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Wilson on millennial temperature reconstructions

Last week I attended a lecture given by Rob Wilson at the University of St Andrews. This was a two-hour marathon, a format that is excellent if your lecturer is good enough to carry an audience, as it enables issues to be addressed in much more depth than is the norm. In the event, the time shot by, and if you read on you will see why.

Rob was doing a review of the millennial temperature reconstructions, following the story from the First Assessment Report through to AR5. As readers here know, Rob is no kind of a sceptic (a point he repeated over lunch), but on the northern hemisphere paleo studies his position is not a million miles away from mine. In places our positions are identical, as you will see.

Because of the prominence of Michael Mann's work in the area, some of the lecture was devoted to the Hockey Stick, to the 2008 paper (the "upside down Tiljander" study to the initiated) and to Mann's most recent area of focus, the influence of volcanoes on tree ring growth. Students learned that the Hockey Stick included a whole lot of inappropriate proxies and heard something of the issues with its verification statistics. The wallpapering of the Third Assessment with Mann's magnum opus and John Houghton's claims about unprecedented warmth based on this single study were described as "ridiculous". "Ultimately a flawed study" was the conclusion, with a gory list of problems set out: inappropriate data, infilling of gaps, use of poorly replicated chronologies, flawed PC analysis, data and code withheld until prised from the grasp of the principals. In the paper's defence, it was noted that it was an early attempt at a millennial reconstruction and that it did at least attempt to discern spatial variability, something that had not previously been done.

We also heard about Mann's  minumus parvum opus, The Hockey Stick and the Climate Wars, which Rob, like so many others, had given up on in fairly short order, and then saw an excerpt from Iain Stewart's Climate Wars TV programme. Having seen Mann's paper criticised so forcefully, I assume that Stewart's unquestioning faith in the graph will have left the audience with a pretty low opinion of his abilities.

That was the gentle beginning. When we got onto Mann et al 2008, we learned about the silliness of the screening process, and students were invited to try screening a set of random generated timeseries in the way Mann had gone about this study. Tiljander didn't get a mention, but I guess there are only so many flaws one can take on board, even in a two-hour lecture.

The real fireworks came when Mann's latest papers, which hypothesise that tree ring proxies have large numbers of missing rings after major volcanic eruptions, were described as "a crock of xxxx".

Away from the Mann stuff, this was, as I have suggested a very fair representation of the science of millennial temperature reconstructions, with the overwhelming impression being of a field that is still trying to work out if is possible to constrain the answers to the point where they are useful. The students were undoubtedly hearing the truth, warts and all, about the field they were studying. If only policymakers could hear the truth too.


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Reader Comments (126)

Creationism and darwinism are the same sort of science in that they cannot predict anything useful.

Unless someone has a proposal around of human 2.0 ?
Never mind flu HN5.9

Oct 21, 2013 at 11:31 PM | Unregistered Commenterptw

Ah, the code has finally been released, it is repetitive but revealing:-

-- . -- / ... --- ...
-- . -- / ... --- ...
-- . -- / ... --- ...


Oct 21, 2013 at 11:35 PM | Registered CommenterGreen Sand

Steve Koch, Rob and others: I forgot to paste the link to the post on Pinatubo. Here it is:

Let me repeat:

1) Mann believes tree rings associated with the largest volcanos must be missing because the tree ring record doesn't show any drops of 2 degC in the appropriate years. The expectation of a 2 degC drop comes from climate models with a high climate sensitivity.

2) Rob and others demonstrate that no tree rings as missing.

3) QED, climate sensitivity must be lower. A full analysis of Pinatubo gives a lower figure for climate sensitivity.

Oct 21, 2013 at 11:40 PM | Unregistered CommenterFrank

Steveta :"ABC, could you point me at any of the "handful of fossil fuel lobbyists" to whom you refer?"

When I worked in the wind industry it was obvious that many of the big wind companies were oil companies like shell.

A while ago I checked and everyone one of those who are counted as "BIG OIL", had wind divisions making money from the global warming scare.

So the literal answer to your question is that there are many many fossil fuel company lobbyists ... the only problem is that their money is behind the scare and is against those who are scientifically sceptical.

However, to be entirely fare. There appears to be a credible rumour that in the early naughties someone in US coal was employed as a lobbyist. However, as I've met plenty of pro-warmist fossil fuel lobbyists but never seen any evidence for myself of one on our side, it is pretty safe to say they are all alarmists.

And ... just to show how gullible you must be to believe fossil fuel companies are against rising energy prices .... who do you think benefits most when governments push up oil prices?

Oct 21, 2013 at 11:54 PM | Unregistered CommenterMikeHaseler

Of course, in a field as woolly and malleable as climate changeology, the objectivity and impartiality of researchers is critical importance, far more so than in more rigorous fields, where the controlled experiment is the final arbiter.

Browsing through Mickey Mann's Twitter feed, 'objectivity' and 'impartiality' are not words that spring to mind.

Oct 22, 2013 at 12:53 AM | Unregistered CommenterJake Haye

Thanks Rob for forthright and honest discussion to the students, sure it was appreciated and they need this kind of guidance to develop & advance.

Mann reminds of the old westerns I watched many years ago, there was good, bad & confused motifs (seemed ok to cheer on the good guys then, as I was young) but came to realize this world view was very simplistic as I grew older and now ?
- not sure where Mann & Co fits into my narrative (but the Ringo Kids maybe ?) but McIntyre sure makes a good sheriff & the Wanted posters (alive by the way) in the UK are beginning to have an effect (maybe) thanks to all the effort & time by folks like the Bishop & others.

ps. whenever I am out walking I now look for tree stumps/old trees which may of use to people like you. has been a great learning curve for me (funny old world in 'nit).

Oct 22, 2013 at 1:05 AM | Unregistered Commenterdougieh

Since Darwin came up earlier, The Guardian has a first rate article on the discovery of a skull that might require evolutionary theorists to roll back some of their claims. The Guardian's headline reads:

"A haul of fossils found in Georgia suggests that half a dozen species of early human ancestor were actually all Homo erectus."

This finding does not threaten the basics of the Darwinian story. What it does is emphasize that "natural variation" is no less powerful than the drivers of evolutionary change. It seems that Homo Erectus was a member of a community that included some or all of a half dozen species that were thought to have succeeded him/her. According to the Guardian:

"The scientists went on to compare the Dmanisi remains with those of supposedly different species of human ancestor that lived in Africa at the time. They concluded that the variation among them was no greater than that seen at Dmanisi. Rather than being separate species, the human ancestors found in Africa from the same period may simply be normal variants of H erectus."

"Normal variants" are the products of natural variation.

Oct 22, 2013 at 3:09 AM | Unregistered CommenterTheo Goodwin

Oct 21, 2013 at 11:20 PM | Skiphil

Michael Mann's outpourings on Twitter have dug his holes deeper, even as he struggles to explain himself. Now he is denying that Rob Wilson's criticisms are offered in "good faith" --

"@dougmcneall I have no problem w/ good faith criticism. But I don't see Rob Wilson's latest as falling into that category :-(

Ah, so Mann invokes the "good faith" gambit!

I've seen this gambit invoked by Richard Klein and Richard Betts [citations available on request] ... and now Michael Mann!

I think it would be interesting to learn how each of these individuals determines that "arguments" or "criticisms" are offered "in good faith" - and how they would determine that "arguments" or "criticisms" are not put forward "in good faith".

A little over three years ago, in a moment some might describe as "false modesty" (but I couldn't possibly comment!) believe it or not, Mann actually declared to the BBC that:

“I always thought it was somewhat misplaced to make it (i.e. the “hockey-stick” -hro) a central icon of the climate change debate,” [Mann] said.

Then again this was reported by the Telegraph's Louise Gray on the heels of his "exoneration" by Penn State; so perhaps one should not put too much stock in the veracity of the claim.

Nonetheless, back in the USA, in what I would deem to be "good faith", The Daily Caller's Scott Ott attempted to engage Mann on the implications of Mann's purported claim. I related this very sorry saga in a blogpost. For those who might be interested, pls see:

The surprisingly reticent Michael Mann

Oct 22, 2013 at 7:24 AM | Registered CommenterHilary Ostrov

Aussie story about crock monitoring.
Late 1980s, I was giving evidence to a Senate Inquiry into world heritage at Kakadu. The witness before me was Prof Harry Miller, an American physics professor then at University of Sydney, who had devised satellite transponders to go on the necks of animals to monitor them in the wild. He chose the crocodiles of the Top End. Hence croc monitoring.
Harry showed the Inquiry a blow-up of a large male, strung up by the tail on a tripod, perhaps 4-5 m long. It had been left by poachers hearing the law arriving and was some smelly days old when Harry arrived & took the photo.
Harry said "Just look at the waste".
The Chairman, Senator Olive Zakharov, was almost in tears. "I image" she said "the waste of tremendous gene potential".
"S*** (as in crock) NO", said Harry. "The skin, lady, the money lost with that rotten skin !!"

Oct 22, 2013 at 7:43 AM | Unregistered CommenterGeoff Sherrington

Sorry to be a spoilsport, but calling someone a denier seems a pretty tame response to someone who’s called your work a crock of sh*t.
Of course, we know the context, and the personality of those involved; but a journalist coming looking for a story would just see two scientists, both of whom believe in dangerous man-made global warming, being rude about each other. No story.

Oct 22, 2013 at 8:50 AM | Registered Commentergeoffchambers

Oct 21, 2013 at 11:00 PM | Registered CommenterMikeHaseler
Excellent analysis, Mike.
I'm sure you know that when the little old lady (it's always a little old lady!) with her first computer phones the helpline because it "isn't working", the first question is "Is it plugged in?" and the second is "Is it switched on?" and, I'm told, you'd be surprised at the number of times those two questions solve the problem.
And there is the story of the customer who rang because (s)he couldn't get the machine to progress beyond a screen bearing the message "Press any key to continue" and wanted to know which was the 'any' key!
Apocryphal no doubt, but as they say symbolic of a greater truth!!
And writing this I was just reminded of a comment by an old friend of mine, a first-class science teacher now deceased, whose parting words to his sixth-formers always was: "Remember that science lives in the laboratory. Once it sets foot outside the door it becomes technology and that is a different animal altogether."

Oct 22, 2013 at 8:56 AM | Registered CommenterMike Jackson

See, there are honest and competent people in climate too.

Oct 21, 2013 at 9:45 AM | Unregistered CommenterRichard Tol

That has always been accepted here, mostly. Our complaints over the ast 10 years has been how invisible other non-believing climate scientist have been and therefore tacitly supportive of Mann, Briffa, Jones UK Met off etc.

It is good to see the likes of Judy Curry stepping out in more recent times but it iss toooooo late. The crime is done and the worlds population is lumbered with 25 years of liability for bat mincers and roof covers. Worst still, because governments are beginning to panic as they see their stupidity rushing up to slap them, they have no time study other power generating methods except nucliare by uranium. Opportunities have been lost through deceit, lies and bluster.

Oct 22, 2013 at 9:33 AM | Unregistered CommenterStephen Richards

I have come to this late. Rob - kudos for speaking up, you have done much to enhance scientific integrity, and it makes me pleased and proud that you are based in a Scottish University. (Any positions for Salby in the Physics department?)

Here's my take, which doesn't scan that weel but St Andrews is not far from McGonagall's home town, so it is worth a go:

There was a climatologist from Penn State
whose graph suggested global temperatures had rocketed of late
but when questioned by MacIntyre (and others with intellect higher)
he just called then 'denier'
even Prof. Rob Wilson he did berate.

Oct 22, 2013 at 9:56 AM | Registered Commenterlapogus

@Stephen Richards
Maybe we need a model Stephen. Comparing where we are now, with the CAGW scam and where we would have been without it

Oct 22, 2013 at 9:59 AM | Unregistered CommenterEternalOptimist

Until any paleo admits outright that there is no anthropogenic signal to be gleaned from proxy records or modern temperature records and that splicing them together is totally unscientific and diabolically misleading then they are neither honest or competent. Any paper that comes out which pretends to somehow magically gain this insight at some point in the future so that utterly inadequate models may be properly constrained is deluded. If only they would do their work without any reference to pre-supposed anthropogenic signals then they might eventually have something worth looking at. At the moment there is not a single NH or global reconstruction worth a crock and there won't be until more actual proxies are gathered.

Oct 22, 2013 at 10:11 AM | Unregistered CommenterJamesG

MikeHaseler, I've a similar story about how a production process can go wrong.

I was working in GEC Semiconductors, in the engineering group, in the late 70's. There was a problem with a batch of failing ICs which was proving hard to track down. The tests on components while still on the wafers was fine, but post-packaging many were failing. Some clever work with very high-tech hardware found traces of salts on the surface of the die causing the problem, but only on a small subset of the product.

So somone from QA was assigned to track back from the batch of components through each step of manufacturing, and found a common variable in all the failing parts was one of the operators in production. The final stage prior to cutting wafers into individual chips was placing them in an ultrasonic freon bath to remove any contamination. One of the operators hadn't been shown the tool to be used to hold the tray of wafers - she was putting them into the bath and removing them using an ungloved hand - hence the contamination. Surprisingly, apart from a bit of dry skin, she came to no obvious harm.

Oct 22, 2013 at 10:27 AM | Unregistered Commentersteveta_uk

Oct 22, 2013 at 9:56 AM | Registered Commenter lapogus

Not bad, but McGonagall eschewed the limerick form -- at least, I can't find one in his literary omnibus. However, your stanza does put me in mind of the composition of a more general "Summary History of Michael E Mann", which would have the haunting refrain: "T'was verily written down in MBH99, Which will be remember'd for a very long time."

Oct 22, 2013 at 10:37 AM | Unregistered CommenterDr Slop

Excellent stuff! I'm sure if 'Scotland's Other National Bard' had thought to turn his hand to the limerick he would have produced something like that.

Oct 22, 2013 at 10:54 AM | Registered CommenterMike Jackson

Creationism and darwinism are the same sort of science in that they cannot predict anything useful.

They don't have to predict anything useful, just predict things. Whether a prediction is useful or not doesn't make it any more or less of a prediction. It's successful if it's accurate.

Darwinism predicted that transitional fossils would be found; they have been. Creationism predicts that no extinct animals would be found (because God made no design mistakes and Noah saved all those made); yet extinct animals have been found.

Creationism then had to handwave an explanation for the data's failure to conform to the hypothesis - that God created fake fossils too, and inserted them into the fossil record to challenge our faith. This is precisely what climate psyence has done since it became apparent that rising CO2 is no longer warming the earth; it has handwaved a warming of the oceans that's not possible in physics to explain the missing heat.

Climate science upholders like their creationism parallels but do not or will not understand who are are the dogmatic fact-denying bigots here.

Oct 22, 2013 at 11:31 AM | Unregistered CommenterJustice4Rinka

@Oct 22, 2013 at 8:50 AM | geoffchambers

Geoff - what's source for the goose eh? Mann's main MO on social media is abuse. Quite how he finds time to work, given the volume of his Twatter feed and Facebook activity, is another matter altogether. Were it my taxes that were funding this, I'd be on to Penn State in a flash.

Oct 22, 2013 at 2:44 PM | Unregistered CommenterJeremy Poynton

Darwinism does predict useful things -- such as that bacteria will develop antibiotic resistance if you kill only part of the population - that's why it's important to finish a course of anitibiotics rather than stopping as soon as your symptoms go away.

Oct 22, 2013 at 3:00 PM | Unregistered CommenterJoseph W.

"Darwinism does predict useful things -- such as that bacteria will develop antibiotic resistance"

I'm not sure Darwinism predicted this before it started happening. It happened and then observers said it's likely to happen again.


Oct 22, 2013 at 5:35 PM | Unregistered CommenterBad Andrew

...and it has happened again, which is good enough to make it both a prediction and useful.

('course a lot of creationists admit to "microevolution" and so don't find this incompatible with their view of things; but the useful predictions come from the limited Darwinism they accept rather than the creationism they insist on for larger-scale changes.)

Oct 22, 2013 at 7:03 PM | Unregistered CommenterJoseph W.

Bad Andrew

"Darwinism does predict useful things -- such as that bacteria will develop antibiotic resistance"

I'm not sure Darwinism predicted this before it started happening. It happened and then observers said it's likely to happen again.


Come on, Andrew! Don't resist the obvious Darwinian truths - that insect exposed to insecticides will develop insecticide resistance, or that humans exposed to diseases develop resistance to bacterial (leprosy, venereal, pox, etc) and viral diseases (the common cold)... Cf, Western indians, for instance.


Oct 23, 2013 at 11:32 AM | Unregistered CommenterOrson

Volcanic eruptions suppress tree-rings. Well, nothing if not fascinating.
Any suggested mechanism by which this crock theory might operate?

Oct 24, 2013 at 8:48 AM | Unregistered CommenterTomcat

Ah do we also get to dismiss the theory of gravity - oh sorry "Newtonism" - because people observed stuff fell downwards long before that "theory" was developed?

There is no such thing as "Darwinism". There is the Darwinian theory of evolution, which is an incredibly successful theory of the origin of species, and represents a key development within biology without which many areas (medicine, genetics, etc etc) would be nowhere near as far developed as they are today. On the shoulders of giants and all that (oops more Newtonisms)

Oct 26, 2013 at 12:53 AM | Unregistered CommenterSpence_UK

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