In the thread Intelligence and the hockey stick commenter “Robert” challenged a well known quote about the MWP from 2006 by Dr. David Deming in his statement before the Senate EPW committee which is the title of this post.
I thought it was worth spending some time setting the record straight on what the original quote actually was and point out that it has been paraphrased, but the meaning remains the same.
Robert says:
The quote is a fabrication. Jonathan Overpeck’s exact words are:
“I get the sense that I’m not the only one who would like to deal a mortal blow to the misuse of supposed warm period terms and myths in the literature.”
Christopher Monckton, like Andrew Montford before him, alters the text to instead read:
“We have to abolish the medieval warm period.”
My reply:
I checked for a citation, and the quote you state is correct:
http://di2.nu/foia/1105670738.txt
From: Jonathan Overpeck
To: Keith Briffa , t.osborn@uea.ac.uk
Subject: the new “warm period myths” box
Date: Thu, 13 Jan 2005 21:45:38 -0700
Cc: Eystein Jansen , Valerie Masson-Delmotte
Hi Keith and Tim – since you’re off the 6.2.2 hook until Eystein hangs you back up on it, you have more time to focus on that new Box. In reading Valerie’s Holocene section, I get the sense that I’m not the only one who would like to deal a mortal blow to the misuse of supposed warm period terms and myths in the literature. The sceptics and uninformed love to cite these periods as natural analogs for current warming too – pure rubbish.
So, pls DO try hard to follow up on my advice provided in previous email. No need to go into details on any but the MWP, but good to mention the others in the same dismissive effort. “Holocene Thermal Maximum” is another one that should only be used with care, and with the explicit knowledge that it was a time-transgressive event totally unlike the recent global warming.
Thanks for doing this on – if you have a cool figure idea, include it.
Best, peck
–
Jonathan T. Overpeck
Director, Institute for the Study of Planet Earth
Professor, Department of Geosciences
Professor, Department of Atmospheric Sciences
Mail and Fedex Address:
Institute for the Study of Planet Earth
715 N. Park Ave. 2nd Floor
University of Arizona
Tucson, AZ 85721
As to this being a fabrication (as Robert claims), no, it’s a summation or a paraphrase of a long quote, something that happens a lot in history. Monckton and Montford aren’t specifically at fault in this, as the summed up quote has been around for a long, long, time and it appears to have originated with Dr. David Deming’s statement to the Senate. (see update, it goes back further than that- Anthony)
The conversion to a paraphrase maintains the meaning. “Mortal blow” certainly equates to “get rid of” (as it is often said) or “abolish” as you (and Monckton/Montford) state it, and “we” equates to “I’m not the only one”.
The most important point is that Overpeck thinks the MWP (misuse) should be gotten rid of so that people that don’t agree with his view can’t use it (as citations).
And that, is the real travesty.
[Added] And, by eliminating citations, he effective kills the the existence of the MWP in science, relegating it to an unsubstantiated claim. As we see in related links below, that has not happened.
UPDATE: The room is often smarter than me, and many have more historical experience than I, and for that I am grateful. Dr. Tim Ball points out (as does David Holland) in comments:
With the publication of the article in Science [in 1995], I gained significant credibility in the community of scientists working on climate change. They thought I was one of them, someone who would pervert science in the service of social and political causes. So one of them let his guard down. A major person working in the area of climate change and global warming sent me an astonishing email that said “We have to get rid of the Medieval Warm Period.”
He later reiterated this in his presentation to the Senate on 12/06/2006 here
http://www.epw.senate.gov/hearing_statements.cfm?id=266543
Notice he didn’t say who sent the email, but rumours developed that it was Jonathan Overpeck.
As I recall Overpeck denied being the author of the e-mail , which precipitated extensive commentary by Steve McIntyre;
http://climateaudit.org/2010/04/08/dealing-a-mortal-blow-to-the-mwp/
Steve McIntyre points out in his article:
Be that as it may, while Overpeck was concerned that Deming might produce a “fake email” purporting to show Overpeck seeking to “get rid of the MWP”, Overpeck hasn’t challenged the authenticity of the Climategate email in which he aspires to “deal a mortal blow” to the MWP.
Related articles
- Intelligence and the hockey stick (wattsupwiththat.com)
- New paper shows Medieval Warm Period was global in scope (wattsupwiththat.com)
- BREAKING NEWS: CRU’s Jones admits climate data problems, and Medieval Warm Period (briefingroom.typepad.com)
- ScienceMag: Medieval Warm Period global, 0.65 °C warmer than present: ‘The largest ocean was 2 °C warmer than today when ancient civilizations exploded’ (climatedepot.com)
http://climateaudit.files.wordpress.com/2006/08/wahl.c10.gif
Barry quotes..”It’s clear he acknowledges previous warm periods in the next paragraph, too.
“Holocene Thermal Maximum” is another one that should only be used with care, and with the explicit knowledge that it was a time-transgressive event totally unlike the recent global warming.”
Sorry, he already called the literatre (not the sceptics use of it) a made up myth. now he backtracks and get zero points here. Why, because the resolution of the proxy regressions is, at best 100 years or greater, so of course shorter periods could well be hidden in the proxy regressions, and not show up. (His entire quotes structure, like much of the CAGW proponents science, is not logical, and a desperate attempt to argue on all sides, as long as they perpetuate the “myth” of “supposed” CAGW.
Now notice I have called CAGW a made up fable, just as Overpeck called the MWP the same. I am clear, as was Overpeck. The fact that at times I also argue strictly on a scientific basis, does not mean I accept CAGW as anything but a fable and a myth. Overpeck’s use of the words supposed, and myth, applied NOT to sceptics, but to the MWP literature.
Realclimate on PCA decentering
“Contrary to MM’s assertions, the use of non-centered PCA is well-established in the statistical literature, and in some cases is shown to give superior results to standard, centered PCA. See for example page 3 (middle paragraph) of this review. For specific applications of non-centered PCA to climate data, consider this presentation provided by statistical climatologist Ian Jolliffe who specializes in applications of PCA in the atmospheric sciences, having written a widely used text book on PCA. In his presentation, Jollife explains that non-centered PCA is appropriate when the reference means are chosen to have some a priori meaningful interpretation for the problem at hand. ”
Ian Joliffe himself, shortened message
” …. I’d be grateful if my comments could be displayed wherever it is appropriate for them to appear.
… my views have been misrepresented, and I would therefore like to correct any wrong impression that has been given.
… In reacting to Wegman’s criticism of ‘decentred’ PCA, the author says that Wegman is ‘just plain wrong’ and goes on to say ‘You shouldn’t just take my word for it, but you *should* take the word of Ian Jolliffe, one of the world’s foremost experts on PCA, author of a seminal book on the subject. He takes an interesting look at the centering issue in this presentation.’ It is flattering to be recognised as a world expert….
… However there is a strong implication that I have endorsed ‘decentred PCA’. This is ‘just plain wrong’.
…certainly does not endorse decentred PCA. Indeed I had not understood what MBH had done until a few months ago.
…An argument I’ve seen is that the standard PCA and decentred PCA are simply different ways of describing/decomposing the data, so decentring is OK. But equally, if both are OK, why be perverse and choose the technique whose results are hard to interpret?
…. it’s arguable whether you should be using any type of PCA.
…I am by no means a climate change denier. My strong impressive is that the evidence rests on much much more than the hockey stick. It therefore seems crazy that the MBH hockey stick has been given such prominence and that a group of influential climate scientists have doggedly defended a piece of dubious statistics. Misrepresenting the views of an independent scientist does little for their case either. .
Ian Jolliffe”
Ian Jollife on the decentered PCA.
“Apologies if this is not the correct place to make these comments. I am a complete newcomer to this largely anonymous mode of communication. I’d be grateful if my comments could be displayed wherever it is appropriate for them to appear.
It has recently come to my notice that on the following website, http://tamino.wordpress.com/2008/03/06/pca-part-4-non-centered-hockey-sticks/ .. , my views have been misrepresented, and I would therefore like to correct any wrong impression that has been given.
An apology from the person who wrote the page would be nice.
In reacting to Wegman’s criticism of ‘decentred’ PCA, the author says that Wegman is ‘just plain wrong’ and goes on to say ‘You shouldn’t just take my word for it, but you *should* take the word of Ian Jolliffe, one of the world’s foremost experts on PCA, author of a seminal book on the subject. He takes an interesting look at the centering issue in this presentation.’ It is flattering to be recognised as a world expert, and I’d like to think that the final sentence is true, though only ‘toy’ examples were given. However there is a strong implication that I have endorsed ‘decentred PCA’. This is ‘just plain wrong’.
The link to the presentation fails, as I changed my affiliation 18 months ago, and the website where the talk lived was closed down. The talk, although no longer very recent – it was given at 9IMSC in 2004 – is still accessible as talk 6 at http://www.secamlocal.ex.ac.uk/people/staff/itj201/RecentTalks.html
It certainly does not endorse decentred PCA. Indeed I had not understood what MBH had done until a few months ago. Furthermore, the talk is distinctly cool about anything other than the usual column-centred version of PCA. It gives situations where uncentred or doubly-centred versions might conceivably be of use, but especially for uncentred analyses, these are fairly restricted special cases. It is said that for all these different centrings ‘it’s less clear what we are optimising and how to interpret the results’.
I can’t claim to have read more than a tiny fraction of the vast amount written on the controversy surrounding decentred PCA (life is too short), but from what I’ve seen, this quote is entirely appropriate for that technique. There are an awful lot of red herrings, and a fair amount of bluster, out there in the discussion I’ve seen, but my main concern is that I don’t know how to interpret the results when such a strange centring is used? Does anyone? What are you optimising? A peculiar mixture of means and variances? An argument I’ve seen is that the standard PCA and decentred PCA are simply different ways of describing/decomposing the data, so decentring is OK. But equally, if both are OK, why be perverse and choose the technique whose results are hard to interpret? Of course, given that the data appear to be non-stationary, it’s arguable whether you should be using any type of PCA.
I am by no means a climate change denier. My strong impressive is that the evidence rests on much much more than the hockey stick. It therefore seems crazy that the MBH hockey stick has been given such prominence and that a group of influential climate scientists have doggedly defended a piece of dubious statistics. Misrepresenting the views of an independent scientist does little for their case either. It gives ammunition to those who wish to discredit climate change research more generally. It is possible that there are good reasons for decentred PCA to be the technique of choice for some types of analyses and that it has some virtues that I have so far failed to grasp, but I remain sceptical.
Ian Jolliffe”
David A says:
So when you hear somone say that they want to get rid of “myths”, like, say, the “Bigfoot myth”, your first conclusion is that they want to go out and kill Bigfoot? Not that they want to just get rid of the myth itself?
Well, umm, that’s a very creative way to interpret Overpeck’s words, at least.
It amazes me that this is even being argued about. Hmm, well, on the one hand, we could just present Overpeck’s words and let people interpret them how they will, or on the other hand, we could paraphrase it however we prefer, (potentially) completely changing the meaning. “Potentially”, since it seems to be ambiguous enough that there’s disagreement, although it seems pretty clear to me what Overpeck is saying, and it’s not “let’s expunge the MWP from the data record”. You can’t try to expunge what you don’t even believe exists, and Overpeck does not believe that a significantly large MWP exists.
But, hey, people here are all about transparency and honesty, right? So Dana Nucitelli recently gets raked over the coals for misspeaking about Pielke on Twitter (justifiably — it was obviously a mis-speak, but a blatantly incorrect one), but this kind of re-interpretation and mis-speaking gets a free pass?
That sure looks like a double standard. “Honesty and transparency for me, but not for thee”.
“So when you hear somone say that they want to get rid of “myths”, like, say, the “Bigfoot myth”, your first conclusion is that they want to go out and kill Bigfoot?”
False equivalency fallacy. There is no bigfoot, no scientist ever recorded it.
Nick Stokes says deliberately misleading BS on December 9, 2013 at 6:35 pm
Piltdown Mann et all wrote three hockey stick papers, which I referred to in my post as (MBH98 etc.). The first went back about 600 years, the next 1000 years and the next 2000 years (from memory – I can’t be bothered to look up that crap).
So the first Mann paper eliminated the LIA, and the second and third papers eliminated both the LIA and the MWP.
Nice try to mislead Nick. Maybe Piltdown will give you a job. Looks like you have the necessary credentials.
“But, hey, people here are all about transparency and honesty, right”
People differ.
I think straight unadorned apology for the mistake is correct, and then pursue the known actual words and actions and results of Overpeck.
Some persons calling themselves scientists never learn that real facts of the warm period in the past can’t be removed….
”Most of the Viking expansion took place during what scientist refer to as the dimatic optimum of the Medieval Warm Period dated ca, A.D. 800 to 1200 (Jones 1986: McGovern 1991); a general term for warm periods that reached chere optimum at different times across the North Atlantic (Groves and Switsur 1991). During this time the niean annual temperature for southem Greenland was 1 to 3°C higher than today.” Julie Megan Ross, Paleoethnobotanical Investigation of Garden Under Sandet, a Waterlogged Norse Farm Site. Western Settlement. Greenland (Kaiaallit Nunaata), University of Alberta, Department of Anthropology Edmonton. Alberta Fa11 1997, sid 40
Mann’s “Decentered PCA” is a data normalization error that has the effect of emphasizing red-noise (AKA “Drunkard’s Walk” or integrated white-noise) signals that happen to curve away (as almost ALL do, to a significant degree) at the ends (arcsine law). McIntyre and McKitrick in their famous paper showed this. It is a FORM of “selection bias”. It is amazing how very little “ordinary” selection bias is necessary to produce hockey sticks. It is easy to fool yourself into thinking you are just throwing out a few pathological data points. Decentered PCA is perhaps more subtle. It does its dirty work through the inherent programming. It “pinches” a group of signals together at one end and necessarily forces them further apart at the other end (rather than grasping then more nimbly at the middle). If you take the trouble to see what you have done, you will easily understand your (quite literally) “schoolboy error”. If you don’t look, you may just be happy to find the results you were hoping for, BOGUS as they are, and stop thinking.
Every graph I’ve ever seen from the IPCC and Mann has the MWP deleted. So whether the quote is correct, incorrect, or mis-attributed, they DID make the MWP DISAPPEAR.
Funny, that.
Windchaser says: December 9, 2013 at 9:47 pm
David A says:
What Overpeck desires to do is make the MWP into a myth of supposed warm periods, and so preclude any attempt by sceptics to say that the current warming falls within past natural behavior of climate
===============================================
So when you hear somone say that they want to get rid of “myths”, like, say, the “Bigfoot myth”, your first conclusion is that they want to go out and kill Bigfoot? Not that they want to just get rid of the myth itself?
Well, umm, that’s a very creative way to interpret Overpeck’s words, at least.
======================================
Windchaser, please reread what I wrote, as your analogy is a complete fail. If someone thinks bigfoot is “supposed”, and a “myth” in the scientific literature, (read the synonyms given for those words) that means they do not believe it exists, and if they demonstrate that, then they take away all credibility of those who claim to have found bigfoot, or the supposed mythical MWP.
So Overpeck, and he was not alone, wanted to take away the ability of skeptics to use the existing literature to claim a “supposed” “mythical} period of warming, (his words referring to the scientific literature) as evidence of natural climate change equal to the change from 1975 to 1995. It is not a foreign language, it is what he said. He did not want to kill Bigfoot, who is a myth, he wanted to kill stories about bigfoot, (the MWP, which he called a myth, and supposed warm period.)
The dictionary paraphrase of Overpeck is,…”I get the sense that I’m not the only one who would like to deal a mortal blow to the misuse of an imaginary, made-up, fictional and invented warm period terms, and the fairy tales in the literature. The sceptics and uninformed love to cite these periods as natural analogs for current warming too.”
The literature he is referring to sceptics “citing”, is the literature they cited at the time, the scientific literature regarding the MWP, which Overpeck calls a imaginary, made-up, fictional and invented fairy tale “in the literature.”
I love the hypocrite Mosher calling everyone out for an alleged misuse of this quote when he is fabricating that he is a “scientist”,
http://www.linkedin.com/pub/steven-mosher/1/b07/27b
Since when does a B.A. in English Literature and Philosophy, with a career in Marketing make you a scientist?
Waste of time asking Stevnick Stokesher.
His reply is the perfect circlular jerk; “Scientists are those who do science. Science is whatever scientists do.”
Hansen’s chihuahua is best described as a schmutterist – his business is in clothing the naked emperor in the latest fashion.
Hey, let’s give ’em all a polygraph test!
Anyone who declines is obviously lying…
Further to what I said a few days ago regarding the Chinese actually sailing around Greenland. This interesting information was taken from the book by Gavin Menzies called 1421, the Year China Discovered America. Mr.y Menzies has chapter about a fellow named Zhou Wen who lead a fleet of Chinese ships that circumnavigated Greenland in 1423 or thereabouts. This is astounding!! and tends to show that it was much warmer at that time and is within the time frame of the Medieval Warm period as is being address here. Caleb is correct in stating that there was a warm interval, but it culminated perhaps a little later than he indicates in his communication. And for the area of which I speak, to be ice free there would have had to have been quite a few years when it was also warm prior to 1423. Specifically Gavin Menzies mentions that from 1420 to 1428 the summers were “exceptionally warm” Also for the Norse to have settled in western Greenland, and even farmed around this time, the climate would have had to have been much milder than the present.
Poptech says:
December 10, 2013 at 8:13 am
What makes Steven Mosher a scientist is precisely what makes Michael Mann and Phil Jones non-scientists. Steven publishes his work in a transparent manner, and accompanies it with all the data, code, and information that supports it. In addition, he answers questions and requests for information.
That’s what makes a scientist, not the possession of a PhD. A scientist is a person who follows the scientific method. The scientific method works like this:
• I make a falsifiable scientific claim in a public forum, and I publish all of the math, data, arguments, logic, and computer code that supports my claim.
• I hand around the hammers and invite people to see if they can destroy my claim.
• If they can destroy my claim, I admit I was wrong, and we move on. If they can’t, my results stand until such time as someone can destroy them, and we move on.
The important point is that the scientific method lives and dies on transparency. If I don’t publish my data and code, if I refuse to answer questions, if I hide my methods, then no one can falsify my work. That doesn’t mean I’m wrong. It just means that without transparency, it’s not science. Hey, maybe I don’t want to reveal my method because I want to make money on it. And that’s fine … but it’s not science.
And it is that aversion to scientific transparency on the part of many of the leading climate “scientists” like Mann and Jones that shows that they are not scientists under any meaning of the word. Scientists practice the scientific method, and they don’t.
Finally, your willingness to descend to ad hominem attacks on those with whom you might disagree drops the odds of you being a scientist. If you don’t like Mosh’s science, rather than besmirching his name, how about you show us where you think his science wrong?
All the best,
w.
Who could be best described as “deniers” here? Isn’t that a good description of people who want to rewrite history…
Wiilis, you haven’t been reading Mosher’s definitions. Those are your definitions and close to mine, as well, but they are not Mosher’s.
He did not say anything about sharing being part of the definition.
It was whatever scientists do. Not about the scientific method. Not about sharing. Not about sum of knowledge.
His evasions and broad unsubstantiated attacks bring responses. As he helped with attacks on you at Dr Roy’s, predicting cowardice from you.
” Steven Mosher says:
October 10, 2013 at 2:39 PM
At some point Roy they will claim that any minor difference in Willi’s formulation and prior formulations amounts to “a difference” In the extreme they will argue that nobody ever posted charts that look exactly like Willis’ charts.
Its a variant of the true scotsman fallacy”
Willis,
Mosher offers a prediction that you will never admit to “the truth” of Dr. Roy’s charges, and “they” will do any amount of presenting fallacy in order to evade.
“They” would have no leg to stand on if you had admitted that Dr. Roy was correct in his charges, so he’s saying you will never admit to the truth.
If Mosher’s behaviour is the sign of a scientist, I don’t want to know any.
[Snip. Enough insulting of our host. There are plenty of other blogs whetre you can do that. — mod.]
Ah yes, our resident house carpenter is defending the English major.
I am sorry but Mann and Jones are real scientists, whom may be unethical and ideologically biased but unlike you and Mosher they have relevant credentials and are employed as such.
The definition of the profession of a “Scientist” that is widely accepted is,
“a person who is trained in a science and whose job involves doing scientific research or solving scientific problems”
Neither you nor Mosher are scientists despite your delusional fantasies.
Has the delusional echo chamber here really reach a point where you guys are so separated from reality that Willis and Mosher believe themselves to be scientists?
[Reply: Stop fixating on individual personalities. Confine your comments to the article topic. ~ mod.]
I disagree with Poptech, and Willis. “Science” is a prescribed pattern of logical analysis of observations and objective experiments. Anyone faithfully following the scientific method is a “scientist” There are armature scientist, and professional scientist. Poptech is reflecting a mirror to Mosher, ineffective communication, but accurate if a bit harsh.
IMV, Mosher is a smart numbers man, better at that and statistics then most. However he repeatedly is critical of many in general (group insults) and engages in arrogant condescension towards those who disagree. The arrogance is expressed in general insults plus cryptic comments delivered with an aura of finality, and a refusal to then dialogue with those who disagree. This thread is quintessential Mosher…
Steven Mosher says:
December 8, 2013 at 11:16 am
[snip – Mosh, you are welcome to resubmit this comment sans the childish name calling – Anthony]
followed by…. If that was snipped, then what was it, as here is Mosher toned down; Steven Mosher says: ” Deming doesnt have the mail. We have nothing but hearsay. The monktopus is pretending that this is not hearsay. And none of you skeptics have the balls to call him on it.”
So, personal insult to Monckton, false claim of hearsay to a respected congressional eyewitness, and group insult, all rolled into a few sentences.
Willis, as others have pointed out, you also have been a target of Mosher’s immaturity. Beyond that, in my view, Mr. Mosher gets lost in the trees of numbers, and so cannot see the forest of corruption surrounding those numbers. (Consider that I have asked several times for an elevator explanation of the TOB adjustments, as well as specific examples, like the US adjustments and their increasing divergence from RSS, and some specific Iceland station adjustments. Mr. Mosher chooses not to lower himself to respectful dialogue) So, although I disagree with Poptech, I consider his comments to be Mr. Mosher’s well deserved karma.