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.
=============================================================
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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Seth says:
November 26, 2012 at 10:56 pm (Edit)
“I realise that the vilification of Mann is part of the mantra here, but this is a very normal scientific exchange.”
I’d say the Mann vilifies himself rather nicely all by himself.
This is how science works. People write papers. Other people disagree. A consensus eventually emerges that usually includes aspects of the original views.
Bingo! It’s too bad that for the last dozen years the funding of science has been used to stifle this normal scientific process.
By the way, which aspects of Mann’s original views do you expect to withstand the cross examination and scrutiny of evidence?
kadaka (KD Knoebel) says:
November 26, 2012 at 3:43 pm
…………….
It is very simple: filtering is not suitable for active data which are updated one step at the time, as I do. Perhaps you should construct graphs to your own requirement but I prefer to show and look at data in the unprocessed form, if available.
Seth says:
November 26, 2012 at 10:56 pm
This is how science works. People write papers. Other people disagree. A consensus eventually emerges that usually includes aspects of the original views
Consensus is not part of the scientific process.
Mosher writes “people need to take a deeper view of Briffa.”
+1 for this. IMHO Climategate showed Briffa to be a well intentioned scientist in with the wrong crowd.
Seth says:
November 26, 2012 at 10:56 pm
“This is how science works. People write papers. Other people disagree. A consensus eventually emerges that usually includes aspects of the original views.”
Except for when the consensus is defined by the IPCC, a body that has as its MISSION STATEMENT to find evidence in favor of man made global warming, and discard all evidence against it.
Lousy C rated scientists like Mann thrive in this atmosphere.
It has always been obvious to me that Briffa was strong-armed by Mann in 1999 in Tanzania and that it was political, to create fake science. Then one has to look deeper. The problem is that following the publication in 1997 of data showing CO2 followed T in the Antarctica ice cores, ‘The team’ had to destroy the MWP.
My approach, having worked all my life on energy and carbon issues has been to create the real science thereby to go back in time to when the real mistakes were made. This was Houghton in 1977. Most physicists have a shallow understanding of radiation physics because Planck gave up when he had to introduce the ‘photon’. It doesn’t exist except at the unique moment when Poynting Vectors interact.
Every professional process engineer who has like me worked in the metallurgical industries where we measure and predict reality instead of political messages immediately sees what went wrong with the Trenberth Hansen climate modelling, also intended to deceive. There can be no CO2-AGW because its surface IR is turned off by atmospheric thermal emission and they create a perpetual motion machine.
The only reason the two-stream approximation works is because the errors cancel out. Sorry Mosher – the boundary conditions which assume pyrgeometers measure an energy flux are completely wrong. The proof is simple: put two back to back in zero temperature gradient and the net signal is zero. Take one away and the net signal jumps to a temperature measurement. The explanation comes from Maxwell’s Equations, the only true arbiter!
The second snow storm on NYC and snow in the UK by the weekend show the World is cooling fast as we head towards the new Little Ice Age. Let’s hope that there will be retraining courses available for all the climate scientists taught incorrect physics so they are unemployable in proper science.
@Seth:
“This is how science works. People write papers. Other people disagree. A consensus eventually emerges that usually includes aspects of the original views.”
Consensus is only useful in choosing the most likely of a given set of scientific theories. However, consensus still leaves the science at the theory stage, and cannot preclude the possibility that the consensus (and hence the theory it prefers to support) is completely wrong. Scientific truth is reached when the theory demonstrates it can be used to make accurate predictions of previously unsuspected facts. Newtonian mechanics demonstrated its scientific truth by its usefulness in predicting the motions of objects in numerous situations. Climatology will demonstrate it has scientific truth when it can make accurate predictions of future climate. So far climatologists have predicted that rising CO2 levels will cause a rise in temperature. Over the last 15 years significant rises in CO2 have caused no increase in global temperature. The theory has therefore already been disproved. This state of affairs should be admitted, the consensus discarded and new theories considered with an open mind. Sadly the situation has become too politicised for this to happen.
Ryan
If you replace “theory” with “hypothesis” then you would be completely correct
The suspicion continues to grow that Briffa’s conscience is getting to him. As we stand, his place in history is likely to be as an embodiment of the Mark Twain quotation above; as a journeyman scientist whose work has been taken and repackaged by powerful vested interests in the green industry. There is speculation that Briffa is the mythical FOIA, the whistelblower behind the Climategate revelations.
If this is so, Briffa needs to go one step further. He needs to come out in a blaze of glory and dissociate himself from the Lysenkoist claptrap of global warmery; he needs to say loud and clear that his work cannot be used by those vested interests in the service of the AGW doomsday cult; that the eco-political-scientific-business complex is scaring the pants off the citizenry for no good reason; that he will no longer be a part of it.
Thanks for sharing your insights, which should be viewed as insights and not as an attempt to apologize for Keith Briffa. Whether or not Briffa was partly compelled by circumstances, as you seem to be saying, he needs to rehabilitate his image in science. I am not a dendro person myself but were I, I would not co-author a paper with the likes of him. Briffa needs to publically repudiate the practice of ignoring data requests and offer a mea culpa for his past behavior. That would be a start toward his rehabilitation. Next he should repudiate such contrivances as are offered by the world of dendroclimatology. Jim Bouldin has shown the way. Briffa swallowed upside-down Tiljander. He needs to spit that out. There are other things he might do. Then he needs to be ever conscious of his shady past and walk straight and in the light. My thoughts are that people like Briffa are starting to realize that they are not going to get away with it, after all.
Come Wilson or come Climategate 3!
mpainter says:
November 27, 2012 at 4:10 am
I’m in broad agreement, but I also think that the practical side of this needs to be taken into account. If you are a tenured academic with a decent pension on the horizon but still a few years off, and the choice is between biding your time till retirement, or getting a short-term blaze of publicity for ‘coming out’ against what’s been going on, followed by being frozen out of your professional field for the rest of your working life as a consequence (which tends to happen to whistleblowers however laudable their actions), the choice might not look so clear-cut. Just a thought.
I’m not sure if joeldshore’s comment is really relevant here. He writes:
However, I don’t see any actual data here. From joel’s account, it doesn’t sound as though the coaters actually measured the thickness of the coating and reported it as 200A. They assumed their settings were correct for a 200A coating, and they weren’t.
Perhaps I’m misunderstanding the story, but as I read it there was no actual measurement in the first place, merely an assumption that all was as it should be.
Talking about Mann, how’s the law suit going, anybody knows?
“Speculation this bald could give dendrochronologists a bad name.” Oh snap! Already happened.
AndyG55 says:
November 26, 2012 at 5:21 pm
Mycroft, do you have links to those specific papers, particularly #4
Thanks.
AndyG55
all over on the HOCKEYSCHTICK site.Anthony has a list on the home page right hand side
just scoll down the home page when you look at th H/S site.
It was posted above but seems to have sunk, like Mann
http://principia-scientific.org/supportnews/latest-news/71-the-courts-hans-jelbring-and-the-kiwis-bring-joy-for-greenhouse-gas-deniers.html
Needs validating
Another example of putting models ahead of empirical facts – sigh
AlecM says:
“There can be no CO2-AGW because its surface IR is turned off by atmospheric thermal emission and they create a perpetual motion machine.”
All bodies above absolute zero radiate power, I don’t think anyone has suggested otherwise.
Where’s the perpetual motion machine?
Sun emits UV — UV hits Earth surface during day– Earth warms to T=X during day, cools to T=Y at night — Earth emits IR, transfers heat to Atmosphere — Atmosphere absorbs energy from surface (conduction, convection, & IR) — Atmosphere warms — Atmosphere emits IR to space & Earth — Earth/Atmosphere temperature gradient reduced thereby reducing heat loss at night — Earth cools to T=Y` at night. The only energy input is from the Sun, nowhere else is energy “created” even in this simplified scenario, only the transfer rates through the system and most importantly from Earth to Space is changed. If not for the atmosphere the Earth would be like 100 degrees C during the day and -173 at night, like the moon.
Mosher,
You can look at this and tell me Briffa is an honest scientist? Briffa defends this to this day, to my knowledge. I think he’s just jealous of the fame Mann had achieved.
He can’t have a change of heart now, and still defend past bad acts.
DaveS
You have touched on one of the ugly aspects of climate science. My nose tells me that it gets even uglier as one peers deeper.
Here’s something from March 2008 regarding Bristlecone Pines.
Stephen Richards said:
Seth says:
November 26, 2012 at 10:56 pm
“This is how science works. People write papers. Other people disagree. A consensus eventually emerges that usually includes aspects of the original views”
Consensus is not part of the scientific process.
Consensus IS part of the scientific process. But that has to be an organic one. The AGW consensus was doomed to be a forced one the moment the IPCC was created, as that organization was created to to produce that very consensus. It by design became a perpetual information merchant unlike any other for any other branch of science. Any work that suggested that things were not as bad as the committee expected was rejected as incorrect because it didn’t match the expected worst scenario outcome. Then when other peer reviewed papers, say from Dr. Roger Peilke Sr, are presented as a buffer, they are rejected by the community at large.
Why.
Because they are not in the IPCC. It has become it’s own canonized bible and prophecy machine
From JamesS on November 27, 2012 at 5:01 am:
One of the first things to notice is no tolerance was given, for example 200 Angstroms +/- 20A. All such specs need a tolerance, you can’t get a perfect uniform precisely 200A coating on all of a part.
Specs for coatings and platings are often interpreted as minimum thicknesses. If you’re specifying 0.0003″ of nickel for corrosion resistance, if the platers give you less then you don’t have enough resistance, if they give you a little more and the part sizes are all still within tolerance then there’s no problem. There is also geometry to consider. On points and edges (points in cross-section), especially if acute angles, you can have the minimum thickness built up on the sides and be under on the points. I suspect they gave him a good 200A minimum coating, no spot was under that.
Other possibility, considering it’s generally not good for a business to argue with a customer, they did give him an ~200A coating, then when he complained they made up a “tooling factor” that confirmed what the customer believed. Same if the coating was done in-house, management doesn’t like interdepartmental squabbling. But since Joel didn’t measure it himself, and is going by what his model said, good possibility the “tooling factor” became a notation, “Use 133A (two-thirds) on this part, not 200.”