was the discoverer of the AMO phenomenon”
Well, he didn’t say he “discovered” the AMO, just that he coined the term.
Of course the paper is paywalled.
He has to pay for all those lawsuits somehow.
Left wing law firms do the job pro bono for Mann….lawsuits are a weapon to shut down opposition.
His legal expenses are paid for by his university who don’t want to be sited as co-conspirators in a charge of malfeasance.
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.
And there you have it, Mannian Climate “Science” in a nutshell. The output of a computer model is now considered to be evidence, and trumps actual temperature measurements
Volcanic eruptions are not cyclical but any long cycle pattern in the data will do when stretching a correlation beyond reason. If they can do that with volcanoes then certainly they can look sideways at individual solar cycles to stretch a point that is not really there. It’s close enough for government work, hand grenades, and Mann models. That phrase extension is a new modern era concept.
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
Next
Michael Crichton
This material may be protected by copyright.
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.
So far in his career Mann has denied the existence of the MWP, minimised the LIA and now seeks to demonstrate that the AMO is not a quasi-periodic internal variation but an artefact of external forcings.
He “proves” this by referencing a climate model – because the climate model doesn’t produce the AMO, except by inducing it by applying external (prior) forcings based on the combination of aerosol forcing curves and well mixed GHG forcing curves, ergo the model is true and the explanation arrived at. So by a circular argument Mann has arrived at the point where he can argue his sophisticated climate model explains anything he wants.
The problem with this argument (other than the circular reasoning, of course) is that it depends entirely on the input priors to the climate models. Without the input priors (forcing curves) climate models just generate random noise.
By the same logic it is now a simple step to argue that any observation can be explained by adding something suitable into the prior forcing. What’s next – El Nino’s inserted into the priors? Then the models will be almost perfect.
Climate models are basically driven via a reductive decomposition . By creating a series of input prior forcings, the model is driven to give the required output ie match the temperature series. It is self-delusion on a grand scale. The proof this is true is that if we average many models the random behaviour largely cancels and we are left with a temperature response over time. The average temperature response over time can be almost perfectly reconstructed from the input prior forcings, ergo the GCM’s are just lipstick on the pig.
What’s even more incredible is that people believe this crap.
“In M. Mann’s world, it’s always the humans who are to blame.”
His manntasy is: Humanns save Gaia from humans.
From a comment posted by me a few days ago to the RealClimate blog:
“Once again we see the old, tired “explanation” for the mid-20th century cooling as the masking of an underlying warming trend by industrial aerosol emissions. . .
When we examine temperature records for regions with little or no industrial activity, lo and behold: the expected warming trend fails to appear. Now I have no idea whether or not the “Atlantic Multidecadal Oscillation” is a real phenomenon or an artifact. But using industrial aerosols to explain the very real cooling trend we see from ca. 1940 through ca. 1979 (40 years!) would appear to be a serious error, produced by the failure to invoke the most fundamental scientific controls.
For details, I refer the reader to the following blog post (http://amoleintheground.blogspot.com/2021/03/thoughts-on-climate-change-part-10.html#more ), where I present relevant temperature data for the Arctic, the Antarctic, Africa, Madagascar, Siberia, Afghanistan, Burundi, Haiti, Kyrgistan and New Caledonia. In all cases, the data for the period 1940-1979 fails to reveal any trace of the assumed warming trend, despite the absence of much in the way of industrial activity.”
Predictably, my comment was consigned to their “bore hole” in a crude attempt to divert attention from embarrassing evidence.
We had slow refreeze this winter in the Arctic and I wonder if this could have meant currents flowing from the Arctic increased the volume entering the North Atlantic. The years since 2007 have been fast freezing up till now as I recall.
Whatever is causing the ups and downs in the Earth’s temperatures, the AMO temperature profile is repeated all over the world. The AMO profile shows it was just as warm in the Early Twentieth Century as is is today.
Here is the US surface temperature chart (Hansen 1999) which closely resembles the temperatue profile of the AMO.
Other regional surface temperature charts from all over the world show the same temperature profile as the AMO and the US Hansen 1999 chart.
Hansen 1999:
Weekly_rise March 9, 2021 5:26 am
You’ve left out some words, and in doing so you are conflating modelworld with the real world. Let me fix it for you.
Like Shania Twain said, “That don’t impress me much“. All you’ve told us is that climate models are unable to replicate AMO variability unless they’re fed some specially selected modeled forcings. Guess what? They’re also not able to replicate the PDO, the El Nino/La Nina phenomenon, tropical cyclones, the AMO, and a host of other natural phenomena.
Not only that, but the specially selected modeled forcings are modeled eruptions up until modern times, when somehow they miraculously die out and are replaced just in the nick of time by modeled anthropogenic CO2 and sulfate forcings … yeah, that’s totally legit.
All that means is that the models are not up to the task … it does not mean the AMO is not the result of internal variability.
w
Willis, surely you see why your comment is a non-response? Maybe there is something wrong with the models here, and that’s the explanation, but you have not shown that. Why do you believe, specifically, the model control runs don’t show AMO while forced runs do? Can you provide evidence to substantiate your position?
Weekly, I have no idea why the model control runs wouldn’t show a modeled AMO, while when they are forced with some specially selected model forcings they do show a modeled AMO. I also have no idea why model runs don’t show a modeled El Nino, or a modeled AAO, or many natural phenomena.
The curiosity to me is why you would take any of that as evidence about the real-world AMO.
In addition, some of the model control runs DO show a modeled AMO. Here’s Mann et al. on the subject.
You do seem confused, however, about the abilities of models. Here’s the 411.
I’ve been programming computers about as long as anyone on the planet. I wrote my first program in 1963, nearly sixty years ago now, on Hollerith punch cards for a computer that took up a small room. And based on a lifetime’s experience in the field, I can assure you of a few things.
1) A computer model is nothing more than a physical realization of the beliefs, understandings, wrong ideas, and misunderstandings of whoever wrote the model. Therefore, the results it produces are going to support, bear out, and instantiate the programmer’s beliefs, understandings, wrong ideas, and misunderstandings. All that the computer does is make those misunderstandings look official and reasonable. Oh, and do it really fast. Been there, done that.
2) “Iterative” computer models, where the output of one timestep is fed back into the computer as the input of the next timestep, are notoriously cranky, unstable, and prone to internal oscillations and to falling off the perch. Generally, they need to be “fenced in” in some sense to keep them from spiraling out of control.
3) As anyone who has ever tried to model say the stock market can tell you, a model which can reproduce the past absolutely flawlessly may, and in fact very likely will, give totally incorrect predictions of the future. Been there, done that too.
4) This means that the fact that a model can hindcast flawlessly does NOT mean that it is an accurate representation of reality.
5) There is an entire branch of computer science called “V&V”, which stands for validation and verification. It’s how you can be assured that your software is up to the task it was designed for. Your average elevator software has been subjected to more V&V than any of the computer models.
6) Computer modelers are all subject to a nearly irresistible desire to mistake Modelworld for the real world. Unless some computer model’s software has been subjected to extensive and rigorous V&V. the fact that the model says that something happens in modelworld is NOT evidence that it happens in the real world.
7) The more tunable parameters a model has, the less likely it is to accurately represent reality. Climate models have dozens.
8) The climate is arguably the most complex system that humans have tried to model. It has no less than six major subsystems, viz, the ocean, atmosphere, lithosphere, cryosphere, biosphere, and electrosphere. None of these subsystems is well understood on its own, and we have only spotty, gap-filled rough measurements of each of them. Each of them has its own internal cycles, mechanisms, resonances, and feedbacks, and each one of the subsystems interacts with every one of the others. Finally, there are both internal and external forcings of unknown extent and effect. For exmple, how does the solar wind affect the biosphere? Not only that, but we’ve only been at the project for a couple of decades. Our models are … well … Tinkertoy representations of real-world complexity.
9) Many runs of climate models end up on the cutting room floor because they don’t agree with the aforesaid programmer’s beliefs, understandings, wrong ideas, and misunderstandings. They will only show us the ones that they agree with, not the ones where the model went off the rails.
As a result of all of these considerations, anyone who thinks that the climate models can “prove” or “establish” or “verify” something that happened five hundred years ago or a hundred years from now is living in a fool’s paradise. They are in no way up to that task. They may offer us insights, or make us consider new ideas, but they can only “prove” things about what happens in modelworld, not the real world.
Finally, be clear that having written dozens of models myself, I’m not against models. However, there are models, and then there are models. Some models have been tested and subjected to extensive V&V and their output compared to the real world and found to be very accurate. So we use them to navigate interplanetary probes and design new aircraft wings and the like.
Climate models, sadly, are not in that class of models. Heck, if they were, we’d only need one of them, instead of the dozens that exist today and that all give us different answers … leading to the ultimate in modeler hubris, the idea that averaging those dozens of models will get rid of the “noise” and leave only solid results behind.
I hope this explains my position on M. Mann’s claims about models and the AMO.
w.
Willis, this answer is worth a separate post.
(More especially the part starting with ‘I’ve been programming’)
Thanks, Wim, good idea. I’ll do that. I’m tired of folks accusing me of “not liking models” and that kind of thing.
Appreciated,
w.
Willis:
You are blowing smoke.
“Models” cannot model El Ninos or La Ninas because they are caused by random volcanic eruptions, and increasing or decreasing levels of Anthropogenic SO2 aerosol emissions,
Further, there is zero evidence that CO2 has any climatic effect, and any model incorporating CO2 will necessarily fail.
You are doing everyone a great disservice by your failure to recognize the overwhelming effect of atmospheric SO2 levels.
Oh, piss off. I don’t stand for anyone telling me that I’m “blowing smoke”. I tell the truth as best I know how. Go whine at someone else. Not interested.
w.