the Air Vent

Because the world needs another opinion

Another Powerful Email from Climategate

Posted by Jeff Id on December 9, 2009

You have to listen carefully to some people. Oppenheimer was completely dishonest in the recent CNN interview and unless you want to give your IQ points away (and my wife will tell you, at least one of us cannot afford to), you probably shouldn’t listen to that drivel. Steve McIntyre, whom has yet to blog substantially on these emails (and he should soon), made a point to the CNN reporter that Briffa had commented it was as warm in the medieval warm period MWP as it is today. It’s an older email (1999) but it’s NOT consistent with the messages presented in the IPCC reports- ever. Kieth may have changed his mind on ALL of the points in this email, but half the SKEPTIC arguments were made by Keith Briffa over ten years ago in a private email – pre Wegman. The whole thing makes me wonder if team pressure has pushed an otherwise blunt and honest Doc into some unusual positions.

The email is shown twice below, once with a few bolds, the second time with inline comments in green.

From: Keith Briffa <k.briffa@uea.ac.uk>
To: “Folland, Chris” <ckfolland@meto.gov.uk>, ‘Phil Jones’ <p.jones@uea.ac.uk>, “Michael E. Mann” <mann@multiproxy.evsc.virginia.edu>
Subject: RE: IPCC revisions
Date: Wed Sep 22 16:19:06 1999
Cc: tkarl@ncdc.noaa.gov

Hi everyone
Let me say that I don’t mind what you put in the policy makers summary if there is a general concensus. However some general discussion would be valuable .

First , like Phil , I think that the supposed separation of the tree-ring reconstruction from the others on the grounds that it is not a true “multi-proxy” series is hard to justify. What is true is that these particular tree-ring data best represent SUMMER temperatures mostly at the northern boreal forest regions. By virtue of this , they also definately share significant variance with Northern Hemisphere land and land and marine ANNUAL temperatures – but at decadal and multidecadal timescales – simply by virtue of the fact that these series correlated with the former at these timescales. The multi proxy series (Mann et al . Jones et al) supposedly represent annual and summer seasons respectively, and both contain large proportions of tree-ring input. The latest tree-ring density curve ( i.e. our data that have been processed to retain low frequency information) shows more similarity to the other two series- as do a number of other lower resolution data ( Bradley et al, Peck et al ., and new Crowley series – see our recent Science piece) whether this represents ‘TRUTH’ however is a difficult problem. I know Mike thinks his series is the ‘best’ and he might be right – but he may also be too dismissive of other data and possibly over confident in his (or should I say his use of other’s). After all, the early ( pre-instrumental) data are much less reliable as indicators of global temperature than is apparent in modern calibrations that include them and when we don’t know the precise role of particular proxies in the earlier portions of reconstruction it remains problematic to assign genuine confidence limits at multidecadal and longer timescales. I still contend that multiple regression against the recent very trendy global mean series is potentially dangerous. You could calibrate the proxies to any number of seasons , regardless of their true optimum response. Not for a moment am I saying that the tree-ring , or any other proxy data, are better than Mike’s series – indeed I am saying that the various reconstructions are not independent but that they likely contribute more information about reality together than they do alone. I do believe , that it should not be taken as read that Mike’s series (or Jone’s et al. for that matter) is THE CORRECT ONE. I prefer a Figure that shows a multitude of reconstructions (e.g similar to that in my Science piece). Incidently, arguing that any particular series is probably better on the basis of what we now about glaciers or solar output is flaky indeed. Glacier mass balance is driven by the difference mainly in winter accumulation and summer ablation , filtered in a complex non-linear way to give variously lagged tongue advance/retreat .Simple inference on the precidence of modern day snout positions does not translate easily into absolute (or relative) temperature levels now or in the past. Similarly, I don’t see that we are able to substantiate the veracity of different temperature reconstructions through reference to Solar forcing theories without making assumptions on the effectiveness of (seasonally specific ) long-term insolation changes in different parts of the globe and the contribution of solar forcing to the observed 20th century warming .
There is still a potential problem with non-linear responses in the very recent period of some biological proxies ( or perhaps a fertilisation through high CO2 or nitrate input) . I know there is pressure to present a nice tidy story as regards ‘apparent unprecedented warming in a thousand years or more in the proxy data’ but in reality the situation is not quite so simple. We don’t have a lot of proxies that come right up to date and those that do (at least a significant number of tree proxies ) some unexpected changes in response that do not match the recent warming. I do not think it wise that this issue be ignored in the chapter.
For the record, I do believe that the proxy data do show unusually warm conditions in recent decades. I am not sure that this unusual warming is so clear in the summer responsive data. I believe that the recent warmth was probably matched about 1000 years ago. I do not believe that global mean annual temperatures have simply cooled progressively over thousands of years as Mike appears to and I contend that that there is strong evidence for major changes in climate over the Holocene (not Milankovich) that require explanation and that could represent part of the current or future background variability of our climate. I think the Venice meeting will be a good place to air these isssues.

Finally I appologise for this rather self-indulgent ramble, but I thought I may as well voice these points to you . I too would be happy to go through the recent draft of the chapter when it becomes available.

cheers to all
Keith

Nearly every single SKEPTIC complaint about proxy reconstructions is included in this email and its TEN YEARS OLD! Hell it’s a wonder Wikipedia didn’ t add him to the skeptic blacklist. Wiki needs money BTW, but I ain’t givin’ them a penny, there’s too much slant in the information.

I don’t know the best way to do this but I’ll put the same email as above with my comments inline in green.

Let me say that I don’t mind what you put in the policy makers summary if there is a general concensus. However some general discussion would be valuable .

First , like Phil , I think that the supposed separation of the tree-ring reconstruction from the others on the grounds that it is not a true “multi-proxy” series is hard to justify. What is true is that these particular tree-ring data best represent SUMMER temperatures mostly at the northern boreal forest regions. By virtue of this , they also definately share significant variance with Northern Hemisphere land and land and marine ANNUAL temperatures – but at decadal and multidecadal timescales – simply by virtue of the fact that these series correlated with the former at these timescales. The multi proxy series (Mann et al . Jones et al) supposedly represent annual and summer seasons respectively, and both contain large proportions of tree-ring input. The latest tree-ring density curve ( i.e. our data that have been processed to retain low frequency information) shows more similarity to the other two series- as do a number of other lower resolution data ( Bradley et al, Peck et al ., and new Crowley series – see our recent Science piece) whether this represents ‘TRUTH’ however is a difficult problem. I know Mike thinks his series is the ‘best’ and he might be right – but he may also be too dismissive of other data and possibly over confident in his (or should I say his use of other’s). After all, the early ( pre-instrumental) data are much less reliable as indicators of global temperature than is apparent in modern calibrations that include them and when we don’t know the precise role of particular proxies in the earlier portions of reconstruction it remains problematic to assign genuine confidence limits at multidecadal and longer timescales. I still contend that multiple regression against the recent very trendy global mean series is potentially dangerous. You could calibrate the proxies to any number of seasons , regardless of their true optimum response. (Lessee multiple regression is dangerous because you could calibrate proxies to ANYTHING. Especially true with a TRENDY global mean series. It’s hard to know where to begin, how about find any signal you want with CPS poor man MV regression, or every point I made in Mann Analog vs Digital. They know this crap is crap, and they have known it since they started. Think about what that means. How about the point that I’ve made repeatedly that the real reason for using the high trend dataset in reconstructions is improved correlation numbers. Wow, just absolutely wow. Not for a moment am I saying that the tree-ring , or any other proxy data, are better than Mike’s series – indeed I am saying that the various reconstructions are not independent (this was one of the primary findings of the Wegman report. PRIMARY FINDING—- think about that. Every time someone points out that you can’t do multivariate regression against a slope with noisy data, because you get whatever you want, they say — look it’s confirmed by this other study. In fact that’s how the Advocaticians at Real Climate just defended Briffa’s Yamal last month. but that they likely contribute more information about reality together than they do alone. I do believe , that it should not be taken as read that Mike’s series (or Jone’s et al. for that matter) is THE CORRECT ONE. I prefer a Figure that shows a multitude of reconstructions (e.g similar to that in my Science piece). Incidently, arguing that any particular series is probably better on the basis of what we now about glaciers or solar output is flaky indeed. Glacier mass balance is driven by the difference mainly in winter accumulation and summer ablation , filtered in a complex non-linear way to give variously lagged tongue advance/retreat . Glacier retreat isn’t temperature. Simple inference on the precidence of modern day snout positions does not translate easily into absolute (or relative) temperature levels now or in the past. Similarly, I don’t see that we are able to substantiate the veracity of different temperature reconstructions through reference to Solar forcing theories without making assumptions on the effectiveness of (seasonally specific ) long-term insolation changes in different parts of the globe and the contribution of solar forcing to the observed 20th century warming .
There is still a potential problem with non-linear responses in the very recent period of some biological proxies ( or perhaps a fertilisation through high CO2 or nitrate input) . Another primary issue SKEPTICS have with reconstructions is that even if tree’s respond to temperature, how do we know it’s linear. Before the science was completely corrupted people used to discuss these things. Today, it’s heresy, UNFUNDED heresy. Craig Loehle has a recent, and amazingly clear paper on the topic – it’s almost ignored in climatoknowledgy. I know there is pressure to present a nice tidy story as regards ‘apparent unprecedented warming in a thousand years or more in the proxy data’ but in reality the situation is not quite so simple. We don’t have a lot of proxies that come right up to date and those that do (at least a significant number of tree proxies ) some unexpected changes in response that do not match the recent warming. I do not think it wise that this issue be ignored in the chapter. This is admission that the politics are corrupting the science. The pressure exists for consensus even ten years ago, no pre-industrial warming can be tolerated if goals are to be achieved.
For the record, I do believe that the proxy data do show unusually warm conditions in recent decades. I am not sure that this unusual warming is so clear in the summer responsive data. I believe that the recent warmth was probably matched about 1000 years ago. I do not believe that global mean annual temperatures have simply cooled progressively over thousands of years as Mike appears to and I contend that that there is strong evidence for major changes in climate over the Holocene (not Milankovich) that require explanation and that could represent part of the current or future background variability of our climate. I think the Venice meeting will be a good place to air these isssues. Now at this point, I don’ t think Dr. Briffa can do anything but say he’s changed his mind since that time. However, he can’t say it’s because of new studies of the ‘same friggin’ data’ he might tho. He can’t say it’s because of the improvements in multivariate regression – they are the same. Think RegEM, TTLS, TLS, CPS (in an odd way), EIV and whatever Mann09 is called.

Finally I appologise for this rather self-indulgent ramble, but I thought I may as well voice these points to you . I too would be happy to go through the recent draft of the chapter when it becomes available.

I don’t know about you, but from a history of skepticism, Steve’s right, this email is a beast.

Don’t worry tho, there are many more. Tom Fuller rightly stated that Climategate is settling down as the drive by’s keep going. However, the better stories are yet to come.

From: Keith Briffa <k.briffa@uea.ac.uk>
To: “Folland, Chris” <ckfolland@meto.gov.uk>, ‘Phil Jones’ <p.jones@uea.ac.uk>, “Michael E. Mann” <mann@multiproxy.evsc.virginia.edu>
Subject: RE: IPCC revisions
Date: Wed Sep 22 16:19:06 1999
Cc: tkarl@ncdc.noaa.gov

Hi everyone
Let me say that I don’t mind what you put in the policy makers summary if there is a general concensus. However some general discussion would be valuable . First , like Phil , I think that the supposed separation of the tree-ring reconstruction from the others on the grounds that it is not a true “multi-proxy” series is hard to justify. What is true is that these particular tree-ring data best represent SUMMER temperatures mostly at the northern boreal forest regions. By virtue of this , they also definately share significant variance with Northern Hemisphere land and land and marine ANNUAL temperatures – but at decadal and multidecadal timescales – simply by virtue of the fact that these series correlated with the former at these timescales. The multi proxy series (Mann et al . Jones et al) supposedly represent annual and summer seasons respectively, and both contain large proportions of tree-ring input. The latest tree-ring density curve ( i.e. our data that have been processed to retain low frequency information) shows more similarity to the other two series- as do a number of other lower resolution data ( Bradley et al, Peck et al ., and new Crowley series – see our recent Science piece) whether this represents ‘TRUTH’ however is a difficult problem. I know Mike thinks his series is the ‘best’ and he might be right – but he may also be too dismissive of other data and possibly over confident in his (or should I say his use of other’s). After all, the early ( pre-instrumental) data are much less reliable as indicators of global temperature than is apparent in modern calibrations that include them and when we don’t know the precise role of particular proxies in the earlier portions of reconstruction it remains problematic to assign genuine confidence limits at multidecadal and longer timescales. I still contend that multiple regression against the recent very trendy global mean series is potentially dangerous. You could calibrate the proxies to any number of seasons , regardless of their true optimum response . Not for a moment am I saying that the tree-ring , or any other proxy data, are better than Mike’s series – indeed I am saying that the various reconstructions are not independent but that they likely contribute more information about reality together than they do alone. I do believe , that it should not be taken as read that Mike’s series (or Jone’s et al. for that matter) is THE CORRECT ONE. I prefer a Figure that shows a multitude of reconstructions (e.g similar to that in my Science piece). Incidently, arguing that any particular series is probably better on the basis of what we now about glaciers or solar output is flaky indeed. Glacier mass balance is driven by the difference mainly in winter accumulation and summer ablation , filtered in a complex non-linear way to give variously lagged tongue advance/retreat .Simple inference on the precidence of modern day snout positions does not translate easily into absolute (or relative) temperature levels now or in the past. Similarly, I don’t see that we are able to substantiate the veracity of different temperature reconstructions through reference to Solar forcing theories without making assumptions on the effectiveness of (seasonally specific ) long-term insolation changes in different parts of the globe and the contribution of solar forcing to the observed 20th century warming .
There is still a potential problem with non-linear responses in the very recent period of some biological proxies ( or perhaps a fertilisation through high CO2 or nitrate input) . I know there is pressure to present a nice tidy story as regards ‘apparent unprecedented warming in a thousand years or more in the proxy data’ but in reality the situation is not quite so simple. We don’t have a lot of proxies that come right up to date and those that do (at least a significant number of tree proxies ) some unexpected changes in response that do not match the recent warming. I do not think it wise that this issue be ignored in the chapter.
For the record, I do believe that the proxy data do show unusually warm conditions in recent decades. I am not sure that this unusual warming is so clear in the summer responsive data. I believe that the recent warmth was probably matched about 1000 years ago. I do not believe that global mean annual temperatures have simply cooled progressively over thousands of years as Mike appears to and I contend that that there is strong evidence for major changes in climate over the Holocene (not Milankovich) that require explanation and that could represent part of the current or future background variability of our climate. I think the Venice meeting will be a good place to air these isssues.
Finally I appologise for this rather self-indulgent ramble, but I thought I may as well voice these points to you . I too would be happy to go through the recent draft of the chapter when it becomes available.

cheers to all
Keith

42 Responses to “Another Powerful Email from Climategate”

  1. mrpkw said

    WHOA !!!
    Briffa was ahead of most of the skeptics with his doubts???

    Welcome to the club, Ken !

  2. mrpkw said

    DOH !!!!
    Keith, not Ken !

  3. boballab said

    Hmm that 1 email it makes it look like Briffa was sailing along and bascially making the skeptic case, realized he was and threw in the obligatory stament of I believe this warming today is unprecedented.

    People point to other emails saying Briffa was just like the others, what will be interesting to see is if in this one it was just him sending to Phil with no CC’s and the others had CC’s. If that is the case, it would seem to be a matter of when talking to the whole gang you got to put forth the image, and when it’s just him and Phil, Briffa lets out his concerns.

  4. boballab said

    Doh missed the CC to Tom Karl

  5. Jeff Id said

    #3 It was prior to the criticisms of these reconstructions. That’s what makes it so jaw dropping.

    This is pre MM, pre wegman, pre- NAS. I wish I would have put this up on the second day after the thing broke.

  6. JWDougherty said

    OT – perhaps. I’ve been searching information about this and have not found anything pertinent so far. However, perhaps someone on tAV may point it out. The question is this: the Vostok delta-T/CO2 lag is about 800 years over the late Pleistocene. If we look back in time 800 years from the present, that puts us at AD 1200, smack in the middle of the MWP – and curiously enough CO2 readings are climbing at present. Is anyone aware of studies that look into whether a temperature/CO2 lag continues or at least is detectable? I’ve looked for information but without any luck so far.

  7. Paul Linsay said

    Briffa tiptoes up to the edge and then backs away. He still isn’t willing to dismiss tree rings as thermometers. Let’s face it, that idea flunks third grade biology and high school algebra. The growth of a plant depends on temperature, but not very strongly as anyone knows who’s grown a bean sprout on a wet paper towel. Plant growth also depends on CO2, water, fertilizer, and sunilight. Water is usually the dominant factor. Which brings in high school algebra. You need as many equations as unknowns to solve for even one of the unknowns. Tree ring width is only one equation relating the width to all the growth factors we learned about in third grade. Where are all the other equations, at least four, we need to extract temperature? Bringing the discussion to college level, the relations are all non-linear too making it really interesting trying to solve those equations, if anyone even knows what they are.

    I keep vowing to get a different hobby, but then the team does something spectacularly stupid and I get drawn in to watch the latest train wreck.

  8. Bernie said

    Briffa is clearly a lot more clear thinking than some of the other members of the team. But this makes his Yamal stuff difficult to understand. Something must have happened to blunt his very sharp analysis.
    OT:
    Sorry for going OT so early but I think Jeff you may want to post the John Christy/Gavin Schmidt video. John Christy did superbly on the Situation Room with Wolf Blitzer: Clear, succinct and supremely confident. Gavin nattered away like a teenager caught doing something wrong. He made mistakes in not saying exactly what hide the decline consisted of. John Christy nailed it. It had to give Wolf Blitzer, who is not dumb, something to think about.

  9. Layman Lurker said

    And of course Jeff, underlying all of the uncertainty (read – noise captured in calibration) that Dr. Briffa describes means that there will be more noise and less signal in the reconstruction period. Interestingly, Dr. Briffa does not explictly mention the hockeystickish consequences of this effect (however he does outline his belief in a warmer MWP). Perhaps he (and likely the rest of the Team) didn’t fully understand the systematic implications of the problems he was describing 10 years ago.

  10. VG said

    wonder if Briffa is the mole?

  11. Ryan O said

    Email this one to Revkin. 😉

  12. Mark T said

    Paul Linsay said
    December 9, 2009 at 10:27 pm

    You need as many equations as unknowns to solve for even one of the unknowns. Tree ring width is only one equation relating the width to all the growth factors we learned about in third grade.

    Nope, it doesn’t work that way. You need at least as many proxies as you have unknowns, each proxy representing another “equation.” Recall that polynomial equations are nothing more than vectors of some dimension, as are proxies. A length 1000 tree ring record is potentially a vector in a 1000-D space (at most). In a polynomial space, the vector elements are the coefficients for each power, e.g., 1*x^0 + 2*x – 7*x^2 is represented by the vector [1 2 -7] in the 3-dimensional polynomial space.

    The utility of PCA, of course, is to rotate the space in such a manner that the entire space can be spanned by only a few vectors, presumably the original sources. The assumption, of course, is that there are more proxies than original sources. Obviously if there were only some number of proxies M less than the number of original sources N, the system would be underdetermined and typically results in an infinite solution space. Interestingly, if M is greater than N, i.e., an overdetermined system, there is no guarantee that ANY solution exists!

    Bringing the discussion to college level, the relations are all non-linear too making it really interesting trying to solve those equations, if anyone even knows what they are.

    This, however, is correct. They aren’t just non-linear, btw, there are also issues with correlated sources and stationarity of the distributions (which is similar to non-linearity).

    Mark

  13. Jeff Id said

    #12 I’m with paul on this.

    What you’ve shown is that a MV regression can be solved, what the problem is is that you haven’t disentangled the signals. What’s more, this method amplifies the noise in the little bit of real thermometer data at the recent end in relation to the previous data. Briffa got that in his comment when he said–I still contend that multiple regression against the recent very trendy global mean series is potentially dangerous.

  14. Eric Barnes said

    #8 and 10
    Briffa displays the most objectivity out of the lot and I get the feeling he’d be happy if he could do *just* science and all the AGW advocacy would just go away. He seems to say the “right” things in some emails, but there is one in particular were he just rants about Mann to another colleague.
    The above is a fairly early email in the series and I’m sure Mann made sure Keith knew such “indulgences” weren’t appreciated. If anyone deserves sympathy in that group, it’s Dr. Briffa.

  15. Harold Vance said

    #13 Ouch!

    So what drove Briffa to join the man behind the curtain? (Or should I say the CRU behind the curtain?)

    Promises of fame and glory?

  16. boballab said

    What’s interesting is that you notice that Briffa hasn’t uttered one word since Climategate broke. Jones, Karl, Trenberth, Wigley, Hulme, Mann and Gavin ad nauseam but not Briffa. Another interesting MIA is Ian “Harry” Harris. You would think reporters would be camped out at his house 24/7 when Harry Read Me went viral.

  17. low iq guy said

    VG said
    December 9, 2009 at 10:48 pm
    wonder if Briffa is the mole?

    been thinking that as well, either the whistle blower, or part of the blow team

  18. Adam Gallon said

    It reads very much that Dr Briffa is a real scientist and is struggling to balance his concerns about the inconsistancies and other explanations that the tree “proxy” data shows, with a reluctance to criticise/upset his co-workers/friends, especially those with a great deal of political clout?
    Possibly also with an eye on the funding of his work, should it be shown to be of dubious support for the AGW hypothesis, by scientists working within that field?

  19. Hoi Polloi said

    “Steve McIntyre, whom has yet to blog substantially on these emails (and he should soon)”

    Indeed, he should soon. I’m amazed that he hasn’t already done that and expressed that before on the CA temporary blog a week ago. IMO he’s losing precious time after the first blow. To use a sportive metaphore (he does competitive like sport), McSteve knocked them down in the first round, but allowed them to recover and make a come back. It’s evidently that the Mann/Jones cabal are making a coordinated counter attack with scripted arguments. Mann himself has done 100 interviews, while I believe McSteve one or two. In case live interviews are a burden, why not send them Lord Monckton or Lindzen? They’re used to speak in public? I’m no fan of Monckton, but he knows how to chop up guys like Schmidt. We know Schmidt and Mann talk crap, but it’s about how the MSM viewers are percieving both sides. Only then it’s possible to shift the momentum to the scpetic side.

  20. Mike said

    Apologies, I thought the “cite” tag would put things in quote boxes, not Capitalize Every Blasted Word.

  21. Mike said

    Trying again – maybe Jeff can delete my comment #20 above since the Every Word Capitalized thing is so distracting and hard to read (and #21, since it refers to #20). Anyway, it looks like Mann wasn’t all that reactive, at least overtly. Briffa’s email above was 0938031546.txt. Email 0938018124.txt has Mann’s reply, which I’ve excerpted:

    Walked into this hornet’s nest this morning! Keith and Phil have both raised some very good points. And I should point out that Chris, through no fault of his own, but probably through ME not conveying my thoughts very clearly to the others, definitely overstates any singular confidence I have in my own (Mann et al) series. I believe strongly that the strength in our discussion will be the fact that certain key features of past climate estimates are robust among a number of quasi-independent and truly independent estimates, each of which is not without its own limitations and potential biases. And I certainly don’t want to abuse my lead authorship by advocating my own work.

    I am perfectly amenable to keeping Keith’s series in the plot, and can ask
    Ian Macadam (Chris?) to add it to the plot he has been preparing (nobody
    liked my own color/plotting conventions so I’ve given up doing this myself). …

    That having been said, it does raise a conundrum: We demonstrate
    (through comparining an exatropical averaging of our nothern hemisphere
    patterns with Phil’s more extratropical series) that the major
    discrepancies between Phil’s and our series can be explained in terms of
    spatial sampling/latitudinal emphasis (seasonality seems to be secondary
    here, but probably explains much of the residual differences). But that
    explanation certainly can’t rectify why Keith’s series, which has similar
    seasonality
    *and* latitudinal emphasis to Phil’s series, differs in large part in
    exactly the opposite direction that Phil’s does from ours. This is the
    problem we
    all picked up on (everyone in the room at IPCC was in agreement that this
    was a problem and a potential distraction/detraction from the reasonably
    concensus viewpoint we’d like to show w/ the Jones et al and Mann et al
    series.

    So, if we show Keith’s series in this plot, we have to comment that
    “something else” is responsible for the discrepancies in this case. Perhaps
    Keith can
    help us out a bit by explaining the processing that went into the series
    and the potential factors that might lead to it being “warmer” than the Jones
    et al and Mann et al series?? We would need to put in a few words in this
    regard. Otherwise, the skeptics have an field day casting
    doubt on our ability to understand the factors that influence these estimates
    and, thus, can undermine faith in the paleoestimates. I don’t think that
    doubt is scientifically justified, and I’d hate to be the one to have
    to give it fodder!

    Here’s the only thing close to a “pointed” comment, down at the end:

    SO I think we’re in the position to say/resolve somewhat more than, frankly,
    than Keith does, about the temperature history of the past millennium.
    And the issues I’ve spelled out all have to be dealt with in the chapter.

    One last point: We will (like it or not) have SUBSTANTIAL
    opportunity/requirement to revise much of this discussion after review, so
    we don’t have to resolve everything now. Just the big picture and the
    important details…

    I’m sure we can can up with an arrangement that is amenable to all, and I’m
    looking forward to hearing back from Keith, Phil, and Chris in particular
    about the above, so we can quickly move towards finalizing a first draft.

  22. Mark T said

    Jeff Id said
    December 9, 2009 at 11:36 pm

    #12 I’m with paul on this.

    Excuse me? Are you saying that it takes more than just one type of measurement to resolve more than one source? I’m sorry, but you are incorrect. If the original sources are uncorrelated, all it takes is one proxy per source.

    What you’ve shown is that a MV regression can be solved, what the problem is is that you haven’t disentangled the signals.

    What you are talking about is resolving independence (or correlatedness), which is a different matter – not one that Paul mentioned. I did, however, point out this problem. It cannot be resolved using component analysis, not without information regarding how the sources are correlated. Different types of measurements won’t be sufficient for that.

    <

    What’s more, this method amplifies the noise in the little bit of real thermometer data at the recent end in relation to the previous data. Briffa got that in his comment when he said–I still contend that multiple regression against the recent very trendy global mean series is potentially dangerous.

    This has nothing to do with his Paul’s point. More types of measurements do not resolve this. These methods will isolate uncorrelated signals, and all it takes is as many proxies as sources. If the sources are correlated, then more types of measurements will not help.

    Mark

  23. Mark T said

    My blockquote above is broken. My post continues with “This has nothing…”

    Mark

  24. Mark T said

    Mark T said
    December 10, 2009 at 11:45 am

    What you’ve shown is that a MV regression can be solved, what the problem is is that you haven’t disentangled the signals.

    What you are talking about is resolving independence (or correlatedness), which is a different matter – not one that Paul mentioned.

    I should add that this may also be an issue of assigning outputs to the sources, which is something PCA cannot do at all. If the sources were uncorrelated, then knowing what each looked like would be sufficient, which may be what you are referring to Jeff? That assumes, of course, that the solution arrived at via PCA was the proper rotation, of course.

    Mark

  25. Jeff Id said

    #24, There was a thread at tamino when he was discussing PCA – the intellectual elite over there were prattling on about PC1 is temperature, PC2 is moisture, PC3… PC4… or something like that. It might be fun to go back and point out the silliness of their comments. It’s all from memory but as you point out in 24 it has good humor potential.

    Even if PCA was able to sort the signal’s of moisture and temp in recent time because they were completely uncorrelated orthogonal signals (fat chance of that), where is the guarantee that it’s going to be equally orthogonal in the past. You have to love science humor.

  26. Jeff Id said

    #22 I’m a little busy at work right now and just read this, I think you’re correct about this point.

    I misread Paul’s sentence last night — You need as many equations as unknowns to solve for even one of the unknowns.

    He’s right to the fact that this resolves one point. I misread his post last night though – my bad.

    As far as correlated signals, the only way to resolve those that I’m aware of, is to take a different kind measurement, using methods, with different yet known levels of sensitivity making the original proxies basically useless.

  27. Mark T said

    Yes, so we do agree, I see. This is a slightly different problem than equations and unknowns, which is really the only point I was making in 13.

    Indeed, there is no direct calculable physical relationship between the “sources” and ring width that can guarantee either linearity or stationarity over time. You are correct: even if they are so now, we cannot know if they were in the past. This is, ultimately, what the problem of divergence reveals: that the tree-rings do not correlate well now is proof of non-linearity and a lack of stationarity.

    Mark

  28. Mark T said

    Jeff Id said
    December 10, 2009 at 12:27 pm

    As far as correlated signals, the only way to resolve those that I’m aware of, is to take a different kind measurement, using methods, with different yet known levels of sensitivity making the original proxies basically useless.

    Which is unfortunate from a science standpoint, though I really don’t care what the temperature during the MWP was. I don’t care if warming now is unprecedented, for that matter. What we, as a species, have proven above all is our ability to adapt. We should be adapting to whatever changes occur, be they due to warming, cooling, or aliens sucking our brains out. We spend trillions trying to “stop” warming, then suddenly we’re economically devastated and another ice age hits, or aliens come down and suck our brains out, then what? Extinction, that’s what.

    Mark

  29. Jeff Id said

    I think if we spend trillions on stopping AGW, it will not be our brains they are coming to get.

  30. Kenneth Fritsch said

    I find it difficult to believe that other climate scientists and probably most have had to have the same doubts as Briffa about regressed proxy validity. Briffa had doubts that he was willing to share in private emails but not go public with. Others evidently did not want to go that far with their doubts. What was or could be constraining them. I truly think it has been all about keeping the consensus in place and not allowing the dissenters an opportunity to question it.

    The tree ring and other proxy girls and boys understand their doubts about their field of specialty and the modelers have the same doubts about theirs, but they imagine that the other guy knows what he is doing and therefore the conclusion of AGW remains in effect and they thus do not mind suppressing the uncertainties. The IPCC is the piece de resistance where one sees the effects of the consensus thinking and where all but the true believers must wonder at the lack uncertainty expressed in the conclusions

  31. BlueIce2HotSea said

    #21, It seems that Dr. Briffa nearly succeeded in ‘corrupting’ the Mann cabal with intellectual integrity. But as Mann’s response shows, there was plenty of opportunity for dealing with it after the review process. I find it easy to believe that Dr. Briffa never really sold out to the ‘dark-side’, but rather chose to bide his time while remaining within the system.

  32. BlueIce2HotSea said

    Please give me a pass if I press this point too far. But, in what may have been an indication of contempt, Briffa references Mann’s penchant for using other people’s data. This is coming from a scientist who laboriously personally built his own data-sets while working in the sub-arctic; e.g. slogging through mud while enduring hellish storms of monstrous mosquitoes.

  33. Tom C said

    Jeff –

    You are right to highlight this one. It is probably the most damning of all of them. The reason is that after writing this, Briffa went on to join in publicly savaging Soon and Baliunas and others who dared to suggest that there was an MWP.

    Steve was also correct to say that the MWP vs. modern question is the real battleground issue; not the models, not the surface record, etc. The reason is simple: the MWP was way warmer and humanity thrived. Therefore, no need for alarm even if AGW is correct.

  34. BlueIce2HotSea said

    #33, You say “Briffa went on to join in publicly savaging Soon and Baliunas and others who dared to suggest that there was an MWP.”

    Please give a reference.

  35. BlueIce2HotSea said

    #33,

    Briffa went on to join in publicly savaging Soon and Baliunas and others who dared to suggest that there was an MWP.

    I found at wikipedia that Michael Mann criticized Soon & Balunas at RealClimate and cited this Briffa paper:

    Science 10 February 2006:
    Vol. 311. no. 5762, pp. 841 – 844
    DOI: 10.1126/science.1120514

    The Spatial Extent of 20th-Century Warmth in the Context of the Past 1200 Years
    Timothy J. Osborn* and Keith R. Briffa

    But Briffa’s paper asserts a MWP! It does claim that the geographical extent of the MWP is less than the 20th warming extant. This, of course, cannot be interpreted as character assassination.

    Please provide a reference.

  36. Tom C said

    Blue Ice

    http://www.geo.umass.edu/faculty/bradley/mann2003a.pdf

    So he signs papers with the gang saying that there was no world-wide MWP and that it is much warmer now, while writing E-mails to colleagues saying that the MWP was as warm as today

  37. BlueIce2HotSea said

    #36, Thank you for the reference.

    The article is disappointing in that it throws in an appeal to authority i.e. the ‘robust consensus view’.

    It also precedes the article I cite where Briffa asserts the MWP. But, nevertheless it admits:

    relative hemispheric warmth during the 10th, 11th and 12th
    centuries, and cool conditions during the 15th to the early 20th century

    Given that Michael Mann is the lead author (and presumably the motivating strong-arm force behind the show of unity) it’s interesting that the full choir sings a different tune than MBH alone.

    So, I would attribute that to the moderating influence of Briffa (and others). Which co-authors do you see as most reasonable?

  38. BlueIce2HotSea said

    OK. My last comment on Briffa for some time… thank you for your indulgence.

    IMO Briffa’s major sin is the secret miserly core count (12) at Yamal. AND I believe he is ashamed of it. AND I wonder if he might have paid his penance and got his revenge with a double-agent role in Climategate. It’d be a good story, no?

  39. Jeff Id said

    #38, It was a group of grad students in my opinion. People who are into climatology, young enough to pull a stunt like post it on RC with a link from CA and familiar enough to know what things mean.

    It was an insider by the emails and if they ever figure out who did it, I hope they get a medal. Not because the embarassment of CRU is that great, just because they exposed what we’ve known.

  40. BlueIce2HotSea said

    Yes. Young, rebellious, rascals. A more likely scenario than mine, but not as dramatic.

  41. BlueIce2HotSea said

    But don’t forget Briffa’s obvious working relationship with the Russians. Sorry, I could say more, but won’t. That’s it.

  42. Mark T said

    I would not be surprised if whoever (er, whomever? I never remember) did this has sought legal counsel and has been advised to be quiet awaiting a better feel which way the tide is turning on this.

    Mark

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