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« Josh 27 | Main | McIntyre in Die Weltwoche »

Tamino on the Hockey Stick Illusion

Tamino has a rave review of the Hockey Stick Illusion up at Real Climate. I'm reading it now.

A few initial observations - there is a lot of discussion of proxy selection rules in Tamino's piece. This is complex for those who aren't embedded in the nitty gritty of the science, but stand back and ask yourself this: if you have over 100 series in your database, and one of these is the fourth most important pattern in the tree rings of a couple of closely related tree species in one area of the western USA, how comfortable are you that this series should form the basis of the temperature reconstruction for the northern hemisphere? The idea that you can reconstruct hemispheric temperatures in this way is deeply unsatisfactory.

Tamino doesn't try to defend the use of the bristlecones. It's not clear why it's worth arguing about PC retention if everyone (including the NAS and Wegman panels) agrees that bristlecones are inappropriate.

The observation that "McIntyre argued that the entire Gaspe series should be eliminated because it didn't extend all the way back to 1400" is wrong. MBH had its steps starting at 50-year intervals. Gaspe should therefore have been in the 1450 step not the 1400 one. There is probably an argument that Gaspe should be excluded because the update that was taken didn't show the same shape (although it was never published and everyone seems to have subsequently forgotten where the actual location of the trees is).

There's a lot of discussion of reconstructions being hockey stick shaped. The critical issue is of course the relative warmth of the medieval and modern periods.

Remembering Matt Ridley's article about straw men? I am criticised for complaining that hockey stick shape proxies dominate reconstructions and apparently I imply "unfairly" so. I explain how the hockey stick shaped series come to dominate the reconstruction, but I don't imply unfairness as far as I remember. Of course, since Tamino doesn't actually quote anything I said that implies unfairness, it's hard to respond in a precise way.

I'm accused of quote mining re the "better for our purposes" quote. Given that I start by saying that an innocent explanation is possible, I'm not sure this is reasonable criticism. I don't think it's a "killer quote" but it was there and McIntyre raised it in his correspondence with Nature, so it needed to be discussed.

There are very few quotes of any kind from the book (go figure), but certainly some I'd like to use on the cover of the next printing:

"A narrative worthy of the best spy thrillers"

"...spins a tale of suspense, conflict and lively action, intertwining conspiracy and covert skullduggery, politics and big money".

My publisher is going to love it.

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Reader Comments (229)

Thanks for that Dr Curry. It's good that RC have acknowledged the existence of the book and I guess I am pleased that this is the best they can come up with.

Jul 23, 2010 at 12:25 PM | Registered CommenterBishop Hill

No sign of Dr Curry's post yet. I have commented too at RC, just to see what happens.

Jul 23, 2010 at 1:44 PM | Unregistered CommenterPhillip Bratby

Dr Curry - No sign of your post at RC as yet. Perhaps it's wafting around in the luminiferous aether of "moderation"

Jul 23, 2010 at 1:52 PM | Unregistered CommenterGrantB

At 8:52 Eastern, Judith's comment has not appeared.
I also found Tamino's presentation odd. I posted the following:
23 July 2010 at 7:44 AM
Any PCA that generates multiple presumably significant factors has to explain/interpret all the factors. Plotting and focusing on a single factor without explaining the others is not legitimate – regardless of what kind of centering you use. This is especially true when analyzing a limited number of data series.

My experience with PCA in a very different field (i.e, psychometrics) is that with small sets of data you really need to be careful that your factors don't essentially turn out to be simply a subset of your data series (i.e., a cluster analysis). To avoid this you need to (a) check the loading against the data series and (b) make sure you interpret all the factors. If you do this then odd data series like Bristlecone pines simply jump out at you. The SI that accompanies any PCA based analysis should present the raw and rotated factor weights so that they can be examined to avoid the major error of identifying a pattern that is due to a single or small subset of data.

Jul 23, 2010 at 2:12 PM | Unregistered CommenterBernie

RC is and always has been a PR site for a certain worldview.

wikipedia on EMS

"Environmental Media Services (EMS) is a Washington, ... was founded in 1994 by Arlie Schardt, a former journalist, former communications director for Al Gore's 2000 Presidential campaign, ...
[They provide] web hosting and support for environmental issues sites like RealClimate
EMS is closely allied with Fenton Communications (where they shared the same office space and personnel)"

This is a matter of public record.

Jul 23, 2010 at 2:20 PM | Unregistered CommenterJack Hughes

Meanwhile, on the other side of the Pond

Just in case you are worried that your continuing efforts to stop the AGW madness aren't having an effect, I do have an interesting tidbit to warm your cockles, or whatever.

Reid throws in towel on climate bill

Jul 23, 2010 at 2:30 PM | Unregistered CommenterDon Pablo de la Sierra

I just read the Tamino post. What really struck me were the comments, it was like the shrieking adulation of a bunch of 13 year old girls after their playground princess bitchily puts down another girl for wearing the wrong colour lipstick. It was a great surprise and a revelation to me.

Jul 23, 2010 at 2:40 PM | Unregistered CommenterLiam

Back from Troll Land

Found the postings from ThinkingScientist and JC on the RC. Gavin is a hostile personality, isn't he?

ThinkingScientist says:
23 July 2010 at 6:15 AM

There is one small point forgotten about here concerning the MBH98 algorithm/methodology.

When tested with stationary (no trend) noise the algorithm still produces a hockey stick. Therefore the method cannot be classified as “robust” or having any merit.

[Response: Well, I'm sure you've done the calculations for this (being a 'thinking scientist'), and so I'm curious as to why you don't mention the fact that the amplitude of such an artifact is an order of magnitude smaller than the actual HS in the data? The reason that the final reconstruction is robust is precisely because the signal is in the data. But let's be clear, if you don't like the original method, fix all the supposed problems and do it over. Oh yes, already done. - gavin]

Judith Curry says:
23 July 2010 at 6:20 AM

JC’s grade for the review: C-

pros: well written, persuasive

cons: numerous factual errors and misrepresentations, failure to address many of the main points of the book

If anyone is seriously interested in a discussion on this book, I can see that RC isn’t the place, people elsewhere are already describing their posts not making it through moderation.

[Response: Grading on the Curry Curve perhaps? Judith, the fact is that endless repetitions of allegations of corruption do make them true. Really, do you think that collaborators having a 'purpose' is some terrible indictment of their research? Tamino has demonstrated clearly that Montford's book is full of errors and insinuations that have no basis in fact. And now you come along and tell us that, no those weren't the important bits at all, it's the other stuff. Which you still haven't actually described. You might find it amusing to play hunt the thimble, but excuse me if I find it a little tiresome. Please make your actual point. - gavin]

Jul 23, 2010 at 2:42 PM | Unregistered CommenterDon Pablo de la Sierra

Stilll making half-baked, generalised and unsubstantiated allegations I see Dr. Curry.
How scientific.

Jul 23, 2010 at 2:44 PM | Unregistered CommenterBishop Phil

Many thanks Judith. A note of sanity and balance, and much appreciated as ever.

Jul 23, 2010 at 3:17 PM | Unregistered CommenterJosh

As others have noted, Judith's comment is now up together with a curt response from Gavin. It looks like it took 3 hours to get through moderation. My assumption is that someone is monitoring this site and realized that not posting it was going to be more trouble than simply dissing it. I hope Judith finds time to soon to identify what she sees as Tamino's oversights.

In the mean time, if you noted Tamino's issue on recentering and his citing of Huybers argument, please look at Steve and Ross's very thorough response in GEOPHYSICAL RESEARCH LETTERS, VOL. 32, L20713, doi:10.1029/2005GL023586, 2005 ( ) . Peter Huybers apparently has not responded formally to the points raised by Steve and Ross ( ) This is a perfect example of misrepresenting the argument.

Jul 23, 2010 at 3:18 PM | Unregistered CommenterBernie

Ah well, my very moderate post didn't get through moderation.

I know it's been said before, but aren't Gavin, Eric et al paid by the US taxpayers to do their day jobs?

Jul 23, 2010 at 3:32 PM | Unregistered CommenterPhillip Bratby

Phillip Bratby

Perhaps Gavin hasn't come up with a puerile enough retort. He has his standards to maintain, you know.

Jul 23, 2010 at 4:33 PM | Unregistered CommenterDon Pablo de la Sierra

Has the makings of a Hollywood Blockbuster.

Who would play the leading roles? What would be the title of the movie be?

Harrison Ford as Steve McIntyre, Michael Gambon as Phil Jones, Nicolas Cage as Michael Mann in "Honey I Shrunk The Medieval Warm Period"

Of course there has to be a love interest (Angelina Jolie?) and a car chase scene, "Quick follow that climate scientist"

Jul 23, 2010 at 4:34 PM | Unregistered CommenterMac

Thinking Scientist at RC got a response from Gavin

ThinkingScientist says:
23 July 2010 at 9:47 AM
RE: Gavin’s reply to #72

...First part requires tracking the prior discussion, But Gavin's response to the next point is intriguing.

RE: #67 if in MBH98 the Hockey Stick result lies in PC2 and this method fails red noise tests, and in MM03 it appears in PC4 then just exactly what do the MAIN signals in the proxy record in PC1 (MBH98) or MM (PC1, PC2 and PC3) correspond to in the climate record? After all, a look at the Hockey Stick result suggests that climate was pretty much flat (slightly declining) for 600 years and yet apparently the Hockey Stick (with its enormous deviation and variance) does not appear in PC1. Why not?

[Response: You are confusing one element in the proxies (the north american tree rings) with the whole thing. <B>PC's are just a way of reducing data - they do not come with obvious interpretations necessarily. Sometimes they can be clearly seen to be related to known phenomena (for instance the first PC for tropical Pacific temperatures is closely related to El Niño), but not always. Emphasis added Multi-proxy methods like this look for patterns in the data that are correlated to other proxy records and the target temperature data and so purely local elements, whether climatic or not, get down-weighted. The test of whether this is useful is whether you have some predictability in the validation interval, and whether the basic patterns hold up when you add more data, change the method, hold back some data etc. And they are. - gavin]

Read it carefully. Gavin does not have a clue or is being deliberately obtuse. Steve and Ross did what he says to do. Mann, originally, did not. End of discussion.

Jul 23, 2010 at 4:45 PM | Unregistered Commenterbernie

Please delete earlier post I screwed up the tags

Thinking Scientist at RC got a response from Gavin

ThinkingScientist says:
23 July 2010 at 9:47 AM
RE: Gavin’s reply to #72

...First part requires tracking the prior discussion, But Gavin's response to the next point is intriguing.

RE: #67 if in MBH98 the Hockey Stick result lies in PC2 and this method fails red noise tests, and in MM03 it appears in PC4 then just exactly what do the MAIN signals in the proxy record in PC1 (MBH98) or MM (PC1, PC2 and PC3) correspond to in the climate record? After all, a look at the Hockey Stick result suggests that climate was pretty much flat (slightly declining) for 600 years and yet apparently the Hockey Stick (with its enormous deviation and variance) does not appear in PC1. Why not?

[Response: You are confusing one element in the proxies (the north american tree rings) with the whole thing. <B>PC's are just a way of reducing data - they do not come with obvious interpretations necessarily. Sometimes they can be clearly seen to be related to known phenomena (for instance the first PC for tropical Pacific temperatures is closely related to El Niño), but not always.</B> Emphasis added Multi-proxy methods like this look for patterns in the data that are correlated to other proxy records and the target temperature data and so purely local elements, whether climatic or not, get down-weighted. The test of whether this is useful is whether you have some predictability in the validation interval, and whether the basic patterns hold up when you add more data, change the method, hold back some data etc. And they are. - gavin]

Read it carefully. Gavin does not have a clue or is being deliberately obtuse. Steve and Ross did what he says to do. Mann, originally, did not. End of discussion.

Jul 23, 2010 at 4:46 PM | Unregistered Commenterbernie

Just for the record, my simple Real Climate comment asking what happened to the right hand ends of Tamino's proxy plots didn't get through moderation. Now I am amused to read some lines from Doug Bostrom on that thread

"...if those claiming to have had posts deleted are honest and of course we have no way of making a final determination on that question." (in the context of this particular comment 'post' means 'comment')

I guess that those who see their comments deleted will _know_ who is being honest.

Jul 23, 2010 at 4:56 PM | Unregistered CommenterZT

RC comments == Potemkin Village

Jul 23, 2010 at 5:12 PM | Unregistered CommenterJack Hughes

Review seems to be a stock RC attack of the snarks, but no suprise there. A fictional Scotsman said it better:

Life's but a walking shadow, a poor player
That struts and frets his hour upon the stage
And then is heard no more: it is a tale
Told by an idiot, full of sound and fury,
Signifying nothing.

Until the RC crew can find a decent explanation for the divergence problem and why standard sampling principles can be ignored in creating 'global' time series analyses, they're probably best left helping alienate people with enquiring minds.

Mac: Like the title, not sure a car chase would work. Santer and the rat incident would be cheaper than finding a horse's head and our hero could go chasing the Hummer. But they're environmentally friendly people (allegedly), so bikes or segways vs 6L V8 wouldn't quite work.

Jul 23, 2010 at 5:25 PM | Unregistered CommenterAtomic Hairdryer

Bernie - thanks - I have more simple questions in moderation and also a supporting comment for Judith's plea for openness. If that isn't posted, I'll post here but RC should get the benefit of the doubt and the chance to post it first.

This is the first time ever I have had a subsequent comment or reply posted at RC

...and now the RealClimate server is either overloaded or has gone down!

Jul 23, 2010 at 5:46 PM | Unregistered CommenterThinkingScientist

ZT - I directly addressed Doug Bostrom's comments. His arguments are circular.

I am waiting to see if my reply to his comments make it through unscathed. If not I will post here to see if people think what I proposed was reasonable.

RC should be given the chance to open up and post my comment. Its called giving them the benefit of the doubt and appealing to their better nature.

Jul 23, 2010 at 6:04 PM | Unregistered CommenterThinkingScientist

For those interested, my reply to Doug Bostrom at RC (see ZT above) was published in full, including the references to CA, Bishophill and WUWT which are normally deleted as standard [edit].

Jul 23, 2010 at 6:30 PM | Unregistered CommenterThinkingScientist

Doug Bostrom is beyond hope. He is constantly 'surprised' that people complain about RC comment deletion when his comments always get through. Figure that out. The other habit is that of posting comments with their gavin responses added (after having given it much thought). This is to prevent the fauthful from making goofy responses which weaken the blog's argument, by opening other channels of inquiry. Once the Gavin Response frames criticism to any strong or substantial comment, the rest can jump through the same hoops easily.

Gavin's main line of complaint against Dr JC's post is that there is 'endless allegations of corruption'. Where exactly does Bishop talk about corruption in his book?

My guess is - Gavin has not read the book.

Jul 23, 2010 at 6:36 PM | Unregistered CommenterShub

One of the things that Cuccinelli investigation is going to look into is whether public research grant money was used to commit fraud. If the Team has engaged in a concerted effort to cover-up defects in their work product such that those defects would not interfere with their ability to get additional grants, then that conduct could be the basis for a fraud indictment. For example, if the Team used grant money to pay someone to troll around on Wikipedia erasing any evidence of controversy related to the Hockey Stick, that could be a problem. If the Team used grant money to pay someone to write reviews that knowingly distort the facts in order to create an appearance that criticism is not credible, that could be a problem. If the Team paid people to moderate RC comments to erase evidence of controversy, then that could be a problem. Taken together, all of these things would be strong evidence of a concerted effort to defraud the public. It would be a bit like a pharmaceutical company paying people to erase evidence that a particular drug was defective. Or, it would be like a car company paying people to erase evidence of sudden acceleration problems with a particular vehicle. Or, it would be like an oil company erasing evidence of pressure problems in a particular deep water well.

Jul 23, 2010 at 6:41 PM | Unregistered Commentermpaul

Atomic Hairdryer, "alienating people with enquiring minds" is likely RCs mission statement. and, Thinking Scientist, we stand in awe of your persistence and resilience.

Jul 23, 2010 at 7:14 PM | Unregistered CommenterZT

ZT - Actually in my own field I am usually characterised as "not suffering fools gladly" and I am famously short-termpered and intolerant with spurious argument. But sometimes you have to be patient, make your case politely and coherently and hope that the other party sees your point. With RC, no other strategy could possibly have got that post #97 through as I have previously found out when my other posts on a similar point about censorship were not allowed.

Interestingly my two technical follow-on comments to Gavin's replies to mine are still awaiting moderation. I suspect they are too close to the bone technically and will not see the light of day, or will but with throwaway answers. They were posted 90 minutes ago and 45 minutes ago, but perhaps the moderator is taking lunch as nothing has appeared yet after my comment #97

Jul 23, 2010 at 7:23 PM | Unregistered CommenterThinkingScientist

I am not entirely sure you are aware of the full spectrum of comment mangling, deletion, and the attendant distortion it creates.

If I post a comment X, which is hostile to RC's argument, it will appear with all the rhetorically strong argumentative points taken out by "[edit]" and the remainder of the post will be responded to with the Gavin Response, along with multiple other commenters following quickly, whose comments, unlike mine, will appear with much greater rapidity.

If I post a comment X, which is rhetorically very effective, it will not make its appearance until hours. If I make a lame comment Y, it will appear immediately.

If I post a substantive comment X, it wont appear for days together. If I make a fluffy comment Y on the same subject, it will appear immediately.

The overall focus here, is not to answer your criticisms per se. The effort is always guided by the knowledge of how a thread will read, by a third person. Threads are contoured and moulded activitely, responses are lined up, released or jettisoned according to the maximum protection that can be afforded to the blog's position.

Gavin always moans about having to 'shoot down' tired old 'debunked' 'talking points', 'memes' etc. Why have the blog open at all then - I am sure everything has been debunked, just close down Realclimate for a job well done.

Jul 23, 2010 at 7:38 PM | Unregistered CommenterShub

It amazes me that when there are historical records of a MWP we need a temperature reconstruction at all. Even more that when we get the Hockey Stick, people dump the historical records in favour of a bunch of suspect proxies and even more suspect statistical methods?
Greenland did not get its name because it was white Duh!

Jul 23, 2010 at 7:50 PM | Unregistered CommenterDung


Just returned from a visit to Troll Land and read not only your comments but others. As a psychologist, which I do have some small knowledge in, you are wearing him down. Gavin is on the defensive now, looking over his shoulder. He knows he has made serious mistakes in his previous flippant remarks to both you and JC.

Keep up your present present tack and patience. You are scoring points on him and he dare not "silence" you because if he does, everybody will know it, and he knows it.

WEAR THE BASTARD DOWN! As well as Dougie, boy scientist.

Josh, take notes, you may have another cartoon coming out of this!

Jul 23, 2010 at 7:51 PM | Unregistered CommenterDon Pablo de la Sierra

I wonder if Tamino now regrets taking on HSI? In my view, he appears to have done more harm to his position than strengthen it.

As for Gavin, he clearly has no idea what the f*** he is talking about, particularly statistics. His comment:

The test of whether this is useful is whether you have some predictability in the validation interval, and whether the basic patterns hold up when you add more data, change the method, hold back some data etc.

is totally wrong. It is forward prediction that matters i.e. true prediction of that which has not yet occurred. And playing with the data as he suggests is nothing more than statistical masturbation.

Jul 23, 2010 at 8:03 PM | Unregistered CommenterDon Pablo de la Sierra

I have been following this subject with great interest for a couple of years. In fact, I recognized a lot of the characters referred to in the book from reading various blogs and scientific (peer-reviewed haha) papers. I am almost through the book and will certainly finish it. Having said that, the conclusion I as a layperson must come to is that someone on one side or the other isn't being truthful. Either you remove a few proxies and the Medieval Warming period reappears or you remove them and the hockey stick remains validated by many other proxies that don't include NOAMER bistlecone pines or GASPE. Both sides sound very scientific but are saying the opposite. Am I wrong? I'm not sure reading more blogs will clear this issue up for me. It comes down to who can one trust. Or are both sides cherry-picking toward an end result? Sometimes I feel like we as the public are victims of mass "perception management" and it is very frustrating to try to sort through to reality.

Jul 23, 2010 at 8:22 PM | Unregistered CommenterC Johnson

Gavin's comment at the end of #106 concerning inclusion of Briffa in IPCC is interesting.

Regarding #110 by Didactylos, this is such silly comment that I am surprised Gavin let it through. I have responded as politely as possible but Gavin must know as well as I do that MM2005 running what are essentially spurious correlation tests using stationary red noise is an entirely valid and commonplace practice for testing techniques such as the unusual method of MBH98 where no standard methods may exist. We'll see if my rebuttal to that makes it...

Jul 23, 2010 at 8:32 PM | Unregistered CommenterThinkingScientist

Well, it seems I've been snipped over RC once again. Here's my comment in full in the case it's been redirected to dev/null:

Jean S says:
Your comment is awaiting moderation.
23 July 2010 at 2:29 PM

Tamino: “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).”

Let’s get facts straight. First, “Preisendorfer Rule N” alladgedly used by Mann et al is by no means a “standard” selection rule. In fact, it’s an obscure ad-hoc method used by few climatologist and unknown in real statistical literature. Using some selection rules common in the true PCA literature the 4th PC does not get selected. Moreover, the rule as described in the original literature is based on variance arguments and therefore can not be even applied to “noncentered PCA” (whatever that is supposed to do) as used by Mann et al. Second, the use of “Preisendorfer Rule N” is not described in MBH98 (or related literature), and it is not found in any MBH9X relesed (or leaked) code. Moreover, it is easily demonstrated that Rule N was not consistently used in MBH98. Last, but by now means least, what on Earth one should conclude about work that is supposed to describe general temperature patterns of an entire northern hemisphere but is extremely depended on the _fourth_ most important pattern in a proxy network covering merely western USA? The word “robust” is definitely not on lips of any thinking man.

Tamino: “It was also pointed out (by Peter Huybers) that MM hadn’t applied “standard” PCA either.”

Huybers was mistaken. Tree ring series are already in common units. In such cases the covariance based PCA (as done by MM) is recommended. The correlation based PCA (as advocatd by Huybers) is used only in cases where no common units among variables exist.

Tamino: “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.”

Oh, I guess you simply forgot to exclude also the “Gaspe series” you later describe as “the most hockey-stick shaped proxy of all”. Why don’t you publish your results with the 19 remaining proxies?

Tamino: “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.”

Let’s face facts folks – Tamino’s claim is beyond reason and downright ludicrous – and Tamino knows it. The four year unreported ad-hoc extension makes all the difference whether “the most hockey-stick shaped proxy of all” gets included or excluded to AD1400 network. Without it (and the infamous bristlecones masked as “PCs”) the hockey stick is an endangered species.

Tamino: “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.”

How many times do you think you can play this leave-one-but-only-one-out -game and still people would buy the rotten argument?

Jul 23, 2010 at 8:54 PM | Unregistered CommenterJean S

Jean S, why, your ridiculous question sounds exactly like someone seeking a pre-determined conclusion. You could dismiss more and more data, or realise, to paraphrase what was so eloquently put on RC, that the hockey stick - the one kickass graphic totem that sticks in your craw so much, resides in the data. Which, as we know, consists of more than tree ring analysis.
The world is warming despite groupw@nksessions by your denialist faction.
The only real question is how to accommodate that unwelcome fact.

Jul 23, 2010 at 9:33 PM | Unregistered CommenterBishop Phil

It seems there is an attempt to discredit you Bishop. chek at #116 says:

"Keith, I suspect the reason Curry “thinks highly” of Montfords book is because he’s created a narrative that’s easily followed. We don’t actually know her reasons because whenever one tranche of evidence is dealt with she alludes without specifying to a mysterious other, different set as was evident on that thread on C-A-S backin April. And when inescapably confronted over Wegman for example, she chose to figuratively speaking stuff her fingers in her ears and announce she didn’t want to hear anymore about it.

What Dr. Curry seems unaware of is that creating narratives is what writers do, and for various reasons. Montford’s book, as Tamino, Deep Climate and John Mashey are showing) is nowhere near as comprehensive as she appears to believe and selectively creates a narrative. How could Montford have examined GB’s of emails and interviewed any of the participants in the time available? That’s an easy question to answer – he didn’t. Some might call his expediency and haste to jump on the (co-ordinated?) bandwagon fabrication, or charlatanry, or creating a fiction but then, that’s what writers do. The one thing it isn’t is credible science.

Essentially Montford is to climate science what von Daniken was to archaeology."

I don't think these people engage their brain before writing. Russell managed to write a long report without interviewing Jones. Biographers manage to write historical biographies without interviewing anybody.

Tamino and the Team followers at RC are doing you a great favour with all this publicity. One thing they aren't doing is helping their own cause.

Jul 23, 2010 at 9:35 PM | Unregistered CommenterPhillip Bratby

So that's it! Tamino keeps repeating the Hockey Stick by always retaining one or more of the questionable proxies while removing others. Is that it? Just want to understand where manipulation is occurring.

Jul 23, 2010 at 9:38 PM | Unregistered CommenterC Johnson

Don Pablo, you are right there is a lot of comic mileage here.

I am enjoying the way this thread is turning into a pleasant echo of the one at Real Climate - if you can't get your comment up there you can post it here, e.g. Jean S comment. Brilliant, thanks Jean!

Jul 23, 2010 at 9:51 PM | Unregistered CommenterJosh

C Johnson, that is indeed the essential technique. It has become more complex over recent years as the menu of "questionable proxies" from which they can select has increased, but the method is still easily recognizable if you keep an eye out.

Jul 23, 2010 at 9:56 PM | Unregistered CommenterJonathan

C Johnson you deserve a better response than I can give but atm, the heavyweights from this forum are busy area bombing RC so.......

The Hockey Stick as investigated by Steve McIntyre fails on a number of tests.

The most convincing for me is the red noise test. If you put random data through Manns model you still get a hockey stick.

The North American Academy of Science said years ago that tree rings should be avoided as proxies because they are unreliable so there should be no tree ring data in there.

However they are right to say that you can leave out all the tree rings and still get a hockey stick. That is because the short centering of the data (explained at the start of HSI) gives the most weight to any data series that ticks up in the 20th century. Even if there is only one data series that ticks up you will get a hockey stick.

So in answer to your question you only need to leave out the tree ring data but also you need to avoid the short centering.

The whole of the Hockey Stick debate is (as someone else posted here) about whether or not there was a MWP that was warmer than today (In which case we have no reason to worry about current warming).

However there was a Holocene Maximum about 2000 years ago that was even warmer than that. The evidence shows that todays temperatures are not unprecedented.

Jul 23, 2010 at 9:59 PM | Unregistered CommenterDung

My moderate post to RC got moderated; but it is acceptable for others to post there with no other content than to call Judith Curry a troll! Says it all about RC's policy.

Jul 23, 2010 at 10:03 PM | Unregistered CommenterPhillip Bratby

Of course, the one thing beyond the parrots' comprehension would be why the proxies would be questionable (other than that any historical reconstruction isn't what you want to hear about).

I'll allow you extra time to confer with Uncle Steve.

Jul 23, 2010 at 10:04 PM | Unregistered CommenterBishop Phil

Another thing that does not seem to get discussed is the relative level of atmospheric CO2 today compared to historical levels.
Shortly before the current interglacial, levels of atmospheric CO2 dropped to 250 parts per million. I have read that the minimum level of CO2 needed to support vegetation on the planet's surface is 220 ppm. We know that way way back levels of CO2 were up in the tens of thousands of ppm and that that level has been falling consistantly over the billions of years of climate history.
It seems to me that we are in much greater danger from falling levels of CO2 than from rising temperature and that taking CO2 out of the atmosphere is lunacy.

Jul 23, 2010 at 10:10 PM | Unregistered CommenterDung

Bishop Phil if you are unsure about why tree ring proxies are questionable I will explain it to you.
BUT you have to ask nicely :)

Jul 23, 2010 at 10:16 PM | Unregistered CommenterDung

C Jonson, Dung (and also to the non-arguments of impersonators such as "Bishop Phil")

There is a beautiful reconstruction of glacier fluctuations in the Alps that is very difficult to reconcile with Hockey Sticks: Holzhauser and others, 2004,

Not to mention eight other reduced ice periods as described by Hormes and others 2001:

and the comments of a far more objective AR3 describing a more "unsettled science":

Glaciers are generally not in equilibrium with the prevailing climatic conditions and a more refined analysis should deal with the different response times of glaciers which involves modelling (Oerlemans et al., 1998). It will take some time before a large number of glaciers are modelled. Nevertheless, work done so far indicates that the response times of glacier lengths shown in Figure 2.18 are in the 10 to 70 year range. Therefore the timing of the onset of glacier retreat implies that a significant global warming is likely to have started not later than the mid-19th century. This conflicts with the Jones et al. (2001) global land instrumental temperature data (Figure 2.1), and the combined hemispheric and global land and marine data (Figure 2.7), where clear warming is not seen until the beginning of the 20th century. This conclusion also conflicts with some (but not all) of the palaeo-temperature reconstructions in Figure 2.21, Section 2.3 , where clear warming, e.g., in the Mann et al. (1999) Northern Hemisphere series, starts at about the same time as in the Jones et al. (2001) data. These discrepancies are currently unexplained.

(emphasis mine)

Jul 23, 2010 at 10:27 PM | Unregistered CommenterPatagon

Thnx Patagon, the first link didnt work for me but the second one did :)

Jul 23, 2010 at 10:36 PM | Unregistered CommenterDung

Dung, the f of "pdf"is missing at the end:

(if you click rather than copy paste, it should work)

Jul 23, 2010 at 10:42 PM | Unregistered CommenterPatagon

Hmm I clicked on the new link in your latest post and I still got an error message mate :(

Jul 23, 2010 at 10:45 PM | Unregistered CommenterDung

I should add, figure 2 is the key in the Bern paper. It is also confirmed by speleotherms in Austria : Although they were shy in making the delta sup{18} O link to temperature.

So the argument of if you remove a data series or other proxies than tree rings support the Hockety Stick seems rather weak.

Dung, the link error is weird, I changed browsers and it works for me. Try this:

Jul 23, 2010 at 10:51 PM | Unregistered CommenterPatagon

Patagon, you seem enamoured of imagining that regional data (i.e. the Alps) acts as a proxy for global data, thus entirely missing the point of the 'G' in AGW. (emphasis mine)

Jul 23, 2010 at 10:57 PM | Unregistered CommenterBishop Phil

@Bishop Phil
"so eloquently put on RC" = Oxymoron Alert. The only eloquence exhibited at RC is seen by the moderators.
Yup but whose posterior is getting spanked more and more as each day passes.
Surely, you don't mind me calling you surely do you Phil, not all the brethren like a cold shower so much, that you take a warm one out of spite?
Climate science is in free-fall at the moment, for me it's about the misrepresentations, the obfuscation, the clear and obvious cowardice exhibited by some when scurrying under the skirts of a, less than disinterested, cast of establishment pupeteers.
As for the Science or the Stats, I leave that to those who come over as being sincere and trustworthy and have no moneyed slime trail to follow.
I can state, with X% confidence, that Y% of Climate Science has been tainted by the skullduggery of Z% of its practitioners.
To the Y percenters I will ask just one thing. Why do you let them go free?

Jul 23, 2010 at 11:10 PM | Unregistered Commenterroyfomr

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