Mann dismisses Wyatt and Curry's 'stadium wave' paper, claims the pause is 'fleeting'

From Penn State: Slowdown of global warming fleeting

By A’ndrea Elyse Messer

UNIVERSITY PARK, Pa. — The recent slowdown in the warming rate of the Northern Hemisphere may be a result of internal variability of the Atlantic Multidecadal Oscillation — a natural phenomenon related to sea surface temperatures, according to Penn State researchers.

“Some researchers have in the past attributed a portion of Northern Hemispheric warming to a warm phase of the AMO,” said Michael E. Mann, Distinguished Professor of Meteorology. “The true AMO signal, instead, appears likely to have been in a cooling phase in recent decades, offsetting some of the anthropogenic warming temporarily.”

According to Mann, the problem with the earlier estimates stems from having defined the AMO as the low frequency component that is left after statistically accounting for the long-term temperature trends, referred to as detrending.

“Initial investigations into the multidecadal climate oscillation in the North Atlantic were hampered by the short length of the instrumental climate record which was only about a century long,” said Mann. “And some of the calculations were contaminated by long-term climate trends driven or forced by human factors such as greenhouse gases as well as pollutants known as sulfate aerosols.  These trends masqueraded as an apparent oscillation.”

Mann and his colleagues took a different approach in defining the AMO, which they report online in a special “Frontier” paper in Geophysical Research Letters.  They compared observed temperature variation with a variety of historic model simulations to create a model for internal variability of the AMO that minimizes the influence of external forcing — including greenhouse gases and aerosols. They call this the differenced-AMO because the internal variability comes from the difference between observations and the models’ estimates of the forced component of North Atlantic temperature change.  They found that their results for the most recent decade fall within expected multidecadal variability.

They also constructed plausible synthetic Northern Hemispheric mean temperature histories against which to test the differenced-AMO approaches.  Because the researchers know the true AMO signal for their synthetic data from the beginning, they could demonstrate that the differenced-AMO approach yielded the correct signal.  They also tested the detrended-AMO approach and found that it did not come up with the known internal variability.

The detrended approach produced an AMO signal with increased amplitude — both high and low peaks were larger than in the differenced-AMO signal and in the synthetic data.  They also found that the peaks and troughs of the oscillation were skewed using the detrending approach, causing the maximums and minimums to occur at different times than in the differenced-AMO results.  While the detrended-AMO approach produces a spurious temperature increase in recent decades, the differenced approach instead shows a warm peak in the 1990s and a steady cooling since.

Past researchers have consequently attributed too much of the recent North Atlantic warming to the AMO and too little to the forced hemispheric warming, according to the researchers.

Mann and his team also looked at supposed “stadium waves” suggested by some researchers to explain recent climate trends.  The putative climate stadium wave is likened to the waves that go through a sports stadium with whole sections of fans rising and sitting together, propagating a wave around the oval.  Random motion of individuals suddenly becomes unified action.

The climate stadium wave supposedly occurs when the AMO and other related climate indicators synchronize, peaking and waning together.  Mann and his team show that this apparent synchronicity is likely a statistical artifact of using the problematic detrended-AMO approach.

“We conclude that the AMO played at least a modest role in the apparent slowing of warming during the past decade,” said Mann.  “As the AMO is an oscillation, this cooling effect is likely fleeting, and when it reverses, the rate of warming increases.”

Others working on this project were Byron A. Steinman, postdoctoral fellow in meteorology, and Sonya K. Miller, programmer/analyst, meteorology, Penn State

The National Science Foundation supported this work.

=========================================================

The paper:

http://onlinelibrary.wiley.com/doi/10.1002/2014GL059233/abstract

 

WUWT post on the stadium wave:  http://wattsupwiththat.com/2013/11/30/climate-stadium-waves-and-traffic-waves/

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norah4you

Seems to be lacking or “fleeting” knowledge in “high” circles 🙂

Ken Hall

Translation: We really had to mess with a lot of models in order to really torture the data to create yet another hypothesis, which we present as fact, in order to prop up our CAGW hypothesis.

bushbunny

Can some explain the above to me, it is ‘double dutch’. However, Penny Wong once Environmental Minister spoke on the night of the 2010 General election, when asked if axing the ETS (?) resulted in their poor showing in the polls. She replied, ‘The general consensus is now that the planet is cooling..’ That was the time Julia Gillard announced ‘There will be no carbon tax in a government I lead.” but held on for another few years until she was again displaced as leader by Kevin Rudd. (who she replaced)

Peter Miller

“They also constructed plausible synthetic Northern Hemispheric mean temperature histories against which to test the differenced-AMO approaches.”
I can only think the English translation of this means: “we constructed a model which showed that our theories were correct, as the actual observational numbers did not support those theories.”
So, classic ‘climate science’.

lee

‘They also constructed plausible synthetic Northern Hemispheric mean temperature histories against which to test the differenced-AMO approaches.’
Because the old ones had been tortured too much. If this doesn’t work- will they have plausible deniability?

rogerknights

Well, this dispute should be resolved within three years.
(Unless we get a middling response from the climate system.)

Louis

“…this cooling effect is likely fleeting…”

Is that the best they can do, use a weasel word like “fleeting”? Depending on the context, fleeting can be anything from partial seconds to millions of years. Since they claim to be dealing with “settled science,” why can’t they give us an actual time frame for when warming will resume? That way we could either validate their claims or falsify them. Are they afraid we’ll discover just how little they really know about the climate? The IPCC gave us a list of scary things that would begin to happen by the end of this century. That’s a long time frame, but at least it’s measurable. A meaningless word like “fleeting” can be used, after the fact, to represent whatever time passes before some warming, natural or otherwise, occurs. In fact, that’s probably why they used it.

rogerknights: “Well, this dispute should be resolved within three years.”
How? The AMO has a period of about 70 years. We’re currently in a peak phase, but it might take a couple of decades to determine when exactly the peak was in the standard 30y climatic window.

Douglas Levene

Unless I’m mistaken, Prof. Mann has offered a falsifiable hypothesis. His theory predicts that “this cooling effect is likely fleeting, and when it reverses, the rate of warming increases.” How soon will this happen, Prof. Mann? I’m happy to wait and see if you’re right or wrong. I think everyone else should wait, too. We could take up crocheting in the meantime.

It is hard to know exactly what controls our weather and climate, but one reliable indicator is a paper or pronouncement by “Dr.” M. Mann. He is always wrong. He is most often way wrong all the way to absurdity. And today he has shown us yet more idiotic fallacy. We should collect some of his best absurdities for the museum of irreproducible results.

Dr Burns

Bushbunny, What is the source of Penny Wong’s quote? I can’t find it.

Stephen Richards

constructed plausible synthetic Northern Hemispheric mean temperature histories
What the eff is that. “We played around with a meaningless bunch of data to see if we could convince ourselves that the cooling isn’t real and voilà we made this graph which says it is but won’t last any longer than 30 years.

bushbunny

Dr Burns, you won’t find it, it was broadcasted on the ABC Tally Room on the night of the election results. I was watching it at the time, and there was a brief comment in the press the next day, and that disappeared too. She also said once as finance minister, we need the carbon tax to put the budget back in black. (like the mining tax?) Some things are shoved under the carpet and better unsaid! Get my gist?

Ken Hall

@Luis April 9, 2014 at 12:39 am
“The IPCC gave us a list of scary things that would begin to happen by the end of this century. ”
—————————–
They will not give more near term predictions, because it does not take as long to falsify them. As the list of 100 failed predictions on this site proved:
http://wattsupwiththat.com/2014/04/02/the-big-list-of-failed-climate-predictions/

Ken Hall

@Douglas Levene April 9, 2014 at 12:52 am “Unless I’m mistaken, Prof. Mann has offered a falsifiable hypothesis. His theory predicts that “this cooling effect is likely fleeting, and when it reverses, the rate of warming increases.” How soon will this happen, Prof. Mann? I’m happy to wait and see if you’re right or wrong. I think everyone else should wait, too. We could take up crocheting in the meantime.”
—————————————
The currently building El Nino will be all the alarmists require to confidently state that the runaway warming has resumed, whereas us realists will have to wait until 2020, to determine if the current decade is wamer or cooler than the previous one.
Climate science really is the reverse of normal science. In normal science it takes one falsification to kill a hypothesis. In Climate science it only takes one remaining validation to refute all falsification and keep a hypothesis alive.

JohnM

17 years is fleeting 🙂

Mann: “I cannot admit that anyone else could possibly be right, so I’m going to make up some more stuff to prove I’m right and they’re wrong.”. In other words, my guess is better than your guess. Nah Nah Na Hah Han..

Tim Hammond

This isn’t science, it’s just messing about with models.
All it shows is how little we understand about what is going on, and how rudimentary our models are.

knr

Definition of ‘different’ as , that which is designed to give us the result we need regardless of facts or reality , which we can they make great claims based on which are in fact total BS.

Bloke down the pub

So when temps go up it’s caused by our emissions, and when it goes down it’s caused by natural cycles. Sounds like science to me.

Lawrie Ayres

I’m just surprised that this galoot has the hide to continue to do such dubious science when he has faulted so often in the past. At what stage do the journals tell Mann he is no longer credible?

If Global temperatures dip to -0.2C on average below current levels by mid/late 2015, then I suspect that this conclusion will need to be re-written.

David L.

Everyone can explain away the so -called pause in hindsight. Where were the predictions of the pause before it hsppened? If these climologists really understood their “science” they would have predicted the pause. But they didn’t which simply means they don’t really understand what’s going on, and all this hand waiving right now is guessing.
Since they couldn’t predict the so-called pause I don’t trust they can predict anything. It’s that simple.

“The recent slowdown…..”
Hah!! And I’m also sure your “recently purchased” car is ready for the junkyard.

rogerknights

Steinar Midtskogen says:
April 9, 2014 at 12:51 am

rogerknights: “Well, this dispute should be resolved within three years.”

How? The AMO has a period of about 70 years. We’re currently in a peak phase, but it might take a couple of decades to determine when exactly the peak was in the standard 30y climatic window.

Mann said the pause is fleeting, according to his SWAG. If it’s still around in 3 years, or has cooled, we’ll have our answer.

Kenny

“The true AMO signal, instead, appears likely to have been in a cooling phase in recent decades, offsetting some of the anthropogenic warming temporarily.”
Please correct me if i’m wrong….But I thought the AMO was in a possitive phase now. I thought it wasn’t going nebeative until around 2020.

Kenny

^negative

Alberta Slim

It seems to me that every time the temp goes up it is CAGW.
When it stops, levels out, or dips, it is from “natural” causes

Carl

I thought it was a “faux pause”, but now it’s a “fleeting pause”. Maybe it’s a fleeting faux pause or a faux fleeting pause.

Espen

Steinar Midtskogen says:
The AMO has a period of about 70 years.
I’m not sure we know enough about the AMO to conclude that it’s really cyclic and not just a random walk. That the AMO peaked in the 90s, however, completely defies common sense.
Has anyone found any non-paywalled information on how Mann defines his “true AMO” index?

Eliza

I cannot believe anybody is giving this guy ANY attention after the Hockey Stick Fraud…He has been soundly debunked totally by Steve Mcyintyre

Pierre DM

“Initial investigations into the multidecadal climate oscillation in the North Atlantic were hampered by the short length of the instrumental climate record which was only about a century long,” said Mann.
But he believes anthropogenic warming since 1950 is solid?
“They also constructed plausible synthetic Northern Hemispheric mean temperature histories against which to test the differenced-AMO approaches.”
I am not sure the author of this piece has a clue what science is given the first quote and the second statement I clipped out, offered in the same article…. and we the taxpayers paid for it?
Our winter might have been too much for MM.

Mann is right — “The Pause” is fleeting — much like his so called “warming” — a warming of little consequence.
We should always acknowledge the truth — no matter who utters it.
The earth has been here several Billion years. It will survive Dr Mann, his Mann-made warming, his fellow-travelers and much else besides.

Claude Harvey

No matter how many times Mann saws off the limb on which he perches, you look up and he’s still sitting in the tree. This tree is either magical or imaginary.

Steve from Rockwood

No pause in warming. Slow down in warming. The pause in warming is likely fleeting.
He is walking very slowly toward the truth.

Bruce Cobb

Interesting how he calls a 17 1/2 year halt a “10-year slowdown”, which is “temporary”, partly due to the AMO. Funny how he “forgets” PDO as well. Both AMO and PDO are now in the cooling phase, and that means we’ll be cooling for at least another 20 years. You can smell the desperation and fear in these prison-bound climate shysters.

Ulric Lyons

Quote:
“They call this the differenced-AMO because the internal variability comes from the difference between observations and the models’ estimates of the forced component of North Atlantic temperature change.”
There is no internal variability, the “forced” phase of the AMO is its cold phase, e.g. from 1965 to 1995 where the heat content of the northern north Atlantic Ocean was declining:
http://i35.tinypic.com/28vsnzq.png
The warm phase from 1995 is simply declines in solar plasma forcing, causing an increase in negative AO/NAO episode frequency and intensity, a more southerly jet stream track, and increased poleward warm sea water transport. The whole thing is a negative feedback with a large overshoot, and is responsible for a significant proportion of the rise in global mean surface temperature since 1995.
Quote:
“We conclude that the AMO played at least a modest role in the apparent slowing of warming during the past decade,” said Mann. “As the AMO is an oscillation, this cooling effect is likely fleeting, and when it reverses, the rate of warming increases.”
Apparently it caused the warmest decade on record, and it is behaving as it should do. That is to give a sharp step up in global mean temp as poleward sea water transport is increased, followed by a leveling off in temp, because the external solar forcing is reduced. With increased solar forcing, the AMO will return to its cold phase, which is very unlikely while solar activity is at such low values (as in the 1880/90’s).

Ed_B

The use of the word “pause” is symptomatic of how the AGW lobby torture the language, and of their circular logic.* They should call it a “cessation” or a “stop”. If the world resumes a warming trend later on then, and only then, can it be called a pause.
“Fleeting” is another interesting word. If 17 years is “fleeting”, what would we call the period from 1980 to 1997 when the globe really did warm?
* For those that don’t know, circular logic means assuming what you set out to prove.

Theo Goodwin

“They compared observed temperature variation with a variety of historic model simulations to create a model for internal variability of the AMO that minimizes the influence of external forcing — including greenhouse gases and aerosols. They call this the differenced-AMO because the internal variability comes from the difference between observations and the models’ estimates of the forced component of North Atlantic temperature change.”
Apparently, Mann wants to be recognized as the greatest practitioner of the Alarmist Method. That method is to combine some statistical manipulation of some data with some scenarios created on computer models until there is a result that supports Alarmist Dogma. The final touch is that all this creativity is presented as science.
How long must we be abused by such nonsense. Results of model runs are not data. Models are not data. Therefore, comparisons between model runs and data are worthless.

Harry Passfield

As I understand it, the ‘warming’ period was 22 years and it stopped 17.5 years ago. That means that the ‘pause’ is currently running at 79.5% of warming for longevity. Of course, it all depends where the pause is taken from, some people say it’s been 20 years…

jayhd

I would like to know what the Penn State students think of this. Because if they are buying into this absolutely abysmal excuse for science, then Penn State will be graduating absolutely worthless scientists.

Harry Passfield

Claude Harvey says:
April 9, 2014 at 5:15 am

“No matter how many times Mann saws off the limb on which he perches, you look up and he’s still sitting in the tree. This tree is either magical or imaginary.”

It’s magical, Claude. It’s the same one he got the tree ring cores from.

Chuck Nolan

I thought Dr. Mann was a tree guy?
Does he think he may have lost his hockey stick somewhere in the Atlantic?
cn

Pamela Gray

hmmmm
Differenced-AMO. What next? Upsided downeded detrendeded homogenizeded spliceded tree rings-ed? Sounds like they massaged-ed that data till it sang “the tune”.

Pamela Gray

Oh wait…Mann already did the treed one.

Gary Pearse

“… Mann and his team show that this apparent synchronicity is likely a statistical artifact of…”
Well he is a specialist in these artifacts so he could be right. He took a good course from Steve M about such artifacts.

Claude Harvey

Re: Harry Passfield says:
April 9, 2014 at 6:22 am
“It’s magical, Claude. It’s the same one he got the tree ring cores from.”
Of course! I’d forgotten his ability to sort through thousands of trees and find that handful of “magical hockey-stick trees”. Hockey-stick tree limbs are immune to the effects of gravity! I wonder if “pause trees” are so endowed?

John West

“Synthetic data” in my world is called pencil whipping.

It’s good to see Mr. Mann producing solid science again! Oh, wait….

CaligulaJones

“Mann and his colleagues took a different approach”…
So does my father-in-law when it comes to navigating. He’ll tell you the absolute best route to take, based on the fact that the drove there 20 years ago, and you haven’t.
Yes, he is now invariably late for things…