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
==============================================================
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.
=============================================================
UPDATE 3: Rob Wilson leaves this comment at Bishop Hill today, bolded section is my emphasis:
Nov 26, 2012 at 9:00 PM | 
Rob 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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I think Mann understood perfectly. But, he was led down the garden path by his hubris, followed later by his hairline (hey, I’m bald, I can make bald jokes) and didn’t expect anyone with credentials to publicly rebuke him.
I suppose now he’ll be calling Wilson and the rest shills for big oil.
Mughal…this is news precisely because it is different than the norm for this particular sector of scientists. It’s not correct to make a trend out of a single instance, though. You can go back to “hoax” and “all scientists” strawmen with comfort.
Mughal,
Alas, you did not address any points from me (or others) above, and instead offered your own strawman caricature. All I can say is that what you attribute is not what I think, so you must be addressing someone else. If that’s your idea of a rational discussion then you are not offering anything to contribute to this thread.
I would personally appreciate Rob Wilson and others providing any info on the backstory from the previous 7 years or more concerning Mann’s and Jones’: 1) coercive axis of bias in climate science; 2) intimidation of journal peer review and; 3) active IPCC process manipulation.
It is time to open the backstory, I hope.
John
Policy Guy said (November 25, 2012 at 9:37 pm)
“…So how does one demonstrate that a tree does not generate a ring under certain circumstances?…”
Well, their normal practice was to go through all the data and pick out only those that showed the current warming.
So it’s either use some trees with “missing” rings to prove their point, or use data with “missing” TREES because the existing rings didn’t prove their point.
There have been at least 3 climate change headlines per day on my Yahoo homepage, ever since the election.
I found this headline and clicked, intending to comment that it was refreshing to see scientists studying poop instead of global warming.
http://news.yahoo.com/human-poop-helps-scientists-snoop-history-200636433.html
They are really scraping the bottom of the cesspool now.
The resistable rise of Michael Mann.
Pamela Gray said on November 26, 2012 at 6:32 pm:
Maybe Mann should look under the table skirt for his missing data.
Question: When is it a table skirt, and when is it a table kilt?
I’ve seen some rather masculine tables in my time, don’t want to cause any offense by calling it the wrong thing.
So Mikey is willing to sacrifice the field of dendrochronology on the altar of treemometers.
Gotta love the part of his response: “Although we welcome alternative hypotheses, we note that their comment does not provide a plausible alternative explanation for this vexing problem.”
Why should they offer an alternative hypothesis in a comment? They’ve pretty much demolished his which was only needed because there was a problem with his temperature model.
But if MIkey needs an alternate hypothesis, I would like to posit: Sometimes, treemometers ain’t.
The illuminiti: UN IPCC (least) and UN General Secretary (Greatest) and UN Council and UN Security Council (Lower, by rank).
The Illuminitus: ‘Ms. Figueres, the executive secretary of the convention’ from http://www.nytimes.com/2012/11/27/business/energy-environment/un-climate-talks-promise-little-drama.html?pagewanted=2&_r=0
From Wikipedia:
Abduction[1] is a form of logical inference that goes from data description of something to a hypothesis that accounts for the reliable data and seeks to explain relevant evidence. The term was first introduced by the American philosopher Charles Sanders Peirce (1839–1914) as “guessing”.[2] Peirce said that to abduce a hypothetical explanation from an observed surprising circumstance is to surmise that may be true because then would be a matter of course.[3] Thus, to abduce from involves determining that is sufficient (or nearly sufficient), but not necessary, for .
For example, the lawn is wet. But if it rained last night, then it would be unsurprising that the lawn is wet. Therefore, by abductive reasoning, the possibility that it rained last night is reasonable. (But note that Peirce did not remain convinced that a single logical form covers all abduction.)[4]
Peirce argues that good abductive reasoning from P to Q involves not simply a determination that, e.g., Q is sufficient for P, but also that Q is among the most economical explanations for P. Simplification and economy are what call for the ‘leap’ of abduction.[5]
In abductive reasoning, unlike in deductive reasoning, the premises do not guarantee the conclusion. Abductive reasoning can be understood as “inference to the best explanation”.[6]
From Wikipedia:
Deductive reasoning, also called deductive logic, is the process of reasoning from one or more general statements regarding what is known to reach a logically certain conclusion.[1] Deductive reasoning involves using given true premises to reach a conclusion that is also true. Deductive reasoning contrasts with inductive reasoning in that a specific conclusion is arrived at from a general principle. If the rules and logic of deduction are followed, this procedure ensures an accurate conclusion.
An example of a deductive argument:
All men are mortal.
John is a man.
Therefore, John is mortal.
The first premise states that all objects classified as “men” have the attribute “mortal”. The second premise states that “John” is classified as a “man” – a member of the set “men”. The conclusion then states that “John” must be “mortal” because he inherits this attribute from his classification as a “man”.
Deductive reasoning (also known as logical deduction) links premises with conclusions. If both premises are true, the terms are clear and the rules of deductive logic are followed, then the conclusion of the argument follows by logical necessity.
Now Consider The Principal 2 of The IPCC.
The role of the IPCC is to assess on a comprehensive, objective, open and transparent basis the scientific, technical and socio-economic information relevant to understanding the scientific basis of risk of human-induced climate change, its potential impacts and options for adaptation and mitigation. IPCC reports should be neutral with respect to policy, although they may need to deal objectively with scientific, technical and socio-economic factors relevant to the application of particular policies.
Ah Ha! That Phrase:
“Human Induced Climate Change”.
Human Induced Climate Change MUST EXIST in Order For The IPCC … To EXIST.
So the Entire Reason For Being Of The IPCC (and all there in) … Is False. Simple.
Just a lot of money funding cocaine and heroin, prostitutes, slavery and debauchery, and a lot of Government Travel Reimbursement Requests (NSF, White House, NOAA, USGS, EPA, DoE … the list goes on and on and on) at such an expensive place as Doha, Qatar.
And Doha, Qatar! This is OIL TOWN! Electricity is FREE for residents … ah hem … Bedouin.
Advice: Don’t look like a Gaigin in Doha.
🙂
Maybe it simply requires some “adjustment”.
Jeff Alberts says:
November 26, 2012 at 7:06 pm
“Trust?” No. “Trust but verify,” Yes.
Stacyglen has it right, I think. Stacy asks why we don’t settle this with some experiments? With well-designed experiments, we ought to know in a few years under what conditions trees fail to produce rings. (And no, I won’t be satisfied with the “photosynthesis index” proposed above without some solid work to back it up.) So what if it takes time and trees — that is how we did biology before all the yahoos with math degrees showed up. It would also be an excellent idea to go ask tree experts instead of “climate experts”. Just sayin.
Anyone else sense the dendrochronologists have seen the writing on the wall regarding Mann and are distancing themselves from Mann’s downfall?
Policy Guy says: “Who needs evidence, just propose a theory and say that you’ve modeled it.”
If I may…
Who needs science, just propose research, collect the funding, and claim a Nobel.
“Trust but verify” is part and parcel for science. I took it as understood. 😉
The lack of verification (except by buddies) is why we’re in this mess in the first place.
people need to take a deeper view of Briffa.
Some background. Jones was a co author of both Briffa and Mann.
Early on in the climategate files you will find Mann applying pressure to Jones, Briffa and osborn
with regards to some things that Briffa had written.
Also, Briffa and osborn appear to be preparing a criticism of mann that would have raised some of the points Mc raised. the paper doesnt get written.
Recall that Briffa doesnt get the lead in Ar3, that goes to the freshly minted Phd, mann.
come 2005, Mann is complaining to Jones that he cant face the skeptics all by himself.
Up until 2005 Jones had been sharing data with others, even mcintyre.
Briffa sends Jones a pile of press clippings attacking Jones and comments that the skeptics are getting traction with the data sharing argument.
You would think, Jones would take the hint. To me it looks like Briffa trying to win his boss back over. Jones however sides with Mann and that very day sends warwick hughes the famous reply
“why should I share my data”
In writing Ar4 briffa is under big pressure to out do mann’s HS. he argues against this. he complains that people should not cave to mann’s pressure.
Unlike the HS, briffa’s chart never makes it into the policy maker summary.
Briffa wasnt perfect. But a deeper look at things and you find somebody who was never a fan of mann.
Instead of lumping all scientists into the same box, the way mann lumps all skeptics as oil shills, folks might focus a bit more attention on the details.
Privately a critic of Mann’s, Briffa seems to have bitten his tongue when it came to public criticism.
He fought, perhaps not hard enough, against manns influence in Ar4.
people all understand staying silent. Everytime you see a dragon slayer comment and remain silent, you’re basically doing what Briffa did.
joeldshore says:
November 26, 2012 at 5:43 am
“Louis 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.”
The relative role of model vs data depends upon the signal to noise ratio of the measured data.
On one extreme, it is a one way street. If we model the weather, we know if the prediction was correct. We have no doubt if it rained or not. My experience in modelling is similar—we model where there might be oil, then drill a well. The model is tested. (Gasp! a big oil shill)
On the other extreme, a theoretical physicist might have some very good calculations and the applied physicist some hint of a signal. Model and measurements play a more equal role in guessing what is the truth.
Measurements in climate are not as hard as we make them out to be. When models fail, it is the models which should be tortured, not the data.
This is how science works. People write papers. Other people disagree. A consensus eventually emerges that usually includes aspects of the original views.
I realise that the vilification of Mann is part of the mantra here, but this is a very normal scientific exchange.
Jones is missing data,
Mann is missing rings,
Piltdown is the missing link.
Hi – Hi! We’re your Dendro Boys – Ah-huh –
And have we got news for you – You better listen!
Get ready, all you lonely IPCC tree-ring huggers!
And leave that faux Nobel prize certificate at home. – Alright! –
CO2 is rising – but sea level’s still just as low
According to all sources, Penn State’s the place to go
Cause tonight for the first time
Just about half-past ten
For the first time in history
It’s gonna start raining Mann…
It’s Raining Mann! Hallelujah! – It’s Raining Mann! Amen!
I’m gonna let FOIA and Climategate
Hockey-stick-whack Mann on his head
It’s Raining Mann! Hallelujah!
It’s Raining Mann! Every Yamal Specimen!
Short, bald, fat and green
Malicious, devious, wrong, and just plain mean…
God bless Mother Nature, she’s a climate scientist too
She took off to UEA and she did what she had to do
She got poor old Harry to upload some email files
So that each and every skeptic could find the perfect rile…
It’s Raining Mann! Hallelujah! – It’s Raining Mann! Amen!
It’s Raining Mann! Hallelujah!
It’s Raining Mann! Ameeeeeeeennnn!
wrecktafire says:
November 26, 2012 at 8:58 pm
[…]It would also be an excellent idea to go ask tree experts instead of “climate experts”. Just sayin.
Why would we do that?
Surely you realise by now that Climate Biology is different to Biological Biology and can’t be done by mere tree experts, any more that Climate Statistics can be done by mere statisticians, Climate Physics by mere physicists or Climate Economics by mere economists. You need a Climate Expert for such complex matters or you’ll end up with all the wrong answers!
Mann needs to show a cooler past to make a steeper modern warming trend and it looks like he has tried too hard and has pissed off the neighbors. This is more team tennis. The Antarctic doesn’t heat like it’s been projected to, the skeptics point this out and we get Steig 09’s weak back hand. Spencer writes a paper showing lower climate sensitivity due to clouds, here comes Trenberth and Dessler charging the net! The temperature is flat for 16 years and Mann hits a short lob shot.
This isn’t science as I perceive it…it’s about winning an argument, environmental advocacy, and politics.
Dennis Nikols, P. Geo. says:
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.
Or possibly even Dendrology 101 🙂
It’s interesting how whilst climate scientists very often are downright rude to anyone outside their group having anything to say about “climate science” they themselves often have plenty to say about things from history to mathematics…
The data disagrees with the model, therefore the data must be in error and must be discarded.
Here we go again.