There’s been a relatively lively discussion at realclimate here on O&B . I’ve got a couple of thoughts for now on (1) the independence of authors and (2) differences between datasets – two issues which I’ve frequently discussed.
"Independence" of Studies
Mann reproduced the Wikipedia graph (which I recently discussed) and stated of it:
the global and hemispheric-scale warmth of the past few decades appears anomalous in a very long-term context–has stood up remarkably well in many independent studies (see Figure 1).
A reader promptly observed:
Of the 10 reconstructions, 6 of them include authors listed together in your second reference (at the bottom of your article), while a 7th includes a further author (Schweingruber) who is also a joint author of one of the others. Osborn and Briffa are also included. So most of these reconstructions were carried out by a group of interconnected scientists. This doesn’t sit well with the claim of "many independent studies". Just an observation.
To which Mann replied:
[Response: This isn’t the place to play Six Degrees of Kevin Bacon. Lets keep this on the science from now on, and lets avoid ad hominems. – mike]
Wait a minute. How is this an ad hominem? Mann asserted that the studies were "independent". Whether the authors are "independent" or not is not a Kevin Bacon-game . The reader is not saying that the authors are secretly funded – only that the Wikipedia citations are not "independent". The reader is right.
Independence of Proxies
A little later, Rob Wilson weighed in and said (reporting D’Arrigo et al 2006):
we cautiously conclude that there really is not enough data prior to ~1400 to make such definitive statements about comparing MWP and recent conditions – at least at these large scales.
To which Mann replied:
[Response: Fair enough Rob. D’Arrigo et al is a nice contribution. But keep in mind that your conclusions were based entirely on a particular RCS tree-ring data set. Osborn and Briffa’s conclusions are based on an entirely different multiproxy dataset. So there is no proper "control" in this comparison.
Now let’s keep in mind that "completely different dataset" has a strange meaning in Hockey Team talk. For example, 14 of the 17 proxies in Jones et al [1998] (supposedly "independent") were used in MBH98. I’ve talked frequently about proxy overlap. So what’s the situation here. I’ve summarized the proxies used or considered in the two studies which pertain to the MWP.
O&B have 10 proxies which pertain to the MWP; DWJ have 12. Of these, 5 proxies unambiguously are common between the two studies: Icefields; Tornetrask; Taymir; Mongolia and Yamal [note – this is updated on info from Rob Wilson: they used Briffa’s RCS reconstruction for Yamal as well. I’m going to look at why.] This is enough of an overlap that the data sets are not "completely different". But there are some subtle further overlaps. 2 of the 10 O&B proxies are the bristlecones and foxtails; these were considered by DWJ and rejected as not meeting local gridcell requirements. Conversely, Jaemtland was one of the Esper series rejected by O&B on gridcell temperature grounds (but accepted by DWJ). One of the DWJ series used in the MWP was their series from the Alps; O&B also used a series from the Alps, but a short form of still uncertain provenance.
So if you define the data sets as being series used and considered, O&B had 12 pertinent proxies (the 10 plus Jaemtland, Tirol); while DWJ had 14 pertinent proxies (the 12 plus bristlecones, foxtails). There are 9 sites in common between the two data sets: thus 9 of 12 for O&B; 9 of 14 for DWJ. These are hardly "completely different" data sets, even in Hockey Team talk.
What’s different between the two of them? The three series in O&B are Chesapeake Bay and Fisher’s Greenland – neither of which contribute to hockey stickness – and the Yang China composite which is a carrier for Thompson’s Dunde and Guliya data in a smoothed grey form. In the DWJ data, the 5 series are all from Alaska and the Yukon.
| O&B Site | MWP | DWJ Site | MWP |
| Icefields, Alberta | yes | Icefields | yes |
| Tornetrask | yes | Tornetrask | yes |
| Taimyr | yes | Taymir | yes |
| Mongolia | yes | Mongolia | yes |
| Polar Urals | substituted Yamal | Polar Urals | substituted Yamal |
| Austria (Tirol). | short | Alps (*) | yes |
| Jaemtland | discarded | Jaemtland | yes |
| MBH PC1 | yes | Bristlecones | discarded |
| Foxtails | yes | Foxtails | discarded |
| Yang’s China composite | yes | Seward AK | yes |
| Chesapeake Bay Mg/Ca | yes | NWN Alaska | yes |
| Fisher’s Greenland O18 | yes | Yukon | yes |
| Wrangells | yes | ||
| Coastal AK | yes |
Climate Audit 
42 Comments
Perhaps a good proxy for the credibility of the discussion threads on real climate are the density and comment width of the blue responses. In earlier threads, ‘discussion’ (or that left after censorship) was mainly adulatory and non-critical but it seems now that contributors are becoming more critical and asking real questions and the real climate authors are being forced more onto the back foot.
In fact if you plotted that proxy as a function of time I’m sure it probably resembles a hockey stick! and is due to the efforts of both M&M for keeping people focused on the scientific issues. Well done.
I tried to post a statement similar to the follwoing (I can’t remember exactly how it was stated) at realclimate.lies:
“Would someone here please address Steve McIntyre’s assertion that a few sets of questionable tree ring data are responsible for the hockey blade in most of the reconstructions.”
I was very shocked and surprised that the post was not accepted….
OOOOOOps. They did post it. My mistake.
Jae,
I always keep a copy of what I post at RC.
I have followed the discussion on CA and RC for some time now, and have been struck by what seems to me, in some quarters, a lack of willingness to embrace or follow the principles of scientific method. I recall, many years ago now, at high school being taught the principles of scientific method, and particularly the importance of disclosing methods and results so that other capable scientists could replicate your results independently, and so confirm them. So I did a Google search on “scientific method replication of results”. There are of course many search results on this topic, so I have simply extracted what seems to me to be pertinent from the first two that came up:
‘Scientific Method and the Nature of ScienceDr. Pamela Gore, Georgia Perimeter College http://gpc.edu/~pgore/Earth&Space/GPS/scientificmethod.html
S6CS1. Students will explore the importance of curiosity, honesty, openness, and skepticism in science and will exhibit these traits in their own effort to understand how the world works.
S6CS1a. Understand the importance of – and keep – honest, clear and accurate records in science.
S6CS1b. Understand that hypotheses are valuable if they lead to fruitful investigations, even if the hypotheses turn out not to be completely accurate descriptions.
S6CS7b. Recognize that there may be more than one way to interpret a given set of findings.
S6CS8c. As prevailing theories are challenged by new informaiton, scientific knowledge may change and grow.
S6CS9. Students will investigate the features of the process of scientific inquiry.
S6CS9a. Scientific investigations are conducted for different reasons. They usualy involve collecting evidence, reasoning, devising hypotheses, and formulating explanations.
S6CS9c. Accurate record keeping, data sharing, and replication of results are essential for maintaining an investigator’s credibility with other scientists and society’.
And from http://www.psy.plym.ac.uk/year1/scimeth.htm
“As I said in the lecture in my book it isn’t science without public disclosure of methods and results. A full description of the method allows for replication in other labs by other scientists. It’s there that your results will come under the sharpest scrutiny when the question is asked “Does this result replicate?”
It is also interesting to apply a commercial due diligence test to the exchange that Steve refers to on RC where Mann claimed support from “many independent studies”, but when questioned on it, rather than giving a reasoned, informative response, came back with “This isn’t the place to play Six Degrees of Kevin Bacon. Lets keep this on the science from now on, and lets avoid ad hominems. – mike”. I don’t think that response would wash with any due diligence lawyer (or board for that matter) that I know of.
RE 2, 3 jae
You’ll have seen the response:
“One gets the impression sometimes that data sets are defined as controversial purely on their 20th century characteristics. The O&B study demonstrates that the issue of calibration is not key to determining whether the patterns of warmth seen in these long proxy records demonstrate an anomalous late 20th Century. Since the methodology (say Jones and Mann vs O&B etc.) isn’t so important for this conclusion, the argument then shifts to the suitability of the proxies. As has been said eleswhere, the number of suitable proxies for this kind of excercise is limited. The recent D’Arrigo paper has a few more that also demonstrate the same thing, and O&B’s result is robust to the removal of any three of the proxies. Since this methodology is relatively straighforward, any other proxies can be easily added in to the mix (and hopefully will be). The more data there is, the less important any single proxy will be – however, given the data we have so far, the result seems to be robust. -gavin”
So that clears it all up then! What on Earth were you worried about?
LOL
I select a group of 14 red cars.
I then test the hypothesis that cars are red. This is overwhelmingly accepted. (Over 99% confidence!).
I verify the robustness of this finding by removing any combination of three cars and confirming that my hypothesis that all cars are red is valid.
For an encore, I divide the cars into two groups and use the results from the first group to predict the colour of the cars in the second group – once more, irrefutable evidence that my hypothesis is valid.
Is not the scientific method a wondrous thing to behold?
Just to clarify a little – my point on the classic Hockey Team studies is that they are not “independent” in their choice of proxies as there are stereotype overlapping proxies and a few give the hockey stick ness to them: here I’m talking about the Wikipedia studies that I’m relatively familiar with and have studied as much data as I can. The active ingredients in them are: bristlecones/foxtails, Briffa’s flawed Polar Urals proxy, Thompson’s questionable Dunde proxy (amount effect rather than temperature effect) and a couple of others. For studies that are supposed to be independent, there’s way too much overlap of critical proxies. The proxies are not independent (in addition to the non-independence of authorship).
As usual, I’m not taking a position here on the relative warmth of the MWP and modern periods – only on whether the various HOckey Team studies in Wiki prove the point and prove it independently.
Now D’Arrigo et al has been out for a couple of days. It looks to me like a better calibre study than many Hockey Team studies. It’s possible that D’Arrigo et al avoids all the problems of prior Hockey Team studies, but I think that time will show that the Hockey Team is not out of the woods. Again, the proxies do not appear independent nor are D’Arrigo and Jacoby independent of the Wiki Hockey Team authors. When realclimate first bruited the Hockey Team, Jacoby was someone who seemed to me to be on one of the lines.
Even if D’Arrigo et al were to avoid the various pitfalls of this type of study, that does not disprove of any of the criticisms of the prior Hockey Team studies. If the focus is to turn to D’Arrigo et al, then they have an obligation to archive their data immediately. It is total crap for the Hockey Team to “move on”, produce a new study as a deus ex machina which is impossible to evaluate without access to data – leading to one or more years of quasi litigation to get the data before being able to seriously analyse the study. Whereupon the Hockey Team will once more have “moved on”, with a new study showing the same result replacing the study now found to be flawed, again withholding the data, again resulting in a new litigation cycle. But even on the present record, there are some aspects to D’Arrigo et al which indicate that it is not salvation and I’ll be writing on this in the next week or so.
If you notice the list above – O&B substituted the Yamal site for the Polar Urals site. The Polar Urals site was updated in 1998 and R’Arrigo et al include the update in their RCS chronology. I posted up my calculation of the RCS chronology for Polar Urals updated which had an elevated MWP period; the Yamal dataset substituted by O&B has an elevated 20th century. It’s just too typical. Why didn’t Schweingruber and Briffa report the updated Polar Urals site? Why didn’t Osborn and Briffa use the updated Polar Urals site?
“The O&B study demonstrates that the issue of calibration is not key to determining whether the patterns of warmth seen in these long proxy records demonstrate an anomalous late 20th Century.”
I couldn’t disagree more. Based upon my own examination of the MBH98 data, I think calibration is critical. Without proper calibration, you have no way of telling whether any “growth spurt” in the 20th century represents higher than usual temperatures or a climb out of lower than usual temperatures – even assuming the growth spurt is temperature related, even though in many cases it seems that it is not. If there was a long period of gradual cooling, then a short period of sudden warming, it’s important to be able to detect that I think. Without proper calibration, how can you?
When Dano, Tim Lambert and others post up criticism of Steve’s critiques, they invariably focused on the fact that Steve wasn’t going out and chain-sawing 2000 year old trees in the name of climate sciences, or drilling out 2000 metre ice cores in central Greenland. Their criticisms revolve around the fact that Steve hasn’t done any “original” science – ie. he hasn’t added any more proxies to the record.
I see no such objections when the Hockey Team continually recycle the same old proxies, supposedly using different statistical corrections and weightings. When was the last time Mann went out and sampled an ice core? What has his efforts added to the data record?
Those who criticise Steve and Ross for failing to go out there and get the data are highly selective. Briffa and co. are interpretative seat warmers, re-analysing data from past excursions into the wild. Mann is a similar computer jockey, either unable or unwilling to shed the tweed jacket and retrieve objective data to support (or disprove) his assertions.
As a freely admitted “non-scientist”(a lawyer, no less), my fundamental problem with the Hockey Team remains their continual re-hashing of the same old data, with a slightly different statistical spin. Every time they do this, somehow the study becomes new or different in some way.
I would ask, when was the last time Michael Mann sampled a tree ring, or cored a block of ice? If the test of a true scientist is going out there and sampling the rate at which Californian shrimp have deposited their exoskeletons during the past millennia, when was the last time Mr Mann cast his wise eyes upon a fossilised shrimp?
It seems that, in the Hockey Team and amongst their supporters, a single expedition during a 40 year career qualifies one for scientific status, and negates the need to ever again collect fresh data.
This is the core of a lack of independence in their studies – they keep reinterpreting the same old things. I don’t see Mann, or Briffa, or Rutherford pulling on the woolies and trudging off to Greenland.
It makes it all the more grating when they accuse Steve and Ross of not being scientists, or when the Hockey cheer squad turn up on these threads and tell Steve that he won’t have any credibility until he goes out and cuts down a tree.
Well, I would like to know how much of the Hockey Team’s papers rely on their own, “independent”, “new”, “original” work? No need to answer, it’s already there in black and white.
People such as Peter H., Dano and Tim L. have directed daggers towards Steve and Ross – ie. you aren’t true scientists, because you don’t go out and core stuff, or cut down stuff – their heroes fail the same test. When was the last time Tim Lambert confirmed Michael Mann’s temperature recontructions as a result of field work? Show us the Antarctic ice on your boots, Mr Lambert.
If I told you, “The sky is always blue during the day,” and presented you with my data, which showed that during the days I’d sampled, the sky was always blue, I could produce any number of papers confirming exactly that fact.
If other people used the same data, “They would surmise, with obvious surprise, that, ‘It’s true, it’s true, the sky is ALWAYS blue!'” I find it difficult to believe that reputable scientific journals are being so readily fooled by Dr Suess logic.
So, this is my fundamental objection to the Hockey Team – they most certainly are not adding to the record, nor are they doing fundamental experimental science. Instead, they seem to be engaged in a multi-year exercise in re-interpreting, re-analysing, and re-hashing the same old data, and presenting it to scientific journals as new, exciting, ground-breaking and confirmational research in the field.
I do wonder how any of the “scientists” or “reviewers” involved in this grubby exercise can look their children in the eyes.
Re: #12: Yeah, and then they keep saying they are “moving on.”
BradH, if I “invariably” do this thing, then you can perhaps point to an example where I have done such a thing?
I looked up the word “entirely” on answers.com, which reports its meaning as:
Given the relationship between most of the dataset, this represents loose and inaccurate language. Especially when you consider this is the same person who accused Steve McIntyre of being dishonest and a liar (“off-the-record”, whatever that might mean after writing it in a letter). Seems Mann has missed the beam in his own eye.
I wish I were a climatologist, so I could get famous by publishing dozens of peer-reviewed articles using the same data.
Rob Wilson has written me to say that DWJ also used Briffa’s Yamal for their RCS reconstruction because he could not get homoscedastic variances from the Polar Urals data. Rob only has the RCS reconstruction as provided by Briffa, who refused to give him the measurements (so it’s not just me that has trouble.) The STD reconstruction used 3 Polar Urals data sets russ176 and russ021 (larch) and russ022 (spruce). So the exact overlap is actually 5 not 4 and I’ve edited the aboev table.
He also used different versions for STD and RCS in the Alps.
Re: #17 I think the time is fast approaching for a Freedom of Information Act request for this data. This farce has gone on too long.
O&B will no doubt be the central focus for yet another scary “assessment” by the IPCC, and nobody other than “real” climate scientists will be able to inspect their data.
I’m amazed that this situation has gone on so long.
A cabal of rogue climate scientists is denying access to primary data and key methodological steps while making extraordinary claims about the analysis made upon that data. These extraordinary claims are then given the full press treatment around the world.
Mr McIntyre — I believe the fact that Dr Connolley is an (and maybe the principal) editor/maintainer of the wiki spaghetti graph (so independently proferred as support) should also be disclosed at RC. Likely Dr Lambert would agree, given his rather strident disclosure standards?
NOTE: I’ve also had some trouble posting at RC, most recently on ocean-chemistry misperceptions (re: CO2 & pH) by some of their blog readers. A more cynical view might be that having some of their readers believe that fish “disintegrate” in an anthropogenic CO2-acidic ocean, is a misperception they don’t (s)care to refute.
Re: 12 and 14 — I also don’t recall Dr Lambert either consistently or singly embracing that specific criticism (that which Mr Dano drones often).
Dr Lambert — any updated progress/estimate on opening up the old AGW/climate threads on your new blog? I still have responses, in particular for disinfocycle. And, yes I did see your response of about 2 weeks ago, but am reluctant to post again on your more general threads. I typically read and most often post on weekends, so I bring this up sparingly in part because of that.
#12, 14, 19. I agree with #19. The issue of my not personally coring trees is really Dano’s beef and I think some others, but I don’t recall Lambert piling onto this issue.
re#20
Yeah, Steve, but you know all these warmers look alike! We need bios of the principal trolls to remember what their characteristic complaints are. The only thing we don’t need to worry about is what scientific points they each harp on since that’s a null set for every one of them.
One reason why the demand for Steve doing real science,(coring trees and ice) is that this is a long tedious job and would effectively put him out of circulation. Standard academic ploy to deflect scrutiny.
That said, reanalysing existing data with new insights and theories is part and parcel of science. So Steve’s approach is quite correct. (I am always highly suspicious of any study that relies on complex statistical processing of data to extract information – it implies that the data are not self evident and that the choice of a particular statistical technique is merely to confirm the a preconceived theory).
The grubby part of this whole issue is the Hockey Team’s reluctance to show their code and their data. This has been going on for, what over two years?
If this was happening in the mining industry there would be subpoenas out for the data by now.
Louis, Thompson has been sitting on his Puruogangri data for 6 years now; Hughes on the Sheep Mountain updates for 4 years. Can you imagine withholding exploration data like that? It’s beyond a joke.
McCall, if you click on the Wikipedia graph you willl find that the maintainer is Dragon’s Flight, not Connolley.
The tech support person at scienceblogs will be back on the 20th. I don’t know when he will be able to fix the MT problem so I can migrate everything.
Re: #14 Tim, I apologize for including you in the group calling for Steve to pull out the ol’chainsaw before he could qualify as a “real” scientist.
In reviewing your previous posts, it’s apparent that you have not been one of those pushing that line.
Re #12. Brad, I think you make the point, since you spend most of your post criticsing the ‘team’ for not obtaining any new proxy data (and, I think they do need new data to improve the recons).
Indeed, such is our agreement ;), this, with two changes and one omission, is how I’d write your penultimate para:
“So, this is my objection to the CA team – they most certainly are not adding to the record, nor are they doing fundamental experimental science. Instead, they seem to be engaged in a multi-year exercise in re-interpreting, re-analysing, and trashing the same old data, and presenting it to scientific journals as new, exciting, ground-breaking and confirmational research in the field.”
Exactly!
I’d say that studies which show that world famous scientific results are the result of sloppy work in the very areas which the original team claims to have “significant skill” is pretty ground-breaking. It’s not often that one sees such highly publicised examples of not only poor science, but actual resistance in the field to correcting these problems.
Just as the people who exposed Hwang’s frauds got a lot of press, so should the people who have shown the massive mistakes in creating the famed “Hocket Stick” graph be heavily publicised, and the studies seriously reviewed.
As Steve has said, dismissing his work in this fashion is similar to dismissing the work of an auditor who has found a major problem with company’s books, simply because he or she does not run a company personally.
Re # 23
Steve,
Your spam filter might censor me if I actually penned my actual thoughts to comment here but Warwick Hughes has been trying for ? 20 years to get Jone’s data, and that is total BS. As you and I both know, the instant that Hockey Stick was published, our BS radars, (well mine overloaded) went into overdrive but for different reasons. The rest is history.
Personally I regard not releasing data as an admission of guilt of the sin of cooking of accounts and the salting of assays. That their resistance is verging to the hysterical only adds weight to this impression. Their data cannot pass scrutiny. As the audit team would describe it “creative accounting”.
Great untruths are being uttered and there is not a thing we can do about it except continue the efforts here.
However I do sense a degree of panic amongst the HS mob – they are becoming more strident, accusing Peers of the realm of bare-faced lying and with the sudden appearance of some of the HS team on Jennifer Marohasy’s blog reacting to Ian Castle’s posts these last few days, I suspect we are at last getting some traction.
So guys keep at it. There is light at the end of the tunnel.
Oh I might add that those who have access to Climate Sceptics to take note of a recent comparision between NCDC and UAH data – posted today to keep the innocent anonymous.
I am off rig-pigging for a few weeks 🙂
(Oz term for geologist sitting in front of drilling rig logging chips and core and collecting samples in the heat of the day with flies, more flies …..:-))
One other point of expecting Steve and us to produce new data.
Consider a mining ore reserve – there is a right and wrong way to calculate them. It involves correct procedure in sampling but more crucially, depends on how that data is subsequently processed.
1. Do it wrong and the company goes bankrupt.
2. Do it right and you make a profit.
Steve has identified, in one area, that the Hockey Team are engaged in method 1. Others are finding other areas where climate science is, as the Hebrews did for 40 days and nights, wandering in the darkness.
It is that simple.
Re: 24 Dragon’s Flight (DF) is the maintainer of the Wiki Spaghetti … thanks, Dr Lambert.
It’s clear that DF is not a sock, nor a historical pawn for Dr Connolley. There is some evidence of recent spaghetti graph editing and influence taken from the latter, most recently, the Oerlemans data addition (in dark red). But one must acknowledge that DF’s “Copyright” and “Notes” references* disclose that influence far better than that expressed or implied in the “independent” verification statements of the hockey team, that Mr McIntyre justifiably highlights.
So I withdraw my disclosure request of para 1, post 19 plus the other accusations where I charge an active dependent lead role between Dr Connelley and the Wiki Spaghetti — this evidence does not support such an accusation. However given his recent and highly controversial support for Wiki administrator status of Dr Connolley (first conditional then changed vote to support, by DF on 8-JUL-05)**, plus the disclosures below, it does make sense (IMO) to watch for continued independence of “Dragons flight’s Temperature Record Series” on wikipedia.
http://en.wikipedia.org/wiki/Image:2000_Year_Temperature_Comparison.png#file
*“Copyright
The original version of this figure was prepared by Dragons flight from publicly available data.”
“Notes
2. Data for Oerlemans was provided by William M. Connolley.”
**
http://en.wikipedia.org/w/index.php?title=Wikipedia:Requests_for_adminship%2FWilliam_M._Connolley&diff=19798051&oldid=19795692
Side query — does anyone know if William Connelley has a PhD (and if so, in what)? There seems to be some degree controversy on the above link. “It is a vanity page where he entitles himself to a degree that he has acknowledged not to have. Mr. William Michael Connolley …”
Re # 30
McCall
Connelly works for BAS (British Antarctic Service) and his bio has him as Dr. http://www.antarctica.ac.uk/met/wmc/
Fascinating. For some odd reason, a post I made on that RC thread is getting delayed, whereas a one I made later went right through. The one I made later said that I thought trees in a Marine West Coast climate setting may be OK as temperature proxies. But the one getting delayed calls into question the use of an arid, continental climate species such as a Bristlecone, since Bristlecones may be more driven by moisture than temperature, in terms of growth. I wonder if it will ever make it through their “post censor?”
Well my Bristlecone critique did make it through after all. It will be interesting to see if a response gets edited in later. What a can of worms!
Just posted on one of the other RC threads:
RE: “That said, it’s also clear that glaciations (which have not been present throughout much of history, with ice-free conditions existing as recently as 30M years ago and the current severe glaciations – the Pleistocene – having kicked in just a couple of million years ago) have not been able to exist in the past whenever CO2 has been above a certain level in the atmosphere.”
It was a long time ago. I attended a talk by I believe Arawmick (again, it may have been someone else, but I think it was he) that proposed something a bit different from this. Namely, that the Pleistocene may have started with the closure of the Isthmus of Panama during the previous orogeny. Again, this was long ago and no doubt “discredited” by numerous “climate scientists.” Just thought I’d share my own experience here.
Steve S., if you look at the Mann Corrigendum, you’ll notice that a number of Oregon and Washington sites, listed in the Original SI, were not actually used in MBH calculations. This was admitted in the Corrigendum although they claimed that the misrepresentation did not “matter”. As I recall, these sites definitely do not have hockey stick shaped ring width chronologies.
For the Jacoby (northern) sites, the ones that tend to have hockey stick shapes were south facing sites, while sites in valleys or north facing did not have hockey stick shapes. This seems like an odd phenomenon. Of course, Jacoby has not archived all his sites, only the “good” ones.
RE: #35. Fascinating. By my reckoning (with substantial reinforcement from a number of archeological dendro studies, one of which is actually linked from Mann’s *own web page!*) swamp cypress and Piedmont hardwoods are to be considered moisture proxies, not temparature proxies. Bristlecones may be either proxies for some complex combination of moisture, fertilization, competition from like and other species, and temperature, or, as I see, possibly moisture alone. Based on results from the Urals and other northern treeline locations, those species may simply be, by nature, a hodge podge of positive and negative responders, perhaps a consquence of plain old genetics. That would seem to leave softwoods in West Coast Maritime climates (particularly in the northern, immediately coastal, less-drought-prone portions of them) and *perhaps* certain hardwoods in humid continental climates as the only reasonable proxies for temperature. And yet, they claim that self same trees do not matter? It is an outrage.
Post number 44 on the RC thread …. only deafening silence thus far from the usual suspects …
“Setting aside for a moment any debate regarding proxies such as tree rings and formanifera, from the standpoint of cultural / archeological indicators (as well as historical accounts of things such as life ways, clothing, food and drink and the like) what are the things that tend to confirm and refute a global MWP of substantial degree (that term is somewhat loaded, but by “substantial” I mean things that have impacts similar to things thought to accompany the theorized coming warm up). For example, in Europe, people wore substantially thinner and less layered clothing during the MWP timeframe, versus what they wore during the Rennaissance, Enlightenment, Neo-Classical and Industrial Revolution time frames. That indicates the shift from the warm peak to the cold valley. Cathedrals were thought to be attractants to worship because they gave respite from the heat (even though some of them were not completed in time to reap the most benefit, we must look at the times of their initial conception / early project planning.) Take as another indicator the cultivation of citrus. Etc. What, if any, similar observations and anecdotal evidence are there in the Americas, Africa, Australia and Asia? I have not studied this and welcome what folks have to say in these regards.
“Comment by Steve Sadlov”
Since RC have been getting back into attack mode again (attacking a broad list of victims, now greatly expanded from only attacking M & M) I thought I unearth this old thread.
re #37 Has anyone looked at using residential buildings as a temperature proxies? The hypothesis being that the design of buildings would have reflected changes in climate throughout the last few thousand years. This would seem to offer substantial accessible data in terms of structural insulation, construction techniques, materials etc etc.
Proxy,
I think the problem would be that building styles are influenced by many factors apart from climate.
As an example, our three hundred year old farm house in the South of France is well designed for the current climate. However, this is not the case for new houses that are being built in the same area. Our thick walls, large eaves, small windows and heavy shutters mean that we stay cool in the summer while our friends in new developments swelter.
Building materials that are good for warmer weather are also good for colder weather. This means
the direction of the correlation would be ambiguous.
Mark
Re #39, Proxy, you say:
Not to my knowledge, nor could they. The problem is that our predecessors asked much less of their homes than we do. I live in the Hawaiian uplands, where it gets quite chilly. None of the homes built here 50 years ago have any form of heat, no fireplace, nothing. All the modern homes have heat.
Does this prove that Hawaii is cooling? … Don’t think so, just that the old paniolos were tougher than I am.
w.