As a preamble and reprise, I think that it is reasonable for Cowtan and Way to take exception with HadCRU’s failure to estimate temperature in Arctic gridcells and to propose methods for estimating this temperature. At a time when the climate community argued that differences between the major indices and accessibility to CRU data didn’t “matter”, I thought that both mattered. One of the reasons for transparency in CRU data and methods was so that interested parties could carry out their own assessments, as Cowtan and Way have done. They have diagnosed a downward bias in recent HadCRU results. On previous occasions, I’ve observed that the community is more alert to errors that go the “wrong way” than to errors that go the “right way” and this opinion remains unchanged. As noted in my previous post, it doesn’t appear to me that their slight upward revision in temperature estimates has a material impact on the discrepancy between models and observations – a discrepancy which remains, despite efforts to spin otherwise.
In today’s post, I’ve re-examined Robert Way’s contributions to the secret SKS forum, where both he and Cowtan (Kevin C) have been long-time contributors. In my first post, I took exception to Way calling me a “conspiracy wackjob”. However, relative to the tenor of other SKS posts in which their colleagues fantasize about “ripping” out Anthony Watts’ throat and Anthony and I being perp-walked in handcuffs, Way’s language was relatively mild.
In addition, re-reading the relevant threads, other than a couple of occasions (ones to which I had taken exception), Way’s language was mostly temperate and well-removed from the conspiratorial fantasies about the “Denial Machine” that pervade too much of the SKS forum. In addition, this re-reading showed that, on numerous occasions, Way had agreed with Climate Audit critiques, sometimes in very forceful terms and usually against SKS forum opposition. Way typically accompanied these agreements with sideswipes to evidence his disdain for Climate Audit, but seldom, if ever, contradicted things that I had actually said.
I think that readers will be surprised at the degree of Way’s endorsement of the Climate Audit critique of Team paleoclimate practices.
Let me start this review with Way’s surprisingly temperate remarks (General Chat/2011-02-09-Antarctic Temperature Trends.html) regarding a dispute between Real Climate and Climate Audit arising over Steig’s efforts as a reviewer to prevent publication of O’Donnell et al 2010. As CA readers will recall, Steig, as an anonymous reviewer, did everything in his power to prevent publication of O’Donnell et al 2010, requiring changes that, in my opinion, diminished the article. Ryan O’Donnell published a post at CA that was expressed more angrily than I would have written, but Ryan was pretty mad. This prompted an exchange at Real Climate, with Steig consigning even technical criticisms to the Borehole, a practice that had been criticized by skeptics on other occasions, but which was particularly virulent. Way objected to Steig’s conduct, which he described as a lesson in what “NOT to do as a scientist”:
There’s a feud going on pertaining to this post on RC
followed by these two by climate audit:
I’m gonna be honest, this should be a lesson on what NOT to do as a scientist. Steig is refusing to read the criticism of his criticism and is refusing to engage the authors of the paper he is criticizing. In the “Borehole” at RC you can see some examples of comments by the others that are purely technical and include no *snark* that Steig calls snark and put in the Borehole. I know how ravenous the *auditors* can get but this type of non-response is exactly what gives skeptics momentum.
Way was immediately challenged by SKS forum participants, but re-iterated his objections to Steig’s conduct. He also observed that statistically Steig was “wrong” and CA was “right”. He also (in my opinion) accurately perceived the belittling character of Steig’s initial remarks and understood and sympathized with why Ryan O’Donnell (and others) fired back:
to be clear in all this, steig is wrong. CA is right in terms of their reconstruction and their subsequent response. They included way too much snark over at CA but that doesn’t detract from them being right statistically.
Personally I think that if you are curteous and deal with the guys like Ryan O and Jeff ID properly then they will respect you. I watched the initial response and I remember thinking that some of the comments steig made in response to Ryan O were snarky and belittling. I’m not shocked they fired back, not shocked at all.
As scientists aren’t we supposed to take the high ground and just go where the facts lead us?
After a SKS forum commenter defended Steig, Way concluded the thread as follows, expressing, among thing things, a “little shock to learn that Steig et al. made the same principal component mistake that Mann et al 1998 did”. Way tempered his criticism with a sideswipe at me for being unresponsive to a question from him about temperature data:
Having read Steig’s response I don’t really know what my opinion on the whole matter is. I think realistically both of the children need a time-out. That being said Mcintyre needs to learn to call off the attack dogs. If he wants to work on “bridging” the gap between scientists and skeptics then he has to learn to not act like a child himself. I remembered I had question on something to do with temperature data way back and I sent an email to Gavin Schmidt and one to Steve Mcintyre. I got two responses: One from Gavin with some detailed instructions and two publications to look at and one from Mc stating something like “I’m too busy for this, ask someone else”
What I find interesting about that is that if I were steve Mc I would post that exchange on my blog and use it as evidence that the other side was being dismissive… really shows the hypocrisy of it all.
Nevertheless I think that O’donnell and Codon and them are probably more right than Steig statistically and I’m a little shocked to learn that Steig et al. made the same principal component mistake that Mann et al 1998 did but nevertheless the statistics in all this aren’t the lesson to be learned.
What should be taken from this little issue is that tone is very important. If Steig et al remained curteous (even with the attacks) then for those watching on the sidelines it would be obvious that the science is in good hands. To react somewhat snarky just brings us down to their level. Keep talking the science and stay away from personal stuff and you will win in the hearts and minds.
Hide the Decline
Later in March 2011, the SKS forum discussed (General Chat/2011-03-25-Lunacy continues at WUWT and Climate Audit.html) a then current CA post about other incidents (besides the IPCC TAR and WMO cover) in which Briffa had deleted adverse data to hide the decline. Julian Brimelow (Albatross) claimed that I was trying to “brain wash” people and fantasized about Anthony or me being perp-walked in handcuffs:
McIntyre is losing it and with each day and passing is showing his true (and scary) colours, not to mention his incredible desperation. I have noted that WUWT and CA are working a lot more closely now, probably in an effort to brain wash as many people as possible, and to keep the converted convinced that this is all a conspiracy– despite the shit hitting the fan all around them.
I have no idea how one deals with this– to be candid, McIntyre or Watts in handcuffs is probably the only thing that will slow things down. Note that i did not say “stop”. These guys are relentless, and have many faithful followers.
After some equally intemperate commentary by other SKS forum participants, Way commented sensibly that he did not support the deletion of adverse data and, if I was right on this point (as I was), then Briffa has some “explaining to do”:
I’m not sure what my opinion on this subject is at this point. If Steve Mc is correct then I do think that Briffa has some explaining to do. Personally I’m not a fan of the deletion of data for a figure either way… I would get blitzed by my supervisor if I did it in any document so I don’t know why the same standards shouldn’t apply.
Either way though, it just goes to show that some tree ring datasets are probably too difficult to use and other proxies like ice cores…etc… will be better for reconstructions.
The discussion then veered into a discussion of the Mann’s upside-down Tiljander. Ross and I had pointed out this problem in a short comment published in PNAS (250 words max.) Mann denied the problem, calling the (correct) criticism “bizarre”. SKS forum participant grypo, like William Connolley and others, claimed that Mann’s failure should be blamed on Ross and me for not explaining the problem clearly enough:
Had he used a better phraseology that argument may have been settled one way or another, but Mann, apparently, had no idea what he was saying and called it ‘bizarre’.
Way then observed that I was “right” on the Tiljander issue, but, as elsewhere, accompanied this concession with a sideswipe, this time calling me a “conspiracy wackjob”:
The Tiljander debate showed that Mc was right on that issue. Kaufmann had to fix his series because he also used it upside down. Didn’t make too much of a difference but Mann’s response of “Bizarre” was pretty lazy if you ask me. The original Tiljander series people even said Mann and Kaufmann used it wrong. That being said Mc is a conspiracy wackjob…
“McIntyre’s New Target”
In September 2011, I did some posts on Andrew Dessler. Grypo started an SKS Forum thread (General Chat/2011-09-29-McIntyre’s new target.html) urging a response, mostly complaining about me, but with the following backhanded compliment:
Part of Mcintyre’s magic, is his ability to take his statistical ability (whether right or wrong) and transfer that into rhetoric that the normal person can understand.
Way observed that many of the points that I bring up are “valid” and commented that I was a “tough person to target… even for the experts”, again accompanying the concession with the obligatory sideswipe, claiming that I turned an ordinary mistake into a “conspiracy” (an allegation that I reject and do not believe to be supportable by the record):
McIntyre is a tough person to target… Even for the experts. The fact of the matter is that a lot of the points he brings up are valid the challenge is that he associates them with too much skepticism. He finds a mistake and suddenly its a conspiracy whereas a normal person would call it a reasonable mistake. But I wouldn’t want to go up against that group, between them there is a lot of statistical power to manipulate and make the data say what it needs to say.
Neal King, apparently agreeing with Way’s warning about the statistical power at Climate Audit, observed that he tried to stay away from real data and statistics as much as possible – doubtless a wise precaution for an SKS participant:
Real data and statistics are a subtle subject. I try to stay away from both, as far as possible.
SKS forum participant Julian Brimelow then wondered whether there were hackers who might attack me:
Make no mistake, there is some social networking going on here behind the scenes (does that group who hack mega corporations also hack emails of people like McIntyre?).
Grypo then returned to the “problem”, again making a backhanded compliment about my supposed ability to “form narratives”:
But McIntyre’s magic is in forming narratives that permeate through to the mainstream. I agree SkS has limited ability to do anything about this. Just brainstorming here.
Way then commented that I had “brought up some very good points” about the original Stick, agreeing that the original confidence had been “vastly overstated”, and that he didn’t like to talk about “the HS stuff, because I know a lot of people who have doubts about the accuracy of the original HS”:
I don’t mean to be the pessimist of the group here but Mc brought up some very good points about the original hockeystick. The confidence affirmed to it by many on our side of the debate was vastly overstated and as has been shown in the recent literature greater variability on the centennial scale exists than was shown. The statistical methodology used by Mann did rely too much on tree rings which still are in debate over their usefulness to reconstruct temperature and particularly their ability to record low-frequency temperature variations. I’ve personally seen work that is unpublished that challenges every single one of his reconstructions because they all either understate or overstate low-frequency variations. My personal experience has been that Moberg still has the best reconstruction and his one does show greater variability. That’s why I don’t like to talk the HS stuff, because I know a lot of people who have doubts about the accuracy of the original HS.
Just like we complain about skeptics like Pielke and Christy etc letting their work be miscontrued, Mann et al stood by after their original HS and let others treat it with the confidence that they themselves couldn’t assign to it. They had just as much of a responsability to ensure their work was used to promote properly just as Christy et al do. It is a tight rope we must all walk afterall.
Pressed to explain further, Way provided a lengthy exposition forcefully stating that “the original hockey stick still used the wrong methods and these methods were defended over and over despite being wrong”.
Mann’s science is mostly good and I certainly think that his papers have discussed most of the caveats. However his reconstruction failed certain statistics (can’t remember if it was r2 or RE) and even his newest reconstruction doesn’t validate past 1400 if you don’t include disputed series (which I have no idea why he’s including them at all). Lets make this clear. There is a hockey stick shape in the data, but the original hockey stick still used the wrong methods and these methods were defended over and over despite being wrong. Just because a better analysis (Wahl and Amman 2007) using the same data shows very little difference doesn’t change the fact that the technique was wrong. PCA isn’t the best choice anyways… but that’s irrelevant.
Way then reviewed an exchange at Tamino’s where Tamino’s invocation of Ian Jolliffe as a supposed authority for de-centered PCA had resulted in Jolliffe himself disowning Mann’s application of the technique, as follows:
This is where my problem lies:
“Contrary to MM’s assertions, the use of non-centered PCA is well-established in the statistical literature, and in some cases is shown to give superior results to standard, centered PCA… For specific applications of non-centered PCA to climate data, consider this presentation provided by statistical climatologist Ian Jolliffe who specializes in applications of PCA in the atmospheric sciences, having written a widely used text book on PCA. In his presentation, Jollife explains that non-centered PCA is appropriate when the reference means are chosen to have some a priori meaningful interpretation for the problem at hand. In the case of the North American ITRDB data used by MBH98, the reference means were chosen to be the 20th century calibration period climatological means. Use of non-centered PCA thus emphasized, as was desired, changes in past centuries relative to the 20th century calibration period.”
I. T. Jolliffe, Principal Component Analysis, Springer-Verlag, New York, 1986.
Comment by Dr. Jolliffe at Tamino’s
“…It has recently come to my notice that on the following website, http://tamino.wordpress.com/2008/03/06/pca-part-4-non-centered-hockey-sticks/ .. , my views have been misrepresented, and I would therefore like to correct any wrong impression that has been given… In reacting to Wegman’s criticism of ‘decentred’ PCA, the author says <>
It is flattering to be recognised as a world expert, and I’d like to think that the final sentence is true, though only ‘toy’ examples were given. However there is a strong implication that I have endorsed ‘decentred PCA’. This is ‘just plain wrong’.
…(my talk)…It certainly does not endorse decentred PCA. Indeed I had not understood what MBH (Mann 1998) had done until a few months ago. Furthermore, the talk is distinctly cool about anything other than the usual column-centred version of PCA. It gives situations where uncentred or doubly-centred versions might conceivably be of use, but especially for uncentred analyses, these are fairly restricted special cases. It is said that for all these different centrings ‘it’s less clear what we are optimising and how to interpret the results’.
I can’t claim to have read more than a tiny fraction of the vast amount written on the controversy surrounding decentred PCA (life is too short), but from what I’ve seen, this quote is entirely appropriate for that technique. There are an awful lot of red herrings, and a fair amount of bluster, out there in the discussion I’ve seen, but my main concern is that I don’t know how to interpret the results when such a strange centring is used? Does anyone? What are you optimising? A peculiar mixture of means and variances? An argument I’ve seen is that the standard PCA and decentred PCA are simply different ways of describing/decomposing the data, so decentring is OK. But equally, if both are OK, why be perverse and choose the technique whose results are hard to interpret? Of course, given that the data appear to be non-stationary, it’s arguable whether you should be using any type of PCA.
I am by no means a climate change denier. My strong impressive is that the evidence rests on much much more than the hockey stick. It therefore seems crazy that the MBH hockey stick has been given such prominence and that a group of influential climate scientists have doggedly defended a piece of dubious statistics. Misrepresenting the views of an independent scientist does little for their case either. It gives ammunition to those who wish to discredit climate change research more generally.
[THIS IS THE EPITOME OF HOW I FEEL-Robert Way]
…distinguishing between the hockey stick and the MBH hockey stick is the key issue. The latter is where the problem lies because of what I deemed ‘dubious statistics’. It is this one particular paper, and in particular the defence of the technique used as recently as this year, which has caused so much grief…
The only reason I got involved is because the ‘dubious statistics’ were still being defended this year and my name was being used in support. “
Ian Jolliffe, PH.D Statistics
I. T. Jolliffe. Principal component analysis. In: Encyclopedia of Statistics in Behavioral Science, (eds. B. S.Everitt and D. C. Howell), Vol. 3, 1580-1584, Wiley, New York, 2005.
“Dr. Jolliffe has convinced me that applying decentered PCA invalidates the selection rules which are applied when choosing which PCs to include in one’s model. But the “relevant” (hockey-stick shaped) PC would have been included anyway, applying valid selection rules to centered PCA. And the PCs which are omitted (because they’re suppressed by the method rather than the statistics) don’t seem to correlate with temperature in the calibration interval. Therefore it seems to me that the method is flawed, but the flaw has little or no impact on the final result.”
With respect to Steig,
I think he didn’t handle the whole issue well at all. He fed the fire. Truth is that his method did spill over some of the warming into places where it wasn’t. JeffID and them had their method prolly reduce the warming a bit. At the end of the day Steig really fed the fire with those posts at RC and so on… These guys really go for blood.
Neal King agreed that “Mann (and maybe Steig) are examples of how NOT to proceed”. King also ventured the question about the tree ring “divergence problem” that bothers most skeptics, commenting that he guessed that there was an answer, but “no one has ever given it to me”:
- I don’t follow all the details, but my impression is that Mann and buddies have sometimes gone out on a limb when that was unnecessary and ill-advised. My impression is that Mann, for all his technical ability, is sometimes his own worst enemy.
- Similarly, with regard to “hiding the decline” in Climategate, I am left with the impression that the real question is, Why would you believe the tree-ring proxies at earlier times when you KNOW that they didn’t work properly in the 1990s? I guess there is a good answer to that, but no one has ever given it to me.
I believe a good 50% of the game is being able to avoid booby traps. Because the science is at the edge of ignorance, mistakes WILL be made. The question is, How do you avoid putting your foot in the traps? I think Mann (and maybe Steig) are examples of how NOT to proceed.
Way then briefly discussed the post-hoc selection bias that has been discussed from time to time on blogs(recently in connection with Gergis et al), referring to Jeff Id’s discussion in connection with Mann et al 2008. Way conceded that Jeff Id was right on this points, accompanying the concessions with the usual sideswipe, this time calling Jeff a “douche”:
So responding to other stuff.
Mann 2008 CPS
“As an exercise assume you start with 1000 sets of random very noisy set of data which swings up and down by 4 degrees C and you average them. You should get a relatively flat line with wiggles of a magnitude much smaller than any of the individual peaks.
If you take the same random data, calibrate its endpoint to today’s temperature (offset it so the end matches today’s temperature) and then sort it (throw data out) so that only data which correlate to a temperature rise at the end 5% of the dataset remains. Then you average the remaining data you would get a relatively flat line with an upward spike at the end. The averaged data would have an end spike which would almost certainly be of greater magnitude than the rest of the curve”
This is from JeffIDs site and although I do think he’s a douche he does bring up a good point. Even with a hockey stick in the dataset the method will result in excluding datasets which support the hockey stick the least.
I think that the challenge in this whole debate is that Mc et al are looking to find any excuse they can to distort the truth and milk and manipulate it as best as they can. Mann et al (and Steig et al) gave them excuses to quite often. Kill them with kindness or kill them with your brilliance, don’t leave yourself open to criticism when people are watching.
They then made the sensible observation that scientists should not insist on results that they cannot back up – a point on which we are in agreement:
I think all of us here at SkS are on Mann’s side, not McI’s. Nonetheless, it is necessary, if you want to improve, to admit that it is your own side that is sometimes falling down. Insisting on results that you cannot back up 100% is “leading with the chin”. One CANNOT do that sort of thing: One must pay McI et al. the acknowledgement that they will detect that error and go for the throat.
Tom Curtis then advanced the Real Climate party line that our criticisms didn’t matter and were merely “minor points”. Way firmly rebutted them, asserting that we had got “major points correct”, making as forceful defence of our position as can be imagined:
I don’t think these are minor points. I think they get major points correct. MBH98 was not an example of someone using a technique with flaws and then as he learned better techniques he moved on… He fought like a dog to discredit and argue with those on the other side that his method was not flawed. And in the end he never admitted that the entire method was a mistake. Saying “I was wrong but when done right it gives close to the same answer” is no excuse. He never even said that but I’m just making a point. What happened was they used a brand new statistical technique that they made up and that there was no rationalization in the literature for using it. They got results which were against the traditional scientific communities view on the matters and instead of re-evaluating and checking whether the traditional statistics were valid (which they weren’t), they went on and produced another one a year later. They then let this HS be used in every way possible (including during the Kyoto protocol lead-up that resulted in canadian parliament signing the deal with many people ascribing their final belief in climate change being assured by the HS) despite knowing the stats behind it weren’t rock solid. Of course someone was going to come along and slam it. In the defense of the HS method they published things on RC like what I showed above where they clearly misrepresented the views of the foremost expert on PCA in atmospheric sciences who basically says that Mann’s stats were dubious.
Mcl didn’t actually provide a reconstruction. They were just showing the difference with a different set of rules applied. They didn’t have the balls to do one themselves. Either way 2 pcs was probably too few but rationalizing the 5 that would have to be kept to get the HS shaped PC is also an interesting topic.
“As the proxies are chosen for a known, physically based covariance with temperature,”
In mann 2008 the relationship with temperature in the overlapping period that was used for a cutoff was r2 > 0.1
Do you think that only having 10% of the variance in a proxy explained by temperature changes is an appropriate cutoff? I really think that’s not exactly a “physically based covariance with temperature” that I would trust.
Julian Brimelow concluded the thread observing that “one can’t hand them stuff that is easy to critique”, but, more importantly, that I needed to “go down, it is quite that simple”.
McIntyre need to go down, it is quite that simple.
Mann et al 2008
Previously, in August 2010, Cook had (Authors/2010-08-10-List of rebuttals and who’s doing what) set out a list of rebuttals, eventually leading to this page. Way withdrew his previous “dibs” on Climate’s changed before. He warned potential authors to stay away from Mann et al 2008 since “much as I hate to admit it they are right about the issue of the study failing verification statistics past 1500 for one”:
I was going to do #2 Climate’s changed before but have now decided I will stay away from it for now. I was wondering if you could remove my dibs. Also I have to tell you that you should warn those doing that particular one to stay away from Mann’s 2008 paper if they take this topic as it seems it has actually been invalidated by climate audit (as much as I hate to admit it they are right about the issue of the study failing verification statistics past 1500 for one)
At the time, we had just learned (via a sly inline comment at RC by Gavin Schmidt) that Mann had already conceded that the Mann et 2008 no-dendro reconstruction did not pass his own verification methods. Way reported this as follows:
So what this means is that 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 Tijlander sediments. The tijlander sediments were used incorrectly and upside down from the original published version and a corrigendum by Kaufmann et al. (who also used it upside down) was issued pertaining to this. http://climateaudit.org/2009/10/26/the-kaufman-corrigendum/
I’m not one of those climate audit junkees and I certainly disagree with how Mcintyre handles a lot of the stuff but I’ve been shown before by even climatology profs in my university time that it might be best to stick clear of Mann’s reconstructions until the dust settles (although this debate has been going on for 10 years)
Despite Way’s warning, other SKS authors used the Mann et al 2008/2009 reconstruction in the SKS article on the Medieval period.
Cook’s Call to Action
As a last thread in today’s review, on March 3, 2011 (Climate Misinformers/2011-03-08-Call to action – help collect quotes on skeptics), Cook called on the SKS team to collect adverse quotes from targeted skeptics, including me in a list of five targets. (This enterprise appears to have led to their Skeptics page here):
So skeptics that I suggest we focus on, assuming we launch with 12 skeptics (welcome changes):
Pat Michaels Fred Singer Steve McIntyre Roger Pielke Sr Freeman Dyson Chris de Freitas
Unless you think others are more deserving of being on the list.
Way replied that it would not be easy to locate embarrassing quotes from me, observing that others had already tried without success, again with the usual sideswipe:
McIntyre will be hard to pin down. Many before us have tried and not proven to be terribly successful. He is of the weasely type.
A week later, Dana Nuccitelli observed that Michaels, Pielke Sr, de Freitas and I were still outstanding targets, adding that I was the “tough one”:
I bet Gareth could get us some good de Freitas quotes. Michaels should be easy. The tough one is McIntyre.
As noted above, except for the offensive sideswipes, Way’s language in the SKS forum is mostly temperate and a far cry from some of his bloodthirsty colleagues. While he re-assures his colleagues of his disdain for both me and Climate Audit, it is extremely hard to locate discrete points of disagreement.