Dendros stick it to the Mann

UPDATE3: professor Rob Wilson leaves some scathing comments about the Mann paper. See below.

UPDATE2: There’s been some additional discussion on the dendro listserver, and it seems quite clear now that the scientists in the dendrochronology field don’t think much of Dr. Mann’s effort – and it appears there is a rift now between former co-authors. See the must read below. I’ll make this a sticky for about a day, and new posts will appear below this one. – Anthony

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People send me stuff.

In case you don’t know, ITRDBFOR is an electronic forum (a listserver) subscribed to by most of the world’s dendrochronologists. What is most interesting is that Hughes and Briffa are co-authors of the response to Mann.

—– Original Message —–

From: Rob Wilson

To: ITRDBFOR@LISTSERV.ARIZONA.EDU

Sent: Sunday, 25 November, 2012 20:43

Subject: [ITRDBFOR] Comment to Mann et al. (2012) at Nature Geoscience

Dear Forum,

In February of this year, Mike Mann and colleagues published a paper in Nature Geoscience entitled, “Underestimation of volcanic cooling in tree-ring based reconstructions of hemispheric temperatures”. Their main conclusion was that a tree-ring based Northern Hemisphere (NH) reconstruction of D’Arrigo et al. (2006) failed to corroborate volcanically forced cold years that were simulated in modelling results (e.g. 1258, 1816 etc). Their main hypothesis was that there was a temporary cessation of tree growth (i.e. missing rings for all trees) at some sites near the temperature limit for growth.

This implies Dendrochronology’s inability to detect missing rings results in an underestimation of reconstructed cold years when different regional chronologies are averaged to derive a large scale NH composite.

We scrutinized this study and wrote a response to Nature Geoscience. We are pleased to announce that our comment, along with a reply by Mann et al., was finally published on Nov. 25, 2012 (http://www.nature.com/ngeo/journal/vaop/ncurrent/index.html) – 8 months after submission.

Our comment focuses on several factors that challenge the Mann et al. (2012) hypothesis of missing tree rings. We highlight problems in Mann et al.’s implementation of the tree ring model used, a lack of consideration for uncertainty in the amplitude and spatial pattern of volcanic forcing and associated climate responses, and a lack of any empirical evidence for misdating of tree-ring chronologies.

We look forward to a continued discussion on this subject.

Kevin J. Anchukaitis, Petra Breitenmoser, Keith R. Briffa, Agata Buchwal, Ulf Büntgen, Edward R. Cook, Rosanne D. D’Arrigo, Jan Esper, Michael N. Evans, David Frank, Håkan Grudd, Björn Gunnarson, Malcolm K. Hughes, Alexander V. Kirdyanov, Christian Körner, Paul J. Krusic, Brian Luckman, Thomas M. Melvin, Matthew W. Salzer, Alexander V. Shashkin, Claudia Timmreck, Eugene A. Vaganov, and Rob J.S. Wilson

———————————————————————–

Dr. Rob Wilson

Senior Lecturer in Physical Geography

School of Geography & Geosciences

University of St Andrews

St Andrews. FIFE

KY16 9AL

Scotland. U.K.

http://earthsci.st-andrews.ac.uk/profile_rjsw.aspx

“…..I have wondered about trees. They are sensitive to light, to moisture, to wind, to pressure. Sensitivity implies sensation. Might a man feel into the soul of a tree for these sensations? If a tree were capable of awareness, this faculty might prove useful. ”

“The Miracle Workers” by Jack Vance

———————————————————————–

UPDATE: RomanM locates the Mann paper in comments, writing:

The original Mann article seems to be available at his web site:

http://www.meteo.psu.edu/holocene/public_html/shared/articles/MFRNatureGeosciAdvance12.pdf

==============================================================

UPDATE2: More from the listserv

From: “Malcolm Hughes” <mhughes@LTRR.ARIZONA.EDU>

To: <ITRDBFOR@LISTSERV.ARIZONA.EDU>

Sent: Monday, 26 November, 2012 16:42

Subject: Re: [ITRDBFOR] Comment to Mann et al. (2012) at Nature Geoscience

> Ron – no dendrochronologists were involved in the offending Mann et al

> 2012 paper. What Rob described was the response of a number of us to

> some of the multiple flaws in the original  paper. Cheers, Malcolm

>

> Malcolm K Hughes

> Regents’ Professor of Dendrochronology

> Laboratory of Tree-Ring Research

> University of Arizona

> Tucson, AZ 85721

—– Original Message —–

From: RONALD LANNER

To: ITRDBFOR@LISTSERV.ARIZONA.EDU

Sent: Monday, 26 November, 2012 03:48

Subject: Re: [ITRDBFOR] Comment to Mann et al. (2012) at Nature Geoscience

“a temporary  cessation of tree growth” resulting in no rings for all trees? Now that is a hypothesis that I am willing to bet good money has no empirical support since studies of trees began 200 years or so ago. Speculation this bald could give dendrochronologists a bad name.

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UPDATE 3: Rob Wilson leaves this comment at Bishop Hill today, bolded section is my emphasis:

Nov 26, 2012 at 9:00 PM | Unregistered CommenterRob Wilson

Hi Again,

Our comment and Mann’s response to it can be accessed from this link:

http://www.st-andrews.ac.uk/~rjsw/all%20pdfs/Anchukaitisetal2012.pdf

his original paper is here:

http://www.meteo.psu.edu/holocene/public_html/shared/articles/MFRNatureGeosci12.pdf

Hmmm – what do I think of Mann’s response. Where does one start!

Well – he has provided NO evidence that there are stand (regional) wide missing rings for major volcanically forced cool years. Let’s focus on 1816 as an example – The “Year without a Summer” – where historical observations clearly show cool summer conditions (related to Tambora in 1815) throughout NE North America and Europe. Using either long instrumental records or historical indices, there is no evidence of a stand-wide missing ring in temperature sensitive tree-ring chronologies in Labrador, Scotland, Scandinavia or the Alps. Mann would probably turn around and say – well, actually, my model says that 50% of the sites would express missing rings – just not those in NE America and Europe. Sheesh!

To be less flippant, and putting aside criticisms of tree-ring series as proxies of past climate, the method of crossdating is robust and easily verifiable by different groups. I would be surprised if Mann has ever sampled a tree, looked at the resultant samples and even tried to crossdate them. He has utterly failed to understand the fundamental foundation of dendrochronology.

I undertook most of the analysis in D’Arrigo et al. (2006) and we clearly stated in the original paper that due to the paucity of sites (only 19) around the northern hemisphere, the reconstruction was most robust at time-scales greater than 20 years. Using the D’Arrigo reconstruction to look at inter-annual response to volcanically forced cool summers was a poor choice. Maximum density records, as shown in our response, would clearly be a far superior tree-ring parameter to use for such an exercise – as Briffa clearly showed in 1998. See also this paper:

http://www.st-andrews.ac.uk/~rjsw/all%20pdfs/D’Arrigoetal2009a.pdf

There is a lot more I could say, but this can all wait until next week at the AGU Fall Meeting.

One final observation is I urge you to look at Figure 1 in Mann’s original article. The instrumental record (black line) in Figure 1a (upper panel) clearly does not show strong cool temperatures in 1884 related to Krakatoa as seen in the two models. Following Mann’s hypothesis, the instrumental data must be wrong.

Time for some red wine

Rob

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john robertson

Paywalled naturally. But given its output from the Mann, do I care enough to pay ? Nope. I’ll wait for Climate Audit or WUWT to run the errors, I have faith, its pretending tree rings sort of equal temperature, those pseudo-temperatures then smeared out across the world and then given great certainty by proclamation of the Mann. Or as described by another WUWT commenter, Garbage In Gospel Out. Maybe what I should be saying, is let the great one speak, give us more of your divine wisdom , Oh Great Doctor of the trees.Flattery is a better tool to encourage the true prat to spout on and the mann is too wonderful a tool to lose. Your call.

Aldous Tenpenney

Cue the Mannian-grade righteous indignation in 3, 2, 1…..

Arno Arrak

I quote: “…We highlight problems in Mann et al.’s implementation of the tree ring model used, a lack of consideration for uncertainty in the amplitude and spatial pattern of volcanic forcing and associated climate responses…”
Interesting. I have proved that volcanic cooling of the troposphere is a myth and that so-called “volcanic” cooling incidents are nothing more than accidental coincidences in timing of a La Nina cooling period with an expected volcanic cooling that is said to follow an eruption. Read pages 17 to 21 in my book “What Warming?” available from Amazon.

The-Booky-and-The-Real-Book!

Oh Dear!
And just a few days ahead of the American Geophysical Union Fall Meeting ’12 Michael E. and Anthropocentric Mann Gala and Festival of Gay Warming Global non-Naturalis. The EGU at the General Assembly ’12 gave Mann a Gold Medal … for … well we are still trying to figure that one out but do not fret.
So ‘Naturally’ the AGU High Command Illumaniti MUST render a medal, some medal, any [snip] medal, to MEM and with Plaque and A life time membership … Oh they raised our membership fee from $20 to $50 just to pay for the ‘Supreme Executive and High Administrative Salaries’ … what [snip] THIS!.
Dirty Harry one proclaimed, “A Man’s Got’a Know His Limits!’.

Well, Mann did have the good sense to use BEST data in his response.
should make for an interesting discussion
REPLY: When is it ever good sense to use data that has failed to pass peer review? – Anthony

I am not a dendro but I have worked with and sampled trees in the very far north ±60. Some times you need a lens or a microscope to count the rings, they are very fine. I strongly suspect missing is simply not on. Maybe these people need to re-take Botany 101. More hypothetical baffle gab to cover your ass, Mike?

Andyj

Ouch!!
This paper is spitting in the face of all his acolytes and pro-AGW robots who tried to proclaim his findings were viable and fact to all and sundry. How embarrassing! hehehe.
Was that previous tree ring, IPCC approved paper buddy reviewed too?

Caleb

I have always had the feeling that Briffa wasn’t corrupted to the degree which some others seem to have been corrupted. Instead he seemed to be swept up by something he didn’t understand.
Briffa may have been involved in “hide the decline,” however all he did was find some data, be enthusiastic about what it “might” show, and then get a huge amount of praise for it.
I myself have seldom been praised for my ideas. Helpful people are swift to show me my errors. However on very rare occasions I have blundered into situations where I get praised. I can tell you, praise is exhilarating and intoxicating. You feel on top of the world, but it doesn’t last. Just as the depression of having your mistakes pointed out doesn’t last forever, neither does the euphoria of being told you are right. Sooner or later you get back to business.
I wonder if Briffa, unlike Mann, is getting back to business, the business being science.

David Ball

Steven Mosher says:
November 25, 2012 at 7:02 pm
So did SkS,……

Manfred

With all the errors introduced by Mann into climate science since 1998, a vast amount of manpower, time and resources have just been consumed for trying to clean this mess up and perhaps even consumed more for derailing such an effort.

Pamela Gray

So Mann is saying that for certain temperature years using the BEST data, the rings he looked for appear to be missing. I think what he means to say is that at certain times, trees do not make good thermometers. Is he trying to lay the ground work for justifying his “trick”? A preemptive strike perhaps?

Lew Skannen

I assume that Briffa will soon be in the dock along side Mark Steyn now that he has dared to question He Who Shall Not Be Questioned.

Jan Verbeeren

It has even been suggested – don’t remember where and by whom – that Briffa might have leaked the climategate mails. In the same period he disappeared somewhat from the scene due to health problems. I have no confirmation nor proof of this but his attitude is intriguing.

Eight months! to get published a letter questioning a paper.
Biffra should have come here. It would have been posted in it entirety in less than eight hours — and probably done more good for both sides of the debate.

Jeff Alberts

Caleb says:
November 25, 2012 at 7:53 pm
Briffa may have been involved in “hide the decline,” however all he did was find some data, be enthusiastic about what it “might” show, and then get a huge amount of praise for it.

I disagree. Briffa’s Yamal chronology is just as egregious as Mann’s original Hockey Stick. As far as I know, he hasn’t admitted that allowing ONE tree to overwhelm all the others in the recon was wrong.

bob

Speaking of the BEST dataset, can someone tell me why the thing diverges so much from all other datasets?
http://i45.tinypic.com/23tqi3m.jpg

Theo Goodwin

Isn’t it amazing that the need for empirical research into the characteristics of the proxies is now taken for granted. The ClimateGaters did not give it a thought. Just a year ago or so there were serious arguments on this website about the necessity of empirical research into proxies. Things are looking up in a serious way.

Reblogged this on Climate Ponderings and commented:
Mann has a bad day

Policy Guy

So how does one demonstrate that a tree does not generate a ring under certain circumstances? Personally, I’m not a dendrocrat, but it would appear to be a convenient theory for some unknown purpose, for how would one know? Tree rings are not date stamped. What was the comment earlier about climate models… Garbage in Gospel out? The models can say whatever people are willing to believe. Who needs evidence, just propose a theory and say that you’ve modeled it.

John F. Hultquist

We look forward to a continued discussion on this subject.
Not me. By the time they finish their discussions I will be cold or dead. I’m thinking cold first. But, maybe dead and cold in rapid succession. Anyway, trees can be used for all sorts of wonderful things but a thermometer isn’t one of them. One of the best uses is for charcoal and grilling steak, chicken, brauts . . . Set the carbon free! Cold is not good.
http://www.flickr.com/photos/kristinnwf/3190016130/sizes/l/in/photostream/

thisisnotgoodtogo

Will Mann cite Loehle next ? The dendros didn;t calculate on anything but unimodal response!
Go Mikey Go!.
Like cannibalistictadpoles – go go go guys!
Steyn on tap for this.

Steve

With regard to Keith Briffa, II think he always had reservations about conclusions others have drawn from his work. At worst, Briffa was used by Mann to foster his self serving Funding scheme…..more a victim than anything else, for which Michael Mann owes him both a professional and personal apology.
There are some real slimeballs in this whole sordid affair….Briffa is not on that list.

u.k.(us)

Steven Mosher says:
November 25, 2012 at 7:02 pm
Well, Mann did have the good sense to use BEST data in his response.
should make for an interesting discussion
=============
Have you anything of interest to say ?
Dendro wise, or just about BEST.
I’ll assume the latter, unpublished ? study.

bob

On second thought, this has to be a mistake or I plotted this the wrong way, you can skip publishing my previous comment if you want.

A quote from Jack Vance, balsam for my soul…
Centuries from now Jack Vance shall be known as a “classic,” one of the “true great ones,” etc.
But never forget, Jack worked his butt out as a carpenter to support his family, while writing all those wonderful books. That’s how our progressive society of unionized educators, editors, gamers, pot smokers, food stamp recipients and Peace Corps volunteers having fun on a public dime in South Seas rewards a real talent.
P.S. More evolved (and hair-raising) view of trees’ capability of awareness see in Jack Vance’s masterpiece, Maske: Thaery.

Caleb says:
November 25, 2012 at 7:53 pm
A very good point, Caleb. I concur with your suspicions regards Briffa. Here’s hoping we are right..

Mike Jowsey

“Set the carbon free! Cold is not good.” – John F. Hultquist
Good teeshirt. I want one!

Mike Jowsey

“and a lack of any empirical evidence for misdating of tree-ring chronologies.”
Wow – knock out punch right there. Will Mann sue? His grasp on the throats of tame editors seems to be loosening a tad. Will he show his empirical evidence? For example, if tree rings are missing in certain tree populations, they should be discernible in other populations thereby corroborating the theory. But somehow, I doubt that he will. Even with this clear slap in the face from his colleagues.

Richard111

My interpretation is if the models predict it should have happened then Nature is at fault. End of story. /disgust

UK Sceptic

Charting the non-existant? Rather sums up the whole AGW agenda, doesn’t it.

Venter

Yeah, the BEST data and study which was touted in press conferences, rejected as crap and unpublished till today, a year and half after the tall pronouncements.

cui bono

With luck, coverage of the forthcoming AGU meeting will be dominated by whatever news from Curiosity has the JPL scientists excited, rather than by the usual AGW doomsterism. Mars vs. Mann in the publicity battle? I’d bet on Mars.

George.S

Mann is brave in his obfuscation because he knows there are just too many powerful bankers, politicians, and academics who can’t afford to have the CAGW gravy train derailed. Note that Mann’s legal fund is being backed by George Soros, the green energy hedge fund backer and currency speculator–tells you everything you need to know.

Paul Matthews

On the same theme, JIm Bouldin (of RC) has started a blog that seems to have gone largely unnoticed except by J Jackson at CA. Jim has a series of posts (two currently) on the subject of
“Severe analytical problems in dendroclimatology”
in which he is very critical of tree ring reconstructions, saying
“Each of these issues by itself would be a serious problem, but collectively they render unreliable all long-term estimates of climate change from ring widths”
He also heaps praise on a 2009 paper by Craig Loehle. See
http://ecologicallyoriented.wordpress.com/2012/11/24/severe-analytical-problems-in-dendroclimatology-part-two/

Peter Hannan

Yes, from what I’ve read I think Briffa is more scientific, in the best sense, than others involved, It would be nice if he’d come off the fence! I know it’s hard, but real science is about honesty: not fooling yourself, and so not fooling others (Feynman).

Missing years may not be related to cold years, but to the oceanic currents circulations in the North Atlantic. There is a temporal misalignment between atmospheric pressure variability affecting the summer precipitations and the temperature changes. Both are factors in the tree growth.
This graph
http://www.vukcevic.talktalk.net/AP-AMO.htm
shows relationship between the Sub-Arctic summer atmospheric pressure and temperature anomalies. Yamal (Mann et al) peninsula is on the Arctic Circle.
Hence, dendrochronologists can’t accurately describe the temperature movement since they are not always synchronous with local precipitations.
Steven Mosher’s drive to his office is occasionally disrupted by road works, so he has some missing minutes or even hours in his work schedule.

Mann’s finally reached a new level in bad science – basing the conclusions of a paper on missing evidence.
Policy Guy asked
“So how does one demonstrate that a tree does not generate a ring under certain circumstances? Personally, I’m not a dendrocrat, but it would appear to be a convenient theory for some unknown purpose, for how would one know? Tree rings are not date stamped.”
But in a sense they are. Dendro-dating uses ring-width patterns to compare timber samples with sufficient rings with others with longer ring-series until a chain of matches is established to a sample of known date. I’d suggest this technique would provide the “missing empirical evidence” referred to by Anchukaitis et.al, and is in fact what they’re implying. “Missing ring” series would be matched with series from nearby, but generally warmer locations until matches are found for patterns pre and post the postulated “ring-gaps” but with the “missing rings” intact. The process would likely require a lot more work than was involved in the original ring-proxy analysis, and of course would require that suitable ring-series were available.
Given the apparent absence of evidence it doesn’t say much for the peer-review process involved in the Mann paper.

mogamboguru

So while the rising heat content in the oceans due to CO2 keeps missing, the missing cold in tree rings isn’t missing at all?
Do I miss something here?

Eliza

Dendros are jumping ship it seems to me LOL

Anyone who cites Jack Vance (Dr. Rob Wilson) has got to be on the right side.
/Mr Lynn

Rob Wilson posted to the dendro list in part:

[Michael Mann claimed] … failed to corroborate volcanically forced cold years that were simulated in modelling results (e.g. 1258, 1816 etc).
Our comment focuses on … and a lack of any empirical evidence for misdating of tree-ring chronologies.

Guess it’s time for the reminder that hard data trumps models. The action should be on proving the data wrong, not assuming the models are right.

Stephen Richards

Steven Mosher says:
November 25, 2012 at 7:02 pm
Well, Mann did have the good sense to use BEST data in his response.
Did BEST create any new raw data ??

Louis Hooffstetter

This is classic. Once again Mann et al. question empirical data because it fails to match a model run. We saw this in MBH98 and more recently in the GSA presentation of Mann, Kozar, and Emanual:
https://gsa.confex.com/gsa/2012AM/webprogram/Paper206358.html
Scientists everywhere should be shaking their heads in disbelief. This is completely ass-backwards. Empirical data is used to verify and constrain models, not the other way around.

Jimbo

“…..I have wondered about trees. They are sensitive to light, to moisture, to wind, to pressure…….”

and deer crap over newly opened routes.
http://wattsupwiththat.com/2009/10/02/a-hands-on-view-of-tree-growth-and-tree-rings-one-explanation-for-briffas-yad061-lone-tree-core/#more-11409

RomanM

The original Mann article seems to be available at his web site:
http://www.meteo.psu.edu/holocene/public_html/shared/articles/MFRNatureGeosciAdvance12.pdf

joeldshore

Louis Hooffstetter says:

Scientists everywhere should be shaking their heads in disbelief. This is completely ass-backwards. Empirical data is used to verify and constrain models, not the other way around.

I am always amused here when people who have probably never actually done science believe that they understand science better than those who have. In fact, the relationship between models and empirical data works both ways. Sometimes the data points out problems with the models and sometimes the models point out problems with the data, which is, after all, not ordained by God.
In fact, as a modeler, I can remember many times when I have used modeling to find problems with the data. For example, one time we had some OLED devices coated and I found that my optical model was quite insistent on the notion that the layer of Aluminum (Al) was about 300A thick, not 200A thick and this seemed to be a quite robust result not sensitive to other assumptions (like other layer thicknesses). We asked the coaters to check their coater for the Al and they came back and told us that their “tooling factor” turned out to be off by a factor of 3/2…I.e., the modeling was precisely correct in detecting a problem with the empirical data.
Whether the problems in the case of volcanic cooling end up to be with the data or the models or some combination of the two is still unsettled, but to just assume that it is a problem with the models and not with the data is no more scientific than to assume the opposite. One has to entertain both possibilities.

John West

Rome wasn’t built nor did it fall in a day. The edges of the Empire are crumbling under the weight of overextended extrapolation, logical fallacies, and arrogance.
”There is something fascinating about science. One gets such wholesale returns of conjecture out of such a trifling investment of fact.” – Mark Twain

Stephen Rasey says:
November 25, 2012 at 9:04 pm
Eight months! to get published a letter questioning a paper.
Biffra should have come here. It would have been posted in it entirety in less than eight hours — and probably done more good for both sides of the debate.
====================================================
I would have liked to have been a fly on the wall for the internal debate about allowing the publication of the letter !!

Gail Combs

Stephen Rasey says:
November 25, 2012 at 9:04 pm
Eight months! to get published a letter questioning a paper….
_____________________________________
AH, but the timing is perfect. Just before the next Eco-Fest to renew Kyoto. Makes one wonder….

Steve Keohane

Thanks for the link to Mann’s paper, RomanM. Because of this practice:
Trees growing near the latitudinal or elevational treeline are typically selected for use
in reconstructing past temperature changes

The detection of warm is much more likely than cold, since the trees are already at the threshold of growth/no growth. It seems to me to rectify this, trees must be chosen at an “elevational treeline”, where there are dead trees at higher altitude that grew when the climate was warm to be included in the dataset. The idea that trees are thermometers rather than general overviews of optimal/suboptimal climate for tree growth is silly. To extend this into sub-degree discernment of ‘climate change’ lacks sanity.