Guest commentary by Tamino
Update: Another review of the book has been published by Alistair McIntosh in the Scottish Review of Books (scroll down about 25% through the page to find McIintosh’s review)
Update #2 (8/19/10): The Guardian has now weighed in as well.
If you don’t know much about climate science, or about the details of the controversy over the “hockey stick,” then A. W. Montford’s book The Hockey Stick Illusion: Climategate and the Corruption of Science might persuade you that not only the hockey stick, but all of modern climate science, is a fraud perpetrated by a massive conspiracy of climate scientists and politicians, in order to guarantee an unending supply of research funding and political power. That idea gets planted early, in the 6th paragraph of chapter 1.
The chief focus is the original hockey stick, a reconstruction of past temperature for the northern hemisphere covering the last 600 years by Mike Mann, Ray Bradley, and Malcolm Hughes (1998, Nature, 392, 779, doi:10.1038/33859, available here), hereafter called “MBH98” (the reconstruction was later extended back to a thousand years by Mann et al, 1999, or “MBH99” ). The reconstruction was based on proxy data, most of which are not direct temperature measurements but may be indicative of temperature. To piece together past temperature, MBH98 estimated the relationships between the proxies and observed temperatures in the 20th century, checked the validity of the relationships using observed temperatures in the latter half of the 19th century, then used the relationships to estimate temperatures as far back as 1400. The reconstruction all the way back to the year 1400 used 22 proxy data series, although some of the 22 were combinations of larger numbers of proxy series by a method known as “principal components analysis” (hereafter called “PCA”–see here). For later centuries, even more proxy series were used. The result was that temperatures had risen rapidly in the 20th century compared to the preceding 5 centuries. The sharp “blade” of 20th-century rise compared to the flat “handle” of the 15-19th centuries was reminiscent of a “hockey stick” — giving rise to the name describing temperature history.
But if you do know something about climate science and the politically motivated controversy around it, you might be able to see that reality is the opposite of the way Montford paints it. In fact Montford goes so far over the top that if you’re a knowledgeable and thoughtful reader, it eventually dawns on you that the real goal of those whose story Montford tells is not to understand past climate, it’s to destroy the hockey stick by any means necessary.
Montford’s hero is Steve McIntyre, portrayed as a tireless, selfless, unimpeachable seeker of truth whose only character flaw is that he’s just too polite. McIntyre, so the story goes, is looking for answers from only the purest motives but uncovers a web of deceit designed to affirm foregone conclusions whether they’re so or not — that humankind is creating dangerous climate change, the likes of which hasn’t been seen for at least a thousand or two years. McIntyre and his collaborator Ross McKitrick made it their mission to get rid of anything resembling a hockey stick in the MBH98 (and any other) reconstruction of past temperature.
Principal Components
For instance: one of the proxy series used as far back as the year 1400 was NOAMERPC1, the 1st “principal component” (PC1) used to represent patterns in a series of 70 tree-ring data sets from North America; this proxy series strongly resembles a hockey stick. McIntyre & McKitrick (hereafter called “MM”) claimed that the PCA used by MBH98 wasn’t valid because they had used a different “centering” convention than is customary. It’s customary to subtract the average value from each data series as the first step of computing PCA, but MBH98 had subtracted the average value during the 20th century. When MM applied PCA to the North American tree-ring series but centered the data in the usual way, then retained 2 PC series just as MBH98 had, lo and behold — the hockey-stick-shaped PC wasn’t among them! One hockey stick gone.
Or so they claimed. In fact the hockey-stick shaped PC was still there, but it was no longer the strongest PC (PC1), it was now only 4th-strongest (PC4). This raises the question, how many PCs should be included from such an analysis? MBH98 had originally included two PC series from this analysis because that’s the number indicated by a standard “selection rule” for PC analysis (read about it here).
MM used the standard centering convention, but applied no selection rule — they just imitated MBH98 by including 2 PC series, and since the hockey stick wasn’t one of those 2, that was good enough for them. But applying the standard selection rules to the PCA analysis of MM indicates that you should include five PC series, and the hockey-stick shaped PC is among them (at #4). Whether you use the MBH98 non-standard centering, or standard centering, the hockey-stick shaped PC must still be included in the analysis.
It was also pointed out (by Peter Huybers) that MM hadn’t applied “standard” PCA either. They used a standard centering but hadn’t normalized the data series. The 2 PC series that were #1 and #2 in the analysis of MBH98 became #2 and #1 with normalized PCA, and both should unquestionably be included by standard selection rules. Again, whether you use MBH non-standard centering, MM standard centering without normalization, or fully “standard” centering and normalization, the hockey-stick shaped PC must still be included in the analysis.
In reply, MM complained that the MBH98 PC1 (the hockey-stick shaped one) wasn’t PC1 in the completely standard analysis, that normalization wasn’t required for the analysis, and that “Preisendorfer’s rule N” (the selection rule used by MBH98) wasn’t the “industry standard” MBH claimed it to be. Montford even goes so far as to rattle off a list of potential selection rules referred to in the scientific literature, to give the impression that the MBH98 choice isn’t “automatic,” but the salient point which emerges from such a list is that MM never used any selection rules — at least, none that are published in the literature.
The truth is that whichever version of PCA you use, the hockey-stick shaped PC is one of the statistically significant patterns. There’s a reason for that: the hockey-stick shaped pattern is in the data, and it’s not just noise it’s signal. Montford’s book makes it obvious that MM actually do have a selection rule of their own devising: if it looks like a hockey stick, get rid of it.
The PCA dispute is a prime example of a recurring McIntyre/Montford theme: that the hockey stick depends critically on some element or factor, and when that’s taken away the whole structure collapses. The implication that the hockey stick depends on the centering convention used in the MBH98 PCA analysis makes a very persuasive “Aha — gotcha!” argument. Too bad it’s just not true.
Different, yes. Completely, no.
As another example, Montford makes the claim that if you eliminate just two of the proxies used for the MBH98 reconstruction since 1400, the Stahle and NOAMER PC1 series, “you got a completely different result — the Medieval Warm Period magically reappeared and suddenly the modern warming didn’t look quite so frightening.” That argument is sure to sell to those who haven’t done so. But I have. I computed my own reconstructions by multiple regression, first using all 22 proxy series in the original MBH98 analysis, then excluding the Stahle and NOAMER PC1 series. Here’s the result with all 22 proxies (the thick line is a 10-year moving average):
Here it is with just 20 proxies:
Finally, here are the 10-year moving average for both cases, and for the instrumental record:
Certainly the result is different — how could it not be, using different data? — but calling it “completely different” is just plain wrong. Yes, the pre-20th century is warmer with the 15th century a wee bit warmer still — but again, how could it not be when eliminating two hand-picked proxy series for the sole purpose of denying the unprecedented nature of modern warming? Yet even allowing this cherry-picking of proxies is still not enough to accomplish McIntyre’s purpose; preceding centuries still don’t come close to the late-20th century warming. In spite of Montford’s claims, it’s still a hockey stick.
Beyond Reason
Another of McIntyre’s targets was the Gaspe series, referred to in the MBH98 data as “treeline-11.” It just might be the most hockey-stick shaped proxy of all. This particular series doesn’t extend all the way back to the year 1400, it doesn’t start until 1404, so MBH98 had extended the series back four years by persistence — taking the earliest value and repeating it for the preceding four years. This is not at all an unusual practice, and — let’s face facts folks — extending 4 years out of a nearly 600-year record on one out of 22 proxies isn’t going to change things much. But McIntyre objected that the entire Gaspe series had to be eliminated because it didn’t extend all the way back to 1400. This argument is downright ludicrous — what it really tells us is that McIntyre & McKitrick are less interested in reconstructing past temperature than in killing anything that looks like a hockey stick.
McIntyre also objected that other series had been filled in by persistence, not on the early end but on the late end, to bring them up to the year 1980 (the last year of the MBH98 reconstruction). Again, this is not a reasonable argument. Mann responded by simply computing the reconstruction you get if you start at 1404 and end at 1972 so you don’t have to do any infilling at all. The result: a hockey stick.
Again, we have another example of Montford implying that some single element is both faulty and crucial. Without nonstandard PCA the hockey stick falls apart! Without the Stahle and NOAMER PC1 data series the hockey stick falls apart! Without the Gaspe series the hockey stick falls apart! Without bristlecone pine tree rings the hockey stick falls apart! It’s all very persuasive, especially to the conspiracy-minded, but the truth is that the hockey stick depends on none of these elements. You get a hockey stick with standard PCA, in fact you get a hockey stick using no PCA at all. Remove the NOAMER PC1 and Stahle series, you’re left with a hockey stick. Remove the Gaspe series, it’s still a hockey stick.
As a great deal of other research has shown, you can even reconstruct past temperature without bristlecone pine tree rings, or without any tree ring data at all, resulting in: a hockey stick. It also shows, consistently, that nobody is trying to “get rid of the medieval warm period” or “flatten out the little ice age” since those are features of all reconstructions of the last 1000 to 2000 years. What paleoclimate researchers are trying to do is make objective estimates of how warm and how cold those past centuries were. The consistent answer is, not as warm as the last century and not nearly as warm as right now.
The hockey stick is so thoroughly imprinted on the actual data that what’s truly impressive is how many things you have to get rid of to eliminate it. There’s a scientific term for results which are so strong and so resistant to changes in data and methods: robust.
Cynical Indeed
Montford doesn’t just criticize hockey-stick shaped proxies, he bends over backwards to level every criticism conceivable. For instance, one of the proxy series was estimated summer temperature in central England taken from an earlier study by Bradley and Jones (1993, the Holocene, 3, 367-376). It’s true that a better choice for central England would have been the central England temperature time series (CETR), which is an instrumental record covering the full year rather than just summertime. The CETR also shows a stronger hockey-stick shape than the central England series used by MBH98, in part because it includes earlier data (from the late 17th century) than the Bradley and Jones dataset. Yet Montford sees fit to criticize their choice, saying “Cynical observers might, however, have noticed that the late seventeenth century numbers for CETR were distinctly cold, so the effect of this truncation may well have been to flatten out the little ice age.”
In effect, even when MBH98 used data which weakens the difference between modern warmth and preceding centuries, they’re criticized for it. Cynical indeed.
Face-Palm
The willingness of Montford and McIntyre to level any criticism which might discredit the hockey stick just might reach is zenith in a criticism which Montford repeats, but is so nonsensical that one can hardly resist the proverbial “face-palm.” Montford more than once complains that hockey-stick shaped proxies dominate climate reconstructions — unfairly, he implies — because they correlate well to temperature.
Duh.
Guilty
Criticism of MBH98 isn’t restricted to claims of incorrect data and analysis, Montford and McIntyre also see deliberate deception everywhere they look. This is almost comically illustrated by Montford’s comments about an email from Malcolm Hughes to Mike Mann (emphasis added by Montford):
Mike — the only one of the new S.American chronologies I just sent you that already appears in the ITRDB sets you already have is [ARGE030]. You should remove this from the two ITRDB data sets, as the new version should be different (and better for our purposes).
Cheers,
Malcolm
Here’s what Montford has to say:
It was possible that there was an innocent explanation for the use of the expression “better for our purposes”, but McIntyre can hardly be blamed for wondering exactly what “purposes” the Hockey Stick authors were pursuing. A cynic might be concerned that the phrase actually had something to do with “getting rid of the Medieval Warm Period”. And if Hughes meant “more reliable”, why hadn’t he just said so?
This is nothing more than quote-mining, in order to interpret an entirely innocent turn of phrase in the most nefarious way possible. It says a great deal more about the motives and honesty of Montford and McIntyre, than about Mann, Bradley, and Hughes. The idea that MM’s so-called “correction” of MBH98 “restored the MWP” constitutes a particularly popular meme in contrarian circles, despite the fact that it is quite self-evidently nonsense: MBH98 only went back to AD 1400, while the MWP, by nearly all definitions found in the professional literature, ended at least a century earlier! Such internal contradictions in logic appear to be no impediment, however, to Montford and his ilk.
Conspiracies Everywhere
Montford also goes to great lengths to accuse a host of researchers, bloggers, and others of attempting to suppress the truth and issue personal attacks on McIntyre. The “enemies list” includes RealClimate itself, claimed to be a politically motivated mouthpiece for “Environmental Media Services,” described as a “pivotal organization in the green movement” run by David Fenton, called “one of the most influential PR people of the 20th century.” Also implicated are William Connolley for criticizing McIntyre on sci.environment and James Annan for criticizing McIntyre and McKitrick. In a telling episode of conspiracy theorizing, we are told that their “ideas had been picked up and propagated across the left-wing blogosphere.” Further conspirators, we are informed, include Brad DeLong and Tim Lambert. And of course one mustn’t omit the principal voice of RealClimate, Gavin Schmidt.
Perhaps I should feel personally honored to be included on Montford’s list of co-conspirators, because yours truly is also mentioned. According to Montford’s typical sloppy research I have styled myself as “Mann’s Bulldog.” I’ve never done so, although I find such an appellation flattering; I just hope Jim Hansen doesn’t feel slighted by the mistaken reference.
The conspiracy doesn’t end with the hockey team, climate researchers, and bloggers. It includes the editorial staff of any journal which didn’t bend over to accommodate McIntyre, including Nature and GRL which are accused of interfering with, delaying, and obstructing McIntyre’s publications.
Spy Story
The book concludes with speculation about the underhanded meaning of the emails stolen from the Climate Research Unit (CRU) in the U.K. It’s really just the same quote-mining and misinterpretation we’ve heard from many quarters of the so-called “skeptics.” Although the book came out very shortly after the CRU hack, with hardly sufficient time to investigate the truth, the temptation to use the emails for propaganda purposes was irresistible. Montford indulges in every damning speculation he can get his hands on.
Since that time, investigation has been conducted, both into the conduct of the researchers at CRU (especially Phil Jones) and Mike Mann (the leader of the “hockey team”). Certainly some unkind words were said in private emails, but the result of both investigations is clear: climate researchers have been cleared of any wrongdoing in their research and scientific conduct. Thank goodness some of those who bought in to the false accusations, like Andy Revkin and George Monbiot, have seen fit actually to apologize for doing so. Perhaps they realize that one can’t get at the truth simply by reading people’s private emails.
Montford certainly spins a tale of suspense, conflict, and lively action, intertwining conspiracy and covert skullduggery, politics and big money, into a narrative worthy of the best spy thrillers. I’m not qualified to compare Montford’s writing skill to that of such a widely-read author as, say, Michael Crichton, but I do know they share this in common: they’re both skilled fiction writers.
The only corruption of science in the “hockey stick” is in the minds of McIntyre and Montford. They were looking for corruption, and they found it. Someone looking for actual science would have found it as well.
@290 Judith Curry:
In case anyone has missed it, Steve McI has posted on this issue over at climateaudit
Sorry, I couldn’t make it past McI’s mocking of well-established phenomena like teleconnections, his pathological conflation of science with mysticism (“meridians”, “alternative”, “qi”, etc.), and his smearing dendro as “phrenology”. What grade does that kind of sneering, ingroup-coded writing earn on the Curry Curve?
I wonder if this will bring an end to your claims that blogs such as McI’s are more respectful than mainstream climate blogs. Somehow I doubt it.
I’m hardly the last word on this (!) but by my calculations yes, you can get a hockey-stick shape in the first PC by applying short-centered PCA to red noise. Actually there’s a tendency to get a “step-function”-like shape, but many would still call that a hockey stick. It even seems to me that PC#1 of short-centered red noise is likely to be hockey-stick shaped (especially if one calls step changes a hockey stick).
BUT — and this is a big one — how strong that PC#1 is likely to be (how much of the variance it accounts for) depends on the autocorrelation we impose on the red noise; the whiter the noise the weaker is PC#1. Yet even when I “jack up” the autocorrelation to ridiculously high values, the hockey-stick-shaped PC#1 still doesn’t come close to matching the strength of PC#1 from the MBH98 analysis of the NoAmer ITRDB proxies. By this criterion, the hockey-stick PC#1 for NoAmer ITRDB in MBH98 is demonstrably NOT from “mining” that pattern from red noise.
It’s also clear that the data contains both noise and signal, so the autocorrelation of the data is greater than that of the noise. Hence the noise series used by MM were forged with autocorrelation higher than representative of tree-ring noise. But as I said, even when I jack up the noise autocorrelation it still doesn’t give a strong enough PC#1 to come close to that of MBH98.
Finally: none of that has anything to do with being robust. What makes it robust is that you get essentially the same PC for NoAmer ITRDB data using the MBH98 procedure, or the MM PCA procedure, or fully normalized PCA (a la Huybers). Hence that PC is insensitive to changes in the chosen method of PCA, i.e., it’s robust.
That it would have been a better idea to use full-centered and normalized PCA (as Huybers recommends) is my opinion. That the result would have been the same is a fact.
And the point is doubly moot since recent work (Mann et al. 2008) uses a method that doesn’t involve any data reduction step for representing regional proxy networks.
I for one, Gavin, would like to thank you for putting up with the frivolities and busting through the fog (or smoke). You’re one of those effective science communicators who can clarify essentials for the intelligent layman, without leaving yourself wide open to misrepresentation. Just be sure to take a moment for a cool one in the sun, eh? :-)
When I read Curry’s assertion that she hadn’t been providing her own views, I immediately thought of Mark Twain’s joke about the sleepwalking riverboat pilot in “Life on the Mississippi”.
“And if he can do such gold-leaf, kid-glove, diamond-breastpin piloting when he is sound asleep, what couldn’t he do if was dead!”
tamino@302 — Most clear. Thank you again.
Dr. Curry,
Could you perhaps explain why you are “interested in participating” in the discussion at CA without the stipulation that Tamino and Schmidt be “welcomed to participate in the discussion?” What was the principle at play in comment 107 that is apparently not in play at CA?
Excellent debate.
Did you know that Anothony Watts is raising the dead in order to dredge up Nobel Prize winning global warming denialists?
You’ve got to check this out …
http://wattsupwiththat.com/2010/07/25/seven-eminent-physicists-that-are-skeptical-of-agw/#more-22484
Turns out, these Nobel Prize winners were skeptical of secondhand smoke as well.
Now, back to the debate …
Let us keep the big picture in mind here:
There are very few publishing scientists that do not endorse the IPCC (2007) conclusions that most of the observed increase in globally averaged temperatures since the mid-20th century is very likely due to the observed increase in anthropogenic greenhouse gas concentrations.
Furthemore, there are no credible international bodies of science that hold a dissenting view.
So we are left with three possible conclusions:
1) An overwhelming majority of international climate experts agree about much of the tenets of AGW and are honest.
2) An overwhelming majority of international climate experts are ignorant about their own expertise in a sudden and collective manner. Sometimes called “group think” to sound politically correct.
3) These scientists have all agreed to conspire to delude the billions of folks on the planet and just a very tiny percentage of them (and mostly oil-funded and unpublished) are trying to save us all from this mass hoax.
Common sense and a sense of probability should lead one to the likely correct choice above.
We can argue about how to deal with manmade climate change and we can argue about how bad the impacts will be but arguing about whether there is global warming or whether humans are causing it is, quite frankly, absurd. We might as well argue about the link between smoking and lung cancer.
I sense that the anti-Mann crowd, including McIntyre and perhaps Dr. Curry, thinks #2 is in play. It is a shame because their views are causing delay and delay is robbing my future grandchildren of a better life than I.
JC 290: It would be interesting for RC to rebut McIntyre’s points
BPL: Why? They have done so over and over and over again. McIntyre isn’t saying anything new. Just the same old song. Old dogs, you know.
CS 292: My respect for Dr. Curry continues to grow, as does my amazement at the number of closed minds here.
BPL: “Closed” defined as “unwilling to entertain obvious pseudoscience,” I take it? Someone once said it’s not good to be so open-minded your brain falls out.
Dr. Curry,
You did see that Steve’s first point was to deny the existence of teleconnection in climate. Off the top of my head I can think of at least three teleconnections connected with El Nino: increased precipitation in the SW US, decreased Atlantic hurricane activity and increased storminess along the SW coast of Africa and around the Cape of Good Hope. His very first point is wrong and unscientific and you take him seriously?
74, Judith Curry: cons: numerous factual errors and misrepresentations, failure to address many of the main points of the book
Details? Or are they in subsequent posts? I haven’t had time to read the entire thread yet.
Strange. Judith Curry points us to McIntyre ridiculing the notion of teleconnections. A Google scholar search for teleconnections finds a pile of highly-cited publications in reputable journals – are you saying Judith that these are all new age nonsense, including the ones where you are an author?
Vendicar Decarian (244), are you trying to win an argument or just feel good?
Jean S says “Preisendorfer Rule N” is used only by a few climatologists and unknown in the real statistical literature but in a few seconds with google you can discover this is not true. The selection rule is discussed in a much-cited 1992 book by Ian Jolliffe on Principle Component Analysis. Its used in 50+ papers with 100+ authors mainly working in climatology/hydrology/oceanography but a few in unrelated areas.
It seems like there are different representations of ‘robustness’ going around.
Gavin, Mann, et al, maintain (to my estimation) that the robustness of the work lies in the ability to get at-least-some-degree of a hockey stick temperature pattern using just about all manner of statistical evaluation and data omissions.
McIntyre et al, maintain (to my estimation) that the robustness lies in the ability of any final reconstruction to pass a gauntlet of statistical validations and verifications.
[Response: No. No-one wants reconstructions that don’t have statistical skill. That’s why there are always verification data held back, and checks against the removal of specific proxies or classes of proxies. It just so happens that all of the reconstructions that pass these tests (though with skill that decreases in back in time) show hockey stick like features. The difference between the scientists working on this and McIntyre is that the scientists are actually interested in what the past climate was like and why. McIntyre seems interested only in criticising decisions made in those analyses without ever proposing any constructive alternatives and demonising anyone who makes an effort. -gavin]
If more or less all reconstructions end up delivering some manner of a hockey-stick shape, then why not simply go with the reconstructions that satisfy both conditions of robustness, considering the first one is just about always met..?
[Response: Sure – things have moved on a lot from MBH98 – both in terms of data and in terms of methodology. -gavin]
Is it because this might eliminate various reconstruction images that have the best dramatic appearance, and therefore it must be preserved? At the very least, it would appear these differing views of robustness should each have their day in the peer-review literature, rather than using one to discount the other.
There are many other journals with vehement disagreements in other fields that continue to publish disagreeing polar-opposite research conclusions.
Gavin:
I am not sure how what you say in your response to #316 squares with the results presented in Table 1S in Wahl and Ammann 2007. The NH r2s for the verification period are modest to the point of being vanishingly small. Those after 1820 look intriguing if not overwhelming. Those prior to 1750 account for less than 2% of the variance compared to 50% for the calibration period. This type of finding in my experience suggests that major problems exist in the PCs extracted. They are not robust.
[Response: No one is claiming that the original MBH reconstruction is perfect. The data going back to 1400 are sparse. The question was whether it gave anything useful. The low r2 numbers indicated that it isn’t useful for the high-frequency variations in the earlier part, but that the overall mean does have some skill. Subsequent reconstructions with more data and different methods show very similar patterns (though not identical ones), and so, yes, the general impression of MBH is robust. – gavin]
Just to point out, every utterance of “hockey stick” results in multitudes of counter posts by the “auditors.” Many thousands of words will be spewed, every sentence will be sliced and diced, and many backs will be slapped. McIntyre is up to his second post already.
[Response: …and yet the points never rise to anything constructive, never address anything other than the 1400-1450 ad step in mbh98, never look at the larger data sets now available, and almost always mistakenly assume that this has some terribly important consequence that the world must be made aware of. Yes, we are aware. -gavin]
Clearly, the body of scientific research on human-caused global warming pales as a serious issue in comparison to allegations regarding dastardly censorship in a particular blog’s comments section.
Someone alert Senator Inhofe. Maybe he can get to the bottom of this blog-comments-censoring conspiracy before jackbooted government thugs politely mention why painting roofs white might be a good idea, or something equally Communist.
#74 Judith Curry said: “cons: numerous factual errors and misrepresentations, failure to address many of the main points of the book”
So numerous that she is not able to name even one.
Re Comments in #316
[Response: No. No-one wants reconstructions that don’t have statistical skill. That’s why there are always verification data held back, and checks against the removal of specific proxies or classes of proxies. It just so happens that all of the reconstructions that pass these tests (though with skill that decreases in back in time) show hockey stick like features.[..] -gavin]
Well, in his latest blog S. McIntyre (http://climateaudit.org/2010/07/25/repost-of-tamino-and-the-magic-flute/) claims otherwise for MHB98:
“[..] If a sensitivity analysis is done in which the Graybill bristlecone chronologies are excluded from the AD1400 network, then a materially different reconstruction results – a point made originally in the MM articles, confirmed by Wahl and Ammann 2007 and noted by the NAS panel. In addition to failing the verification r2 test, a reconstruction without bristlecones fails even the RE test.”
[Response: A classic of example of a misleading insinuation. What ‘material difference’ is this?
(WA07 (abstract) (also see fig2). So yes, a difference, but not one that changes anything important. Ho hum. – gavin]
#290 Judith Curry
1. The issue has been argued here already.
2. Why didn’t McIntyre jump in and defend himself here?
3. Have you suggested he come here and defend his position?
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(#290)
“… which are far more detailed and documented than the points i made in my review of Montford’s book.”
Wait, stop right there Judy. You said those *weren’t* your points, and got very annoyed when it was naturally assumed they were. Now you claim them as your own again? Which is it? If they are your points, why did you refuse to defend them when Gavin critiqued them?
#288 Stan Palmer
First, let me point out the glaringly obvious. This whole argument is just one big RED HERRING in the context of the scientific consensus that humans are influencing the climate and making it warmer
http://www.ossfoundation.us/projects/environment/global-warming/human-caused
http://www.ossfoundation.us/projects/environment/global-warming/attribution
While others are more qualified to deconstruct here quantitative arguments in pointing out apparently obvious errors when placed in the context of the quality of the argument itself, in the context of relevance pertaining to scientific consensus, Judith Curry’s argument loses substance as well as relevance. Generally, she is arguing in the noise and ignoring the signal in the scope of the science. There is not argument that science is not perfect, or ever will be
http://www.ossfoundation.us/projects/environment/global-warming/myths/models-can-be-wrong
which does not preclude the ability of humans to make reasonable decisions based on the science as understood.
From everything I have gathered and examined, no matter how you reasonably slice the data with either accepted, or marginally accepted statistical analytic practice, in consideration of the data set at hand, we still end up with a ‘Hockey Stick’ at the end of the day, month, year, decade, whether or not tree ring data is included, or not.
http://www.ossfoundation.us/projects/environment/global-warming/myths/the-hockey-stick
And you think she is being abused?
What is your context? A ‘tea party’, or the climate science community?
Here’s what the security community and concerned organizations are talking about:
Various levels of accelerating economic degradation that has an inertia behind it that gets worse as we move forward in time, even after the entire planet wakes up to the reality, and even if we stop burning fossil fuels. The current ‘conservative’ estimates of human impact from the UN is 1.8 billion dead and dying by 2080.
How do you define abuse?
I think that the level of chaos that is being alluded to, and increasingly expected as described by the CIA, DOD, Joint Forces Command, Army War College, Center for Strategic & International Studies, Center for Naval Analysis, etc. shows abuse to the human race on a massive scale that has never before been considered seriously, by the human race (other than in global thermonuclear war or a global plague), due to our own actions against ourselves.
http://www.ossfoundation.us/projects/environment/global-warming/security
You can call it rude. I call it reasonable cognition of quantifiable and qualifiable evidence in relation to the problem of human-caused global warming.
You can then respond by saying but if Dr. Judith Curry is correct about the fact that there were, or even are, flaws still in the ‘Hockey Stick’ (as I (and others) have pointed out over, and over, and over, all models have flaws, in fact all models are wrong to some degree) then you and she are still barking up the wrong tree.
http://www.ossfoundation.us/projects/environment/global-warming/myths/models-can-be-wrong
The ‘Hockey Stick’ shows up in temperature records that have nothing to do with tree rings. Let me emphasize the last part of the previous sentence, PERIOD. And besides that, we don’t need the tree rings to know the planet is warming, the last 4 months are riding the top of the trend as the warmest in the instrumental record.
Or are you referring to the idea that she may need a hug after being so completely wrong in her relative assertions?
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RE: #267
I asked the question:
“From a stationary stochastic process the MBH98 algorithm detects a non-stationary signal: just how does it do that and still get described as robust?”
Gavin answers this as:
“[Response: I have no idea what this question means. ‘Robust’ means that the signal retrieved doesn’t depend excessively on the method used to get it. …]”
[edit]
[Response: Ok, enough. I thought we were having an actual conversation, and instead you want to play games – boring. The initial PC data reduction step is not done to define what PC1 is, it was done to encapsulate the data in the N. American network. That encapsulation requires a proper selection rule (which is *not* defined as keep PC1 and throw away the rest), and when done properly (and if you don’t like Rule N, suggest something else), makes no difference to the final result as demonstrated over and over and over again, and is even admitted by McIntyre. That is the definition of robust in that very small and uninteresting context. If you want to continue discussions, please move on to something that hasn’t already been done to death in the original post. – gavin]
#323 Gavin
“The initial PC data reduction step is not done to define what PC1 is, it was done to encapsulate the data in the N. American network”
Indeed. Their purpose was data compression. Obtaining a significantly different result compared to not using PCA is *wrong* regardless of what selection rules if any are used.
#317
“and yet the points never rise to anything constructive, never address anything other than the 1400-1450 ad step in mbh98, never look at the larger data sets now available, and almost always mistakenly assume that this has some terribly important consequence that the world must be made aware of. Yes, we are aware. -gavin”
Gavin, look at your answer to #17
Would MHB1998 and MHB1999 not have looked quite different if the results of Vinther et all were known around the time Mann constructed the Hockey Stick? And you know where the HS led to.
“temperatures during the warmest intervals of the Medieval Warm Period,” which they defined as occurring “some 900 to 1300 years ago, “were as warm as or slightly warmer than present day Greenland temperatures”
Vinther, B.M., Jones, P.D., Briffa, K.R., Clausen, H.B., Andersen, K.K., Dahl-Jensen, D. and Johnsen, S.J. 2010. Climatic signals in multiple highly resolved stable isotope records from Greenland. Quaternary Science Reviews 29: 522-538.
[Response: Well, MBH98 wouldn’t be different because it only goes back to 1400. But if you were going to redo any of these reconstructions you would use as much new data as possible – not just one set of new records in Greenland. But note too that Greenland is only one part of the world, and that it was already represented in the earlier reconstructions. In the more recent papers (Mann et al, 2009 for instance), Greenland is already shown as warmer in the medieval period – as are areas in Northern Europe (fig 2), so why you think that Vinther et al will affect these these materially is unclear. But having new data is good and it will surely be incorporated into the next sets of reconstructions. – gavin]
More from Judith Curry:
A number of points are worth raising. First off, whether Judith chooses to post here or not, her comments can still be read and commented upon. Second, I don’t see anything wrong the characterisation of degrees of consensus she quotes, nor is it worth quibbling about exactly where the situation was with respect to paleo-reconstructions in 2000 (I’d say much closer to 3 than 2 for instance). However, Judith still repeats the incorrect comment she later claimed was Montford’s, that TAR used the terms ‘very likely’ in relation to anything related to these reconstructions. It did not, and none of this palaver is related to an inappropriate rush to a ‘high level of confidence’.
Third, the last two sentences appear to imply that anyone who disagrees with her is tantamount to being ‘irrational’ and is declaring that paleo-climate is “settled science”. I have no idea where this comes from – it is certainly not from us (we have recently discussed the inappropriateness of the ‘settled science’ soundbite, and also some interesting new questions in paleo-reconstructions). It is not from climateprogress as far as I can tell. And as for the quote about “radiative transfer”, I can find no trace (via google) that anyone has said anything of sort. Regardless of whether anyone did say it though (and it is not unknown for people to say silly things), it is not a statement that I would agree with.
Thus, I conclude that Judith appears to be battling a strawman. Pointing out that statements by Montford and McIntyre are wrong and misleading is *not* the same as saying that everything is known about the climate of last millennium and that Mann et al’s papers are perfect. The truth of the matter is that much of what Montford and McIntyre say (and more of what they insinuate) *is* wrong *and* we still have some ways to go before we have a full understanding of climate over this period. That understanding will be advanced by new and more extensive data collection efforts, improvements to methods used to synthesise that data, and more extensive and collaborative use of climate model simulations over this period – both to understand the forcing/response of the climate, but also to serve as testbed for the various reconstruction methodologies. It will not be advanced by name-calling or declaring that anyone who thinks that teleconnections exist is a ‘phrenologist’.
This is rapidly becoming a new myth. I think I may have read something similar in Mike Kelly’s submission to the Oxburgh inquiry. I don’t blame him because in characteristic fashion he appears to have set himself the strenuous task of reading lots of unfamiliar papers in a short time.
Re: #325
Hi Gavin,
You have edited the remainder of my post which includes the relevent points I was making. As moderator it is your prerogative to conclude the argument in this way but I will not contribute under censorship. You made several minor edits of my posts earlier which were ok – they were generally off-topic remarks by me, your editing did not affect my argument and you similarly edited opposing views to mine. This kept it fair and balanced. By editing the rest of my points, that is no longer the case.
Regarding my promised reply to Lazar #287 I will post at Bishophill on the Tamino thread – I am sure that any comments Lazar may wish to make there in response to my answers will be posted in full and received with great interest.
I would appreciate it if you could post this in full.
Thanks for the conversation while it lasted!
Best Wishes,
ThinkingScientist :-)
[Response: Time is a precious commodity. Talking about the same thing over and again is a waste of it. Playing games by changing topics half way through and/or confusing different issues might be fun for you, but I’m not interested. Maintaining progress in comment threads is hard, and tight moderation helps with that. This is not censorship, it is focus. You are free to continue substantive conversation here at any time. – gavin]
Not following Eli’s cannonical advice of RTFR (mostly because who wants to bother after 12 years), if the method used in MBH 98, 99 retained several of the PCs to represent the NA tree ring series with most of the variation being in one of them, and a “better”, in the sense of more concise method pushes essentially all of the climate record into a single PC, arguably in the global averaging, it under-represented the climate forcing and increased the variability by including the other PCs.
An observation from an interested observer . . .
There are certainly a few “nutter” out there and from my experience these are equally represented on both sides of the debate. However, my opinion is that most people are geniunely interested in understanding the science and the discussion. This is certainly my position!
From what I have seen MMM (I have added Monford) certainly do not appear to be in the “nutter” category by any stretch of the imagination. If you wanted to challenge their ideas and views the best way by far is with the Science. The truth is the truth and will always win through in the end no matter how much spin is thrown at it.
A few years ago a film aired on network TV in the UK something along the lines of “The Great Global Warming Swindler” – or something similar. For several days afterwards there was a “torrent” of abuse through at the it, but that is all it was abuse! However, after about 4 days someone finally analysed the data and was quickly able to point out the obvious flaws.
In my humble opinion going after the data is far more affective then simply saying how bad they are?
What a sad debacle.
http://scienceblogs.com/illconsidered/2010/07/hey_jc_jc_thats_not_alright_by.php
One of life’s great ironies that we see our own faults in others. I can not imagine more “tribal” behaviour than Judith Curry has exhibited here. Gavin, I don’t see how you could have handled things better, well done!
74, Judith Curry
I do not understand sceptics – if there are some mistakes (now corrected and very few) in the IPCC AR4 WP2, then the whole IPCC (WP1, WP2 and WP3) is wrong.
If someone points out mistakes in a sceptics book – than he/she is missing the main point?
Measuring in two different ways here, aren’t you?
Re #321:
[Response: A classic of example of a misleading insinuation. What ‘material difference’ is this?
[..](WA07 (abstract) (also see fig2). So yes, a difference, but not one that changes anything important. Ho hum. – gavin]
Well, I cannot help but notice, that you did not dispute this part of my citation of S.McIntyre:
“In addition to failing the verification r2 test, a reconstruction without bristlecones fails even the RE test.”
Is it just me or does that quallifies as a ‘material difference’?
[Response: This occurs only for the 1400-1449 step, and so you end up with a hockey stick from 1450 onwards, instead of from 1400 onwards. So no, not a material difference. And this is moot in any case – you can remove all tree rings and get a validated reconstruction back to 1000 AD using the a newer method and more data, as opposed to only 1760 with the MBH98 network/method. Of course, you can systematically remove all the data one-by-one and you will progressively have less information in the past, but that should be obvious no? – gavin]
U2 sums up the “skeptic-problem” pretty well in their classic Sunday bloody sunday with the line; “It’s true we are immune, when fact is fiction and [Fox?] TV reality”.
(Re #38) On privacy and emails: Ask yourselves this, should I as a professor at a public university be required to tape my work phone calls in case someone files a FOIA request about my work? It is a government phone, right? How then are emails different?
I don’t work in climate science and it is very unlikely the press or blog-sphere would take any interest in my work. None-the-less, I’m switching to a private e-mail account. I can only imagine how stifled researchers in controversial areas feel.
Gavin,
Thank you for posting my response in full – you have acted in good faith and I fully acknowledge it. I don’t agree with your comments about playing games (that is not my intention) but I do understand that you have multiple arguments/commentators simultaneously and that as both moderator and responder that gives you quite a high workload here. We have probably both exhausted the dialogue here for the moment and both are repeating ourselves.
Thanks for your invitation to keep the door open for me to continue subtantive conversation – I am sure I will!
Feel free to post or not post this – its meant as a personal acknowledgement that you posted my final message at this time in full and I do appreciate that. I will also acknowledge that at Bishophill where, as I am sure you have noticed, I cross-posted.;)
Regards,
ThinkingScientist
coby #333:
That article on your site sums up my feelings about this whole affair *exactly*. It was almost if I had sat down and written an analysis myself.
When you just look at all the refereed publications by JC:
List of JC publications from Wikipedia
you’d wonder about the shallowness of her posts here. Talk about an alter ego!
@330 “Thinking Scientist”
Are you the same commentor posting at Montford’s who wrote:
Gavin is a master of obfuscation and of course the “one critical only” post before being blocked means no right of reply. In one of my susbsequent posts to RC I pointed out to Gavin how their policy was really self-defeating in the long run. Even if they don’t post it, Gavin probably reads some of it. Have a read of the Gavin post on why CO2 lagging temperature in ice cores is not a problem for AGW and you will see a master obfuscator at work. The arguments are not rational, but of course no right of reply means that challenging it is a waste time. As a consequence RC builds up a back catalog of “smoke and mirrors” and maintains a public face that says only they know what they are talking about. It is a slick but naive exercise in spin and PR.
Interesting.
[Response: Nice find. I find it incredible that intelligent people still can’t get their heads around the fact that climate affects the carbon cycle *and* the carbon cycle affects climate. Not sure where the ‘master’ obfuscation is with that. Maybe I need a PhD? (needless to say, further discussion of this it OT ;-) ) – gavin]
Further to JC’s list on the evolution of a scientific field (see Gavin’s post #328) she seems to be confusing the well established field of climate science which goes back at least 100 years (see Spencer Weart’s “Discovery of Global Warming) and the more recent field of the human influence on observed warming. The former field is between a 4 and 5 on her scale.
The human component of warming is between a 3 and 4. The reason for the discrepancy is not that specific scientific findings are in dispute but that the warming is only recently emerging in a significant manner from the various natural short and long term background variations.
To try and equate lack of scientific understanding with lack of statistical certainty is not what one expects from a “real” scientist.
I note without comment that The Hockey Stick Illusion is published by Stacey International Publishers.
http://www.stacey-international.co.uk/v1/index1.asp
Steve Metzler @ 339
Stuff can happen to the best of us, sad to say.
The list you linked to is one that she’s posted of on-line papers. Of those, it looks like the last one she took the lead on was 2006:
Mixing Politics and Science in Testing the Hypothesis That Greenhouse Warming Is Causing a Global Increase in Hurricane Intensity
One can speculate about what’s been going on with her, but it may simply be that venturing outside the ivory tower was too much of a stretch for her. Reminds me of that chapter in “The Invisible Gorilla”: what smart chess players and stupid criminals have in common.
Putting the con in ‘confidence.’
My summary.
Technically excellent but I still have worries about lack of good simplified versions of it.
Technical summary. Perhaps this might be sufficient?
1. The lead article
2. Gavin’s comment following #270 here:
https://www.realclimate.org/index.php/archives/2010/07/the-montford-delusion/comment-page-6/#comment-182095
3. Tamino’s comment #302.
———–
Thats it! (apologies if I have omitted some other significant contributions)
———————————–
————————————–
Simplified summary ?
It would have to be written for super-suspicious (ss) people? Remember that such people don’t have a calendar or a clock. They are stuck in the late 1980’s. They don’t or won’t understand that this is not of crucial importance. Their suspicions are still being fueled by propagandists who have echoed thousands of attacks on non-centered PCA’s.Remember that these people may not be able to follow the technicalities but have a sharp eye for anything that looks wrong. So what do they read here?
Tamino’s
and the stonger but more tentative version from Lloyd Flack
ss person.Reads the phrase ‘same in fact’ but fails to reconcile it with the rest. Cognitive dissonance; forgets the phrase. Shouts: RC admits that MBH made a mistake! The house didn’t fall down but that was sheer luck considering the rubbishy bricks they used.(Evidence based on one brick).
————–
I still think it would help if these simplifications were clarified.
Which of any of these possible additions/analogies are relevant?
1. The quadratic equation scandal.
School inspector:
I see that your children have been taught to solve quadratic equations by substituting numbers into the formula:
x= (1/2a)*[-b(+/-)(b^2-4a*c)^0.5]
whereas the correct way according to the book is to calculate
q=(-1/2)*[b+sgn(b)*(b^2-4a*c)^0.5];
giving the two roots as
x(1)=q/a ; x(2)=c/q.
Teacher: But it made no difference!
Inspector: But it might have done, in some circumstances #, and then your unauthorised version could cause us all to become victims of fraud. It’s very suspicious. Perhaps it would be safer to have new teachers, no perhaps a new school.
[# e.g. if a and or c are small as a result of rounding errors]
2. (Back to hockey).Yes this mistake could have made a difference in the wrong hands, but as the more technical arguments show, these researchers were very careful and knew what they were doing …
3. Yes but this is paleoclimatology. What do you expect? Look at the size of the error bars. Look at the noise. It is just wonderful that they have managed to extract so much information. Your fuss reminds me of the student who, given rough data, provides his answers to 10 significant figures just because they are displayed on the calculator, and then complains that someone has dropped a digit in the 3rd. significant place.
Last comment.
The quote from Tamino should extend over two lines. Sorry about mess.
As far as this historic period is concerned, the reconstruction of past temperatures based on deep boreholes in deep permafrost is one of the best past temperature proxies we have (for the global regions with permafrost – polar regions and mountainous regions) – as a signal of average temperatures it’s even more accurate than historic direct measurements of the air temperature, since the earth’s upper crust acts as a near perfect conservator of past temperatures – given that no water circulation takes place, which is precisely the case in permafrost where by definition the water is frozen. In general it will take the signal from a significant air temperature shift around 500-1000 years to reach a depth of some hundred meters.
http://www.eos.ubc.ca/~mjelline/453website/eosc453/E_prints/AnnRev.28.1.339.pdf (see pages 345(propagation of temperature wave) and 356 (historic reconstruction) fx.)
“The incorporation of geothermal data into a multi-proxy reconstruction therefore offers an independent estimate of long-term temperature trends that can be integrated with estimates of annual variability deduced from tree ring widths. Various efforts to effect that marriage (Beltrami
& Mareschal 1992b, Beltrami et al 1995, Putnam et al 1997, Huang & Pollack
1999) have yet to find uniform acceptance.” (p. 359). See also
http://www.nature.com/nature/journal/v403/n6771/full/403756a0.html
http://www.emetsoc.org/annual_meetings/documents/2009/CL4_EMS2009-180.pdf
Unfortunately the high mathematic and statistical finesses of this is beyond my capacity. But as a secondary school teacher in (among other subjects in physical geography) climate and climate change I wonder how far these records from permafrost boreholes are now being used in the general studies of the subject?
(The whole hockey-stick-emails-“climategate”-discussion seems to me to be historic media dust more than anything else. Please remember that scientific historians fx. are still disagreeing severely about what happened on the evening the german Reichstag burned late february 1933 – even when it is rather well established since the early sixties that Göring later in private conversation admitted his central part in arranging the crime. But the interests in denying the obvious among certain (german) power-holders are surprisingly strong and – they still seem to be strengthening! For some reason…
The climate science also sure is subject to severe political pressures from varying lobbyist groups, first and foremost the oil an coal interests which are huge financial powerhouses especially in the US Senate – a body which in reality dictates the whole global “climate policy” or rather the absence of any such – serious climate politicans round the globe in reality have – as we now have seen – no chance at all against the denying forces and their huge media apparatus, as long as the public don’t see some very serious consequences of climate change, fx. food shortages. The possibilities that political leaders will soon agree to effective climate policies seem to be close to zero, they are, as James Lovelock noted in “The Revenge of Gaia”, only seeking just as Chamberlain 1938 to gain time, and they are not very interested in the realm, because most or all of them subscribe to the by far leading religion of our times: the neoclassical so-called economic “science”, which is based on a lot of completely unrealistic assumptions, see fx. http://www.paecon.net/#_A_Brief_History . Please note, that all the world’s leading “climate sceptics”, fx. the danish statistican Bjørn Lomborg, are strong believers in the neoclassical (often called “neoliberal”) dogmas. They will continue to deny any facts whatsoever that are in conflict with their dogmas, as long as they can. Fx. they see nature solely simplistic as economic mathematical functions = “dumps” for vaste, and do not recognize that nature is the indispensable framework and base for any economy and will influence it strongly.
Maybe we should limit our heroic efforts to scientific studies and their poularization among decent people and not hope to be “understood” or even accepted by big financial interests which are all too biased and cynical to even try to grasp the subject matter. But time is always on the side of the truth, and you can only lead the horse down to the water, it makes no sense to force it to drink. In my view, most evidence seem to support that mankind is not very able to deal with unpleasant problems before it’s too late. And in some strange way: the stronger the evidence, the stronger the tendency to deny it. I think, that if we appear more cynical about the whole thing, we have better chances of being taken serious.)
Where’s the science? None of the “M”s are scientists, between them they’ve published what, one deeply flawed paper in total?
So turn it around – if MMM have anything meaningful to say, the best way by far is for them to do so with science, and that means writing stuff up for publication and submitting it for critique and analysis by the scientific community.
Over the last few years I thought we had glimpses of a Judith Curry who could do some good. Alas, the one we now actually have is doing far more harm than good, in a devastatingly embarrassing way. The predictable complaints about bad treatment of her were sure to follow as a lame substitute for any actual scientifically useful arguments.
[Response: Indeed. When she is talking in general about where science needs to go, I’m mostly in agreement though I think she has some specifics wrong. What I don’t get is why she doesn’t realise that she is being held to a higher standard than some anonymous blog commenter, precisely because she is who she is. It matters if she makes and repeats factually inaccurate statements without looking into things. Hopefully we can all learn from this. – gavin]
RE: #340 Comment by Thingsbreak
Yes, those are my comments. If you have any substantive comment on them I am very happy to debate them with you on the thread from whence they came at Bishophill – probably best not here as Gavin has already said this is OT and I agree with him.
[Response: The only comment that really needs to be made is that, along with your posts here, they reveal what you are all about.–Jim]
Re #337 In answer to your question about the need to record telephone calls, as far as the UK is concerned, there is no requirement to do so in order to generate information that might get requested under FOIA. There may be a need to keep a record of a conversation because of it’s importance.
WRT email policies, this is off-topic but the relationship between records and email might need to be a subject of a future post, since the subject keeps recurring.