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« The inescapable urge to indoctrinate | Main | A marvel and a mystery »
Thursday
Sep112014

Manns rea?

Things seem to be hotting up on the Michael Mann front, not least because Steve McIntyre seems to have returned to blogging with a vengeance, assisted as always by his trusty band of followers. Today, the climate auditors have turned up another rather embarrassing problem with Michael Mann's legal submission. This document claims that Mann had nothing to do with the infamous cover graphic for the WMO report of 1999, of hide the decline notoriety. Unfortunately, the claim is directly contradicted by Mann's own CV.

I found myself thinking about another of Mann's claims this morning. This was prompted by a comment on David Friedman's blog about Mann's claim in MBH98 that he had used "conventional" principal components analysis. The author of the comment wondered if this could in fact be true. But readers of the Hockey Stick Illusion will recall that the claim of "conventional" was actually only made about Mann's processing of temperature data. Regarding the tree ring data we were only led to understand that PCA had been used.

At the time there was a question hanging over the eventual use of short-centred PCA for the tree rings: whether the short-centring was an error or a deliberate step. I didn't really go into this in the Hockey Stick Illusion, as we had little way of knowing. However, in the last few years we have some more details.

The most important of these is Mann's own book on the subject, in which he makes it clear that the decision to short-centre was deliberate: he describes this as his "modern" approach to centring the data. This being the case, we are left with a lot of questions. Why would you decide to use a novel approach to data centring? What was wrong with conventional PCA? But more importantly, why, having decided to use such a novel approach would you not mention it in the methods section? Is that not something that readers of the paper would need to understand what was done? Was this not a key methodological choice?

Inquiring minds want to know.

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Reader Comments (30)

+1 for 'Manns Rea', although it would also benefit from an energetically applied boot, IMO.

I'm not sure I would trust him to spell his own name correctly.

Sep 11, 2014 at 1:14 PM | Registered Commenterjamesp

To be fair to Mann , and that is not an easy thing to be , he was writing for area where he knew that what mattered in results was not their accuracy but their ‘usefulness ‘ So the means was no where near has important as the ends.

Sep 11, 2014 at 2:19 PM | Unregistered Commenterknr

Poking at Steve McIntyre with a stick is a bad idea.

Steyn must be loving this. Mann's lawyers - not as much.

Sep 11, 2014 at 2:49 PM | Unregistered CommenterPolitical Junkie

Michael Mann is the eptome of climate "science" integrity. An icon for the Green struggle against evil doers. Who better deserves the title climate "scientist"!

Sep 11, 2014 at 3:04 PM | Unregistered CommenterCharmingQuark

Its very telling that M Mann has chosen not to take SM on in court, you can only assume he knows he would be beaten 10 nothing.

Sep 11, 2014 at 3:21 PM | Registered CommenterBreath of Fresh Air

I honestly wonder if Mann's (current) lawyers are appraised of the fact that McIntyre has previously offered Mann his support in previous actions to come before the courts.
For example: here

It would not look good for them to only discover this in open court.

Sep 11, 2014 at 3:31 PM | Unregistered Commentermichael hart

"This was prompted by a comment on David Friedman's blog about Mann's claim in MBH98 that he had used "conventional" principal components analysis. The author of the comment wondered if this wasn't true. Now readers of the Hockey Stick Illusion will recall that the claim of "conventional" was in fact only made about Mann's processing of temperature data. Regarding the tree ring data we were only led to understand that PCA had been used."

I didn't follow what you're saying here -- might be worth a rewrite.
[Done BH]

Sep 11, 2014 at 3:33 PM | Unregistered CommenterAnon

Tamino supported Mann's use of short centering, citing the leading scholar, whose name slips my mind, as support. Thereafter, that scholar wrote Tamino that he was wrong, and Tamino had to retract his statement. So Mann knows he is full of it when he says what he wrote in the book about short centering.

Sep 11, 2014 at 4:25 PM | Unregistered CommenterPhil Howerton

Mann just makes everything up as he goes along, and it shows, he's the gift that just keeps on giving.

Sep 11, 2014 at 4:40 PM | Unregistered Commenterjaffa

There was a thread at Jeff Id's about short centered PCAs which got the inventor of PCA to post (Joliffe?). He seemed to say that it was not a valid method.

I can't find it off-hand, but I'm sure Jeff has it bookmarked if you ask him.

Sep 11, 2014 at 4:41 PM | Unregistered CommenterSimon

A posting on Steve M's blog about Joliffe's response to Tamino.

http://climateaudit.org/2008/09/08/ian-jolliffe-comments-at-tamino/

Sep 11, 2014 at 5:05 PM | Unregistered CommenterJohn K

Simon wrote:

There was a thread at Jeff Id's about short centered PCAs which got the inventor of PCA to post (Joliffe?)

Jeff Id's thread is at http://noconsensus.wordpress.com/2008/09/19/ian-jolliffe-at-tamino/

The thread where Jolliffe commented was at Tamino's, and has now been deleted. But a copy is archived at:
http://web.archive.org/web/20100206110144/http://tamino.wordpress.com/2008/09/17/open-thread-6/

Sep 11, 2014 at 5:08 PM | Unregistered CommenterNic Lewis

Is Steyn aware of this? It could help him. Cheers -

Sep 11, 2014 at 5:48 PM | Unregistered Commenteragimarc

Someone I know used to work closely with a very famous politician who is well-known as an extraordinary liar. He explained that the politician was so good at lying because he actually believed whatever he was saying at the time (even if it directly contradicted what he had said just the day before). His opinion was that the politician was so convinced of his own special virtue and that the defeat of his opponents so critical to the country’s well-being that whatever he had to say to succeed was, therefore, true and good and right. He somehow actually fooled himself into believing his own BS because he was convinced that he was such a special force for good.

Whatever the personality/mental quirk was that afflicted that famous politician, I sometimes wonder if Mann enjoys something similar. Because the future survival of the earth and mankind requires him to succeed and lead, ‘truth’ is whatever he needs it to be at the moment.

Sep 11, 2014 at 6:37 PM | Unregistered Commenterstan

I was a so-so squash player, just for fun, occasional club level tournaments. I always knew when I had no chance of beating an unknown opponent without a handicap, it was the "killer" look in their eyes. The most amiable individuals transformed into flinty eyed automatons without a hint of mercy. Steve is, amongst other skills, an accomplished competitive Squash player.

Michael Mann, be afraid, be very afraid, Steve is on the Steyn team and your handicap is looking rather suspect.

Sep 11, 2014 at 6:42 PM | Unregistered CommenterMike Singleton

Stan.... a Conservative ex Minister once told me that he believed of a long serving Labour Prime Minister that his concept of "the truth" was anything he could convince some one to believe while he was still talking to them!

Seems like it is an endemic political condition!

Sep 11, 2014 at 6:47 PM | Unregistered CommenterGlebekinvara

@jaffa "The gift that keeps on giving"? More like the git that keeps on driveling.

Sep 11, 2014 at 7:34 PM | Unregistered CommenterThrogmorton

When Mickey Mann was fumbling with his little stick in 1998 there would not have been a single clownatologist on Earth that understood what was wrong with his use of PCA, his clown self included. Probably still isn't.

Having a deep understanding of what you're doing is what proper scientists do, not climatologists.

Sep 11, 2014 at 7:50 PM | Unregistered CommenterJake Haye

Seems like it is an endemic political condition!

Sep 11, 2014 at 6:47 PM | Unregistered CommenterGlebekinvara

As I have said many times, politicians have only 2 skills, but they have them in abundance : Lying and deceit and that may to you and I or themselves.

Sep 11, 2014 at 7:57 PM | Unregistered CommenterStephen Richards

Nic Lewis

Joliffe's comment was also discussed at Climate Audit at the time, see

http://climateaudit.org/2008/09/08/ian-jolliffe-comments-at-tamino/

Sep 11, 2014 at 9:54 PM | Unregistered CommenterBebben

stan

"believing his own BS"

It is perceived as a virtue among politicians, I believe, to be able fake sincerity. Tony Blair could do it, but probably at the expense of his soul.

Sep 11, 2014 at 10:23 PM | Registered Commenterjamesp

Didn't know that Blair had a soul.

Sep 11, 2014 at 11:23 PM | Unregistered CommenterMike Singleton

And Jolliffe's post is no longer available at Tamino's site. I do wonder why...

Sep 12, 2014 at 2:38 AM | Unregistered CommenterInteresting-Coincidences

There was a thread at Jeff Id's about short centered PCAs which got the inventor of PCA to post (Joliffe?). He seemed to say that it was not a valid method.

Ian Joliffe, apparently an "expert" on PCA methods, and he authored some relevant text on the matter... he is not, however, the "inventor" of PCA. PCA is an extension (or relative) of something called factor analysis, which has been around for quite some time (originally used in the psychiatry/psychology field, IIRC). PCA methods are, in fact, even older. Singular Value Decomposition and Eigenvalue Decomposition, for example, are both used in the implementation of PCA, and both have been around since... well, since forever AFAIK.

Mark

Sep 12, 2014 at 3:35 AM | Unregistered CommenterMark T

Sep 11, 2014 at 6:37 PM | Stan
...

We had two such prime ministers in quick succession in Australia ... Kevin '07' Rudd and 'ju-LIAR' Gillard.

Gillard is still so convinced of her non-existant achievements that she persists with describing them to this day. Kevin '07' not so much.

Sep 12, 2014 at 5:32 AM | Unregistered CommenterStreetcred

When the fog clears, folks like Mann will be the only ones stupid enough to be caught with their pants around their ankles. The true culprits will be long gone by then. Consider this carefully because, ultimately, Mann is a mediocre scientist with more ambition than talent which, in other words, simply means that, while a genius in his own mind, he is not actually responsible for the real damage done by "climate change politics".

Sep 12, 2014 at 6:53 AM | Unregistered CommenterBrute

Off Topic Scottish Independance

So Alex Salmond lets all fight Climate Change together drivel.
Make Scotland the Saudi Arabia of Windpower
Without the mega wealth and the huge defense contracts blah blah

Then SNP counter claims not enough oil in the North Sea
Yeah enough oil and gas reserves in the North Sea for another 100 years
All of it Scottish so we can join the Pound not the Euro.

The same dirty polluting North Sea oil and gas that is adding to Global Warming then.

So Alex Salmond don't sound too much like the Mel Gibson Braveheart of Scottish Environmentalism.

Sep 12, 2014 at 10:52 AM | Unregistered Commenterjamspid

the WMO report is here - on the WMO website (Mann's name is clearly there)
https://www.wmo.int/pages/prog/wcp/wcdmp/documents/913_en.pdf

I've made a screenshot graphic of the cover and Mann's citation for the cover graphic
http://realclimategate.files.wordpress.com/2014/09/screenshots-wmo-statement-cover-of-the-report-and-m-mann-attribution-highlighted.jpg?w=900

Sep 12, 2014 at 3:02 PM | Unregistered CommenterBarry Woods

Joliffe's comment has been discussed on CA within the last few weeks, together with a cite.

Sep 12, 2014 at 4:14 PM | Unregistered CommenterPhil Howerton

I'd say it was all to his incompeteness. He did it intentionally, but not because of the effect but because he didn't realize you are not supposed to do it (as the whole PCA loses its meaning). He didn't understand that what he was doing was something "novel" but thought it is ok and a normal thing to do. There are a few indications speaking for this. (i) in his PCA code he is not only short centering but he is also dividing by the detrended variance (of 1902-1980). That being, of course, unheard in the field of PCA but very typical for mike whenever he is standardizing something. (ii) IIRC, we noticed with UC a few years ago when we tried to replicate the full algortihm, that he indeed used his flawed PCA in another occasion. That was when calculating his long temperature PC (which is used in verification).

BTW, Bish, I think you should really revisit the "Casper and the Jesus paper". There seems to be plenty of information in CG2 what went on behind the scenes. It indeed was a close call, several people really woried that they would not make the (already extended) deadline. Additionally, there seems to be evidence of Ammann, Wahl, and mike all feeding the information to Briffa (the lead author in AR4). See especially the "confidential" Briffa/Wahl exchange in July 2006.

Sep 14, 2014 at 3:12 PM | Unregistered CommenterJean S

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