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.
Doug “A “conspiracy.” That’s the best they can do?” – that is all they need to do as far as Deniaworld is concerned. You only need to say “conspiracy”, no matter how absurdly, for it to become self-evidently true.
Science denialism is a mature technology, and the people who do it are paid to create uncertainty. But climate science per se is not that immature. It’s older than genetic engineering, DNA, continental drift, probably a couple dozen other fairly major sciences.
As for the uncertainties, some of them are statistical artifacts.
And one pattern in particular needs to be brought up over and over. I mentioned a thought experiment where 2 schools were among a bunch competing for funding based on the percentage in students’ improvements on standardized tests. The school system has used a number of different systems over the last few years, and records have been kept in a very informal way. Sometimes part-time teacher’s aides compiled scores. Sometimes substitutes. Etc. One of the schools asks for and is given control of the data, so they can “clean it up.” It so happens that they find every inaccuracy at their rival school which would make the test score improvement average higher. At their school, they eliminate every error where their score improvement percentage would be lower.
Confronted with this, they respond that in their OPINION, with no evidence presented, the school system has been keeping fraudulent records all along in their disfavor. That if the rival school wanted to, they could petition to control the data and clean it similarly (though there’s no time left this year for that, sorry). They basically acknowledge their methodology.
But, and this is the key point, they say their MAIN claim is this:
1. We’re eliminating data errors. About 2-3% at our rival school, about 3-4% at our school. In no case are we throwing away an accurate record.
2. Therefore, we are making our rival’s records more accurate. We’re making our records more accurate.
Put so baldly, what’s wrong with this picture is obvious. But it’s the entire basis of the project at Watt’s Up with That. It’s the basis of everything Steve McIntyre does. If you eliminate random noise in a biased way, you introduce a bias.
The school board in this case would be the media (and to a degree, the Congress). The rival school would be climate science, and the data “cleaning” school would be the denialist network. And the latter have run out the clock.
There’s a big difference between the statements:
1) paleoclimate reconstructions are reasonably robust
2) paleoclimate reconstructions are in their early days and the conclusions are still a bit tentative
3) paleoclimate reconstructions are nonsense, and
4) paleoclimate reconstructions are the products of a corrupt system engaged in corrupt practices (implictly with corrupt people).
Montford is writing a history of science, and his conclusion is (4) – corruption. This is a serious accusation.
I think tamino’s and gavin argue we were at (2 – early days) 15 years ago, and now we are at (1 – robust).
I think judith argues that we are now at (2 – early days), but we have to be careful to distinguish (2) from (3 – nonsense), and if we are at (2) we must not claim we are at (1 – robust).
So I am confused by judith’s defence of Montford’s argument. It’s a very serious accusation which Tamino counters by showing that paleo reconstrutions are at least not bad – therefore not the fruit of a corrupt tree.
Erratum: I meant step 6.
In any case, Dhog, for what it’s worth, your smugness shows too.
I never understood why Feynman is idealized so much. Dismissiveness is still dismissiveness, even if it’s Feynman’s. Even philosophers can sometimes provide interesting criticism of Feynman’s ideas. Here’s one analyzing the atomic discourse in the Feynman lectures on physics:
http://bit.ly/daJPre (JSTOR)
At times i get the impression Judith’s talking about paleoclimatology, in which case she makes some sense (Patrick Caldon’s summary above in #503 seems very reasonable to me).
But then she appears to apply the claim to all of climate science, and the risks we face when temperatures rise significantly due to our business-as-usual pouring of CO2 into the atmosphere. As though she thinks the fact that paleoclimatology being a relatively young field makes all of climate science, including the underlying physical science, “immature”.
Re: #505
‘Sociological’ Research
I wonder if Judith Curry, Steve McIntyre and Montford have been asked recently for their best estimate of the climate sensitivity, together with uncertainty range and degrees of confidence?.
This useful kind of investigation has been carried out with several other people.
dhogaza: paleoclimatology is a logical extension of dendrochronolgy. The origin of dendrochronology was when Douglass discovered a correlation between tree rings and the sunspot cycle. So, attempts to reconstruct climate from proxies have been going on for nearly a century.
Other branches of paleoclimatology aren’t exactly young, either. Ice cores have been drilled for a long time.
But “mature”? That’s a value judgement.
Perhaps this is all a distraction from the main effort?
“We believe the political response to climate issues should be based on sound science. Both a free society and the scientific method require an open and honest airing of all sides, not demonizing and silencing those with whom you disagree. We’ve strived to encourage an intellectually honest debate on the scientific basis for claims of harm from greenhouse gases…..”
Koch Industries, as of this year the world’s biggest funder of, er, “debate” as they call it (owner of Georgia Pacific timber, among much else); quoted at
http://wonkroom.thinkprogress.org/2010/03/30/koch-denial-machine/
Remember, as of this year, in the US, corporations are peoplehave the freedom to spend unlimited money on political opinion-making.
Of course, any individual meat-based person can do the same, to the full extent of your means.
For those outside the USA, watch the news you see from here very skeptically
Georgia had a ‘biennial Climate Summit’ in 2006 and 2008:
http://airsummit.gatech.edu/
I haven’t found a page for 2010. Anyone heard anything?
“1. attacking a paper on global warming, before reading it very carefully or understanding the context of the paper, assuming that the author is either dumb or has an “agenda””
Things haven’t really changed at CA. Their defamation against scientists has perhaps been stepped up since then.
502 – Marion Delgado says:
One of the schools asks for and is given control of the data, so they can “clean it up.” It so happens that they find every inaccuracy at their rival school which would make the test score improvement average higher. At their school, they eliminate every error where their score improvement percentage would be lower.
Unfortunately this seems to be what the deniers are saying as well.
How do we move forward from here?
Zorro
Judith Curry’s appeal (in #467) to Peirce’s classification scheme on “fixation of belief” is an interesting approach – but I think its application to this particular discussion would be far more enlightening than her rather cavalier classification of various blogs by it. Are we to trust her authority on this classification, which she seems to cling to with a striking “tenacity” despite the protests of many of her peers here?
Let’s look at the issue of belief in three points straight from the title of Montford’s book
* is the “Hockey stick” an illusion?
* is “climategate” significant?
* is [any part of] science corrupt?
On the method of “tenacity”, Peirce explained his meaning:
Once you have formed any opinion on a subject, it’s a perfectly natural human tendency to cling to that opinion, and “both sides” do it here. From the start most of us with some scientific background and trust in the methods of peer review would have tended to the “No” answer on each of the three questions, though many of us may have had doubts on each point. Clearly on the McIntyre/Montford side, the tendency was to answer “Yes”.
The question regarding Peirce’s classification is to what degree those beliefs were *fixed* by this method of simply clinging to them, despite contrary evidence. Tamino’s review here and past discussions (Mann 2008 in particular, but even all the other reconstructions like Loehle’s) clearly show a certain “robustness” in the “hockey stick” form and the conclusion regarding recent warmth being highly anomalous. What is the evidence on the other side? There were clearly some mistakes made in the analyses (in Mann’s papers, and far worse in Loehle’s) but there doesn’t seem to be any modern reconstruction published in the peer reviewed literature that shows anything other than essentially the picture in MBH98.
So the weight of the evidence on question 1 is very heavily in favor of those who fixed belief in the “No” side of the question, and heavily against those on the “Yes”. Have any of those on the “Yes” side changed their minds in regard to this evidence? If not, then they are clearly stuck in Peirce’s “tenacity” mindset.
Similarly on climategate and corruption, we’ve now had 5 reviews that found at worst some poor communication and data sharing practices. The weight of the evidence is very strongly on the “No” side of these questions. Have any of the “Yes” folks changed their minds as a result? There are some examples: The Guardian’s George Monbiot, for instance, at first thought climategate was significant and called for Phil Jones to resign, but has now stepped back from that (his concern seemed to be chiefly from a deep faith in the importance of FOI-type laws).
Peirce’s method of authority referred to imposition of belief by government or other institutional agents. On the above three questions and in the present discussion it doesn’t seem to me to apply at all. I don’t believe he was referring to “authority” in the sense of expertise; in some sense the role of the IPCC in fixing belief around climate science is similar to Peirce’s “authority”, but it has no enforcement power and to me it seems far more like a step in the process of fixation and communication of scientific information, part of the publishing process, than anything like what Peirce was talking about in method 2.
Peirce’s last two methods of fixation are perhaps the most interesting for scientific discussion: that which is “agreeable to reason” vs that which “coincides with fact”. What is the source of “fact”? Observation of the world around us – raw data, collected and prepared according to scientific standards of care, self-doubt, and open honesty. On top of that data we have analysis and interpretation, which again require scientific care.
As an example of the “a priori” “agreeable to reason” method, Peirce takes an interesting example – classical economics:
In this context, there are several groups that are practicing the scientific method in the sense of actually going out into the world and making observations. The people who study tree rings, those who study borehole temperatures, those who set up and monitor temperature stations, those who study glaciers, sometimes risking their lives, are gathering that basic factual data about the world. On top of that are folks like the CRU and Mike Mann, collecting that data together and analyzing it to see what it can tell us, what the larger-scale picture might be.
That scientific method can have bearing on only the first question: is the “hockey stick” an illusion, an artefact, an accident of the way the work was done? And the only way to answer differently is to do your own reconstruction, go back to the raw data and see what difference it makes. As Tamino illustrates here, that seems to have been done repeatedly by others and they come back with the same answer. So the scientific method, as far as it seems to have been applied at all here, clearly shows a “No” answer to the first question.
But the second and third questions are not matters where we can apply any observations of the non-human natural world to help fix our opinions. These are questions about what people said, what they meant, what in their hearts they honestly were feeling. Since the internal workings of another human being are fundamentally subjective and cannot be determined by any objective method, our only resort on this question, our best option, is to appeals to reason. The “facts” on scientific corruption may be eternally in dispute, but what conforms best to our understandings of the people involved, of reason in this matter? Conspiracy theories can certainly be logically self-consistent, but they are fundamentally destructive to human relationships and progress. The fundamental foundation of all of that has to return to the one question that can be answered by science here: “is the hockey stick an illusion”?
If you want a scientific discussion, that is the only question of relevance. And Tamino addressed precisely that question in his review here. The answer is, No.
Dr. Curry has a long history of publication of scientific articles. If she really had a *scientific* argument to make, she knows how to do it. What she is doing now is a political act, not a scientific act. She is trying to promote the message that climate change is uncertain, the unsaid message therefore that we should do nothing. This is just one
Claims that CA is free of “snark” are frankly ludicrous. SM’s entire writing style is based on snark and worse. “Hockey Team” anyone? Take a look at just about any post … SM cannot help but try to punch out at least a few sarcastic punchlines, usually capitalized for easy reposting. SM makes constant claims that “the Team” engage in fraud, disinformation, obfuscation etc. Clearly the auditors are not interested in science.
But that should be the point. Who cares about snark if the science is correct? Who cares about politeness if the science is wrong? Dr. Curry’s latest @467 is exactly wrong. If a site (or book, or article etc) is WRONG then who cares how polite the people are discussing it? If she is “concerned” simply from a communication point of view then she should be worrying about the accuracy of the message first and the tone second. The fight she is fighting is first and foremost about the accuracy of the science. Dr. Curry has apparently chosen the other side, which explains why she is concerned about “snark”, “uncertainty”, “an immature field” — all things a scientist would not consider impediments to understanding the science. Engaging Dr. Curry as a scientist will not work anymore. She has chosen to publicly abandon that role. She should be engaged as a political hack, a role she has now very publicly adopted.
Some more “striking similarities” to unattributed antecedents (Wikipedia and a couple of text books) in the Wegman Report … in the background section on PCA and statistical models, no less!
http://deepclimate.org/2010/07/29/wegman-report-update-part-1-more-dubious-scholarship-in-full-colour/
Also of note (and definitely on topic here):
Of course, PCA is at the heart of the McIntyre critique of the work of Mann, Bradley and Hughes and therefore central to Wegman et al. The short description above refers to the possibility that the first few principal components (PCs) might “account for” or “explain” most of the variation in the original larger data set. This implies that enough PCs must be retained to accomplish this. Normally at least enough PCs to account for most of the original data set’s variance should be retained, and typically other conditions (such as convergence upon retention of successive PCs) would be imposed.
Tellingly, Wegman et al never once discuss this crucial aspect of PCA, even though a thorough examination of the issue of PC retention criteria was a key element in the most extensive peer-reviewed critique of McIntyre and McKitrick’s work, namely that found in Wahl and Ammann’s Robustness of the Mann, Bradley, Hughes reconstruction of Northern Hemisphere surface temperatures (Climatic Change 2007).
Arthur Smith says: 30 July 2010 at 10:12 AM
That’s a truly commendable analysis, makes me feel ashamed for my superficiality. Dr. Curry reads her email, apparently, perhaps you should send a copy to her?
I agree that Arthur’s comment #512 at present is first rate. It’s well worth a careful read by anyone still here.
It is devoid of snark, very fair minded in recognizing potential problems with unwarranted “tenacity” on all sides, and does a great job is isolating the actual substantive matters which apply for anyone aspiring to be an honest broker in these disputes.
No doubt Dr Curry feels a bit overwhelmed at the all the comments her input here has provoked. The comment by Arthur is one that should stand out head and shoulders above the main pack as something well worth her serious consideration.
Peirce’s method of tenacity might be compatible with his method of science:
> In this paper, I will claim that these two “methods” can coexist, despite
their apparent conflict, so that pragmatism, relying on the method of tenacity, and naturalism, relying on the method of science, can and should coexist, both in science and in metaphysics.
Source: host.uniroma3.it/dipartimenti/filosofia/personale/peirce.pdf
If we don’t want to deal with problems in Peirce’s philosophy of science, simply talking about naturalism and pragmatism might be of help. I’m not sure that this parallel is exact, but it has more currency, nowadays, than tenacity and science.
Arthur, one point that may be relevant. You quote
> “… the doctrine that man only acts selfishly … has had
> a wide acceptance as being the only reasonable theory.”
Verb tense noted. I wonder about the correlation between believing that disproven notion of economics, and believing (any of the many different and often mutually contradictory ideas summed up as “anything but the IPCC”). http://ejpe.org/pdf/1-1-art-1.pdf
While I add my enthusiasm to the growing pile for Arthur Smith’s analysis @512, I would take issue with him on his analysis of the second and third points–that is the significance of the set of cluster coitus known under the rubric of “climategate” and the question of corruption. That Judy thinks these two questions are even relevant indicates to me that she has a rather weak understanding of the scientific method.
First, science is a human endeavor. In the UEA emails we see that very clearly. Research teams work to advance their interests. They disparage and seek to downplay research they perceive as incompetent. If they are wrong, their careers will suffer, and those of their opponents will rise. That’s science.
Now on the question of “corruption”… Please! Are we to really believe that thousands of scientists have colluded to falsify the very science that they’ve dedicated their lives to unraveling? Are we to believe that all the other scientific fields–many of whom will be hurt as research priorities shift toward climate science–are complicit as well, since not a single scietific professional society dissents from the consensus theory of Earth’s climate? Are we to believe they have done so without a single scientist defecting from the conspiracy and thereby becoming a hero to society AND to science? Judy ought to know better.
Scientists are human, so they act in their own interests–and they are smart enough, generally, to perceive that those interests are in exposing rather than hiding the truth. If they do not perceive thus, they tend to have very short careers.
I am sorry, but I see no way to rationalize Judy’s current position with her duties as a scientist. I do not see an answer that does not call into question either her integrity or her judgment.
A quote from that document I linked. I’ve wondered for a long time whether the suspicion that scientists must be cheating comes from this kind of “rational” — and clearly wrong — view of human nature.
“this view leads people to expect others to defect in social dilemmas” (Frank, et al. 1996, 192)…. people who hold such expectations “are overwhelmingly likely to defect themselves” (Frank, et al. 1996, 192)…. they may be animated by a sense of justice in punishing the dishonest co-player, and in such ways come to behave exactly as a selfish person would.”
This morning I ran across this, posted originally on July 27:
http://mensnewsdaily.com/2010/07/28/the-difference-between-true-science-and-cargo-cult-science/
The opinion piece sounded very much like post 467(the last paragraph — the Feynman quotes is the reason why it caught my attention), except FJ Tipler goes further than J Curry.
[edit — sorry, I’m tired of hearing the same baloney]
[Response: Ah yes, Tipler knows what cult science is, that’s for sure. He’s a bonafide expert. Take an answer you like (e.g. take the bible literally), make up some equations, and publish in book form (handily avoiding peer review). Here’s a sampling: ” [Tipler’s] discussion of the scientific possibility of miracles provides … scientific foundation for many of Christianity’s most astonishing claims, including the Virgin Birth, the Resurrection, and the Incarnation.” I’m in no way challenging anyone’s religious beliefs, but this is not science.–eric]
He who’s name must not be mentioned has a new “not a reconstruction” on Mann 08 w/o Tiljander or Dendro proxies. It didn’t feel like wading through the text to see if I could figure out what he did wrong. Previously (a long, long time ago) he claimed that he could not understand RegEM, so my guess is he did something wrong. Could someone who understands the ins and outs of the CPS and/or EIV methods explain?
Heck, I just read his whole damn thing and he only covered the proxies which went back to 1000 CE. Oops.
#522
There’s some discussion of it at DC, from here on:
http://deepclimate.org/2010/07/19/open-thread-4/#comment-4646
It’s CPS recon, so doesn’t involve RegEM I would think. It does not seem to match very well anywhere from 1000-2000.
Oh well, here is my review, FWIW. BTW, I didn’t pay for my copy…
Montford sets up the whole premise of his book with his rather inaccurate and truncated history of paleoclimatology in the first chapter. To Montford (as related by Stevie Mac) legitimate paleoclimatology begins and ends with the poorly sourced figure in the IPCC FAR which was based on Lamb. From then on all of paleoclimatology was an attempt to “get rid of the MWP”.
There is just a slight problem with this thesis. Or maybe more.
For one, the figure which appears to have based on Lamb’s work was dropped in the 1992 supplement, as our esteemed host has pointed out. Secondly (aren’t your glad I didn’t say “Primo” and “Secundo”), during the early to mid nineties I was an active participant in the climate change debates on sci.environment and there was an active disagreement about the extent and “beneficial” effects of the MWP. Gavin cited Hughes and Diaz (1994), but this was only one line of evidence which was apparent at that time.
The truth of the matter, as opposed to Montford’s account, is that there was an increasing body of evidence that the MWP was not a global phenomena. In 1998 MBH decided that there was enough paleo evidence to do a reconstruction which stretched back to 1400 CE on a global scale. Note that 1400 does not include the MWP! In 1999 MBH did a reconstruction which went back to 1000 CE for the Northern Hemisphere and showed a MWP which might have reached mid 20th century levels, given the uncertainties. This seems to have been in line with recent (90’s) thinking on the subject, but the 98 and 99 papers were the first attempts to use all the available evidence to reach a conclusion on this subject. Since then there have been a variety of reconstructions using varying sub and supersets of the original MBH network and varying methods. They all come to the same conclusion (although most show greater long time scale variability than the original MBH study, which I consider to be one of the actual weaknesses of the original methodology. Of course Mann also recognized this…).
Montford’s truncated and distorted history of paleoclimatology is the basis for his subsequent argument, but it must be accepted to make sense of anything else he says in his book. A good example is his argument (as related by Stevie Mac) is that using tree rings as climate proxies is worthless. In reality, work on using tree rings as climate proxies stretches back to the early 20th century and is fairly well established. But Montford (as related by Stevie Mac) boldly forges on trying to show that tree rings are lousy proxies, especially if they corrolate to local temperature! Of course the scientists who work with them admit that they are problematic, but so are all the other proxies — that is what makes this science. If it was easy it would be engineering. As a physicist at Argonne National Lab said on a recent show about the hunt for the Higgs Boson said “I get paid to try and understand things we don’t understand. The more things we don’t understand — that’s job security!”. Or, perhaps more famously, and unattributed AFAIK, “science is what we do when we don’t know what we’re doing”.
The most fundamental flaw in Montford’s book is his (as related by Stevie Mac) refusal to recognize that science is an ongoing process. The back and forth as seen in the scientific literature, or more informally in the dreaded emails, is how progress is made. Montford’s (as related by Stevie Mac) refusal to see this is the basic flaw in the book. The fact that a plurality of the references are to CA posts with no attempt made to address the legitimate criticisms leveled at Stevie Mac’s broadsides just makes the book weaker.
RN – You would also need to be sure that the proxy selection ws the same, which I haven’t done. McI’s version is described as No-dendro, no Tilj while the Mann graphic is minus dendro and 7 other potentially dubious proxies, including Tiljander.
Over at CA, while Dr Curry and Steve M have conceded that Dr Curry’s point 7 above was mistaken, commenters have been bending over backwards to try and demonstrate that it was correct ‘in spirit’, and – if you just add or subtract a few words – it was correct in detail. Heh.
The basis for this is more of McIntyre’s impolite ‘pea and thimble’ [climate scientists are con-men] stuff. His contention being that in the various sensitivity tests the combinations were carefully chosen to leave a mix that gave a Hockey Stick. Remove Bristlecones but leave in the inverted Tiljander, exclude Tiljander but add the Bristlecones back in etc. I read this post as an attempt to demonstrate this by rolling his own No-dendro, no-Tilj version that does not resemble an item of sporting equipment. No modern instrumental temperatures are plotted so this is a comparison of the ‘shaft’ only.
His surmise about why his reconstruction differs from the Mann figure (some commenters have done an overlay and the differences are really not that remarkable, to my eyes) is beyond my ability to parse. To do so seems to rely on having read previous posts where terms are defined. Fair enough, but two points are clear – the two warm periods reconstructed – Medieval and late 1700s are >0.6C cooler than recent NH anomalies of around 1C CRU], which means that while the details differ, McIntyre’s plot is fully consistent with the conclusion of Mann et al 2008 that recent warmth is unprecedented for 1,000 years or more.
[Response: It’s also worth spelling out some of McIntyre’s thimble hiding here. First off, after a 7 years you’d think that he would be aware that the reconstructions are done in a step-wise fashion – i.e. you use as much information as is available as far back as you can. Back to 1500 you use everything that goes back that far, back to 1400 a little less etc. So a proper no-dendro/no-Tilj reconstruction will not just be made with what is available in 1000AD. Second, given all of the bluster about validation statistics, he never seems to compute any. Since the no-dendro CPS version only validates until 1500 AD (Mann et al (2008) ), it is hardly likely that the no-dendro/no-Tilj CPS version will validate any further back, so criticising how bad the 1000 AD network is using CPS is hardly germane. Note too that while the EIV no-dendro version does validate to 1000 AD, the no-dendro/no-Tilj only works going back to 1500 AD (Mann et al, 2009, SI). So again, McIntyre is setting up a strawman, not performing any ‘due diligence’ and simply making stuff up – all in order to demonstrate some statistical prestidigitation to the adoring commenters. – gavin]
Jumping way back to Andy Revkin’s comment at
https://www.realclimate.org/?comments_popup=4431#comment-181651
Perhaps he was thinking of this very recent US 11th Circuit case (which of course doesn’t apply to British law or the CRU, but might well worry any US citizen in the 11th Circuit (Alabama, Florida, Georgia) who might have any private information in email.
https://www.eff.org/deeplinks/2010/07/court-corrects-bad-email-privacy-decision-ducks
“… a prosecutor used a sham grand jury subpoena to obtain the private emails …. the sort of abuse … — a rogue government official seeking to get your emails from your ISP with no court oversight and then turning it over to others who seek to harm you…. is very bad news …
That’s not freedom of information. That’s freedom to misappropriate and misuse private information, by a public official.
Think Cuccinelli, not Revkin, getting hold of the email.
“prestidigitation” what a marvelous word!
And, under the heading of “No good turn goes unpunished,” traffic to my blog has quadrupled because CD linked my translation of JD’s interview in Brazil.
Thus, I have now pasted Dr. Smith’s excellent comment into the beginning of that post.
[reCaptcha: earthiest year]
pjclark,
You made the point I alluded to in my last sentence much better (and gavin, better still) than I did. I was just surprised that the error was so easy to spot. McIntyre really isn’t even trying anymore.
Gavin,
So just to be clear with regard to your response to 525. Under either method (CPS or EIV) it is not possible to get a validated reconstruction to before 1500 without the use of tree rings, or the Tiljander sediments. I understand, of course, that as you remove proxies that the ability to project backward will naturally diminish.
[Response: That appears to be the case with the Mann et al 2008 network. Whether you can say more general things about medieval times using these and other proxies (cf osborn and briffa 2006) is another question. -gavin]
Re: Hank Roberts #526.
Perhaps encryption technology for emails and backups should be used. Although, ‘the horse has bolted’ on this.
Gavin,
Thanks for your response. I had been under the impression that a claim was that the “hockey stick” (which I’m sure is an undefined term) survived even when you eliminated the use of tree rings. Without the period before 1500 I don’t think that this would be a valid statement. Or are you saying that there are other potential non tree ring proxies that weren’t used by the Man et al 2008 network that would push the window back?
[Response: Since the first ‘hockey stick’ paper was MBH98 which only went to 1400, and since almost all of McIntyre’s commentary has been concerned the 1400-1500 step in MBH98, I don’t think there is an implication that HS-ness is related specifically to medieval times. It’s more related to the increase over the 20th C relative to past centuries (which is why the whole issue is kind of moot for anything important). As to proxies that Mann et al 2008 don’t use because it doesn’t fit with that methodology (due to resolution, or whatever), there may well be useful information there. Note that the ‘very likely’ designation of exceptional late 20th C warmth in IPCC was only for the period to 1500 – quite likely because of the drop out of non-dendro proxies at this point. My comments here have purely been about the misrepresentations being made about the various papers, if you want to have a conversation about medieval times, that is a whole other topic. – gavin]
[Further Response: Just to be even clearer – there is no problem in looking specifically at the no-dendro/no-Tilj 1000 AD network along with anything else you like to see what can be said – but showing that this is problematic while implying that someone has made some claim about it that that you are refuting is a classic strawman argument. As we discussed a few months ago, the exact level of the medieval warmth is not a very interesting scientific question (given the uncertainties in forcings) – despite what you might read elsewhere. – gavin]
McIntyre understands the “stepwise” method just fine.
But he also claimed:
Here’s where I think the difference lies. Mann’s graphics all show the results of spliced reconstructions rather than what you get with proxies going back to AD1000. The provenance of the network used in Mann’s November 2009 revision of a figure in his SI isn’t described as clearly as it might be. [Empahsis added]
That claim of lack of clarity simply can’t be supported, as to both “stepwise” method and proxies to be included.
I expound at greater length:
http://deepclimate.org/2010/07/19/open-thread-4/#comment-4662
“the exact level of the medieval warmth is not a very interesting scientific question (given the uncertainties in forcings)”
from when on can we be certain about the forcings?
[Response: Depends what the question is. At the last glacial maximum we know the forcings to a W/m2 or two, but the signal is large (~6 deg C) so the response/forcing ratio is relatively well constrained. At the medieval period, the forcing uncertainty is a maybe half W/m2 (I would estimate), but the signal is in tenths of a degree. The late 20th C is better – a larger signal and larger trend. – gavin]
More McIntyre:
To illustrate the calculation, I’ve picked the AD1000 Mann 2008 data set as an example since it covers the MWP. I’ve used the late-miss version (calibration 1859-1949) to work through, since it will give a look at any potential “divergence problems” in non-dendro data.
So his AD1000 reconstruction appears to use only the calibration period up to 1949 for screening and calibration. No wonder even his 1000-1100 century doesn’t match.
Hank Roberts (#526) writes:
“Think Cuccinelli…getting hold of the email.”
Mr. Cuccinelli is in hot water because he took campaign money from a crook named Bobby Thompson who ran a bogus charity. Friday the IRS and other agencies a raided a house connected with this bogus charity and seized documents and computers.
Rep. Ward Armstrong has observed, \[Cuccinelli] can waste taxpayer dollars going after professors at our public colleges and universities . . . but yet we can’t take a look at Mr. Thompson and his group…You have to wonder if there’s a connection there with the $50,000 contribution.\
http://legendofpineridge.blogspot.com/2010/07/federal-agents-raid-tampa-home-and.html
Ah, so it was a guilty conscience that led Mr. Cuccinelli to begin his witch hunt … :)
I haven’t visited RC for a long time. Returned a week ago. Oh boy what a return! Took me a week to read this entire thread from reply 1 to 536. I don’t feel I can really add anything to this discussion. However I do want to express my amazement about this all.
Montford’s book portrays climate scientists as frauds and tells us we should deeply mistrust any product of the power hungry money machine that climate science is.
Judith Curry is on a mission of rebuilding trust in climate science. How does the promotion of this book further that cause? I don’t understand, and from what she has posted here and on other sites, I take it that she doesn’t either.
Another thing that leaves me completely puzzled is how she prefers to judge people on snarkiness rather than honesty.
re: 537 “Another thing that leaves me completely puzzled is how she prefers to judge people on snarkiness rather than honesty.”
Curry opened an early post on the thread with the statement that she just dropped by to say she must be going.
Several lengthy posts by Curry later, I wonder if she ever managed to get there.
reCaptcha: shirks of
(I kid you not)
Another thing that completely puzzles me is the fact that if one simply averages temperature proxies, as Craig Loehle has done, one sees that the MWP was likely warmer than present times, and the largest problem of the previous 1000 years has been the LIA.
Is there a Tamino/Schmidt rebuttal of this that I could be pointed to?
[Response: Loehle’s reconstruction has dozens of problems – some of which were outlined here. It has no information on relative temperatures between medieval and modern times. To have a simple average work, you need a relatively even spatial sampling, and relatively equal representation in each proxy for a particular area. You can’t for instance average the mean Chinese temperature over the whole country with a single point in India and get a representation of the average variability in Asia. These things are not trivially commensurate. -gavin]
Several months ago I visited this site to educate myself about “Climategate” and AGW. A kind poster recommended Spencer Weart’s “The Discovery of Global Warming,” which I read, enjoyed and learned from. I then moved on to A.W. Montford’s “The Hockey Stick Illusion” to take a look at the other side. Returning to RealClimate I obviously found this thread and followed it. I have to say that I’m disappointed. Polemics and ad hominem insinuations are too frequent. I’m not competent to judge the science or the respective technical merits of different statistical methods, but I can recognize ineffective communication when I see it. This matter cries out for a common public forum–even a series of face-to-face encounters. Dueling websites– essentially mere cyber pep rallies– won’t resolve anything. More of the same serves only to undermine public trust in in scientists and science.
#540 two moon
ad hominem insinuation? Where? Compared to what? Who?
saying your stunned at how wrong something is is not ad hom. Telling someone they are wrong based on a string of evidence or even reason is not ad hom.
If you don’t understand the climate science yet, keep studying because it is important that you do understand it.
Try http://www.skcepticalscience.com
or http://www.ossfoundation.us
as they both do a good overall job of simplification and directly addressing the debate myths.
—
A Climate Minute: The Natural Cycle – The Greenhouse Effect – History of Climate Science – Arctic Ice Melt
‘Fee & Dividend’ Our best chance: – Learn the Issue – Sign the Petition
two moon (540) — As Tamino’s review makes quite clear the book is factually incorrect and unworthy of further considerations as it has no content.
Far better to continue from Weart’s excellent presentation. One direction is to see what happened in the far past with different amounts of warming. I suggest Mark Lynas’s “Six Degrees” and Peter Ward’s “Under a Green Sky”. There is also Wally Broecker’s new book, “The Great Ocean Conveyor”.
Don’t waste your time reading anti-science, please.
two moon,
Montford’s book and most contrarians’ argument share a common theme: climate scientists are frauds that are only in it for the grant money and world domination, and that therefore their science can not be trusted. The contrarians’ position is actually one big ad hominem.
Focus on the substance of the arguments, don’t allow yourself to be distracted by the form. What do you prefer: a polite lie or an honest snark?
Re: two moon above at #540:
Glad you read Weart’s book. Don’t judge what Real Climate has to offer based on Montford’s book or the discussion on this thread. That would be too small of a sample size.
To gain perspective on the ongoing conflict between the scientific consensus and that of denial, I suggest reading historian Naomi Oreskes’ most recent book, Merchants of Doubt, which can be found here.
As always, the best scientific arguments are those that consider all the evidence. You will find that those exhibiting denial do not adhere to that maxim.
The best,
Re Captcha: the innately
The Yooper
“Dueling websites– essentially mere cyber pep rallies– won’t resolve anything. More of the same serves only to undermine public trust in in scientists and science.”
To the contrary, first off the temperature reconstruction curve is not perfect, but serves us well, it shows a recent warming, conforming with AGW theory. It is a success story, and needs respect and praise. Instead it gets assailed as fraudulent from the anti-science venom crowd. What should we do? Sit here , and let the propaganda flow unhindered? There is no debating people making allegations of corruption and cheating, especially when the result of the science work is correct. In this case the correct science is seen in nature now, look all over the world, its hot on planet earth… I’ll repeat this until most people (without a bent agenda) make the connection.
two moon, I’m sorry, but where did you ever get the idea that science was resolved on websites? Why not look at what the actual scientists say? The most recent polling shows 97% agreeing that we are warming the planet? And after you have read Spencer Weart–an actual physicist, why do you then go on to read Montford–who has no particular expertise and no publication record in climate science.
Do you also read the Discovery Institute to get the “other side” on evolution? Velikovsky for the other side of planetary science?
If you really want to know the truth, look at which side is publishing and advancing knowledge of the subject.
The Yooper, the only problem with Oreskes’ book is that substantial portions are wrong as documented by our peer reviewed paper. (Check my web site). You can’t argue for science and against truth.
[Response: Despite your objections to one particular aspect, there is much more to it, and the evidence amassed for their overall thesis is very impressive. – gavin]
It should be convention that every time Montford’s book is mentioned, something better is also on the menu. Further to two moon’s mention, for those who don’t know of it Spencer Weart’s book can be found here. It’s written by a real historian of science and is distinctly less “tribal” than Montford’s offering to his particular totem.
Many thanks for the comments on Loehle’s reconstruction. The same even spatial sampling criticism can be leveled at Mann’s multi-proxy studies can’t it?
It seems to me that Loehle’s elegant approach has the advantage of being less sensitive to the specifics of proxy selection (each component in the average has the same weight) and the method readily provides confidence intervals, which seem to be not present in the PCA studies.
I see that Gavin’s important contributions in tightening the data handling are acknowledged in Loehle’s second paper.
[Response: ‘Important contributions’? ‘Elegant’? Funny. As for spatial sampling, it is clear that you would ideally want as even a spread as possible, but any method you would actually want to use has to be able to deal with the certain heterogeneity. Climate field reconstructions (like Mann et al) do that by breaking down known variability into patterns and then reconstructing the means from the reconstructed patterns. Loehle’s study made no attempt to do any weighting at all, and has no attempt to validate anything. It adds nothing to the conversation unfortunately. – gavin]
[re-posting because of trouble with reCAPTCHA]
Gavin,
Does it not disturb you in the least that Oreskes seems to have knownlingly included refuted claims about the Nierenberg committe report in her book? What does that say about the rest of the evidence she amassed? Most readers can not verify her evidence, much less make sure that she did not cherry-pick it.
[Response: Having read Nicholas Nierenberg’s paper and the relevant parts of MoD, the issue is in the interpretation of William Nierenberg’s actions on the 1983 report. NN claims essentially that the WN synthesis was reflective of the consensus on the committee, Oreskes and Conway see it as slanted towards inaction. It is a pretty nuanced issue, and while I can see why the parties involved have taken the positions they have, I’m not convinced that there is any obvious resolution of these opinions. But having said that, this is but a small part of the O&C case, and the evidence that they bring together overall is very convincing. Note, that further discussion on this is OT here. – gavin]