Response from Briffa on the Yamal tree ring affair – plus rebuttal

Where is his explanation for hiding the data for years?
Where is anything beyond a bland dismissal?
And it is clear from the way he frames the issue that they are not interested in seeing what the trees say. They are out to prove their conclusions.
As said before, they are carving data to fabricate a hockey stick.

Well come on you all:
We all commented the silence of the Team was deafening. Briffa has to release something in the genre “his work against my word I did not do it”, regardless how weak. On one hand they always criticize Steve for the lack of peer reviewed publications but here Briffa retreates behind his work not yet published…
Again the next piece of puzzle will come once the raw Temperature data used for HADCRUT will be released. The stonewalling of data release is disheartening: imagine withholding financial data from IRA or CRA and claim you did not evade taxes…

doesn’t say much really if you ask me

“Do I believe Dr. Keith Briffa? No.”
Same here !!

Not buying it.
“Received inappropriote low weight” = “didn’t recieved the heavy weighting I gave it to get the HS shape”
“He offers no justification for excluding the original data;”
Can Briffa justify excluding the dozens of chronologies in the first place?

“Your delays and roadblocks (such as providing an antique data format of the punched card era), plus refusing to provide metadata says more about your integrity than the data itself. Your actions make it appear that you did not want to release the data at all.”
Thanks for that. In the name of science and the people, who refuses to be traped in these kind of “scientists”.

RE: San Antonio,
I renew my concern that Tom P is a foot soldier in the PR battle, sent in by Real Climate and Fenton Communications, and is not someone seeking the truth.

Another gem: “Having said that, it does appear that McIntyre did not directly instigate any of the ludicrous extrapolations of his supposed findings highlighted above, though he clearly set the ball rolling. No doubt he has written to the National Review and the Telegraph and Anthony Watts to clarify their mistakes and we’re confident that the corrections will appear any day now…. Oh yes.”
Indeed, the proper way is to do the calculation, submit it to Realclimate, wait for their answer and wait for their answer… another 10 years and meanwhile shhhh, not a word, you enemy of science!

We have not yet had a chance to explore the details of McIntyre’s analysis or its implication for temperature reconstruction at Yamal…

Then this isn’t really a response to Steve McIntyre’s analysis, but a general response to the fact that his work is under attack.

One of the questions which Dr. Briffa is NOT answering or even proposing an explantion for is WHY would there be such a marked “outlier” in YAD061.
In fact the general “noise” of the system is so strong, I tend to think of the value for spotting “trends” as “minimal”.
I’m continuously amazed that NONE of these “fine qualified scientists” puts ERROR BOUNDS on their data. That they NEVER do basic statistical analysis to find out their “confidence intervals”.
If I presented this sort of analysis for some of the “Statistical Process Control” work I have done in the past, I would be FIRED, period.
You can’t control to 3 or 6 sigma, if you have no idea what sigma is.

It’s hard to make sense of the statement, but it seems he has sidestepped the critical questions.
Does he agree that he made use of some data but not other data?
If so, why?

“My colleagues and I are working to develop methods that are capable of expressing robust evidence of climate changes using tree-ring data. We do not select tree-core samples based on comparison with climate data. Chronologies are constructed independently and are subsequently compared with climate data to measure the association and quantify the reliability of using the tree-ring data as a proxy for temperature variations.”
really says it all. in fact, they are looking for a connection temperature-CO2 and using any possible mean to validate it.
i am by no means an expert, but i have read several papers, and i found an interesting concept in a few of them, the “instrumental paradox”.
do instuments agree with ringree in the 20th century? some papers i read say they dont.

I can tell flannel and stonewalling when I see it. Here in Briffa’s response it is all too clearly demonstrated. Anthony’s follow up questions and observations are right on the money and Briffa should respond without delay.

My colleagues and I are working to develop methods that are capable of expressing robust evidence of climate changes using tree-ring data

I think he already did that, and look how it turned out.

Re: Frank Stembridge
Many in the press (who should know better) do not realize or choose not to recognize that they are being manipulated by PR flacks and that Real Climate is simply a production of a PR firm. My comments are intended for them.
I support your assertion that this audience should continue to focus on the data.

Briffa is still hiding pertinent information.
“was based on the application of a tree-ring processing method”
No mention of what that method entailed. I suggest the method used was a method that selects based on showing the greatest deviation toward warming.

Sam the Skeptic (09:43:02)
As a UK citizen I can confirm that the RMS Titanic did not sink in 1912. This is because when I was at Brighton I dipped my foot into the sea and didn’t feel a signal, a mast, a portal or anything.
Actually this sort of British reasoning was written up by Bertand Russel in his book “The scientific outlook” where he argued that scientific technique would be sequestrated by the minority to keep the majority in relative ignorance.

Outliers are not a big problem IF the sample size is large enough, but of course here it isn’t. If you’re going to use small samples you really need to trim the outliers off both edges.
Arguing that there was warming in the late 20th century even without the outlier misses the point. I don’t know anyone serious who thinks there was wasn’t warming in the late 20th century. It’s the hockey stick blade “straight for the sky” kind of warming that is being tussled over here.

Instead of the above “no I didn’t” response, the (anonymous) author of
http://www.realclimate.org/index.php/archives/2009/09/hey-ya-mal/
instead lists a number of graphs (more of less describing them to studies or measurement series) that purportedly show hockeysticks of temperature without being based on the Yamal data [snip]
Generally, the point is sarcastically made that you can get hockeysticks everywhere from all sorts of measurements.
Quite how one of the graphs (which appears to show a hockeystick of radiative forcing and/or CO2 rather than temperature) is supposed to support that argument I don’t understand.
But all the others are small unreadable graphs linking to webpages of larger studies that they’re apparently taken from. I went to a few to see what they’re based on (particularly those where a multi-curve graph dies down to 1 curve by the time the hockey stick starts), but I’m not familiar enough to identify them as actually being based on the Yamal [snip] after all (or not).
Not that it would do much good to post a comment there that picks them apart, but It would be interesting if one of the knowledgeable investigators here could dissect their sarcastic list into Yamal uses, other known hockey-stick bases, and other types (such as those with suspect but unreleased data sources).
[snip]

Robinson (09:22:49) :
“Oh dear. My first pass at YAD061 and I’m pretty gobsmacked. The entire record comes down to this one tree, more or less. What a revelation! We must go and hug it.”
That made my day. Thanks for the laugh!!!!

The “team” has rolled out a vast collection of ice core/C02 hockey sticks, borehole hockey sticks, glacier retreat hockey sticks, Had Crut temp hockey sticks, etc. to counter Steve’s outstanding work. Wouldn’t it be interesting to obtain the data behind these other hockey sticks…
Oh wait, they “lost” the Had Crut raw data.

“My colleagues and I are working to develop methods that are capable of expressing robust evidence of climate changes using tree-ring data.”
I caught that too. As a scientist, I’m appalled at such a statement. I was reading through a stats book this morning and ran across the following: “Scientists often hope passionately that a particular experimental result will turn out to be statistically significant, so that they can have a paper published in Nature and get promoted, but that doesn’t make it right.” – Michael J. Crawley, Imperial College, London.

“Leif Svalgaard (09:14:03) :
Although YAD061 looks like an outlier, the other trees do show a rise from ~1820 to today [albeit smaller] so the record [based on those threes] does not look entirely flat to me.
REPLY:[…]There could be hundreds of reasons besides climatic temperature change.
So why the fascination with those trees in the first place? If there can be so many reasons besides climate changes, why get all hot under the collar about something that apparently is a poor indicator?”
Leif,
I’d guess because people want to replicate the damned study and keep getting stonewalled. If all of the details on the study were forthcoming it might be possible to finally show whether it actually stands on its own legs or not. If you don’t believe trees are thermometers and a scientist blindly gives you final numbers saying that they are, you’re going to want to know how they arrived at them, no?

Al Pipkin,
As a fellow ME I would also like to assert that I will never use a tree as a thermometer and also wouldn’t recommend it to others.

It is painful to read RC. I tried reading http://www.realclimate.org/index.php/archives/2009/09/hey-ya-mal/ but my eyes glazed up…
It isn’t a writing style I like. It is dismissive and childish at the same time.
The gavin name plot is interesting. Just because you can find a “hockey stick” doesn’t mean it is valid to what you are trying to measure.
Perhaps they could learn something from that?

I would even suggest to define *scientific result*, in any area of knowledge, as the set composed by: DATA obtained according to the scientific method (raw, or processed under peer-monitoring, if raw data cannot be stored – e.g. LHC) + INTERPRETATION based on consistent logical and mathematical arguments (peer-reviewed articles) + ALGORITHMS used to interpret the data. Any scientific result, to deserve that name, should include all of them! If not, it should be regarded by publishers as non-scientific. It should not only be peer-reviewed, but peer-re-reviewable. If interpretation is given without access to the original data that backs it and/or algorithms used to manipulate it, then it is as reliable as the boy who cried wolf. Scientific misconduct would still occur under this definition – the world is not perfect -, but it would definitely truncate it, to a much lower level than the one we experience today.

“My colleagues and I are working to develop methods that are capable of expressing robust evidence of climate changes using tree-ring data”
Let me help you there Mr Briffa.
1. Design your experiment and analysis prior to gathering data.
2. Control the variables that can be controlled. e.g. Ring cores to be gathered from tree species where the response to temperature is both known, and the current temperature is such that it lies at the midpoint of the up-curve or the down-curve of that species response to temperature variation.
3. Only use trees from virgin forests.
4. Use huge sample sizes, tens and hundreds of thousands, not four or five a given period and location. So that random the noise to signal ratio is reduced.
5. Randomise the selected trees systematically, (hint gather the data from the tree closest to a randomly generated coordinate within suitable forests.
6. Record and publish every step of the process, so that any errors can be spotted by peer reviewers, and those trying to replicate your work post publication.

As part of Briffa’s defense, he offers 4 citations, three of which he was the lead or sole author. The old political adage that if you say it often enough and loud enough, people will believe it is true seems to be alive and well.
That one dramatic sample in YAD061 would be dramatically reduced if averaged with the other samples, unless it was given more weight.
A thought occured to me that all this paleodendrology only gives an indication of how warm the summers were and no indication of how cold the winters were over the same period. Maybe its not significant.

Steve McIntyre replies to Briffa:
http://www.climateaudit.org/?p=7257#comments

What the stations say
http://data.giss.nasa.gov/cgi-bin/gistemp/findstation.py?datatype=gistemp&data_set=1&name=&world_map.x=515&world_map.y=50
no hockeystick in Yamal, check Salehard: 40’s as hot as the 90’s,
local temperature doesn’t match extreme trees.

Look… I am a plumber… can someone please explain how the tree ring data can override the existing arctic temperature records? It seems to me that this alone puts the lie to the Yamal hockey stick… Like I said… I’m a plumber… what am I missing here??
Mike Bryant

Leif Svalgaard (09:36:45) : “So why the fascination with those trees in the first place? If there can be so many reasons besides climate changes, why get all hot under the collar about something that apparently is a poor indicator?”
I think you know the obvious answer to that, Leif, is because Briffa et al. work has been the “industry standard” for so much research that reproduce the failed, broken, and discredited hockey stick.
That stick which is still the darling of the IPCC and the Gore-Media-Complex.
What gets many hot under the collar is not the trees or them being a poor indicator. The trees are what they are and they do what they do.
What really grinds the gears, for me, is is that so VERY much research is depending upon these cherry-picked (or should I say larch “cone-picked”) samples as leverage to extrapolate a whole universe of GCM unreality…and propagate that across the scientific “peer-reviewed” political establishment and the media….who then feed it to the populous.
It truly is the tail wagging the dog here…and thanks to folks like McIntyre, Watts, and other whistle-blowers, this is going to stop.
And I can only think it will in the long run benefit you and your research tools and funding…to get Science back where it is supposed to be: the pursuit of truth.
Chris
Norfolk, VA, USA

Assuming that the goal of Briffa, his team, and those criticizing his work, is to produce honest, professional and ethical work, then there is no justification for Briffa or the journals that published work to withhold any data sets, including meta data. All of relevant data should be produced and evaluated before the knife fighting goes any further.

“Re: #44 Tamino
“Do you really believe that? Do you think, if all data from every study for all time were freely and easily available, that would have stopped McIntyre from useless unfounded FUD? Or even slowed him down?
I don’t.”
My reply:
Perhaps then instead of Steve McIntyre you fulminate about, it would have been a well respected climatology laboratory independently testing the robustness of these proxies the same year the papers were published…

“My colleagues and I are working to develop methods that are capable of expressing robust evidence of climate changes using tree-ring data”:
This is the classic “interrogating the data until it confesses”.

Here’s the most relevant sentence from RC’s “rebuttal” of McIntyre:
“People have written theses about how to construct tree ring chronologies in order to avoid end-member effects and preserve as much of the climate signal as possible.”
And what “climate signal” are we looking for? This GavinSentence is about as clear a reference to the cherry picking methods of the hockey stick Team as has ever been written.

Leif Svalgaard (09:36:45) :
“So why the fascination with those trees in the first place? If there can be so many reasons besides climate changes, why get all hot under the collar about something that apparently is a poor indicator?”
Exactly the point, except that “those trees” are being used to support AGW climate change, where the jist of what I take a way from all of this is that “those trees” aren’t worth bumpkus as a temperature proxy. The real nexus of McIntyre’s work/attention is that anyone with a valid scientific hypothesis should never be afraid of someone else looking at their basic data. All else aside, regardless of the apparent reality of a postulated hypothesis, if a scientist appears unwilling (or is willing) to release their raw data and basic data selection and alaytical methods, it must invariably lead to suspicion of the veracity of their results.

What he said was that he didn’t cherry pick; if any cherry picking occurred, it was H&S wot dun it.
“The Yamal tree-ring chronology (see also Briffa and Osborn 2002, Briffa et al. 2008) was based on the application of a tree-ring processing method applied to the same set of composite sub-fossil and living-tree ring-width measurements provided to me by Rashit Hantemirov and Stepan Shiyatov which forms the basis of a chronology they published (Hantemirov and Shiyatov 2002).”
So his claim is basically that he simply reprocessed all the records H&S gave him.
I had understood from Steve McIntyre’s post that this was not so: “while the CRU archive does not appear to be the precisely the same as the unavailable Hantemirov and Shiyatov 2002 archive, it does appear to be related.” However, he also says “It is highly possible and even probable that the CRU selection is derived from a prior selection of old trees described in Hantemirov and Shiyatov 2002 as follows:” and the following quote includes the line “These were the longest and most sensitive series, where sensitivity is measured by the magnitude of interannual variability.” which would therefore be the selection criteria.
Thus, the implication of this is that, yes, they were cherrypicked for “sensitivity”, but that it was Hantemirov and Shiyatov that made the selection, not Briffa. Steve’s criticism is that Briffa should have realised that this made them unsuitable for application of RCS.
So I’d say Briffa has a point. But don’t forget this bit: “I note that McIntyre qualifies the presentation of his version(s) of the chronology by reference to a number of valid points that require further investigation.” I think that counts as acknowledgement that Steve McIntyre might have a point; which is probably as much as could be expected from the team.

Putting Briffa and Tom P.’s posts together leads me to think you’re missing Briffa’s point, Anthony.
Let me quote from McIntyre’s original post:
“Perhaps the difference between the two versions is related to different aging patterns in the Schweingruber population as compared to the CRU population. The CRU population consists, on average, of older trees than the Schweingruber population. It is highly possible and even probable that the CRU selection is derived from a prior selection of old trees described in Hantemirov and Shiyatov 2002 as follows:
In one approach to constructing a mean chronology, 224 individual series of subfossil larches were selected. These were the longest and most sensitive series, where sensitivity is measured by the magnitude of interannual variability. These data were supplemented by the addition of 17 ring-width series, from 200–400 year old living larches.
The subfossil collection does not have the same bias towards older trees. Perhaps the biased selection of older trees an unintentional bias, when combined with the RCS method. This bias would not have similarly affected the “corridor method” used by Hantemirov and Shiyatov themselves, since this method which did not preserve centennial-scale variability and Hantemirov and Shiyatov would not have been concerned about potential bias introduced by how their cores were selected on a RCS chronology method that they themselves were not using.
Briffa’s own caveats on RCS methodology warn against inhomogeneities, but, notwithstanding these warnings, his initial use of this subset in Briffa 2000 may well have been done without fully thinking through the very limited size and potential unrepresentativeness of the 12 cores. Briffa 2000 presented this chronology in passing and it was never properly published in any journal article.”
Seems to me like Briffa is acknowledging in passing that he intentionally selected longer-lived trees and is defending his choice of exponential normalization, which may cause the most recent tree-rings from the living trees to show an exaggerated warming signal.
I don’t know if there’s some justification for using only longer-lived trees. As McIntyre pointed out, the subfossil larches don’t have the same bias. Maybe any selection of long-lived trees would create an artificial hockey stick.
If the longer-lived trees bias was valid for the living trees, it should have been a valid criterion for the subfossil record. If adding short-lived trees to the recent parts of the record just adds noise and hides the real variability, adding short-lived trees in the subfossil record also adds noise and hides the real variability.
If the longer-lived trees bias was valid, he needed more cores anyway. If he didn’t have enough cores for a good sample, he shouldn’t have published.

More fun than Dan Rather’s memos, also I recall, at the start of a hockey season.
Same, same. So convinced they are of their theory, they willingly and uncritically accept any old BS evidence to support it.
The proof of cherry picking may never be had short of a lie detector test, but it is not too soon to compare the memos to the hockey stick and YAD061 – of which Briffa must surely have been aware – and place them both in a special class of evidence.
A class somewhat less reliable than jailhouse snitch testimony.

To a layman this is a frightening story. That global energy policy could be determined by one guy in a micro-specialty using a nano-view of the world is outrageous. (Of course, it bears similarity to Ancel Keys’ work, too, so I guess it’s not a new phenomenon.)
Funny that global warming is so alarming and so extraordinarily obvious that it only shows up in ONE tree in one grove in remote Siberia.
Please, carry on. The stakes are high.

Leif Svalgaard (09:14:03) :
Although YAD061 looks like an outlier, the other trees do show a rise from ~1820 to today [albeit smaller] so the record [based on those threes] does not look entirely flat to me.
REPLY:[…]There could be hundreds of reasons besides climatic temperature change.
But what is the most important? In other words, which factor is more significant in tree ring growth? (Caveat: I can supply (time is at a premium just now) additional papers showing similar responses, it was cherry picked because the authors put it most eloquently.)
Articles
Ecology
Response of tree-ring width to rainfall gradient along the Tianshan Mountains of northwestern China
Sang WeiGuo 1 , Wang YunXia 2, 3, Su HongXin 1 and Lu ZhaoHua 2, 4
(1) Key Laboratory of Vegetation and Environment Change, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
(2) Institute of Restoration Ecology, China University of Mining & Technology in Beijing, Beijing, 100083, China
(3) Mathematics & Physics Unit, Beijing Officers’ School of Armed Forces, Beijing, 100012, China
(4) Binzhou College, Binzhou, 256600, China
Received: 29 May 2007 Accepted: 5 September 2007
Abstract By comparing the long-term tree-ring growths at various geographic scales, we can make clear the effects of environmental variations on tree growth, and get an understanding of the responses of forest ecosystems to the possible changes in global and regional climate. Radial tree-ring growth of Picea schrenkiana and its relationship to air temperature and precipitation were investigated across longitude transects on the north slopes of the Tianshan Mountains in northwestern China. Tree-ring samples were collected and residual chronologies were developed for three different regions along a gradient of decreasing precipitation from west to east. Response-function analysis was conducted to quantify the relationships between tree-ring chronologies and climate variables, such as monthly mean temperature and monthly precipitation from 1961 to 1998, using the PRECON software program. The statistical characteristics of the chronologies showed that the three chronologies constructed in this study contained significant environmental signals and were well suitable to reveal the impacts of climatic change on tree growth and forest productivity. Annual ring-width variations were similar among the three sites, but the variability was greatest in the east. This research showed that the growth trends of Picea schrenkiana in the Tianshan Mountains have not followed a uniform pattern. Response-function analysis indicated that there were significant correlations between tree growth and climatic factors in all the three regions, among which precipitation was the principal. With decreasing precipitation, the response of tree-ring widths to increasing temperature changed from a positive to a negative correlation. As for precipitation, the positive relationship to tree-ring width always dominates. It could be expected that with increased temperature and decreased precipitation, the importance of precipitation to three growth would increase, and the response of tree growth to environmental changes would also increase. This study emphasizes the importance of regional-scale investigations into the biosphere-climate interactions. The results of this research indicated a substantial increment of tree-ring radial growth as a result of warmer and wetter climate in the eastern regions. However, climate change will have less effect on forest growth and primary production in the western regions.
Leif Svalgaard (09:36:45) :
So why the fascination with those trees in the first place? If there can be so many reasons besides climate changes, why get all hot under the collar about something that apparently is a poor indicator?
Leif : Get real. You become most perturbed when people develop inaccurate conclusions from data, and develop associations based on garbage. This is exactly what concerns us (maybe it’s just me) in this matter. These hockey sticks get a lot of attention in the media, and are used by intellectually deficient policy makers to justify taxation. The ignorant masses believe that the conclusions drawn by the authors of this paper indicate that current temps are much higher, which is categorically incorrect according to the station records. I could care less whether it’s slightly warmer globally than X (any date). But the statistical contortions leading to erroneous conclusions drawn from a few scrawny trees really [snip] me off. These people have no concept of any facet of plant physiology.

Dr Briffa’s evasion of the salient points suggests that should the fundings plug ever be pulled on CRU (which it deserves to be) he would make a good living as a politician.

CA is responding again. Like a snail maybe, but at least it’s alive.
McIntyre has a post up with Briffa’s reply and his rebuttal.

I think many people are misinterpreting this very important sentence: “My colleagues and I are working to develop methods that are capable of expressing robust evidence of climate changes using tree-ring data.” I interpret that to be an admission that present methods are not robust, an interpretation shared by Jennifer Marohasy.
I think the source of the misinterpretation has been the illicit change from the use of the term ‘global warming’ to the term ‘climate change’ yet keeping the onus on CO2 as the cause of ‘climate change’ as the alarmists are wont to do. Interpreted more conventionally and literally, all he is saying is that he is trying to capture the true voice of the dendro record, as it sings its duet of growth and temperature.
===========================================

On an earlier post Al The Brit made a point about exaggerated scales on graphs. This especially occurs on graphs showing temperature anomalies. This is on post, please bear with me as it must be read to the end?
To illustrate my last remark :-
1 The eminent Professor George Manley FRGS produced the Central England temperature graphs from 1650 to 1974.
You need to scroll to Page 14 of the pdf to see the hand drawn graph.
Also it may be of some interest to some on this site where he in effect deals with the urban heat island effect regarding monitoring stations around Oxford. Scroll to Page 2.
2 Now have a look at Hadcruts graph of the temperature anomaly a miracle its a Hockey stick graph?
http://hadobs.metoffice.com/hadcet/
You couldn’t make this up or could you?
It would be nice if you could post the graphs for me?

The concept of tree ring growth as a proxy for temperature is an outright [snip] in and of itself. A tree can grow quite well over a rather wide range of temperatures. It regulates the temperature of its leaves or needles to make up for differences of ambient temperature. Other factors then determine the tree growth.
In radio, there is a little thingy called “signal to noise” ratio. Where ambient temperatures are concerned regarding tree rings, it is all noise and no signal.

“What bothers me the most about this story and appears to be a running theme here at WUWT is that somehow there is this massive conspiracy among scientists ”
I think this is a warmist strawman. It’s not necessary for there to be a conspiracy for “groupthink” to take place.
“We certainly are not getting rich by taking the pro-AGW position. It is just silly.”
I’m not sure who “we” refers to, but certainly Al Gore is getting rich. In any event, nobody can seriously deny that climatologists are receiving enhanced funding, attention, and prestige as a result of concerns over CAGW.
“Hasn’t anybody here wondered why the hockey stick shape keeps appearing regardless of proxy and study author? Perhaps it is a real phenomenon? To suggest that it isn’t implies that scientists are colluding or that every proxy analysis technique always results in the same shape. ”
If I can find you 3 proxy temperature records which do not have hockey-stick shapes, will you concede that you are in the wrong?

Isn’t tree ring growth influenced much more by things other than temperature? Like maybe water? I would bet you take two near identical trees and water one and leave the other to fend for it’s self, the growth differences would be obvious after a few years.
Yep, I did that, and it worked — Watered trees grow faster.
So how can you even consider tree rings as a proxy for temperature without knowing what their entire environment was? Makes no sense.

The trees noted above appear to end measurement in 1990. If so, this is something of a tempest in a teapot. We all know that recent temps were the highest in the 2000’s (until a couple of years ago). Therefore arguing to 1990 doesn’t seem particularly compelling with respect to the current climate.
However, as the data goes, it shows the 1940’s as the highest or equivalent temp in 7 of the 10 samples, against a general background of warming since 1850 (again, not a contested point).

My colleagues and I are working to develop methods that are capable of expressing robust evidence of climate changes using tree-ring data

I don’t usually post without reading a thread, so somebody else may have jumped on this whopper, but doesn’t he pretty much admit that he knows what he is looking for before he starts? Isn’t this the very attitude that keeps him from understanding the objections to his work? He is so certain of global warming that he doesn’t even allow for the possibility that it isn’t there. He seems to be admitting that he is searching for ‘rhetorical’ graphs that can be used in propaganda pieces to convince us all of the “Global Warming Conjecture” that they seem to believe is proven by other means?

Wow, it’s down to a single tree? This just gets better and better.

“We certainly are not getting rich by taking the pro-AGW position. It is just silly.” OK, hows about you give us the benefit of the doubt, and tell your warmie friends that we aren’t getting rich by taking skeptical positions either? Would that be too much to ask?

Scott A. Mandia (11:11:39) :
Given that borehole data reaches back some 500 years, whereas other reconstructions not necessarily including tree rings date back much further, it doesn’t go back sufficiently to record either the holocene optimum, the Roman warm period, or the MWP.

@ brazil84 (11:31:48) :
I did not say EVERY reconstruction is a hockey stick. 🙂
BTW, I do not drive a BMW nor do I live in a big house. 🙂
Most of the researchers are just like me regarding demographics. 🙁
REPLY: Not all – check the latest main page story. Too much money flowing around uncontrolled in our government science programs apparently, you’re just on the low end of the totem pole. – A

addendum to last post.
Here’s loehle’s reconstruction based on non treering data
http://tinyurl.com/y8sn45r

>What is the significance of this statement by Briffa?
“In their work they traditionally applied a data processing method (corridor standardisation) that does not preserve evidence of long timescale growth changes.”
Patrick, it means that the two papers results are not comparable.
The other method that Briffa refers to is not good at comparing temperatures across centuries. They were instead looking for short term changes in temperature. I think the different methods may have led to Briffa getting bad results for his method, as they did all the data collection to suit their methods.
This is why this data should be made public, so that it can be evaluated.

I believe we’ve discovered an answer to the ancient question, “Does a bear crap in the woods?”
Ans: “Right at the base of YADO61!”

“I did not say EVERY reconstruction is a hockey stick. :)”
You pretty much implied it when you claimed that “the hockey stick shape keeps appearing regardless of proxy and study author”
The fact is that the hockey stick DOES NOT keep appearing regardless of proxies and study authors.
“BTW, I do not drive a BMW nor do I live in a big house. 🙂
Most of the researchers are just like me regarding demographics”
Again you are attacking a strawman. The fact is that climatologists are receiving enhanced funding, attention, and prestige as a result of concerns over CAGW. This is true even if they are not getting fancy cars or big houses.

brazil84 11:31:48.
You think warmist strawman, and I think projection. Hey, we’re both right.
brazil16, too, for the symmetry. er, summitry.
========

Really interesting;
Yamal peninsula is really quite near the location where the ‘Tsar Bomba’ was detonated on October 30, 1961. Some 450 km (and maybe 1000 km at it’s farthest point) from the Yamal Peninsula, Novaya Zemlya was the sight of what has been described as the “most physically powerful device ever utilized throughout the history of humanity” (Wiki). The bomb was detonated at a height of 4 km, creating a fireball some 8 km in diameter. It is stated that some 5.25 x10^24 watts (yottawatts) of energy were released, a figure equivalent to more than 1% of the sun’s power output.
At a distance of some 500+km, the radiation would’ve been largely (though not entirely) dissipated, but significant fallout as well as physical effects would’ve reached Yamal, especially on hills with an easterly exposure. Above ground testing at the site began in 1954, ended prior to the test ban treaty in 1963, although subsequent underground testing took place at the site. Seismic activity attributed to this underground testing set off an avalanche which blocked a stream, creating a lake 2 km long.
Now, I’m not saying that Tsar Bomba created mutant growth trees, hell I’m not 100% certain whether the trees being looked at were on the Yamal Pen., or if they were in Yamalia, a bit futher away. What I would say is that if these trees were on the Yamal Pen., they certainly felt the effects of this if not many more bombs. The effects were felt as far away as Helsinki. Flash heat could’ve created glacial pools, or otherwise created an improved water supply, there could’ve been other ecological effects as well. This could’ve been the most unique ‘UHI’ ever to effect the surface T record.
To that end, why did this one tree take off about the same time the above ground testing started? Is there ‘meta-data’ on the actual tree? Grid coordinates, elev. and facing, exposure data, etc.?
Just a wild hare when I realized where this Yamal Peninsula really is, knowing full well where Novaya Zemlya was.
Curious.

“Lucy Skywalker (11:35:30) :
Michael (10:03:34) : I’m trying to put this whole mess in a nut shell for the sheeple. So let me see if I get this straight…
Michael, we are all sheeple to some extent… until we go and investigate for ourselves.”
Lucy,
I admit I am a sheeple on many issues, that’s why I stand open to be corrected with the facts presented to me. That’s also why I believe nothing I read and half of what I see without much thought and scrutiny. I’m a slow reader for a reason.

jlc 11:55:11
Heh, I’ll bet Leif understands the significance of all this. He’s got two bob both ways because his neutral status insists upon it. It would not be consistent to bet otherwise.
====================

Here we see the artful application BS using science laden language. BS should be the call letters of our times. The news today should shout when BS is not used to explain “fill in the blank.” Lots of verbiage but no key question addressed. What a genius.

rain tends to bring the temperature down and during long hot summers, aridity can cause a drought problem. Saying that higher temps correlates to temperature is quite a simplification. Tree growth responds very well to c02 on the other hand. The most important factors to tree ring growth are nutrients, c02, temperature, competition, and water. If you have high atmospheric c02 and plenty of water with moderate/average temperature, then you have greater tree growth than high temperature, low c02, (which is what the pre-industrial average is supposed to be) and drought/aridity

addendum mistake: “Saying that high temperatures correlates greater precipitation”

Leif:
“Although YAD061 looks like an outlier, the other trees do show a rise from ~1820 to today [albeit smaller] so the record [based on those threes] does not look entirely flat to me.”
I think that we would all accept a result that showed a small rise. It’s the sharp rise that results from the methodolgy and the one tree that are the issue.
Leif, if you are still here, I’m dying to get your take on the Svensmark cosmic ray theory. Pretty please with sugar on it!

Leif,
the raw data and processing would greatly help in showing whether it is viable or not, wouldn’t it?

I have been designing and building dams for more than 40 years, so I have an obsessive understanding of recent “climate”:
I am an engineer, like many CA and WUWT readers. Most engineers, look for proof, justification, evidence, logic, common sense, etc. As Steve Mc says, this is the engineering method
If I understand Lief correctly, he is saying that treemometry is nonsense. I think you would be very hard pressed to find an engineer who who would believe that there is anything but a very coarse link between tree ring thickness and temperature.
The reason I take the time to comment on this is that so many people (even engineers) accept at face value the publicised claims based on very tenuous science.
In general, engineers are the most honest and cautious members of any society.
We have an obligation to keep ourselves informed and to speak our minds

Leif:
We seem to agree, but given that the going in assumption is that old tree rings are acceptable as temperature proxies isn’t transparency needed in order to determine the validity of pre-instrumental trees as thermometers? The measurement issue is their value in estimating trees before thermometers relative to other proxies.

I do not believe that McIntyre’s preliminary post provides sufficient evidence to doubt the reality of unusually high summer temperatures in the last decades of the 20th century.

Whatever effect a CO2 increase has on temperature, it’s most significant during winter and in the coldest places on earth. At other times, and in other places, the amount of energy absorbed by CO2 is not only small compared with the total energy flux, but is also swamped by water vapor.
So I ask you, Prof Briffa, why summer temperatures?

Mike Bryant – I’m with you all the way and would value an explanation of why proxies are used for recent times.
I understand why temperature proxies are of value when looking at the past before real measurements were available, but what is the reason for using temperature proxies for the last couple of decades when the real thing exists.
OK, we have had many discussions here about the possible inaccuracies of modern temperature measurement, but surely they are likely to be more accurate, almost by definition, than proxies, since I assume that at some point in time actual temperature measurements are used to attempt to”calibrate” tree ring data.
And why choose trees in Siberia? Has Siberia become a proxy for the whole world.
Wikipedia says about reconstructing a temperature record of the last 1000 years ” A reconstruction is needed because a reliable surface temperature record exists only since about 1850. ” So what possible justification can there be for using proxies after this date.
Forgive me if this is too simplistic but my brain is hurting.
It seems to me that, at the moment, the entire edifice of US and European environmental and economic policy if balanced precariously on a few Siberian treestumps.

“My colleagues and I are working to develop methods that are capable of expressing robust evidence of climate changes using tree-ring data.”

Oops.

****************
Bob Kutz (12:10:47) :
Yamal peninsula is really quite near the location where the ‘Tsar Bomba’ was detonated on October 30, 1961.
*****************
Hmmm … it seems there would be some sort of isotopic signature in the rings.

Bob Kutz (12:10:47) :
Very interesting, and it’s yield was sustained for 30 seconds.
What were the other trees around YAD061 like? New trees, dying trees, diseased trees, burned trees, logged trees , etc?
A tree in a grove that suddenly has access to the the majority of the resources can take off.

I am guessing that he is hiding behind the “not yet published” data because they have not managed to discover any more magic trees yet.
“My science is robust dammit and as soon as I find another 10 trees that back up my religion, I will publish!!!”
He asks why did McIntyre remove those 10 trees?
WHY? well that rates a deserved “well DUH!”
How arrogant and indifferent to your fraud do you have to be to not realise that he did not publish them because they are NOT a representative sample and they falsely skew the results of the temperature record. They are anomalous. They are a fix. They are a CON!
I was waiting for a serious and substantive rebuttal. I should have known better.
Carbon induced climate catastrophe is a serious fraud. Let us all stop wasting incredibly precious time, money and energy attacking the production of an essential trace gas that is necessary for life to flourish, and start, finally, to get a solution to the real and serious environmental catastrophes in deforestation, habitat destruction and wanton chemical pollution. We need to clean up the “trash island” in the Pacific. We need to stop hunting and fishing species to extinction and we need to stop cutting down huge tracts of ancient historic and irreplaceable forests.
It is sickeningly perverse that the Urang-utang is on the very cusp of extinction because climate alarmists and environmentalists have boosted the demand for bio-oils that are planted where these magnificent animals used to have a habitat. It is gut wrenchingly hypocritical of them and I am incensed to a level of frustrated fury every time I think of it. How DARE they lecture and legislate and waste billions of dollars pushing a lie, when the environment is being raped in so many places? Often BY THEM!
Environmentalists are some of the worst environmental vandals in the world and they are desperate to keep us distracted with the fraud, the rubbish that is carbon alarmism.
We should have NONE of it!
Go sick ’em Anthony and Steve. Sick ’em good and proper!

Scientist are getting good at sounding like politicians. To bad I seek out science to take a break from politics.

Dr Briffa says,
“He offers no justification for excluding the original data”
This is desperation. I strongly suspect Briffa knows that the original data was excluded because it was the basis of several of his publications claiming to show a hockeystick effect and excluding it is a reasonable way to determine if he may have cherry picked data in such a way as to create a hockeystick. His response is bluster.

This may be off topic but the Chinese must be laughing their heads off, and, shaking their collective heads in utter disbelief as the free world unravels over the readings of basically one tree. Here they carry most of the States dept, are on the verge to put man on the moon, are fast becoming the worlds number one super power while the free world may go into a financial death spiral chasing tap and trade and green energy.
North America could be energy self sufficient, but blocked by an unproven science, just amazing!

RE: brazil84 in two separte posts
(Re the assertion by AGWers that Denialists think it is a conspiracy) “I think this is a warmist strawman. It’s not necessary for there to be a conspiracy for “groupthink” to take place…For the most part, deniers such as myself DO NOT claim that there is a conspiracy among climate researchers. And DO NOT claim that climate researchers are getting rich from concern over global warming.”
My thoughts exactly. Well said sir/madam. AGW is a groupthink catastrophe.

Scott Mandia beclowns himself by using an official AGW talking point issued a few months back. “You think there is a huge conspiracy amongst climate scientists. That’s crazy, so you and all of you other deniers are crazy!” Read the fine print on the label, Scott, that smear is to be used on the converted or the apathetic, not a crowd of educated and motivated Deniers.
I’ll tell you what’s crazy. Crazy is not expecting anyone like Anthony Watts or Steve McIntyre to appear when you started down this road. Crazy is thinking that you have made a strong enough scientific case to cause western democracies to cripple their economies with trillions of dollars in taxes. Crazy is thinking that the never ending arrogance and contempt shown towards us by the likes of The Team, Tamino, Romm and the rest of you haters would actually help to Save the World.

P Wilson (12:22:36) :
The most important factors to tree ring growth are nutrients, c02, temperature, competition, and water.
But not in that order, you have the dominant one last.

“jlc (12:47:02) :
If I understand Leif correctly, he is saying that treemometry is nonsense. I think you would be very hard pressed to find an engineer who who would believe that there is anything but a very coarse link between tree ring thickness and temperature.
Perhaps I would be a tad gentler [although not my strong side] and say that the link is not understood [rather than ‘nonsense’] and that it therefore must be used with utter reserve and caution, and that research on its potential usefulness is important. However it is used, there must, of course, be transparency and disclosure”
Quite right, Lief.

@ Scott A. Mandia…
“Hasn’t anybody here wondered why the hockey stick shape keeps appearing regardless of proxy and study author? Perhaps it is a real phenomenon? To suggest that it isn’t implies that scientists are colluding or that every proxy analysis technique always results in the same shape. ”
This is classic group-think. NASA said something very similar about foam-impacts on the space shuttle. A paraphrase might go something like this, “Hasn’t anyone here ever wondered why we’ve never lost a shuttle despite all the evidence of ice/foam strikes on the shuttle? Perhaps it is not something to worry about? To suggest that it is something to worry about implies that scientists and engineers are colluding…” Of course, we know how that turned out. Unchecked Group-think in that case led to death for 7 humans.
So please restrain yourself; bite your tongue; pinch your ear whenever you find yourself suggesting that we should stop questioning data. Doing otherwise is contributing to a perversion of science that leads to problems.

All this debate brings to mind the following:
WHY MOST PUBLISHED RESEARCH FINDINGS ARE FALSE, by John P. A. Ioannidis.
Find the paper at:
http://www.plosmedicine.org/article/info:doi/10.1371/journal.pmed.0020124
At the link, near the mid/lower right of the page, are links to papers that build on the above author’s paper.

Bret:
“Why does tree-ring based temperatures having any use in the 20th century except as a sanity check on whether or not trees can ever predict temperature?”
As I understand it, that’s the precise point. The sanity check fails in all but a handful of trees.
By cherry picking a tiny number of trees Briffa found the hockey stick shape which he and the warmists wanted (to suggest that recent temperatures are exceptional) but only by ignoring the vast majority of trees in the area which showed little or no similarity to recent temperatures.
The fact that so many trees don’t match recent temperatures suggests strongly that trees are a poor, at best, way of gauging past temperatures.
If trees are a poor indicator of past temperatures then their use as such in numerous AGW-supporting papers is indefensible and much of the “evidence” for AGW crumbles.
(Please correct me if I am wrong, folks.)

brazil84 12:20:50
Oh, no, I meant Scott Mandia was projecting.
===========================

Here here Ken Hall !!! well said.

Dr Svalgaard has a point about Dendrochronology and the use of such data for temperature proxies. Even at the point of collection, the radial sample cores may not give a complete picture of tree ring growth because very few trees appear to have perfect tree ring symmetry. Even averaging out a great many samples would still leave a very wide margin for error.
I’m also pretty dubious as to how tree rings can translate to an accurate measure of temperature to 0.1 of a degree. Surely you get maximum tree ring growth under what are ideal conditions for a particular species, but those ‘ideal’ conditions cut across a fairly wide gradient of rainfall / environment / temperature and do not correlate well to temperature alone.

Bottom line is that the entire dendro scheme is highly questionable at the very best and downright fraudulent at the worst. With this team, I expect the worst.

One of the advances in silviculture I’ve been waiting for is sterile trees. A lot of the reduction in growth for old wood is due to production of seed. If you could eliminate this, you’d get more wood, less pine cones.
Every now and then a tree naturally appears that is sterile and they grow unnaturally quickly at old age. A famous example was the “golden spruce”, or Kiidk’yaas about which a book was written. It had yellow needles which reduced its efficiency at photosynthesis, but since it was also sterile, it grew fairly quickly.

Leif Svalgaard said:
“Although YAD061 looks like an outlier, the other trees do show a rise from ~1820 to today [albeit smaller] so the record [based on those threes] does not look entirely flat to me.”
I agree, but what does the rest of the series show? From seeing these individual trees, all from the same area displayed above, I conclude that any interpretation can be put on any collection depending on the results desired. All data available must to used to balance the picture with only the outliers excluded, i.e. depending on the sample size you through out the top x and bottom y samples before calculating.
In this case he’s kept the data secret long enough that CO2 changes will be implemented as desired because of the wide use of this data influencing many other reports.

fix typo please, ten, not teny

Gary (09:55:37) :
“OK, regardless of hard feeling about past behaviors, real and imagined… Extracting a pound of flesh, as Shylock learned, isn’t without its costs. By all means the debade should be open and rigorous, but this reply has little if any nastiness and ought to be treated fairly.”
Reasonable point Gary. Except that Briffa writes with the clarity of a PR obfuscationist. And in doing so leaves the ad homs and “nastiness” to the RC Team. There, nastiness, ridicule and condescension toward skeptics remain the Team mandate.
Mr. Briffa and his defenders need to respond not only to the data manipulation charge – but also to the stonewall charge. There is little doubt that the years of delays and impediment to review have made their whole enterprise more than a little suspect.

Since this won’t get posted at RC, I might as well post it here. The reason this event is so damaging to AGW science is that a dozen or so proxy studies were based on Yamal data that was processed, not raw. Basing a proxy study on raw data is acceptable, but basing it on data that has been filtered and then smoothed is not. Briffa’s withholding of his data is poor practice but his choice. But the further use of his processed results is inexcusable.

Bret (14:24:18)
Take 1000 cores and find 10 with a hockey stick shape? All that says is you found 10 hockey stick shaped cores because the trees were fertilized, segregated, better watered, etc.
But take 1000 cores and get 1000 hockey sticks? Now you have something. Take 1000 in 10 places around the world and get 10k hockey sticks? now you really have something.
Also matching to the instrument record is tenuous at best seeing the measurement bias. When you restrict the instrument record to just a few locations near the trees, you have an even better chance of UHI or something similar.

Correction to my previous post, 100% hockey sticks is not necessary at all, but a majority would be significant. But my previous point of selecting individual cores based on a correlation to the instrument record still stands. It is no more valid than matching them up to CO2 (which some do) or rainfall (which some do) or the number of sparrows in Rosslyn VA (which some do too). With a big enough set to sample from you can always get matches to anything.
If Briffa explains that these 10 trees were selected completely randomly from a much larger number of cores, that would be satisfying, at least for that location. Then that process would need to be repeated at many other locations around the world.

@ P Wilson (11:46:42) :
Boreholes go back much further than 500 years. This study goes back 2,000 years:
Huang, S. P., H. N. Pollack, and P.-Y. Shen (2008). A late quaternary climate reconstruction based on borehole heat flux data, borehole temperature data, and the instrumental record, Geophys. Res. Lett., 35, L13703, doi:10.1029/2008GL034187.
Here is an image from that article (striking isn’t it?):
http://www2.sunysuffolk.edu/mandias/global_warming/images/borehole_3.gif
Figure 7d (Huang, Pollack, and Shen, 2008) shows the following: a broad cool minimum around AD 200 that was followed by a warming that peaked AD 1200–1400; the Medieval Warm Period (MWP)), a subsequent cooling to a minimum around (AD 1700–1800; the Little Ice Age (LIA), followed by rapid and substantial warming in the past few centuries. The reconstructed peak temperatures in the MWP appear comparable to the AD 1961–1990 mean reference level, with the bold mid-range curve slightly below. None of the borehole reconstructions show MWP peak temperatures as high as late 20th century temperatures, consistent with the conclusions of both National Research Council (2006) and Intergovernmental Panel on Climate Change (2007) about the warmth of the MWP. The LIA temperature minimum shows an amplitude about 1.2 K below the MWP maximum, and about 1.7 K below present-day temperatures.
@ Scott A. Mandia (11:49:39) :
Anthony’s reply: Not all – check the latest main page story. Too much money flowing around uncontrolled in our government science programs apparently, you’re just on the low end of the totem pole. – A
No problem, tomorrow night’s Mega Millions jackpot is $44.2 million after state and federal taxes. I will be posting from Hawaii on Saturday! 🙂
@ Tim Clark (11:56:42) :
Huh? I said “regardless of proxy” which means corals, sediments, cave deposits, boreholes, ice cores, etc. NOT just tree rings.
@ kim (12:00:53) :
I have to admit I love your passion but not your statements. If you were a scientist you would understand how we think and that it goes against our nature to have “group think.” There may be exceptions but it certainly is not the rule.
The Nobel Prize goes to the first person that can show why we are all wrong about AGW. That is quite an incentive. Ah, but to have one’s name said along with Galileo, Darwin, and Einstein…..
@ brazil84 (12:02:21) :
The fact is that the hockey stick DOES NOT keep appearing regardless of proxies and study authors.
Wrong.
@ jlc (12:47:02) :
Look at borehole data. It is quite compelling. I have a link and some references for you:
http://www2.sunysuffolk.edu/mandias/global_warming/determining_climate_record.html
Huang, S. (2009). Brief introduction to the geothermal approach of climate reconstruction. Retrieved September 20, 2009 from Borehole
Temperature and Climate Reconstruction Database: http://www.geo.lsa.umich.edu/climate/approach.html
Huang, S. P., H. N. Pollack, and P.-Y. Shen (2008). A late quaternary climate reconstruction based on borehole heat flux data, borehole temperature data, and the instrumental record, Geophys. Res. Lett., 35, L13703, doi:10.1029/2008GL034187.
Pollock, H. (2005, December). Reconstruction of ground surface temperature history from borehole temperature profiles. Retrieved September 29, 2009, from http://home.badc.rl.ac.uk/mjuckes/mitrie_files/docs/mitrie_borehole.pdf
Tamino. (2007, May). Notes from Underground. Retrieved September 20, 2009 from Open Mind Website: http://tamino.wordpress.com/2007/05/20/notes-from-underground/
@ Peter Plail (13:09:14) :
It seems to me that, at the moment, the entire edifice of US and European environmental and economic policy if balanced precariously on a few Siberian treestumps
Peter, step back a second. Do you really believe that thousands of brilliant scientists are going to stand together and tell the world that $ BILLIONS need to be spent to fix a problem that a “few Siberian treestumps” tells us about?
There is a tremendous amount of evidence that humans are warming the climate and that we are now dominating natural forcing mechanisms.
Click the link on my name and see what I have presented which is, to the best of my knowledge, a pretty fair summary of what these thousands of scientists are finding. I am just the messenger – I do not do any research. I have nothing to gain by taking this position and I never voted for Gore. In fact, I am a registered Independent. More importantly, I am a scientist that seeks to know what the heck is going on.
I obviously am an AGW supporter and I have a viewpoint that is quite different than most here at WUWT. I appreciate that WUWT allows me to post my dissenting comments and, to give props to WUWT and its posters, I have learned a great deal by their replies. This latest Yamal controversy which I think is “much ado about nothing” has led me to research proxy data and I am more knowledgeable now.
@ Jeremy (14:34:11) :
I never said we should stop questioning data. I think when the data keeps looking the same perhaps we should start thinking that maybe it is accurate. The NASA example you give is comparing apples to oranges (or should I say Tang?)
@ Jakers (15:47:43) :
Isn’t it just amazing that the entire field of climate change was resting on just 10 or 12 trees!
Even Steve McIntyre doesn’t believe this. The hockey stick does not discount the instrumental record which shows tremendous warming in the modern era, especially the last few decades. Trees or no trees.
————————————————-
A person at RC posted an interesting observation. CA, and subsequently WUWT, got into a tizzy because it appeared that only a subset of tree data was being used to reconstruct past climate. Posters at these two sites asked why not use ALL of the tree data instead of a subset?
Shouldn’t all of the data be better than a small subset?
Now let us think about surfacestations.org. The claim there (and often here) is that the full NOAA station record is contaminated by UHI and we should only use a SUBSET of validated rural stations. I think it was 70 out of 1221?
So is this cherry-picking (according to CA and WUWT) or is this just using the “best data” (Briffa) to get the correct reconstruction?
Touche’

“My colleagues and I are working to develop methods that are capable of expressing robust evidence of climate changes using tree-ring data”
Was a grant given to you based on this premise? Is this why you are working to develop these methods?

Leif Svalgaard (09:14:03) :
does not look entirely flat to me
Ahh, but does it look like a Hockey Stick? That would be the issue at hand, wouldn’t it, sir? Maybe you weren’t aware of a graph called the Mann Hockey Stick.
Have you heard of a movie with a man named Al Gore in it called “An Inconvenient Truth”? That graph was featured in it.
Statisticians, scientists, economists, professors, politicians, and many other people from all walks of life have looked in to the issue of this ever so slightly important ingredient to the topic of global warming.
You may wish to take some time to brush up on the topic of global warming before commenting on it.
Or maybe I should lower my expectations of you and ask if you have ever heard of a thing called “GLOBAL WARMING”?

Quote
Quote:
My colleagues and I are working to develop methods that are capable of expressing robust evidence of climate changes using tree-ring data
Mr. Briffa, I need read no further.
You have now explained yourself, and your goal. That goal has nothing to do with Science, or the discovery of truth, it is only the mundane, self-serving goal of proving your pet theory.
Shame on you, and your colleagues.

You don’t think the climate ever changes, and he has to explain himself on that basis, he has to be ashamed of himself? He made no reference to AGW.