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.
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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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Apparently the “scientific method” consists of
1) Determining the proper answer
2) Torturing the data until it agrees
said Mann. “As the AMO is an oscillation, this cooling effect is likely fleeting, and when it reverses, the rate of warming increases.”
===========
there we have it. Mann states that when the AMO oscillation reverses, “the rate of warming increases.”
But then Mann goes on to contradict himself:
“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.”
I was taught that when someone contradicts themselves, what they are saying cannot be true.
He forgot to mention that the warm part of the natural phase would have also caused them to overestimate the attribution of observed warming to CO2, thus underestimat how much of that warming was natural, and thus overestimated the effect/sensitivity of the climate system to that CO2, and underestimated the impacts of natural variations. This results in models whose temperature projections are too sensitive to CO2. The fact that the real world data has left the model envelope in such a short time is why he had to come up with this excuse in the first place. What he then does is fudge the aerosol data (which is an acknowledged HUGE UNKNOWN IN ITSELF) so that he can dismiss the warming impact in the earlier phase, even though Hansen is at the same time using fudged aerosol data in the EXACT OPPOSITE MANNER to claim that is a significant cause of the pause itself. This is not settled science, my friends. The only thing I can see clearly from these folks is that they are willing to fudge data to fit their preconceived notions (not science at all).
Douglas Levene says:
April 9, 2014 at 12:52 am
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It only appears to be a falsifiable hypothesis. Without a time frame, Mann is free to say that “fleeting” has not yet expired. If warming ever does restart, then he’s proven right, but as long as it doesn’t, he hasn’t been proven wrong.
The AMO has been in it’s negative phase for decades?????
Now he’s just making stuff up.
So Mann is saying that warming up until the mid 90s was from the AMO, not GHG feedbacks.
Proving a hypothesis with another hypothesis? Even the old Greeks were against that.
If the cooling effect was “fleeting,” then another way of looking at the warming period from 1980-1995 was that it too was “fleeting.” I think Mr. Mann has discovered, totally by accident of course, the concept of minor warming and cooling climate cycles. “Fleeting” could be defined as “minor.”
First, redefine AMO. How Mannian. Then use your new definition to explain the pause. Yup, this must be out of PSU.
I have been communicating with Dr Wyatt via an introduction from Dr. Curry, who occasionally hosts a guest post from me deconstructing some paper or other facet of CAGW. Marcia tells me she has just finished a reply to Mann. I gather it is not something the Mann is going to be very happy about. Marcia has a whole set of previous Mann dodges including his Rutgers and AGU temperature shambles compared to Hansen (not updated, land only, claiming the pause was not real) plus Steve McIntrye’s deconstruction of his April 2014 Sci Am temperature graph to consider using, as they are in essays for my next book that she has been kindly critiquing. Her reply to Mann will undoubtedly be worthy of note at WUWT when it gets published.
Ken Hall says:
April 9, 2014 at 1:25 am
@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/
I’d like access to your time-machine! Apparently according to you events predicted for 2020, 2050, 2085, etc. have already failed!
Example: “20. “Warm in the winter, dry in the summer … Long, hard winters in Germany remain rare: By 2085 large areas of the Alps and Central German Mountains will be almost free of snow. Because air temperatures in winter will rise more quickly than in summer, there will be more precipitation. ‘However, much of it will fall as rain,’ says Daniela Jacob of the Max Planck Institute for Meteorology.”
FOCUS, 24 May 2006″
Mann was citing the Rocky Horror Picture Show?
Lets do the time warp again.
So the short warming period is significant, a now near identical non warming period is fleeting, as the 1940’s to 1970s was insignificant/irrelevant.
And now the Mann states that the data from the past is actually too sparse and too short to draw conclusions from?
I kind of wish this mann had had the intelligence to understand this in the first place.
But then no one would know his name.
By the time this madness is over, i expect Mann will wish no-one knew his name.
Should change title to “Mann Dismisses Significant Global Warming Feedbacks: Nature Variability Responsible for Significant Warming before Late 90s”.
Phil. says:
Yes, the art of climate prognostication is tricky. It needs to be kept fairly vague, and far enough in the future, to enable them to say, “it still will/could/might/should happen, just you wait and see (if you’re still alive then)”.
So, in some cases, perhaps “failed” was the wrong word. Just plain dumb would have served fine.
MarkW says:
April 9, 2014 at 6:53 am
Apparently the “scientific method” consists of
1) Determining the proper answer
2) Torturing the data until it agrees
——————————————–
You hit the nail on the head. Mann isn’t the only scientist I’ve met that has set their career on proving what they already believe. There are many in science that operate on this principle. I believe it stems originally from Aristotle who felt that you could simply think about the thing for awhile and through shear mental ability come up with the law. My physics professor hated Aristotle because he created the basis of Western scientific knowledge that took over 2000 years to correct. For example, Aristotle believed things fell with a rate proportional to their mass and so did the rest of civilization for thousands of years even though the experiment is so easy to do , as demonstrated by Galileo on the tower of Pisa.
In recent times there’s idol worship of people like Einstein who actually could think up the correct theory, and then 20 years later be proven correct by an experiment. Examples of people who can do this are very far and few inbetween but it seems to be the goal of many scientists to be that person so smart they can think up the law by shear mental ability. The rest of us scientists have to accept we are empiricists
What most of history shows is that science operates along a path of observation (empiricism) followed by hypthesis, followed by experimentation to prove or disprove the hypothesis.
So back in the summer of 1990 after our first year of graduate study, Mike Mann attended a talk on climate change and immediately “saw the light” and switched his PhD program from Theoretical Nuclear Phyics to Climate Change. It was on that single presentation that he accepted Climate Change as real and set out to prove it. A week later he was showing me all the evidence of how he knew it was real. He has never been open minded about it and never attacked the issue from the standpoint of wanting to understand what nature is telling us, but rather looking for the evidence to confirm his belief. Not surprising though. Theoretical Nuclear Physics does not groom you for empiricism but rather coming up with the theories from pure mental ability.
Mann listening to that talk was like a friend of mine who “got religion” late in life and then saw an image of Jesus everywhere: in the bark of a tree, in a piece of toast, and sets out to convert everyone around him.
The is circular logic pure and simple. He defines a mythical AMO based on models and the global data. Since models show warming the mythical AMO must have been in its cooling phase. You then remove the mythical AMO cooling effect and you have warming again. Simple. You start with models and just assume some mythical sine wave and eventually you get the model output back.
Did this idiotic nonsense pass peer review? You’d have to be completely brain dead to sign off on this obvious BS.
I work for a large meteorological company and we cater to public utilities, DOT’s, Emergency management depts etc…and our [chief] science officer had to endure a webinar yesterday in which the city of Baltimore was meeting about potential climate impacts by 2030….they are worried about a 5-7ft sea level rise by then, and they were serious. It’s truly sick out there in the ‘real world’ folks….truly sick.
Woah I just read that a little deeper. They used climate models which did not incorporate the AMO trend or the physics which drive the AMO, to determine the AMO trend, discounting the observations apparently entirely. If you look at Bob Tisdale’s charts on how the world’s oceans have changed compared to how the models thought they would, you would see that this is utter BS. They then used sulphate aerosols as the fudge factor between why their modeled AMO does not match the observed detrended AMO. Sulphate aerosols are one of the big unknowns (among the big unknowns they actually acknowlege).
Bottom line: the climate models didn’t model (and obviously didn’t predict) either the observed pause or the observed AMO evolution, but we are supposed to believe they can be used to back out a modeled AMO which is better than what we derive from observation. Oh and out of the other side of their mouths they claim the models are based on observation and physics with no fudge. Yet the only justification given for this strange set of assumptions is an aersol fudge who’s amount and effects is possibly an even bigger unknown in its own right than either of the two contested model outputs under discussion. This is climate science today.
I believe Ken Hall nailed it. The upcoming El Nino will be used by the mannomatic as proof of the end of the “fleeting” pause.
Mann: Really, really, we’re not lying through our teeth, we’re ‘constructing plausible synthetic histories’.
I think this is a good sign. Mann who was the ‘goto paleo’ guy on wooden thermometers, has decided that: “(when they) compared observed temperature variation with a variety of historic model simulations to create a model ” they abandoned attempting to find a proxy to extend the instrumental record, or the existing Atlantic proxies did not do what he wanted. SO he used several models to create a model to ascribe understanding the the observed data.
It would be neat if the Atlantic proxies could be shown to support the Wyatt Curry paper and then what’s good for Mann, must be good for the Curry.
Just an overall observation for contemplation. Since the end (?) of the 2013/14 fall/winter/early spring season that has been exceptionally cold for the a large part of North America (east of the Rocky Mountains specifically – where a large portion of the US population has chosen to reside) there has been an ever-increasing and ever more shrill “call for climate action(s)” from the MSM and “climatologists/scientists/economists/EPA” et. al. Losing the “hearts & minds” battle to what has been cemented into the collective minds of those most affected by the recent harsh winter in this area must irk the living dog out of those whose livelihood depends on the continuation of the “climate battles” and the subsequent bequeathing of public funds for “research”, “mitigation”, and the like. Therefore, an ever more concentrated “call to action” that we (at least, I) see in the NA MSM in the last few weeks. And, the EPA has asked the US Congress for millions more $$$US and wants to add more “FTE’s (full time employees)” in the next FY (fiscal year) for “climate mitigation”. An excerpt from the Testimony of EPA Administrator Gina McCarthy before Congress, discussing the EPA’s 2015 FY budget proposal (from the EPA Press Release of today, 9 April 2014):
“Building on existing efforts and base budget resources, the Agency has added $10 million and dedicates 24 FTE’s in FY 2015 to support the President’s climate action plan. $2 million is designated for technical assistance for adaptation planning for water utilities at greatest risk from storm surges. Research and development efforts will focus on support tools for at-risk communities and tribes in preparing for the impacts of climate change.”
Please do not misinterpret what I am trying to convey. Adaptation of basic public systems for REAL future conditions is prudent and what public supply systems (and the management planners trusted to run them) are required to do. Just do it for that which is probable, not that which may lie at the extremes of probability. The old “precautionary principle (PP)” at work…heck with the PP we might as well all just hide under the frickin’ covers in our beds for the rest of our lives (and with EPA’s, Agenda 21’s, and the UN-as-a-wholes’ plan very short, cold, and deprived of basic modern comforts such as affordable energy sources lives they will be).
Do not be lulled into thinking this whole thing is nearing the end. I know most that frequent this (and other skeptic/lukewarmer sites) sites know the battle is still ongoing. And I see indications every day that there is a strong push to overwhelm the MSM with “studies” “conclusions” and other “conclusive, incontrovertible what-if, could-be, might-be, we-are-so-good-at-predicting-the-future-you-must-do-as-we-say studies” from researchers and scientists and climatologists targeting our collective hearts & minds. I wish I could tune it all out, but the assault seems never to end..At least mitigation is being bandied about instead of pure energy poverty….but I rant..
.
I seem to remember there were proxies using diatoms in the NA going back 3k to 6k years ago and that their were other sediment studies in that general time. Not sure if there are proxies form 3k ago to present but it seems a proxy paper with splicing the thermal record right on as Mann did would be a fun paper to put in his face.
“The true AMO signal, instead, appears likely to have been in a cooling phase in recent decades, offsetting some of the anthropogenic warming temporarily.”
In fact the true external forcing has been in a cooling phase, which is why the AMO has been warmer since 1995. Increased forcing from GHG’s or solar gives lower Arctic pressure and more positive AO/NAO conditions (which is directly associated with a colder AMO):
http://www.ipcc.ch/publications_and_data/ar4/wg1/en/ch10s10-3-5-6.html
So it would appear in reality that the anthropogenic forcing has done little to mitigate the decline in solar forcing that has produced the warm AMO phase since 1995.
So according to Mann the cooling effect which has slowed down the warming lasted a decade and is fleeting. So at least 10 years is fleeting. Would 15 years be fleeting? What about 20 years? What if the fleeting matches the warming since 1975? Just how long is fleeting?
Various web definitions.
Fleeting = passing swiftly; vanishing quickly; transient; transitory, ‘continuing for only a very short time’