Wednesday, May 23, 2012


date: Fri, 31 Oct 2003 08:16:05 -0500
from: "raymond s. bradley" <>
subject: My perspective on the latest draft
to: "Michael E. Mann" <>,,,,

I just reviewed all the back & forth from Tim, Keith etc. and finally
found the latest version of what you propose to send out.
1) I think this sentence is unnecessarily inflammatory and needs to be changed:
We will refrain from making categorical statements as to the specific
motives, but we will state that it seems clear that MM have made critical
errors in their analysis that have the effect of grossly distorting the
reconstruction of MBH98.
Just state:
It seems clear that MM have made critical errors in their analysis that
have the effect of grossly distorting the reconstruction of MBH98.
Since we "refrain from making categorical statements"....why say that?

2) I must say that I very much agree with Tim that we have to be careful
not to say ANYTHING--no matter how trivial--that is not absolutely,
unimpeachably correct, or it will inevitably lead to a response that will
only further confuse and alienate even the most willing of
observers. Thus, the text we release must not include ANYTHING that could
be argued about. It would be better to make only one point that is
unarguably correct than to list a bunch of points, if ANY of them could be
disagreed with as a matter of opinion. Please go through the text and
eliminate anything that meets this criterion.

Finally, I really don't understand what the rush is. Why is an 8am EST
release so critical? It's Friday--will this really matter if it doesn't go
out until Monday-- or even Wednesday as MKH requests.
Seriously, M & M have done a lot of damage, but Mike, you are too wrapped
up in this to see that a few days at this point won't make a hill of beans
difference. The Senate debate is over, Nature and Science etc won't act
with such urgency, so better to slow down here. I'd rather have MKH's
endorsement of this and I think we should wait until he has time to see it too.

Now you are mad as hell at me, I know. So let me say that you have done an
amazing job of deciphering what MM did, and I greatly admire your tenacity
and insight into all of this. Clearly as "The Man" of Mann et al, it's you
who bears the brunt of all criticism, just as you deserve the bulk of the
credit for the work in the first place. But Tim's comments are right on
target...and a few days of sober reflection won't hurt anything....and
might just avoid falling foul of some problem none of us has yet had time
to think about. I know I have hardly time over the last few days to do due
diligence on this, and obviously Malcolm has not even skimmed the surface
of what's gone on....

At 07:18 AM 10/31/2003 -0500, you wrote:
>Thanks Tim,
>Sounds like the best possible plan under the circumstances. Attached is
>the revised (final?) version, see the note about Malcolm Hughes unable for
>comment--does this seem ok?
>If this looks good to you guys, you don't see any typos, etc. lets
>consider this the final version. I've attached it in both word and
>pdf--only the pdf should probably be sent around.
>As per your suggestions, I'll await receipt of your CLIMLIST/SCEPTICSLIST
>email to send this together to other outlets for joint posting. Will you
>guys will send out to all of the other scientists, etc. who' Timmerata,
>etc. emailed too?
>The appropriate outlets would be: EDF, other NGO groups, Ross Gelbspan's
>site, David Appell's blog, etc...
>So I'll await further word from you,
>thanks again,
>At 12:05 PM 10/31/2003 +0000, Tim Osborn wrote:
>>Mike et al.,
>>we (Keith and I) are happy with this strategy. Rebuttal will be signed
>>Mann and Bradley (Hughes to be added later when available to
>>confirm/modify) and circulated to allies/friends first.
>>As soon as we get a final version from Mike, Keith will forward it with a
>>message to Heike.
>>We will also draft an email from Keith, me and Phil to send to the email
>>lists, expressing our views on this and attaching your final version.
>>As to other people that you mention (Science, EFD), we'll leave that to
>>you, Mike, to do - though you may well want to use our
>>CLIMLIST/SCEPTICSLIST email AND your final version together to send to
>>them, so might want to wait till we've drafted that email.
>>At 11:17 31/10/2003, Michael E. Mann wrote:
>>>Thanks--that sounds absolutely great.
>>>I suggest the following
>>>1) I'll fix any remaining typos I find, and incorporate the latest
>>>comments received from you guys. I expect that I can finalize this in 15
>>>minutes or so--I agree that this needs to get out by 8:00 AM eastern
>>>standard time, U.S.
>>>I like where Keith is heading in terms of discussion of the strategy.
>>>Why don't we sign this document, "Mann, Bradley, Hughes" that will be
>>>ready for distribute to our closest colleagues and allies. I'll prepare
>>>a PDF version for distribution, to make it difficult for others to alter
>>>(you never know w/ these folks)...
>>>Should I go ahead and forward this document to Heike, then, in an email?
>>>Also, should I send this to Dick Kerr at Science separately--Dick has
>>>often been helpful. And maybe Jesse Smith at Science, and a few key
>>>journalists (Andy Revkin at New York Times)?
>>>Perhaps, then, Keith, Tim, Phil--you guys, as Keith suggests, can draft
>>>a separate email to go out to the skepticlist (and all of the scientists
>>>who were forward it), the CLIMLIST, etc. stating your opinons on this,
>>>and perhaps *attaching* at supporting evidence the document signed by
>>>Mann, Bradley, Hughes?
>>>Also, do we ask organizations like Environmental Defense Fund, etc. to
>>>post *both* documents (our document, your supporting email) on their
>>>websites, etc?
>>>What do you guys think?
>>>Thank-you guys have been wonderful, and I am most personally gracious.
>>>This will not soon be forgotten...
>>>At 10:47 AM 10/31/2003 +0000, Keith Briffa wrote:
>>>>Hi all - I too have had some problems as to which specific version is
>>>>where we are at - BUT I think the latest draft as sent by Mike really
>>>>is virtually there (perhaps some typos to be ironed out (e.g. 'were'
>>>>instead of 'was' on line 7 of point 2) but I am generally very happy
>>>>with the tone and balance . Much of Tim's fears (justifiable points on
>>>>not providing them with wiggle out and distraction options) are allayed
>>>>by the calm provisos about not being categorical etc. The question now
>>>>arises as to how to put this out - I believe it does need to go out
>>>>early so as to be available when the rest of the press start to pick up
>>>>the MM propaganda . Whether it should be just signed by MBH is up to
>>>>you . I AM NOT averse to signing , but wonder whether it is a better
>>>>tactic to put out a separate statement (us , Tom W. and whoever as
>>>>suggested by Ray , saying we abhor the way this MM paper has been
>>>>published and publicised without proper scrutiny). I fully agree with
>>>>the statement as now written however , and willing to go with the
>>>>majority view. My suggestion about redoing the "audit" was made in good
>>>>faith and in no way implied I concurred with MM ( in case anyone got
>>>>the impression that I was not wholly "on side" here).
>>>>So what does everyone else say now?
>>>>REGARDING NATURE - spoke to Heike Langenberg , in the London office
>>>>and she said it sounded like a potential NEWS item , and asked me to
>>>>send some details by email and she would forward to the appropriate
>>>>office - seemed positive. I will do. The statement (s) should anyway go
>>>>soon on CLIMLIST and then we could quietly contact a few people we know
>>>>in the media ?
>>>>At 05:38 AM 10/31/03 -0500, Michael E. Mann wrote:
>>>>>p.s. Keith, any word from Nature. Should I contact them independently?
>>>>>And what about Science? Or "Climatic Change" (I have little doubt that
>>>>>Steve S could find justification to publish this their in an instant)...
>>>>>At 03:01 AM 10/31/2003 +0000, f055 wrote:
>>>>>>Dear all,
>>>>>>I've just finished preparing a detailed response offline, only to log
>>>>>>on to
>>>>>>send it to you all and find new versions from Mike plus more comments
>>>>>>and information. Well, I don't have time to change my message now, so
>>>>>>will paste it below this message. But bear in mind that the new
>>>>>>draft may
>>>>>>well have allayed many of my concerns - in particular, a quick glance
>>>>>>shows the figure to be much more convincing than the one Mike circulated
>>>>>>earlier, indeed it seems to be utterly convincing! I'll reply again on
>>>>>>morning once I've had time to read the new draft. In the meantime,
>>>>>>here is
>>>>>>my message as promised.
>>>>>>Dear MBH (cc to CRU),
>>>>>>The number of emails has been rather overwhelming on this issue and
>>>>>>I'm struggling to catch up with them! But I will attempt to catch up
>>>>>>with a
>>>>>>few things here...
>>>>>>(1) The single worst thing about the whole M&M saga is not that they did
>>>>>>their study, not that they did things wrong (deliberately or by
>>>>>>accident), but
>>>>>>that neither they nor the journal took the necessary step of
>>>>>>whether the difference between their results and yours could be explained
>>>>>>simply by some error or set of errors in their use of the data or in
>>>>>>implementation of your method. If it turns out, as looks likely from
>>>>>>investigation of this, that their results are erroneous, then they
>>>>>>and the
>>>>>>journal will have wasted countless person-hours of time and caused
>>>>>>much damage in the climate policy arena.
>>>>>>(2) Given that this is the single worst thing about the saga, we must
>>>>>>not go
>>>>>>and do exactly the same in rushing out a response to their paper. If
>>>>>>claims in the response turned out to be wrong, based on assumptions
>>>>>>about what M&M did or assumptions about how M&M's assumptions
>>>>>>affect the results, then it would end up with a number of iterations
>>>>>>of claim
>>>>>>and counter claim. Ultimately the issue might be settled, but by
>>>>>>then the
>>>>>>waters could be so muddied that it didn't matter.
>>>>>>(3) Not only do I advise against an overly rushed response, but I'm also
>>>>>>wondering whether it really ought to be only from MBH, for three reasons.
>>>>>>(i) It is your paper/results that are being attacked.
>>>>>>(ii) It is difficult to endorse everything that Mike has put in the draft
>>>>>>response because I don't know 100% of the details of MBH and the MBH
>>>>>>data. Sure, I can endorse some things, but others I wouldn't
>>>>>>know. Sure,
>>>>>>I accept Mike's explanation because he's looked at this stuff for 4 days
>>>>>>and I believe he'll have got it right - but that's different to an
>>>>>>check. That must come from Ray or Malcolm if possible.
>>>>>>(iii) If it does come to any independent assessment of who's right and
>>>>>>who's wrong, then it would be difficult for us to be involved if we had
>>>>>>already signed up to what some might claim to be a knee-jerk reaction to
>>>>>>the M&M paper. If that happened, then you would want us to be free
>>>>>>to get
>>>>>>involved to make sure the process was fair and informed.
>>>>>>This sounds like a cop out, but - like I say - I'm not sure about
>>>>>>point (3) so
>>>>>>feel free to try to convince me otherwise if you wish. Anyway Keith
>>>>>>or Phil
>>>>>>may be happy to sign up to a (quick or slow) response, despite my
>>>>>>reservations above.
>>>>>>I really advise a very careful reading of M&M and their supplementary
>>>>>>website to ensure that everything in the response is clearly correct -
>>>>>>precisely to avoid point (2). I've only just started to do this, but
>>>>>>have some questions about the response that Mike has drafted.
>>>>>>(a) Mike, you say that many of the trees were eliminated in the data they
>>>>>>used. Have you concluded this because they entered "NA" for "Not
>>>>>>available" in their appendix table? If so, then are you sure that "NA"
>>>>>>means they did not use any data, rather than simply that they didn't
>>>>>>replace your data with an alternative (and hence in fact continued to use
>>>>>>what Scott had supplied to them)? Or perhaps "NA" means they couldn't
>>>>>>find the PC time series published (of course!), but in fact could
>>>>>>find the
>>>>>>raw tree-ring chronologies and did their own PCA of those? How would
>>>>>>they know which raw chronologies to use? Or did you come to your
>>>>>>conclusion by downloading their "corrected and updated" data matrix and
>>>>>>comparing it with yours - I've not had time to do that, but even if I
>>>>>>had and
>>>>>>found some differences, I wouldn't know which was right seeing as I've
>>>>>>not done any PCA of western US trees myself? My guess would be that
>>>>>>they downloaded raw tree-ring chronologies (possibly the same ones you
>>>>>>used) but then applied PCA only to the period when they all had full
>>>>>>data -
>>>>>>hence the lack of PCs in the early period (which you got round by doing
>>>>>>PCA on the subset that had earlier data). But this is only a guess, and
>>>>>>this is the type of thing that should be checked with them - surely they
>>>>>>would respond if asked? - to avoid my point (2) above. And if my guess
>>>>>>were right, then your wording of "eliminated this entire data set" would
>>>>>>come in for criticism, even though in practise it might as well have
>>>>>>(b) The mention of ftp sites and excel files is contradicted by their
>>>>>>record on their website, which shows no mention of excel files (they say
>>>>>>an ASCII file was sent) and also no record that they knew the ftp
>>>>>>This doesn't matter really, since the reason for them using a corrupted
>>>>>>data file is not relevant - the relevant thing is that it was corrupt
>>>>>>and had
>>>>>>you been involved in reviewing the paper then it could have been found
>>>>>>prior to publication. But they will use the email record if the ftp
>>>>>>sites and
>>>>>>excel files are mentioned.
>>>>>>(c) Not sure if you talk about peer-review in the latest version, but
>>>>>>they acknowledge input from reviewers and Fred Singer's email says he
>>>>>>refereed it - so any statement implying it wasn't reviewed will be
>>>>>>met with
>>>>>>an easy response from them.
>>>>>>(d) Your quick-look reconstruction excluding many of the tree-ring data,
>>>>>>and the verification RE you obtain, is interesting - but again, don't
>>>>>>using these in any response. The time series of PC1 you sent is
>>>>>>different from your standard one - but on the other hand I'd hardly
>>>>>>say you
>>>>>>"get a similar result" to them, the time series look very different
>>>>>>(see their
>>>>>>fig 6d). So the dismal RE applies only to your calculation, not to their
>>>>>>reconstruction. It may turn out that their verification RE is also very
>>>>>>negative, but again we cannot assume this in case we're wrong and they
>>>>>>easily counter the criticism.
>>>>>>(e) Claims of their motives for selective censoring or changing of
>>>>>>data, or
>>>>>>for the study as a whole, may well be true but are hard to prove. They
>>>>>>would claim that their's is an honest attempt at reproducing a key
>>>>>>scientific result. If they made errors in what they did, then maybe
>>>>>>just completely out of their depth on this, rather than making deliberate
>>>>>>errors for the purposes of achieving preferred results.
>>>>>>(f) The recent tree-ring decline they refer to seems related to
>>>>>>tree-ring-width not density. Regardless of width of density, this issue
>>>>>>cannot simply be dismissed as a solved problem. Since they don't make
>>>>>>much of an issue out of it, best just to ignore it.
>>>>>>(g) [I'm rambling now into an un-ordered list of things, so I'll stop
>>>>>>The various other problems relating to temperature data sets, detrended
>>>>>>standard deviations, PCs of tree-ring subsets etc. sound likely errors -
>>>>>>though I've got no way of providing the independent check that you asked
>>>>>>for. But it is again a bit of a leap of faith to say that these
>>>>>>*explain* the
>>>>>>different results that they get. Certainly they throw doubt on the
>>>>>>their results, but without actually doing the same as them it's not
>>>>>>to say if they would have replicated your results if they hadn't made
>>>>>>errors. After all, could the infilling of missing values have made much
>>>>>>difference to the results obtained, something that they made a good deal
>>>>>>of fuss about?
>>>>>>(h) To say they "used neither the data nor the procedures of MBH98" will
>>>>>>also be an easy target for them, since they did use the data that was
>>>>>>to them and seemed to have used approximately the method too (with
>>>>>>some errors that you've identified). This reproduced your results to
>>>>>>extent (certainly not perfectly, but see Fig 6b and 6c). Then they went
>>>>>>further to redo it with the "corrected and updated" data - but only after
>>>>>>doing approximately what they claimed they did (i.e. the audit).
>>>>>>These comments relate to random versions of the draft response, so
>>>>>>apologies if they don't all seem relevant to the current draft. I
>>>>>>don't have
>>>>>>these in front of me, here at home, so I'm doing this from memory of what
>>>>>>I've read over the past few days. But nevertheless, the point is
>>>>>>that a quick
>>>>>>response would ultimately require making a number of assumptions
>>>>>>about what they did and assumptions about whether this explains the
>>>>>>differences or not - assumptions that might be later shot down (in part
>>>>>>only, at most, but still sufficient to muddy the debate for most
>>>>>>A quick response ought to be limited to something like:
>>>>>>The recent paper by McIntyre and McKitrick (2003; hereafter MM03) claims
>>>>>>to be an "audit" of the analysis of Mann, Bradley and Hughes (1998;
>>>>>>hereafter MBH98). MM03 are unable to reproduce the Northern
>>>>>>Hemisphere temperature reconstruction of MBH98 when attempting to
>>>>>>use the same proxy data and methods as MBH98, though they obtain
>>>>>>something similar with clearly anomalous recent warming (their Figure
>>>>>>6c). They then make many modifications to the proxy data set and repeat
>>>>>>their analysis, and obtain a rather different result to MBH98.
>>>>>>Unfortunately neither M&M nor the journal in which it was published took
>>>>>>the necessary step of investigating whether the difference between their
>>>>>>results and MBH98 could be explained simply by some error or set of
>>>>>>errors in their use of the data or in their implementation of the MBH98
>>>>>>method. This should have been an essential step to take in a case such
>>>>>>as this where the difference in results is so large and
>>>>>>important. Simple
>>>>>>errors must first be ruled out prior to publication. Even if the
>>>>>>authors had
>>>>>>not undertaken this by presenting their results to the authors of MBH98,
>>>>>>the journal should certainly have included them as referees of the
>>>>>>A preliminary investigation into the proxy data and implementation of the
>>>>>>method has already identified a number of likely errors, which may turn
>>>>>>out to be the cause of the different results. Rather than repeating
>>>>>>failure to follow good scientific practise, we are witholding further
>>>>>>comments until we can - by collaboration with M&M if possible - be
>>>>>>of exactly what changes to data and method were made by M&M, whether
>>>>>>these changes can really explain the differences in the results, and
>>>>>>eventually which (if any) of these changes can be justified as
>>>>>>equally valid
>>>>>>(given the various uncertainties that exist) and which are simply
>>>>>>errors that
>>>>>>invalidate their results.
>>>>>>Hope you find this all helpful, and despite my seemingly critical
>>>>>>take them in the spirit with which they are aimed - which is to obtain a
>>>>>>strong and hard hitting rebuttal of bad science, but a rebuttal that
>>>>>>be buried by any minor innaccuracies or difficult-to-prove claims.
>>>>>>Best regards
>>>>> Professor Michael E. Mann
>>>>> Department of Environmental Sciences, Clark Hall
>>>>> University of Virginia
>>>>> Charlottesville, VA 22903
>>>>>e-mail: Phone: (434) 924-7770 FAX: (434) 982-2137
>>>>Professor Keith Briffa,
>>>>Climatic Research Unit
>>>>University of East Anglia
>>>>Norwich, NR4 7TJ, U.K.
>>>>Phone: +44-1603-593909
>>>>Fax: +44-1603-507784
>>> Professor Michael E. Mann
>>> Department of Environmental Sciences, Clark Hall
>>> University of Virginia
>>> Charlottesville, VA 22903
>>>e-mail: Phone: (434) 924-7770 FAX: (434) 982-2137
>>Dr Timothy J Osborn
>>Climatic Research Unit
>>School of Environmental Sciences, University of East Anglia
>>Norwich NR4 7TJ, UK
>>phone: +44 1603 592089
>>fax: +44 1603 507784
> Professor Michael E. Mann
> Department of Environmental Sciences, Clark Hall
> University of Virginia
> Charlottesville, VA 22903
>e-mail: Phone: (434) 924-7770 FAX: (434) 982-2137

Raymond S. Bradley
Distinguished Professor
Director, Climate System Research Center*
Department of Geosciences
Morrill Science Center
611 North Pleasant Street
AMHERST, MA 01003-9297

Tel: 413-545-2120
Fax: 413-545-1200
*Climate System Research Center: 413-545-0659
Paleoclimatology Book Web Site:


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