Tim Lambert was quick to pounce on Ross McKitrick’s programming error in calculating cosine(latitude) in a paper not involving me, so it’s ironic to see Lambert’s apparent failure to understand Mann’s erroneous use of cosine(latitude) in his temperature PC calculations, even when brought to his attention. Ed Snack has had an interesting exchange with Tim Lambert at Lambert’s blog here – see around #142. I would certainly hope and expect that, when Lambert realizes that his pronouncements on this topic have been incorrect, he will promptly correct and apologize for his error and issue a prominent denunciation of Mann’s error fully equal in ferocity to his denunciation of McKitrick’s similar error.
Mann’s calculation error was pointed out by von Storch last year in the SI to von Stoech et al [Science 2004] as follows:
Monthly nearsurface -temperature anomalies were standardized and subjected to an Empirical Orthogonal Function Analysis, in which each grid point was weighted by (cos λ)^(1/2), where λ is the latitude (Mann et al. 1998 erroneously use a cos λ weighting).
I’ve mentioned this a couple of times e.g. here . The error can be confirmed in the new source code release.
In response to Ed Snack raising the issue at his blog, Lambert said:
cos(lat) is going to be a good approximation of the correct weighting. Clearly sqrt(cos) is wrong. Looks like Mann is right and Ed Snack is wrong.
Later Lambert said:
Looks to me like von Storch is the one who is wrong here.
It’s pretty easy to find proof that the square root of the cosine (latitude) is the appropriate weighting in a principal components calculation. For example, J.W. Wallace says (page 14) here:
Under certain circumstances it may be advantageous to apply certain kinds of weighting to the various variables xj that enter into the EOF analysis. For example, one might want to weight the variance for each station by the geographical area that it represents. For a regular latitude-longitude grid, this could be accomplished by multiplying each gridpoint value by the square root of cosine of latitude.
If you google “wallace cosine latitude”, a number of references jump up providing further confirmation. Künich et al. state here:
Prior to the EOF analysis the model data was smoothed with a binomial 30-day low-pass filter and weighted with the square root of cosine latitude.
Other examples include Wallace et al., Comments on “Northern Hemisphere Teleconnection Patterns during Extreme Phases of the Zonal-Mean Circulation, Journal of Climate 13, 1037-1039 or Limpasuvan and Hartmann, 1999, Eddies and the annular modes of climate variability, GRL 25, 3133-3136 or the description of a function here . It wasn’t very hard to find authoritative views on the matter.
I am sure that Lambert will promptly correct and apologize for his error and also issue a prominent denunciation of Mann’s error fully equal in ferocity to his denunciation of McKitrick’s similar error. In fact, I would expect that his denunciation will be even more ferocious because of Mann’s poor track record in making code available for cross-checking (obviously contrasting with McKitrick’s exemplary record.)
Update: July 24: Lambert has acknowledged the error only as comment #188 here:
So that to weight by area, the input to PCA has to be weighted by the square root of area. I retract my sugestion that von Storch might have been mistaken “¢’¬? he found an error in MBH98, though he does not seem to think that it was important.
If von Storch didn’t think that the error was important, he wouldn’t have mentioned it. It wasn’t relevant to the points being made in von Storch et al. [2004]. I am disappointed that Lambert has failed to issue a denunciation of Mann’s error equal in ferocity to his denunciation of McKitrick’s error as it shows unfortunate evidence of mere partisanship.
Climate Audit 
58 Comments
Steve
This is indeed going to be interesting because if your are right in your expectation, that would be tantamount to a ferocious denouncement of the Hockey Stick and all it has stood for – and thus a ferocious condemnation of AGW assertions.
We live in interesting times.
You are familiar with the old adage about not holding one’s breath?
Steve, thanks for the additional information. After Lambert’s comeback about von Storch being wrong I have been trying to research the ground myself to check. I should have known better than to take an authority (vS) without understanding the background first ! I think I will just drop a quick note on Lamberts blog though, just for fun.
Lambert has retracted his statement about von Storch being mistaken about the error in MBH98
He now opines that Von Storch “does not seem to think that it was important”.
Well that settles it for me….
John A, when I make a mistake I correct it. When can we expect to see a correction from you for your mistake about entropy?
Steve M, it is rather interesting to see that you couldn’t bring yourself to say what McKitrick’s mistake was. He confused degrees with radians. This is not the error that Mann made. It is misleading for you to claim that the errors were similar.
And I don’t recall you even mentioning that McKitrick had made an error until now. Is this mere partisanship on your part?
Also, could you explain what you found so ferocious about my post that reported McKitrick’s degree/radian confusion? I don’t see anything in it that equals your ad hominem attack on me.
Steve: Tim, before I respond, I appreciated your noting up the anti-spam software that you used at your blog. We’ve installed it as well and it’s been a lifesaver; we’ve been under spam assault, with a peak of about 475 spams in one day. I don’t know whether we would have had the patience to wade through the spam for our posts.
I don’ t think that you can say that McKitrick “confused degrees with radians”. He erroneously assumed that the cosine function in Shazam used degrees rather than radians – an error that’s obviously embarrassing, but not one that arose out of “confusing” the two units. Mann erroneously assumed that you used cosine (latitude) to area-weight prior to PCA, rather than the square root of cosine latitude. A metric of error similarity is pretty much in the eye of the beholder, but how often do you see two parties in a controversy both make errors involving the cosine of latitude. I think that the two errors are pretty similar and that there’s lots of irony involved,
The big difference is that McKitrick promptly admitted the error and issued a correction – have you seen any admission by Mann of his error or correction? By the way, the error has a substantial impact on all Mann’s temperature principal components below the TPC5, as shown here. These TPCs do have a material impact on the reconstruction. I haven’t done the calculations to measure the exact impact of this one error, but I wouldn’t be surprised if it penetrated Mann’s supposed confidence intervals. Von Storch hasn’t done an emulation of MBH98 to test the impact of the error. But the responsibility for assessing and reporting the error rests with Mann: why haven’t they done so?
Ironically, Wahl and Ammann purport to “simplify” Mann’s temperature principal components calculations, merely resulting in irritating benchmark differences. They repeated Mann’s error, even though the error was well known. I discussed this here , noting the McKitrick and Michaels error at the time. I think that some additional severity against Mann is justified because of his failure to admit the error and because of his failure to provide source code (you should give McKitrick some credit here) and some additional severity against Wahl and Ammann is also justified because they repeated the error.
I don’t see any ad hominem contents in my post about you. I thought that the title of your article against McKitrick was pretty ferocious. If you don’t think so, then, borrowing the title from your McKitrick article, I’m sure that you will have no objectio to titling a posting on Mann’s cosine latitiude error as “Mann Screws Up Again!” Perhaps it would even get picked up Quiggin and Andrew Sullivan. It would be presumptuous of me to assume that you won’t do so and so I will refrain from teasing you about it until you’ve had a proper time to prepare your critique of Mann’s cosine latitude error. However, I think that you have an obligation to deal with the issue and, if you don’t do so in a more prominent way than you’ve done so far, it will be pretty hard not to feel that your commentary is diminished.
One other point – I think that people can make errors in their code without being incompetent or without it invalidating every thought that they’ve ever had. Because McKitrick made an error doesn’t mean that Mann didn’t. If anything, it shows that errors can crop up in code. That’s a reason for archiving code. Mann’s PC methodology is a real clanger as far as I’m concerned and it could never have been identified without code (nor could McKitrick’s cosine error). You, of all people, should be insistent on Mann and others disclosing source code to ensure that unintentional but significant errors are not missed.
Allow me.
Lambert, the distasteful aspect of your behaviour is the way you try to imply that McKitrick doesn’t know the difference between degrees and radians, which would make him pretty ignorant.
I don’t know the guy, but I would be prepared to bet that his actual error was not knowing how the relevant computer function likes to be fed its input data – a very different error, and one that is all too easy to make. (Particularly given the strange taste in programming languages displayed by these academics.)
That’s what he did wrong. Far more important is what he did right, which is to make all his code public, which is what enabled you to track down the error. If only your friend Mann would do the same.
I would also dispute your characterisation of Steve’s post above as an ad hominem attack on you. I would like to demonstrate a real ad hom, just so you understand for the future, but it would probably get censored.
Oh, well. Your dog looks like a fine fellow, so you presumably have some redeeming qualities.
For those who are new to the topic, my paper with Pat Michaels has a web site here: http://www.uoguelph.ca/~rmckitri/research/gdptemp.html. For copyright reasons we couldn’t post the paper but I’m happy to send out copies upon request. The IPCC presents the gridded CRU data with the claim that they have been corrected for urban heat island effects etc. There’s a huge literature showing raw station data around the world is affected by local nonclimatic effects. I could see no basis in the IPCC report for believing their claim that the gridded data are ‘clean’. The few papers they use as fig leaves are not at all sufficient to support the claim. Pat and I put together a data base of 218 GISS stations and extracted the post-1979 trends. We regressed that on a matrix of climatic and socioeconomic variables and observed significant effects in the nonclimatic data, as expected. Then we repeat the analysis on the IPCC gridded data, and observe that the same coefficients arise, albeit somewhat smaller, and significant nonclimatic effects remain. Around the time of our publication, de Laat and Maurellis arrived at a similiar conclusion in a GRL paper using a totally different methodology, as did Kalnay and Cai in a Nature paper. Our paper provides numerous specification tests as well as a successful cross-validation experiment where we removed the North and South American data then predicted it using the model estimated on the rest of the world. Because I published my data and code, my highly motivated critics were able to spot a small error. My Latitude data are entered in degrees but the function takes it in radians, which I had not noticed. As Steve has pointed out, this was the occasion for O’Lambert to dance a jig and publish my premature obituary. I fixed the error, re-ran the results and published the correction, with the old and new coeffs side-by-side for comparison (the erratum is posted at the web site). Lambert carried on, saying my results were wrong because I didn’t use a robust standard error estimator. In fact I did, but not the one he thought I should, so I posted STATA code applying the one he thought should be used and of course the conclusions still hold up. At this point, I would like to hear from my critics: if you rejected the results based on the cosine error and the robustness issue, and they’ve been rebutted, does that mean you now accept the conclusions of the paper? For my part I stand by them. I have reproduced them in a totally new data set (paper in prep) and in my read of the literature on land-use impacts on regional temperatures (e.g. http://blue.atmos.colostate.edu/publications/pdf/R-258.pdf) I think the IPCC is very thin ice trying to claim their gridded data are not substantially affected by a nonclimatic warming bias.
Steve, it seems to me that it would be very simple to correct the area weighting error and see how that changes the final reconstruction. Getting different results for components does not imply that the final reconstruction will be at all different. I am perplexed why you think I am obliged to critique the area weighting error. I certainly have not argued that you are obliged to audit the McKitrick-Michaels study. I haven’t even argued that you should correct your co-blogger’s ludicrous claims about entropy. Your ad hominem was your accusation that I am a "devout Mannian". This prompted similar ad hominems from your commentors. Ross, I pointed out the clustering problem in my first post on your degrees/radians error. If I correct the cosine error and deal with clustering by taking the first listed station from each country, economic effects are no longer significant at the 5% level.
Steve: Tim, first of all, the obligation to correct the area weighting error rests with Mann et al. When you pointed out McKitrick’s error, he dealt with it. What’s Mann done? Nothing. Maybe the results are different; maybe not. It’s his job to do the calculations. Now what about Wahl and Ammann? Do they have a responsibility to do the calculation correctly? I think that they do. They made some pointless modifications to Mann’s temperature PC steps – why not modify the cosine latitude? It’s pretty ridiculous to give them a pass – the issue was well-known. As to ad hominems, I was initially surprised that you regard the description of being a "devout Mannian" as being a more ferocious ad hominem than saying "X mucks it up again!" or "X screws it up again!". But on reflection, I can see your point. It really is a much more ferocious ad hominem. It was a very cruel comment to make; it’s hard to imagine saying anything much crueler and I’ve removed the offending comment. I think that you have an obligation to comment on Mann’s cosine latitude problem, because it hasn’t been dealt with by Mann and because you’ve prominently posted on cosine latitude problems and because you know exactly what the problem is with no further research. I have never posted anything on entropy nor do I plan to. The point that you refer to was not raised in a formal post, but merely in a comment and not by me. It’s ludicrous to suggest that I should commence study of thermodynamics because of a casual posting. Similarly, I have never posted anything on the issues discussed in Michaels-McKitrick nor do I plan to. But cosine latitude is something that you’ve specialized in. If you ignore it, then your commentary is diminished in my eyes anyway. I’m sure that you can think up some way of doing so without necessarily going into the full "Mann screws it up again!" routine, satisfying as that would be to many people, but you should do something.
Tim, does you results also work with the last listed station and the mean listed station? Or for instance, a random list of stations, one per country? Those varients should be easy to implement using whatever code you have and would, if they give the same result, make it more robust.
Tim, there were 218 stations in 93 countries. You don’t “deal with clustering” by throwing out over half the data. You can’t just make up methodologies, post them on a web site and think you’ve won an argument. The correction for the group clustering effect is to account for it in the specification of the variance-covariance matrix. In my first model I used White’s variance-covariance matrix which is a generalized treatment for heteroskedasticity, including that caused by grouping, though it is not specifically derived for that situation. In the STATA code I apply a variance-covariance matrix that is specifically derived for handling data sets where some variables are in groups. You can see the comparison of the results here: http://www.uoguelph.ca/~rmckitri/research/gdptemp.log.txt. If the clustering effect really was the basis for your rejection of our conclusion that economic effects are significant in the surface data, then that basis is gone, and you should revise your verdict on the paper.
Steve writes: "But cosine latitude is something that you’ve specialized in." That actually makes less sense than saying "But you’ve specialized in errors by people whose names start with M". At least I’ve actually written about errors by more than person whose same starts with M. I have not specialized in cos latitude errors and it’s a silly way to categorize things. McKitrick’s error was putting degrees into a function that expected radians. Anyone who has ever pressed the cos button on a calculator can understand what he did wrong. Mann’s error was that to weight results in a PCA you have to multiply the input by the square root of the weight. McKitrick’s error made a substantial difference to his final results. Did Mann’s error make a substantial difference to his final results? The fact that you jhaven’t said so suggests to me that you don’t think it does. The only similarities between them are superficial ones like the names of the authors starting with M.
You beg off on John A’s entropy error because it was just a comment and you don’t want to bone up on first year physics. But what I wrote about the weighting error was also just a comment and you expect me to make myself an expert in PCA, something rather more advanced than first year stuff.
Ross, your initial response when I raised the clustering issue with you was to drop some of the data, reducing Canada, US and Russia to one observation each. I followed your procedure for all the countries. How come it’s suddenly invalid?
Steve: I haven’t done the calculations. I was trying to stay away from MBH calculations for a while pending clarification of all little issues. My guess is that it will have at least a 1-sigma impact on quite a few years. When I benchmarked Wahl-Ammann recently, the only difference between versions was whether eigenvectors 7 and 9 were added in or eignevectors 6 and 8 in the 1750-1760 period and this little difference accounted for over 1-sigma differences.
The responsibility for fixing the error and reporting on it is Mann’s. Why aren’t you criticizing him? Why aren’t you criticizing Wahl and Ammann for “mucking it up again”?
Let’s try another example to bring it closer to home. Let’s suppose that McKitrick made an error in principal components calculations in a multiproxy paper that he wrote jointly with someone else, that this error had been publicly identified so that there was no mistake about it and that McKitrick has not acknowledged the error. Can you imagine how vehement you’d be in your demands that I denounce the error? You’d be going crazy. Hunter would be salivating and writing in 20 times a day instead of 6 times a day. And you know what: with a heavy heart, I would write a post denouncing the error and urging Ross to correct it. I’d obviously lay off the most florid forms of rhetoric, but I’d chin up, face the music and do it. That’s what you should do.
In the above example, would you accept my explanation that just because it was an error in principal components analysis that that was not a sufficient reason for me to have to deal with it? No, you wouldn’t. Whether I like it or not, I’ve become identified with principal components issues and I wouldn’t be able to avoid the situation. Likewise, you may not view yourself as a cosine latitude specialist, but you’ve got just as much an obligation to deal with cosine latitude issues, as I would to deal with principal component issues.
I don’t think that the obligation arises because of an injudicious comment by you in a comment to a post; I don’t know about you but I have a psychological distinction between making a post and making a comment to a post. The issue is not your mistake (which is easy enough to do), the issue is Mann’s mistake, his failure to chin up to it and your failure to call him to account. Aside from mere teasing, I actually do think that you have an obligation in this case and that you should get on with it.
We need some cooling down! I have followed the arguments and disucssions on both ClimeAudit and RealClimate for some months now. I find both sites fascinating and I have learned a lot on the reality and myths of global warming and have been able to form my own views on what to believe. However, it is disappointing when discussions appear to move away from the science and maths and into personalities and personal attacks. While the heated exchanges provide some entertainment, they ultimately devalue the excellent work being done.
Steve, I haven’t demanded that you denounce any of the errors that McKitrick has made. And I note that one of them, his claim that average temperature has no physical meaning, is actually relevant to the current discussion. If you accept McKitrick’s claim, then you can’t say that the way Mann weighted his grid points is wrong since it amounts to weighting by area-squared, which according to McKitrick we have no reason to prefer over weighting by area.
I am under no obligation to deal with “cosine latitude issues” because 1. I am not a cosine latitude specialist and 2. there is no such thing as a cosine latitude specialist.
Tim: 2 things. First, I didn’t present the results from trimming Canada, US and Russian stations as a ‘valid’ correction, it was just an illustration to show why clustering effects were unlikely to matter. The ‘valid’ correction is a clustering-robust VC matrix, which shows the results remain significant. Now you know. If the potential clustering effects was truly the basis for your rejection of the results, you are obliged to stand down from that criticism. And why do continue to make such a big deal about the radians/degrees error? It never occurred to me that the Shazam trig function takes the data in radians. I published an Erratum right away (http://www.uoguelph.ca/~rmckitri/research/MM04.Correction.pdf) that puts the old and new results side-by-side, and readers can see clearly that it makes very little difference and the conclusions still stand. It was embarassing to find out that I’d made a programming mistake, but because Pat and I were completely open about our methods and we published an erratum right away we’ve never heard any criticism about the episode, except from you.
Second, you assume that I am in error regarding “average temperatures”, but you’ve never done Chris Essex and I the basic courtesy of posing reasonable questions and inviting a response. My book coauthor is an accomplished thermodynamicist–I am quite sure he can follow your arguments. People who have struggled with this aspect of our book have written us, or phoned, or walked down the hall, or talked to us during and after the many presentations we’ve made on Taken By Storm. We’ve heard all the usual objections and, guess what, the issues are not as simple as you assume. If you really think you know how to compute an average across a nonequilibrium system and show it to be “the” temperature of the system, write up your theory and send it to a thermodynamics journal. We will be the first in line to congratulate you.
Whether the clustering correction you prefer is valid depends on whether the clustering is well described by the model. I think the model assumes that there is the same degree of clustering in each country, which is unlikely to be even approximately true since there are some very big countries and some very small ones. Doing the analysis at the country level seems to be the safest option.
As I pointed out in my original post, the degrees/radians error does make a significant difference to your results:
As for “average temperatures”, my post is here, and already includes a response from you, but if you want to have another go at it, I’d be happy to add any further comments you wish to make.
Tim,
I am sure that Ross can answer for himself. But perhaps you could explain exactly what you mean by “I think the model assumes that there is the same degree of clustering in each country”. The closest I can understand you as saying is that the estimator imposes that the block diagonal elements of the variance-covariance matrix are all the same – but that can’t be what you mean because the block diagonal elements have different dimension based on the number of stations in a country and is, in any case, clearly incorrect. Calculating heteroskedasticity-consistent standard errors is pretty standard stuff using White’s technique and/or a specific clustering adjustment. The key point is that White is specifically designed to provide robust errors when the form of heteroskedasticity is unknown – you don’t have to specify a model or make those sort of assumptions.
Tim, I don’t know what you mean by: “the model assumes there is the same degree of clustering in each country”. If what you mean is that the asymptotic validity of using standard normal tables for evaluating the t-stats depends on assuming each observation is from a single country, that is not necessarily true. White’s variance-covariance matrix estimator can still be consistent even if not all variables vary by gridcell. It depends on the inter-group correlations and the average group size. If clustering mattered then the STATA correction would indicate large effects, but that is not the case. The STATA clustering correction provides a consistent estimator and uses all the information in the data set. Your ad hoc method is inefficient since that fails to use all the available information in the data set.
Our main conclusions were that significant socioeconomic effects in the station data carry over to the IPCC gridded data. The IPCC had claimed their data were adjusted to remove these effects. We tested the claim and the data reject it. We tentatively evaluated the size of the upward bias in the overall trend. The IPCC claimed that nonclimatic biases account for at most one-tenth of the trend in their global average. They had no basis for this claim (Jones et al 1990 does not establish it). As you note, we find nonclimatic effects may account for about one-third of the average trend in our sample, reducing it from .27 to .18.
Steve et al.
I do not understand your presumption that Tim Lambert has some sort of obligation to report both sides of the debate fairly. Tim Lambert is a partisan supporter of the AGW hypothesis and all its proponents. He has no interest in presenting both sides equally.
Jeff
Steve et al. are trying to help Lambert to get away from the dark side. Rather decent of them, really.
Why not do it yourself with Mann’s public code and data, or have MBH, W&A, or climate scientists do it for you? Shouldn’t it be MBH’s responsibility to make the correction and post the results (beyond some, “oh, it doesn’t make much of a difference” comment)?
I’ve seen plenty of people dismiss Steve’s work on MBH because he’s not a “climate scientist,” yet you, Dr. Hunter, and others must think he’s pretty capable because of your additional MBH analysis requests.
Do you notice how Lambert will sometimes intervene quickly as a moderator, but, if one of his posters, repeats the canard that I was somehow involved in the radians/degrees matter, he either doesn’t correct or lets it sit. Ore of his posters has repeated the canard: I guess Lambert either likes having posters make false derogatory statements of this type (which hang there but which he can disown) or maybe he’s too busy preparing his posting on Mann’s EOF errors (provisionally titled in Lambert style as “Mann Screws It Up Again!”) to correct this canard.
I think this basically sums it up. He’s better than many partisans in terms of reporting the other side, but that isn’t saying much, IMO.
Steve M, I can’t say I noticed one of my commentors blaming you for the degrees/radians error. Why didn’t you post a comment correcting the error?
But, when one of your commentors, John A, posts an obviously false claim about me, not only do you not correct him, you try to shut down discussion on the matter.
Steve: I shut down discussion in part because I had no way of knowing whether anyone knew what they were talking about since I was unfamiliar with the topic. I simply do not know whether his claim was false or not and I lack the time to find out. It may be false but it was not “obviously” false. On the other hand, the statement that I had anything to do with radians is obviously false and you know it to be false. You keep an eye on your comments. You’ve contributed to this false impression, which is often repeated; so when the canard is repeated again on your own board, you find it convenient to let the false comment hang, which seems questionable to me.
Tim, care to point out that John A post you refer to in #23 ? I presume it is not that one in this thread.
Tim, it is apparent to all that you do indeed have an partisan agenda and are not dispassionate scientist seeking the truth. If you applied as much zeal to dissecting Mann et al, I am sure you would find major issues with their work as Steve has. Who knows 10-15 yrs from now the Earth could cool down again and you could end up looking like the “Chicken Littles” in the 70’s who were saying there was going to be global cooling and the Earth was coming to and end. A dispassionate scientist looks at the data, and when he is proven wrong admits it and moves along.
Ed, John A’s comment is discussed here.
John F, are you seriously claiming that only way you can be a dispassionate truth seeker is by zealously dissecting MBH98? And have you posted a comment asserting that Steve McIntyre has a partisan agenda because he is not zealously dissecting McKitrick’s work?
Yawn, a strawman argument. How about being at least somewhat interested in seeing if McIntyre and McKitrick’s claims are valid?
Another strawman and also the “no true Scotsman” fallacy as well.
Steve V, you don’t seem to know what a strawman argument is.
Re #28 I think Steve meant a strawmann argument.
Tim, I don’t see any specifically false claims about you, arguable and refutable, yes. When posters on your site make specifically false, verifably false claims, you do not seem to make any effort to correct them. And given the partisan nature of your site, I can’t say that you should be surprised that people don’t always take you very seriously.
With regard to #28, your #26 is a classic strawman, nearly good enough for a “wiki”, try looking it up before you post next time, so you understand what Steve Verdon means. You can find it at http://www.talkorigins.org/origins/jargon/jargonfile_s.html
Ed, John A’s claim is verifiably false. And I do correct false claims made in comments. For example, here. Oddly enough, you participated in that thread, so it is rather odd that you would pretend to be ignorant of this.
Steve: Both of you – please take your discussion of entropy elsewhere.
Tim, I agree that you sometimes correct comments, but you have certainly contributed to a lot of false impressions that I was involved in radians and have made no serious effort to correct this misconception that originates from your melding M&Ms. Think also about your headlines: I haven’t said here that “Lambert doesn’t even know what a square root is” – isn’t there a nice epigram about this that would apply nicely here? Something to do with SFA. I didn’t say that Mann didn’t know what a square root was. I didn’t put up a trivializing diagram saying this is 2; this is the square root of 2: duh . In fact, your misunderstanding is much more worthy of criticism since you were well aware that an issue was involved and came down on the wrong side of the issue without any attempt at due diligence of even a google sort. I don’t even blame anybody for making the goof. The issue is the ongoing failure to acknowledge the goof. McKitrick chinned up to his problem right away and there’s no need to discuss it anymore. My interest is in errors and problems that have not been acknowledged, not in problems that have been dealt with. I also am really trying to keep some sort of focus on procedures for disclosure, due diligence and archiving.
Tim,
John A’s claim is verifiably true. Try actually asking a physics professor. You have no idea what you’re talking about, and are substituting verbosity for knowledge.
Steve: OK, you each had your say. Please take this discussion elsewhere.
Re #32
I assume we’re talking the question of temperature and thermodynamics here? I’m not sure if either you or Tim have ever made statements of sufficient rigor to be checked. How about, since you can post threads here, you post up a thread stating exactly what you want to have accepted and then Tim can post his rebuttal and I and others can check it. Physical Chemistry was always my favorite in College and I’ve got a Thermo textbook setting around here for checking things out. Even if you and Tim end up arguing on what the other said on past threads, at least the question will be settled for the future and we can move on.
Steve: Dave, I’ve asked this discussion to go elsewhere.
Steve, I am very disappointed to find that once again you have made false claims about what I have written. I have never attributed McKitrick’s degrees/radians error to M&M — I attributed it to McKitrick right from the start. I only have three posts about the error: Here, where I first reported the error; here, where I acknowledge that McKitrick had made a correction; and here, where I correct the misconception that you were involved in McKitrick’s error.
Nor did I imply or state that McKitrick did not know the difference between degrees and radians. I said that he had screwed up and that he had mixed them up, and both of those statements are true.
I am rather suprised to find that you find my tentative conclusion 142 comments into a discussion on my little blog more worthy of criticism than McKitrick’s error which was published in a journal, widely promoted as proving that the surface temperature record was flawed, and proclaimed by his coauthor like this
Finally, your claim that your "interest is in errors and problems that have not been acknowledged" sits rather oddly with your attempts to cover up John A’s error.
Steve: Since every syllable that I write seems to be parsed, I’m not trying to check every unchecked thing in the world. I am extremely conscious of not trying to spread myself any thinner than I already am. I’m focussing on multiproxy studies that have been published and widely reported. I’m not saying this simply for controversial purposes, it happens to be the case. You may find odd instances of commenting outside this focus, but I think that you;ll find that I’m pretty consistent. As to the entropy comment, I have no idea who’s right or even whether either of you have any idea what you’re talking about. It’s not something that can be verified in 2 seconds. That’s why I’ve asked you to step outside on this, although you keep dragging this back in.
On the other hand, my non-association with radians is something that you know about. The link that you cited did not contain any repudiation. I agree that the association is something that has been promulgated more by others being misled by your posts – which is why I feel that you have an ongoing obligation to correct the error when it’s made on your comment boards so that you don’t contribute further to the dissemination of misleading information than you already have.
You have shown that there was an error in the units input to the Shazam software, an identification made possible by the archiving of the software by McKitrick, for which you have given him no credit.
As you say, the above over-confident paragraph was written by McKitrick’s co-author, not by McKitrick. I am very unimpressed by academic peer review, which is a very limited form of due diligence in my opinion. McKitrick shares this view. I doubt that he would ever have endorsed the above paragraph in the first place, even before a problem arose.
As far as I’m concerned, an error of the type in this paper makes it all the more necessary to scrutinize papers that are widely relied on for problems: I thought that you of all people would agree with this. Arguably Mann’s tree ring principal component problems arise from a computer programming error, rather than him intentionally misrepresenting his procedure. When you add in the error in the temperature principal components, the unreported R2 statistics, the CENSORED bristlecone pine results, discrepancies between series listed and series used,etc. etc. together with the wide reliance on the paper, I would have thought that this would be right up your alley and that you’d be interested in seeing where it led and all over Mann for his unacknowledged errors.
Steve, I am extremely unhappy with your repeated misrepresentations of what I have written. My post was titled "McKitrick screws up yet again" and nowhere does it mention your name or your work with him. What is the basis for your claim that it misleads people into thinking it was about you? I have also already pointed you to this post where I correct the misconception that you were involved in McKitrick’s error. I am unaware of anyone posting a comment on my blog blaming you for the degrees/radians mixup, but if you can point to such a comment I would be happy to correct it. (snip of a trolling he said-she said on entropy; I have deleted a responding comment by John A to be symmetric).
Steve: The basis for my claim is that I’ve seen many instances in which a discussion of our work described as M&M is followed by a sneer about M&M also goofing on radians, originally linking back to your site, but now it’s a freestanding. In a quick google (and you are not entirely responsible for all after-market usage), the canard was repeated quite often at davidappell by e.g. Thomas Palm and Dano. So whether you intended to mislead, the net effect was that you did mislead. You had a poster a few days ago at http://timlambert.org/2005/06/barton/. The same form of association was used: that they use M&M to discuss our critique of Mann and then use M&M for radians. Obviously you know that there are two different M&M’s and you allow this to pass.
BTW For people who are interested in the entropy topic, it is alive at http://timlambert.org/2005/06/barton/ where Mark Bahnert has posed some questions on thermodynamics to Tim Lambert.
I reviewed the hundreds of posts in this thread. Thomas Palm does mention the degrees/radians error but attributes it to McKitrick, not M&M. So contrary to your claim, he was not misled and I don’t believe that anyone else has been either. There were two comments attributing the error to M&M, which is ambiguous and could be misleading. The issue was clarified by later commenters, but I have also added an editorial note to both of these comments. And if you felt that those two comments were such dreadful canards why didn’t you post a comment of your own correcting them?
Now I’ve corrected the comments you objected to. Contrast that with your conduct about John A’s canard about me. Not only will you not correct it, you are actively trying to cover up his error.
Tim, you’d better add comment #203 on the Barton thread at Deltoid to your list.
Lambert has said that he wanted to talk about thermodynamics on this board. I stopped the topic because I did not know enough to moderate the discussion and it seemed like thre were discussions elsewhere that interested parties could aprticipate in. I specifically identified a thread at Lambert’s blog.
After being challenged by Bahnert with what seem to me to be worthwhile questions and exactly on topic, Lambert refused to answer the questions saying:
I thought that Lambert wanted to talk about thermodynamics. Now he shut down discussion with someone knowledgeable on the topic. We can only hope that Lambert, who is much too modest about his cosine latitude specialty, is working on his forthcoming article “Mann Screws Up Again!”
(snip) John A., please…last words on entropy are already in. Steve.
Steve, as usual, you have it backwards. Bahner hasn’t posted any new comments about thermodynamics for a long time. All he has done is post insults and boasts. Requiring him to actually post something about thermodynamics is not shutting down discussion on thermodynamics — it’s trying to start it.
(snip of taunting familiar from previous posts)
If you had read the questions or understood them, you might have noticed that the "entropy" does not appear. Please correct the error in your comment.
Steve: As I said before, I pesonally have no views on the matter and, as you say, may not have understood the answers. I was just watching out of interest. I thought that you looked petulant in the exchange and could have been a little more forthcoming in your response. I thought that entropy was an imortant concept in thermodynamics, but, if you say that entropy does not appear, I’ll defer to you on this, but may wish to re-visit this if I take an interest in the topic.
Here’s an interesting and unexpected tie-in between Preisendorfer and Chris Essex from Ross, which might make you feel a little more reassured about Essex’ qualifications:
Steve
That’s twice you’ve either deleted or snipped my comments on this thread. Do it again and I shall be forced to follow John Hunter and whine pathetically on realclimate.
Entropy is an important concept in thermodynamics, but it is not, as John A believes, a form of energy. It’s even measured in different units.
Let’s see, Bahner wrote: "Bwahahahahaha! … Ever the arrogant twit, eh? … your arrogant twittering aside, that I’ve forgotten more about thermodynamics than you’ve ever learned … your laughably hypocritical assertion … I have a bit of free advice …" You don’t see anything wrong with his comments, instead you call me petulant.
I’m not sure why you are writing about Essex’s qualifications. The entropy argument is John A’s and is not something that Essex offered. Nor is there any chance of Essex making such an argument.
Steve: I wouldn’t have liked Bahnert’s editorializing either, but I still thought that you might have chinned up and responded. But I don’t know the history and don’t feel very strongly about it.
You made very strong criticisms of Essex and Mc. I don’t get the argument in Taken by Storm either and I don’t plan to study thermodynamics to get there; however, my impression was that your counter-argument was mostly just belligerence. While it’s possible that they made a mistake. I very much doubt whether Essex made a trivial mistake and your argument seemed to be assuming that it was trivial. I hope that you’ll permit to me to have the last word on this topic on my own blog, as I really don’t want to get drawn into a debate about something where I have negligible knowledge, as I’ve made clear. So let’s just leave it there. I’ll follow the discussion on your blog.
Ah, Bahner is "editorializing", while I am "petulant". Must be one of those irregular verbs.
My criticism of Essex and McKitrick is here. Please explain why you think that it is "mostly just belligerence". In particular, if your claim is correct, you should be able to quote multiple paragraphs of mine that are "just belligerence".
Steve: OK both of you were behaving badly. As I said before, I’m not interested in debating the topic at this time. You resisted my invitation to let me have the last word on a topic that I was not prepared to discuss, so there you go, you had the last word.
You claim to be letting me have the last word and yet you take yet another shot at me, accusing me of "behaving badly". I don’t think you can control yourself.
Steve: You had asked that, if I felt that your behavior was petulant, that I also recognize that Bahnert’s language was equally deserving of reproach. I did what you asked. Perhaps I should not have agreed with you merely to end a topic on which I was not prepared to comment, however, that is a point on which reasonable people can disagree. So let’s leave it there.
Since you wish to shut down the discussion on this topic I will not add anything new, but I will correct some errors or misconceptions that have crept into the conversation.
John A’s comments on entropy appear to be very ill founded and entirely different from Bahnert’s. I will also note that (as opposed to some of us) he appears to not be interested in the topic since he made one post on Tim’s site and proudly claimed that he would never post on it again. That seems like a strange way to defend your point of view.
Regards,
John.
Steve: I have no idea whether John A’s comments on entropy are ill founded or not. I have no idea whether you’ve corrected an error and misconception. I’ve asked everyone to take this discussion elsewhere, but everyone sure wants to have the last word and to “correct some errors or misconceptions”. I’ll tell you what: if you’re all so insistent about discussing entropy here, if Lambert makes a prominent post discussing Mann’s cosine latitude error entitled “Mann Screws It Up Again!”, you can discuss entropy here.
Steve: Since every syllable that I write seems to be parsed,
Pot kettle black
Steve, Your normally admirable civility on this site seems to have worn off over time in your comments above, which may disappoint you. Contrary to his invitation to Tim, above, your partner in M&M is one to whom nothing new could be said on the subject of climate science because he professes to know it all already. In fact he knows so much (despite being unqualified in the field) that apparently he and Essex have their gag-packed show "Taken by Storm" on the road playing to raving and rapturous crowds everywhere. I believe it – I’ve seen sillier things, actually. From "Taken by Storm": "… there are very fundamental uncertainties at hand when studying climate. There is no theory of climate. There is no known physical meaning for adding up data and dividing by the number of data that everyone insists on adding up and dividing by. Furthermore once they have this number, no scientific basis exists to show that its behavior has any implications for our lives. There is a lot of hand waving and gesticulating, but no science. The people who like these statistics have a burden that they have not been made to bear. You have to prove a proposition in both directions in order to make an equivalence. We can barely manage past complete handwaving to make it in one direction, and no one seems to have even thought about it at all in the reverse. In fact there is every reason to believe that it is not true at all in the reverse. Temperature statistics can go up in the very small amounts we speak of without any meaningful effect, and similarly they can remain fixed even during huge climate change. Some types of statistic from the Earth’s temperature field are going up while others are going down. This reflects more on the nature of averages than on the state of the Earth’s climate. The system under study is chaotic, and we know from studying simple chaotic systems that classical notions of causality and scale can be thrown out of the window in such situations. The fluid media of climate (air and water) are turbulent, ruling out computation of changes from first principles. The data show hints of following nonstandard distributions that rule out conventional statistical methods. We don’t know what the climate would be like if we were not here. We may not be able to identify climate change, even after the fact. Climate research involves some of the greatest unsolved problems of basic science. It is not the stuff on which to base costly and far-reaching policy commitments. To do so requires one to speak about climate with great certainty. Those who do so are only courting the laughter of the gods." You want more? – you can’t handle any more. The burden that’s not been borne by anyone, in reality, is that of peer review of E&M’s fantastically modest, unpretentious and meaningful little book. Oh, and the usual boring and fusty old academic burden of respecting one’s peers in science sufficiently to not go blundering unbidden and peculiarly unqualified into their field, own trumpet blaring and trousers down.
Steve: I will try to be more civil. I got irritated at being trashed by Crowley in EOS for “threatening” when it was a complete fabrication; I get irritated at the radians dispute; I thought that Lambert was hypocritical in trashing McKitrick; I get irritted at Manns misrepresentations, but have grown serene about it. I will try to return to a more serene disposition overall.
Steve’s idea of being more civil is to falsely accuse me of hypocrisy. Wonderful.
Steve: Come on, Tim. You trash McKitrick for a cosine latitude and won’t write "Mann Screws It Up Again!" for a worse mistake. What do you expect me to think? But I’m getting entangled in other people’s fights, which I don’t want to do. So I’ll lay off for a while. PS. I thought that the history of Spiked! was fascinating.
You have more posts about cos latitude than I do. By your logic it follows that you must be a cos latitude expert. And also by your logic you must post about McKitrick’s error. You have failed to do so, and yet you have not accused yourself of hypocrisy. Weird.
Steve: Tim, you’re sounding like a troll.
You just don’t seem to care whether what you write is true or not. Here is a direct quote from you in comment #31: “In fact, your misunderstanding is much more worthy of criticism”. You claimed that my comment was more worthy of criticism than McKitrick’s degrees/radians mixup and now you are trying to pretend that you didn’t write that.
Dang! Another irony meter busted! This is going to cause a rise in my insurance…
Tim, let’s see:
in # 31 I said:
Then in #50, I said:
In the first passage, I said:
In the second passage, I said:
Read as a whole, I think that the point is perfectly consistent. In the first passage, I said that I “don’t blame anybody for making the goof” and in the second passage I said that I was not being “critical of your error”. In both passages, I was focussing on your failure to criticize Mann. Seems perfectly consistent to me.
In the first passage (but not the second passage), I said that your error was "much more worthy" of criticism than McKitrick’s. There’s nothing in the second passage that resiles from or contradicts this position. But while it was and remains “much more worthy” of criticism, I was criticizing you for somethign different.
There’s an interesting discussion at timlambert.org here http://timlambert.org/2005/08/mcintyre/#comment-9080 in which the redoubtable Per and the equally redoubtable James Lane (occasionally) are trying to winkle out responses from several M&M opponents about, inter alia: 1) how do they justify statistical significance to a model with an R2 of ~0.0? 2) how do they justify not reporting this? Tim Lambert has opined that R2 is not a measure of statistical significance, applying his Lott arguments. Here Lambert seems to be doing the usual realclimate sleight-of-hand, saying that an R2 statistic is not a sufficient condition for statistical significance; ergo, it is not a necessary condition. Watch the pea underneath the thimble carefully.
In reponse to usual arm-waving allegations of manifold "errors" by M&M, Jame Lane asked David Ball to name one – Ball cited the our criticism in MM03 that MBH98 had truncated the Central Europe series from the archived version without any explicit statement; Ball argued that the underlying references said that the proxy quality was lower prior to 1550 and that, if we weren’t so stupid, we’d have known this. Per rather neatly pointed out that MBH98 has simply invented data for the early part of the Gaspe series, which consisted of only one tree. So whatever quality control measures supposedly resulted in the excision of the first 25 years of the CEur series would have excised the early portion of the Gaspe series.
Needless to say, none of the correspondents have satisfactory replies to Per or James Lane on any of hte issues and have resorted to bluster.
Yeah, the problem is you can’t engage these guys on the important issues. I asked David Ball for examples of the “manifold” errors in M&M’s work, and he came back with a response so lame it was self-embarrassing. But ask them about r2 or bristlecone pines it’s all dodging and weaving and in the end “it doesn’t matter”.
In response to the r2 issue, Lambert provides a link to a link which clearly explains what r2 is and why a value of ~0.0 implies zero predictive skill for a model. As they say, go figure. Per clearly has more energy than I do – arguing with these guys is largely a waste of time.
The r2 issue is important, not least because it reflects on MBH standards of disclosure, but it could be argued that the bristlecone pines (BCPs) are more important, as they are also represented in many of the subsequent paleoclimatic reconstructions.
I lied. I’ve had another go at Lambert on r2.
I give Tim credit for finding the original trig error. I gig him for his grudging admission (and immediate, wrong dismassal) that Mann was also in error.
It’s instructive to see the difference in how Ross corrected his error as opposed to Mann. Ross wins. Mann loses.
Hi, All:
I just found this website and do not want to get involved in any fight, but can anybody tell me why some people want to use cos(latitude) and some want to use sqrt(cos(latitude))? Are we doing this to get the area the same for the same latitude increment (delta_latitude) and longitude increment (delta_longitude)?
Thanks,
Aaron
Bottom line is, diminishing returns. Parasitic dissipations consume more and more of the energy of a process as a certain level is approached. Classic example, with implications regarding space travel, Star Trek fantasy notwhithstanding, is that as the speed of light is approached, incremental energy needed to further increase speed approached infinity, and hence, you can’t go faster than the speed of light in this universe assuming no bizarre things like so called “worm holes” and other cheating.
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[…] Steve McIntyre then pounced on my comment, presenting evidence that von Storch was correct. He even stated that my comment was more worthy of criticism than McKitrick’s mixing up of degrees with radians in a journal paper touted as a bombshell that refuted global warming. […]
Steve: Tim, Tim, Tim…. Mann got mixed up with square roots of cosine latitude in a journal paper touted as a bombshell, that not only was peer reviewed in Nature, but was supposedly peer reviewed by entire stadiums full of scientists in the IPCC process and featured by IPCC and many governments. The due diligence supposedly applied to the Mann paper far exceeded that supposedly applied to a journal article. You snickered at the Climate Research peer reviewers – shouldn’t you be ROTFLOL about the IPCC process. You dumped all over McKitrick for making the error; you should be doing the same thing for Mann, entitling your post “Mann Screws It Up Again!” McKitrick provided source code which enabled the error to be identified and promptly acknowledged the error; Mann has failed to acknowledge the error. People make errors – that’s why there should be complete transparency and why you should have commended McKitrick at some point for making his code available. It’s not about beauty contests; it’s about systems of due diligence. I’m critical about your failure to criticize Mann, rather than your error. BTW you’ve made another error in your comment about Fourier series.
[…] Mind you, Steve McIntyre isn’t convinced that there is anything wrong with their argument because “Chris Essex is an accomplished thermodynamicist” and […]