Mann hockey stick co-author Bradley: "it may be that Mann et al simply don't have the long-term trend right"

From the Gore-a-thon on WUWT - click for more

Tom Nelson spots a gem in the Climategate 2 emails:

Hockey stick co-author Ray Bradley:

“it may be that Mann et al simply don’t have the long-term trend right”;

“I hedge my bets on whether there were any periods in Medieval times that might have been “warm”, to the irritation of my co-authors!”

Email 207

Sorry this kept you awake…but I have also found it a rather alarming graph. First, a disclaimer/explanation. The graph patches together 3 things: Mann et al NH mean annual temps + 2 sigma standard error for AD1000-1980, + instrumental data for 1981-1998 + IPCC (“do not quote, do not cite” projections for GLOBAL temperature for the next 100 years, relative to 1998. The range of shading represents several models of projected emissions scenarios as input to GCMs, but the GCM mean global temperature output (as I understand it) was then reproduced by Sarah Raper’s energy balance model, and it is those values that are plotted. Keith pointed this out to me; I need to go back & read the IPCC TAR to understand why they did that, but it makes no difference to the first order result….neither does it matter that the projection is global rather than NH….the important point is that the range of estimates far exceeds the range estimated by Mann et al in their reconstruction. Keith also said that the Hadley Center GCM runs are being archived at CRU, so it ought to be possible to get that data and simply compute the NH variability for the projected period & add that to the figure, but it will not add much real information. However, getting such data would allow us to extract (say) a summer regional series for the Arctic and to then plot it versus the Holocene melt record from Agassiz ice cap….or….well, you can see other possiblities.

[……At this point Keith Alverson throws up his hands in despair at the ignorance of non-model amateurs…]

But there are real questions to be asked of the paleo reconstruction. First, I should point out that we calibrated versus 1902-1980, then “verified” the approach using an independent data set for 1854-1901. The results were good, giving me confidence that if we had a comparable proxy data set for post-1980 (we don’t!) our proxy-based reconstruction would capture that period well. Unfortunately, the proxy network we used has not been updated, and furthermore there are many/some/ tree ring sites where there has been a “decoupling” between the long-term relationship between climate and tree growth, so that things fall apart in recent decades….this makes it very difficult to demonstrate what I just claimed. We can only call on evidence from many other proxies for “unprecedented” states in recent years (e.g. glaciers, isotopes in tropical ice etc..). But there are (at least) two other problems — Keith Briffa points out that the very strong trend in the 20th century calibration period accounts for much of the success of our calibration and makes it unlikely that we would be able be able to reconstruct such an extraordinary period as the 1990s with much success (I may be mis-quoting him somewhat, but that is the general thrust of his criticism). Indeed, in the verification period, the biggest “miss” was an apparently very warm year in the late 19th century that we did not get right at all. This makes criticisms of the “antis” difficult to respond to (they have not yet risen to this level of sophistication, but they are “on the scent”). Furthermore, it may be that Mann et al simply don’t have the long-term trend right, due to underestimation of low frequency info. in the (very few) proxies that we used. We tried to demonstrate that this was not a problem of the tree ring data we used by re-running the reconstruction with & without tree rings, and indeed the two efforts were very similar — but we could only do this back to about 1700. Whether we have the 1000 year trend right is far less certain (& one reason why I hedge my bets on whether there were any periods in Medieval times that might have been “warm”, to the irritation of my co-authors!). So, possibly if you crank up the trend over 1000 years, you find that the envelope of uncertainty is comparable with at least some of the future scenarios, which of course begs the question as to what the likely forcing was 1000 years ago. (My money is firmly on an increase in solar irradiance, based on the 10-Be data..). Another issue is whether we have estimated the totality of uncertainty in the long-term data set used — maybe the envelope is really much larger, due to inherent characteristics of the proxy data themselves….again this would cause the past and future envelopes to overlap.

…Ray [Bradley]

At 01:34 PM 7/10/00 +0200, you wrote: Salut mes amis,

I’ve lost sleep fussing about the figure coupling Mann et al. (or any alternative climate-history time series) to the IPCC scenarios. It seems to me to encapsulate the whole past-future philosophical dilemma that bugs me on and off (Ray – don’t stop reading just yet!), to provide potentially the most powerful peg to hang much of PAGES future on, at least in the eyes of funding agents, and, by the same token, to offer more hostages to fortune for the politically motivated and malicious. It also links closely to the concept of being inside or outside ‘the envelope’ – which begs all kinds of notions of definition. Given what I see as its its prime importance, I therefore feel the need to understand the whole thing better. I don’t know how to help move things forward and my ideas, if they have any effect at all, will probably do the reverse. At least I might get more sleep having unloaded them, so here goes……[Frank Oldenfield]

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

But wait, there’s more

Hockey stick co-author claims that after 1850, critical trees lost their alleged ability to record temperature

Year 2000 ClimateGate email

If you examine my Fig 1 closely you will see that the Campito record and Keith’s reconstruction from wood density are extraordinarily similar until 1850. After that they differ not only in the lack of long-term trend in Keith’s record, but in every other respect – the decadal-scale correlation breaks down. I tried to imply in my e-mail, but will now say it directly, that although a direct carbon dioxide effect is still the best candidate to explain this effect, it is far from proven. In any case, the relevant point is that there is no meaningful correlation with local temperature. Not all high-elevation tree-ring records from the West that might reflect temperature show this upward trend. It is only clear in the driest parts (western) of the region (the Great Basin), above about 3150 meters elevation, in trees old enough (>~800 years) to have lost most of their bark – ‘stripbark’ trees. As luck would have it, these are precisely the trees that give the chance to build temperature records for most of the Holocene. I am confident that, before AD1850, they do contain a record of decadal-scale growth season temperature variability. I am equally confident that, after that date, they are recording something else.  [Malcolm Hughes]

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In his email Bradley says;
“Furthermore, it may be that Mann et al simply don’t have the long-term trend right, due to underestimation of low frequency info. in the (very few) proxies that we used.”
A few weeks ago I wrote an article reconstructing CET back to 1538 (from 1659). It includes almost all of the LIA.
http://judithcurry.com/2011/12/01/the-long-slow-thaw/
I also took the opportunity of comparing the reconstructions of Michael Mann and Hubert Lamb. Figure 15a superimposes the Hockey stick on to other reconstructions. I think Dr Mann was wrong in his assumptions and Bradley is correct in thinking the long term trend was different to the trend that was created.
tonyb.

itsteapot

The truth will out, all we ever want to know is the truth, if you are not sure of you data/facts then it should never have been presented as such, too much money, peoples lives and future well being rests on this.

Steve McIntyre

These were both in Climategate 1 though less commented on than other emails. See
172. 0963233839.txt and 190. 0969618170.txt, The Campito site mentioned here is a strip bark (foxtail) pine site. The central Colorado site mentioned is Almagre, a bristlecone pine site, that was re-sampled by Climate Audit, (See climateaudit.org/tag/almagre) proving that it was possible to update the proxies.

“After 1850 the trees stopped recording.”
Well, if you’re a Druid, I suppose this could make sense. Sort of like the way God changes his views every time the Pope speaks ex cathedra, or every time the Church Elders receive a new revelation.
I’m not sure who would fill the same role for Gaians; perhaps a time-transported 1850 hologram of Margaret Mead ordered the trees to shut off their Temperature Input Channels and start recording other data instead.

“….the eyes of funding agents”….?…. “to offer more hostages to fortune for the politically motivated and malicious.” ,,,?
Yeah, I know…quotes out of context….but revealing nonetheless…at least we know who they really want to impress….
Cui bono? Cui villanus.

Beautiful, saved the best for last!

I am confident that, before AD1850, they do contain a record of decadal-scale growth season temperature variability. I am equally confident that, after that date, they are recording something else. [Malcolm Hughes]

The growth season being about a dozen weeks or so. There simply is no way to determine global temps from tree rings. It is time to move all of that literature to the science fiction area of the library.

JPeden

In any case, the relevant point is that there is no meaningful correlation with local temperature. Not all high-elevation tree-ring records from the West that might reflect temperature show this upward trend. It is only clear in the driest parts (western) of the region (the Great Basin), above about 3150 meters elevation, in trees old enough (>~800 years) to have lost most of their bark – ‘stripbark’ trees. As luck would have it, these are precisely the trees that give the chance to build temperature records for most of the Holocene.
As luck would have it, these stripbark bristlecones in the driest parts, etc., were considered as local precipitation proxies, prior to the time when water turned into temperature. And where, “it has been determined that timberline has retreated downward about 330 feet in the past 1000 years.”
Timberline, Mountain and Arctic Forest Frontiers – Arno [author] and Hammerly [artist], published by The Mountaineers, 1984

All things considered this is just another example of people forgetting what science is about and substituting wishful thinking, ideology and economic self-interest for data analysis and process understanding.

Bloke down the pub

Now if only he’d said that in AR4 we could all have avoided so much aggravation.

hunter

That’s OK. The latest believer rationalization is that the HS does not count. the AGW movement is now playing ‘wack-a-mole’. No matter to the true believer what is shown to be wrong, corrupt or contrived: They will still claim ‘the science is right’, by which they do not mean “CO2 is a ghg” (even though they claim that). But rather, they mean no matter the evidence, they will still act as if we are facing a dangerous CO2 caused apocalypse and the AGW community is justified in demanding ridiculous policies to ‘mitigate’ the climate.

pat

“In any case, the relevant point is that there is no meaningful correlation with local temperature.”
Apparently, according to Warmists, skeptics are too stupid to understand the context of this complex statement. The fact that the preceding sentence discusses the carbon effect [sic] on measured temperature merely adds nuance.
In actuality, we have now read multiple emails from so-called Warmists that voice skepticism about the methodology of modelling, the accuracy of charts and graphs, the relevance or accuracy of proxy measurement, and even effect of CO2 on atmospheric temperature. And an acceptance of the fact that solar variation may have a a huge impact on the same.
It is truly a disappointment that these individuals were and are unwilling to step forward and explain there misgivings, particularly in light of the witch hunt for skeptics.

Andrew

Merry Christmas!
Is this a wonderful gift? Or a lump of coal? I guess its all relative huh. If this were Al Gore’s gift, or maybe Joe Biden’s… Hey, I wonder if they could find a “clean coal plant”…Didn’t Biden campaign in 2008 on getting all the coal plants shut down in the United States and having them move China? Maybe he can bring that up next time he is over there advocating for China’s “One Child” policy.
Has anybody mentioned the how Global Warming extremists have a lot in common with Progressives eugenics movement from the 1930’s?
“Peace on Earth, Goodwill Towards Men”
Andrew

Reed Coray

A quote from the e-mail: “Unfortunately, the proxy network we used has not been updated, and furthermore there are many/some/ tree ring sites where there has been a “decoupling” between the long-term relationship between climate and tree growth, so that things fall apart in recent decades….this makes it very difficult to demonstrate what I just claimed.” (emphasis mine).
“Decoupling”–now there’s an interesting word. During one of the summers of my college years, I worked as a sectionman taking care of some tracks in a railroad switching yard. “Decoupling” had a very clear meaning. When a switchman decoupled a car or cars, the decoupled car(s) rolled freely down the tracks–i.e., they were “decoupled” from the controlling switch engine, but not from the laws of physics. Apparently in climate science “decoupling” has an even stronger meaning. Tree-ring “decoupling” not only implies separation from temperature (the switch engine), but (a) separation from the laws of physics, and (b) heaven forbid the most serious problem, potential separation from funding.
Merry Christmas to all–but especially to Anthony and the “mods”.

Re: “Hockey stick co-author claims that after 1850, critical trees lost their alleged ability to record temperature”
So…
Perhaps the some of the proxies of really correlated to CO2 more than temperature.
Maybe kind of like this…
http://climatesanity.wordpress.com/2010/02/15/tree-rings-proxies-for-temperature-or-co2/

Latitude

It’s just common sense that trees accurately depict temperatures before there were any thermometers………..

No wonder the MSM are ignoring this. Is this comb over of the old emails supposed to be Anthony “missed by a million” Watts idea of science?
As for Ray Bradley, who is a real scientist, here is a quote from a paper nine years after the [2000] expression of uncertainty. No longer hedging his bets; even has an explanation.
// Global temperatures are known to have varied over the past 1500 years, but the spatial patterns have remained poorly defined. We used a global climate proxy network to reconstruct surface temperature patterns over this interval. The Medieval period is found to display warmth that matches or exceeds that of the past decade in some regions, but which falls well below recent levels globally. This period is marked by a tendency for La Niña–like conditions in the tropical Pacific.
The coldest temperatures of the Little Ice Age are observed over the interval 1400 to 1700 C.E., with greatest cooling over the extratropical Northern Hemisphere continents. The patterns of temperature change imply dynamical responses of climate to natural radiative forcing changes involving El Niño and the North Atlantic Oscillation–Arctic Oscillation. //
http://www.geo.umass.edu/climate/papers2/Mann2009.pdf
Written with Mann, et. al. Available online. Includes a hockey stick graph. Read some real science.

Pat Frank

polistra, you’re going to hell for sure. 🙂

LearDog

These statements in confidence are absolutely MIND- boggling. The authors illustrate (to me anyway) complete cowardice and lack of a moral compass in confronting this young fellow Mann.
NO one publically called ‘bullshit’ on this deception – and here we are….the destruction of climate science, science in general and perversion of a failed, backwater, academic niche into a multi-billion dollar scam that will end up hurting the poor of the world.
Have they NO shame?

dizzy,
You link to Mann?? Even after reading Bradley’s comment: “it may be that Mann et al simply don’t have the long-term trend right”?
Michael Mann has been serially debunked, and now a member of his own team says he’s been worong all along. You just bet on the wrong horse, that’s all.

Mashiki

Wait. Wait just a sec. Did I read this right, did the physics of the universe just stop working, or did the science break? I’m not sure. But it seems pretty obvious something happened, and the science is indeed not settled.

ChE

So, possibly if you crank up the trend over 1000 years, you find that the envelope of uncertainty is comparable with at least some of the future scenarios, which of course begs the question as to what the likely forcing was 1000 years ago.

Jones can’t spell or use Excel, but Bradley doesn’t know what begging the question is. At least he’s sophisticated.

davidmhoffer

“This makes criticisms of the “antis” difficult to respond to (they have not yet risen to this level of sophistication, but they are “on the scent”). ”
—————-
There’s the money quote right there. They are wrong, they know they are wrong, and that it is only a matter of time before they are caught.

davidmhoffer

dizzy;
Written with Mann, et. al. Available online. Includes a hockey stick graph. Read some real science.>>>
Could you provide a link to some real science so I can read it? I followed the one you provided and it just links to another paper by Mann.

Political Junkie

Dizzy, it may not be a concern to you, but some people might wonder why the alarmists AT THE TIME were presenting a seamless “the science is settled” front while expressing severe doubts in private.
Is the current solidarity just as porous behind the scenes?

DirkH

dizzy says:
December 24, 2011 at 10:02 am
“Written with Mann, et. al. Available online. Includes a hockey stick graph. Read some real science.”
HockeyStick-Jong-Un.

ChE

davidmhoffer says:
December 24, 2011 at 10:38 am

And he’s vain about it, to boot.

John Whitman

AR4’s certainty of alarming AGW from fossil fuel was manipulated from such pseudo-science.
The IPCC was the vehicle of the pseudo-science.
The ’cause’ of Mann and his fellow travelers has devolved into a wagon circling clique of pseudo-scientists.
What a great Christmas present.
Best wishes to all during this holiday season.
John

crosspatch

The growth season being about a dozen weeks or so.

Usually even shorter than that, about 8 in most cases. The darker end wood created toward the end of the growing season is generally not counted. You are looking at June/July temperatures, mostly July.

pat

Dizzy.
“That is old news”
The classic and meaningless rejoinder of a politician. And absolutely meaningless as a response. As is your cite to Mann. You will note that the citations in the article are the very ones discussed in this piece, with no serious attempt to analyze the variance with measured data to hypothesis. Indeed, there is no attempt to inform the reader that such a variance even exists. Instead Mann extends the proxies into entirely speculative ocean cycles, such as an extremely intense and extended La Nino cycle 1,000 years ago and says that the data aligns nicely. Babble. .

Steve Garcia

I’d read this email in the days after CG2 happened and thought this one would be made a big deal of then. Then with so many other things, I never got back to it. I am GLAD it has been brought up again!
Kudos to Tom Nelson on bringing it up again.
This is possibly deflecting the direction of this post a bit, but the parts about proxies is, I think the most significant.

[Bradley] Another issue is whether we have estimated the totality of uncertainty in the long-term data set used — maybe the envelope is really much larger, due to inherent characteristics of the proxy data themselves….again this would cause the past and future envelopes to overlap.

In any case, the relevant point is that there is no meaningful correlation with local temperature.

It is only clear in the driest parts (western) of the region (the Great Basin), above about 3150 meters elevation, in trees old enough (>~800 years) to have lost most of their bark – ‘stripbark’ trees. As luck would have it, these are precisely the trees that give the chance to build temperature records for most of the Holocene. I am confident that, before AD1850, they do contain a record of decadal-scale growth season temperature variability. I am equally confident that, after that date, they are recording something else. [Malcolm Hughes]

It has become somewhat common for skeptics in recent years to deny their (our) denying. At least denying that they (we) deny that warming is occurring. Whenever I’d hear that, I’d wonder why. Did we really accept the graphs, even when we knew the data underlying them were corrupted? Did we accept the fundamental warming trend because we knew we were coming out of the LIA, so maybe we thought that, even if corrupted, when all was and and done we believed the trend would show up as warming anyway?
Over the last c0ouple of years, as I’ve learned more and more about the tree-ring proxies (especially), bit by bit I’ve wondered louder and louder if the correlation was valid. When I ran across a study of South Carolina cypress trees, using their tree rings as proxies for PRECIPITATION (http://www.scribd.com/doc/51676257/Buried-Cypress-Forest-in-South-Carolina) a few months ago, I kind of crossed the line. A feature cannot be a reliable proxy for BOTH precip and temps – there is simply no WAY to determine which one did how much.
It is also significant that
Then, during the CG2 hubbub Steve McIntyre had a post “Severinghaus and “Hide the Decline” (http://climateaudit.org/2011/11/28/severinghaus-and-hide-the-decline/) in which there was much discussion about tree-rings-as-proxies. That discussion had much on the “Divergence Problem” (DP), which was the underlying issue behind “hide the decline.”
Three is a lot in the CG2 emails about people discussing the DP. From beginning to end of the entire lot of emails – CG1 and CG2 both – about the DP. The DP is the time bomb in all of climate science. The entirety of climate reconstructions is built on the supposed correlation between tree-rings and temperature. Tree-rings are the keystone, the lynchpin and the little Dutch boy’s finger in the dike. Without them, there is no real window into the past.
How can I say that? A few points of data from ice cores at locales in Antarctica can’t tell us much about what is happening in the rest of the world. After all, the Arctic and Antarctic ice right now are doing their see-saw thing – when one is up the other is down. But the very few data points 1,000 or 2,000 years ago can’t tell much, not unless there is a tie-in in some other proxy or instrument data. And that tie-in is tree-rings.
But what if the tree-rings themselves aren’t correlated well? What does that do to ice cores? Based on BEST’s list of data sources, most of the proxies are tree-rings. Take them out and what happens to the reliability of the history reconstructions?
And here, in the CG2 emails, we see, time after time, the scientists are wringing their hands over the DP. And here we have Mann’s own TWO collaborators on the Hockley Stick, and both of them are saying the tree-ring proxies aren’t worth diddly.
For us skeptics, THIS is the lynchpin. This is the card that brings down the entire house of cards.
Tree-rings do NOT correlate well enough – EVER – to be used as proxies for temperature. That they seemed to for climatic short periods has led climatologists down the garden path. Most don’t know it, but they exclude most tree-ring sampling sites because there is not a strong enough signal in the tree-rings. That is why there are so many Arctic sites in the data. And now, even those and their “signals” have fallen apart – and they can’t face up to it. So they have to resort to tricks and bodges and internal conspiracies to keep the secret from getting out.
It is like a nasty family secret that must not, under any circumstances get out, or the family’s reputation will be ruined.
Well, yeah, duh…
When this supposed correlation finally blows up in their faces – and it seems increasingly that it will – climatology itself may completely fall apart. After all, without proxies, what can they possibly know about past history?

Dizzy,
You don’t seem to get it.
Several years ago Bradley publicly and strongly endorsed the hockey stick, while privately questioning it. You point out that later, in 2009, he still publicly endorsed it, ergo he must also privately endorse it. That is a non sequitor.
Another important point: At the same time Bradley was privately expressing his doubts, skeptics who publicly expressed the same doubts were being excoriated as fools or knaves.
Its a dirty business.

cui bono

Mann is cited 45 times in the Ch05_paleoclimate AR5 ZOD. Plus ca change…

davidmhoffer

Political Junkie says:
December 24, 2011 at 10:42 am
Dizzy, it may not be a concern to you, but some people might wonder why the alarmists AT THE TIME were presenting a seamless “the science is settled” front while expressing severe doubts in private.
Is the current solidarity just as porous behind the scenes?>>>
To help you answer that question dizzy, here’s some thoughts about the current state of the science:
1. Tree growth is correlated in any given year to a combination of temperature, precipitation, length of growing season (which is not directly related to temperature during the growing season), CO2 levels, incidence of late frost, incidence of pestilence, competition from other trees and plants, sun spot levels, and many other factors. It is not possible to eliminate all the other factors in order to isolate temperature.
2. Tree growth occurs during the growing season, which depending on latitude may be as little as two months of the year. Tropical trees are nearly absent from tree ring studies because they are not nearly as long lived as, for example, Siberian Larch, and hence useless for long term study. As a consequence, the bulk of tree ring data comes from high latitudes with short growing seasons. There is no possible way for a tree in Siberia to in any possible way grow (and hence measure ANY of the factors regulating growth) in October, November, December, January, February, March, April and May. Even if the tree rings correlated to temperature during the growing season, they would still be useless in terms of determining annual temperatures.
3. No data from the tropics. Nearly no data from low latitude temperate zones. No data from arctic zones. The bulk of the data comes from high latitude temperate zones which have the highest natural variability on the globe. This makes the tree ring data nearly meaningless from both a statistical analysis perspective, and can in no way represent a global average temperature.
So dizzy, given that these things are well known and instantly obvious to anyone who takes even a few moments to think about them, how do you justify calling ANYTHING published about long term climate reconstructions based on this methodology “science”?

lol @ dizzy Dizzy did you bother to apply the concept illustrated in the xkcd cartoon linked in your name? Yes, that’s science, and it works.
Dendrophrenology, OTOH, is a ludicrous posit. Trees with growing seasons of about 12 weeks and you believe we can determine global or even local temps from that? Faith is a beautiful thing when properly placed. A horrible thing when improperly placed.
http://suyts.wordpress.com/2011/11/29/dividing-by-zero/
God Bless and Merry Christmas.

Andrew

Some more Christmas cheer from “Uncle Joe”….
(hey Mods…can you embed this? I promise I will use the Test page next time and figure it out…but I got Christmas stuff to do!…Andrew)

“Joe Biden talks to a 1Sky campaigner about energy policy. Biden is called out on his platform that includes coal. Both 1Sky and the Energy Action Coalition are opposed to the development of new coal fired power plants. Energy Action Coalition is running Power Vote, a national youth based campaign to get 1,000,000 youth voters voting for clean energy this election season.”
…just some more “Google Global Warming Bias”…just for fun..
Andrew

crosspatch

climatereason says:
December 24, 2011 at 8:37 am

I find the notion of a long, slow, thaw to be very likely as we recovered out of the LIA. That would be more consistent with how I believe things would behave. I have a couple of papers around here somewhere on glacial advance/retreat in Alaska, too, that tend to support that notion and wood recovered from one of the glaciers shows two separate periods of advance through forest.
Ah, this is one of them:
http://web.cortland.edu/barclayd/publications/QR_2009.pdf

Steve Garcia

@davidmhoffer December 24, 2011 at 11:19 am:

It is not possible to eliminate all the other factors in order to isolate temperature.

This is absolutely true. How MUCH of the tree-ring “signal” – TRW or MXD, either one – is from temperature alone? No one can separate that out, saying this much is from precipitation, this much from competition with other trees, and THIS much from temperature. Not only is that impossible they KNOW it is impossible. And – in all likelihood – they know that the Divergence Problem is due to one of those – yet in the 20 or so years since the DP was recognized – they haven’t gotten any closer to understanding which other factors are causing it, nor in what measure.

Tropical trees are nearly absent from tree ring studies because they are not nearly as long lived as, for example, Siberian Larch, and hence useless for long term study.

As I have read it, the tropical trees aren’t giving enough of a signal – summer-vs-winter – to make it possible to distinguish one year from the next. They NEED a strong seasonal variation to make this reliably quantifiable. And the most seasonal variation is in the most-stressed regions like arctic, deserts, and high altitude. I think that is basically your point in your item 3, but thought I’d at least re-phrase it.

This makes the tree ring data nearly meaningless from both a statistical analysis perspective, and can in no way represent a global average temperature.

Exactly. Even now, with the NOAA/GISS maps, look at the extremes (some think of it as magnification or sensitivity) shown in the polar regions – how could anyone extrapolate the rest of the globe based on those regions? And then to take a few single-point data each of which represents maybe a decade or a century from those regions and then project that to represent the entire globe for, say, 1,000 years ago, it is pretty weak.
Add to all that something I read last week or so (it might or might not be in the CG2 emails), where one climatologist stated that the pre-1600 tree-ring data was so iffy that he didn’t rely on it himself.
The main issue is that these folks knew – and still know – that the data and reconstructions they are working with are really weak, but that they had – and still have – a compact among themselves to not ever let their doubts out to the public or policymakers.
I don’t think they would dare to. The money tree would dry up. And climate science would go back to the halls of academia and all the trips to exotic locales for conferences would go away, like the Cheshire Cat’s grin. And the prestige – oh, the prestige! – would be gone…

crosspatch

Another interesting paper is this one (paywalled but I can probably obtain a copy)
http://hol.sagepub.com/content/21/1/105.abstract
Basically it clearly shows climate variation in the Alps, particularly a very pronounced change about 4kya where climate becomes more unstable. This paper has been one of those that led me to believe that we actually started sliding into the next glacial period about 2000 year ago (after the RWP) and that process probably actually began with the major climate shift 4kya when we see the monsoon making a drastic change and a migration of the ITCZ where its seasonal range seems to be closer to the equator than it was prior to that shift. This is at the same time the Levant dries out, the Dead Sea begins a drastic decline in level, and trees that existed in that area at that time begin to die out due to drought.

Bob_L

Steve Garcia says:
December 24, 2011 at 11:08 am
I’d read this email in the days after CG2 happened and thought this one would be made a big deal of then. Then with so many other things, I never got back to it. I am GLAD it has been brought up again!
________
I think we are going to see them brazen it out for a while.
I’ve pointed out in the past that most all accounts point to Mann as a bully. Even Dizzy trolls on by with his “real science” paper from Mann and pals with no doubts expressed, while the email points to concern or doubt.that existed in these same people. Does Mann have the strength of personallity to keep these out of the paper?
The “decoupling” – that is simply BS. Either tree rings are a proxy for temp. or not. I think I’m going to make this my central theme for my argument – ask others to explain why trees are a temp proxy until they are not.
Merry Christmas to this accepting community of the curious.
Bob Lackey

Olen

Reading the article I had a vision of a ship’s cargo of hockey sticks sinking.

ChE

In any case, the relevant point is that there is no meaningful correlation with local temperature.

Mann’s already spun that. He said that the Sierra location that the bristlecones are from is the “sweet spot” that represents the whole world through teleconnections.
Dude’s got chutzpah.

Don B

So Bradley thinks the MWP was warm because of solar effects, based on Be10. That must have been what Jasper Kirkby thought in his article justifying CERN’s experiments regarding Svensmark’s theories on cosmic rays and clouds. Nice graphs of Be10 and C14 with temperature proxies on page 3:
http://aps.arxiv.org/PS_cache/arxiv/pdf/0804/0804.1938v1.pdf

Now, now, it is season of good will to all men and Mann. Of course he is wrong, but to be on the generous side, and let us cherry pick the start some 300 years ago, at 1700 there was a mini Hockey Stick, and since the CET correlates well with the so called ‘global temperature’, if there is such thing, then would be one in there too. Not everything is lost though, the temperatures do oscillate with the solar output at about 5-10 times the rate dr. LS tells us they should.
http://www.vukcevic.talktalk.net/miniHockeyStick.htm
I am in real trouble now.
Another glass of ‘bubbly’ please.
Happy Christmas to one and all !

Andrew

Olen says:
December 24, 2011 at 12:33 pm
Reading the article I had a vision of a ship’s cargo of hockey sticks sinking.
“Boy, I got vision, and the rest of the world wears bifocals.” – Butch Cassidy
http://youtu.be/4beP5nKtruo

Pamela Gray

I still say that the mortal wound is in the neglect of oceanic and atmospheric conditions as the major driver of weather pattern variation. It is as if rhese folks don’t even know it exists.

Steve Garcia

@Bob_L December 24, 2011 at 12:11 pm
Bob, the thing is, I never thought that I would come to the point of doubting tree-rings as proxies for temperature. It seems such an entrenched idea, and I had always thought, “Well, the dendrochronologists have all this worked out, don’t they?” But bit by bit, I started wondering, slowly over the course of maybe a couple of years.
The Divergence Problem is a BIG deal. A really big deal. It is VERY important if the instruments in the last 70 years – the best documented, most precisely measured, most widely dispersed period – agree with the tree-rings. And to find out that it wasn’t just “after 1960” that the decline was happening – holy cr*p, Batman!
These guys were losing sleep over this – and not just them. Schweingruber the dendro was worried about it, too – since about 1990. Briffa co-authored papers with him about it. No one has a CLUE what is going on.
The simple explanation is that tree0rings simply aren’t proxies for temperature. But no one wants to be the one who points out the Emperor has no clothes. So they discuss that it exists, while still using the data – the data that isn’t telling them what they think it should. But they carefully mask the full impact of it.
In reading the explosive Climategate “hide the decline” email two years ago, it seemed like this was something new to them, and they were merely scrambling to maybe give them time to figure it out. But that wasn’t the context at all. The real context is that Briffa knew that this was a real problem, that had been known about for a decade or more. And Briffa stood up to Mann for a while and then caved under the Mannian onslaught. Briffa simply did not want to cut off the post-1960 data and pretend it wasn’t there. He knew it was real, even if he couldn’t explain it.
The real gist is this: If during this well-measured period the first shoe that fell was that the two don’t correlate, then the second shoe is when someone in public tells the world that tree-rings aren’t a valid proxy for temperature and all the reconstructions based on them are not reliable.
I came to this conclusion slowly and with trepidation, but after recently reading journal papers about the DP, I am now certain that this is the case. I do recommend people go to the “Severinghaus..” post on CA and read through both the comments and the links. That Bradley and Hughes – 2/3 of the MBH paper authorship – admit to themselves that the correlation is really, really not solid, that is a big thing. A huge thing.

Steve Garcia

@crosspatch:
//”Another interesting paper is this one (paywalled but I can probably obtain a copy)
http://hol.sagepub.com/content/21/1/105.abstract“//
Merry Christmas, and a gift for you:
I found the full paper. Go to http://tiny.cc/1mbr6.

Stephen Wilde

“the neglect of oceanic and atmospheric conditions as the major driver of weather pattern variation”
and the effect of solar variations other than changes in TSI as a driver of changes in atmospheric conditions via the expansion and contraction of the polar air masses.

You know the easiest thing how to kill the hockey stick? Compare CET with NH CRUTEM and you will find excellent correlation. So CET represents the whole Norther hemisphere very well. Now, look at the CET backwards, notice cold cold 1680 followed by abrupt warming until 1740 and compare whether you see something similar on the hockey-stick. You will find nothing of that.

Vuk
That graph of yours, you’ve referenced it before, is there some way it can be shown so we can see the solar-temp correlation as clearly as possible? Would one of those fourier whatsits help? Analysis of cycle correlations? It looks to be of great interest. But IMHO it needs better presentation.
Could it just be simple visuals that show (a) short term correlating fluctuations (b) longer term correlating climate changes (c) the “cumulative heating effect” ie what looks like a cumulative effect of the recent series of higher-than-“normal” solar cycles?? Visually, the old GISS plots were much easier on the eye. Heck THE TEAM understand this in their graphs that nearly fooled the world about the decline hidden under some really graceful, expressive, seductive curves. Keep truth, and use their skills against them.
Now back to Christmas, also celebrating the sunlight – penetrating the darkest time of the year as well as the darkest part of people’s hearts.