HI Keith et al,
Thanks for your message.
This sounds fine. I do have to warn that with a full teaching courseload
this semester, my own free time will necessarily be somewhat limited. Thus,
Scott's involvement here will be key.
Scott has  been dealing w/ the new methodology and analyses, and hence my
concern w/ any plans that expect new analyses w/ our old methodology. The
code is not especially user friendly, though Tim is welcome to use it.
Scott will be able to devote a decent share of his time to these activities
during Tim's visit, though this will necessarily have to be split with time
devoted to activities that Scott is explicitly supported for by our NOAA
grant (ie, the development of a synthetic proxy network from model data,
and wavelet-based calibration methods, as detailed in my previous email).
So I'm sure we'll be able to find common ground. Tim will have free access
to our data and codes, and can make the comparisons indicated below. We of
course appreciate your willingness to make available to us the tree ring
density data.
It may be interesting to do a (highly preliminary!) analysis of both proxy
datasets with our expectation maximization ridge regression scheme, and
that would certainly fit in well w/ both our agendas (your NERC grant, and
our NOAA grant).
Hopefully, our 4-processor Dell server (running Linux) will be back up and
running, so Scott can use our Sun server, while Tim will have the Dell
server to himself if he needs it.
I hope the above all sounds good.
Best regards,
mike
At 10:16 AM 9/25/00 +0100, Keith Briffa wrote:
>Dear Mike
>            I know Tim has communicated with you about plans for his visit
>to Virginia. We have discussed ideas here and I ,for one, am excited about
>the prospects of joint work. Thank you for agreeing to his visit and for
>taking the trouble to arrange things .
>The purpose of this brief message is simply to reiterate what we said in
>our brief discussions in Venice - namely that it is our intention to work
>with you rather than in any sense of competition. Our motivation for
>wanting to do some of the detailed comparisons between the results of our
>work and your own is to understand the sources of uncertainty in both. We
>are also committed to doing some of this work by the terms of our current
>NERC grant.   We wish to involve you as much as possible , get your advice
>, and solicit criticisms of our approach -especially in relation to the
>Palaeo-model comparisons .
>  Our EC proposal was not funded , but we wish to follow it up with another
>to PRESCIENT (a NERC Thematic Programme of research along the same lines),
>and again we would be happy to collaborate with you. Better two way
>communication between here and there would be a major help.
>   It is my feeling that  the relatively short time Tim has with you ,
>might be best spent getting to grips with the finer details of your "old"
>and "new"  approaches, including the details and results of your other work
>that is only partly described in the publications ( seasonal
>runs,  different data sets etc.) and , most importantly, discussing
>approaches and philosophies for data-model comparison work. That way he
>could come away with some concrete plans , and the means of fulfilling
>them, on his return. Any time you can spare to discuss and liaise along
>these lines would be much appreciated. He has discussed the specifics of
>your suggestions and I am happy with the approach and prioritization he has
>expressed.
>While he is with you , we can always exchange emails if any issues need
>wider discussion.
>very best wishes
>Keith
>--
>Dr. Keith Briffa, Climatic Research Unit, University of East Anglia,
>Norwich, NR4 7TJ, United Kingdom
>Phone: +44-1603-592090    Fax: +44-1603-507784
>
>
>
_______________________________________________________________________
Professor Michael E. Mann
Department of Environmental Sciences, Clark Hall
University of Virginia
Charlottesville, VA 22903
_______________________________________________________________________
e-mail: mann@virginia.edu   Phone: (804) 924-7770   FAX: (804) 982-2137


Dear all
Here's another MWE reference, originally announced by the Idso's. I
looked up the abstract from the South African Journal of Science and
here's its URL

That puts the MWE and LIA into South Africa.
Cheers
John D.
--
John L. Daly
"Still Waiting For Greenhouse"
~daly
"All science is numbers, but not all numbers is science"


Myles and Curt,
Attached are the NH and SH averages from the new variance corrected
analyses (HadCRUTv). When the paper comes out in JGR (probably early next
year) you'll see that variance correction is only possible from 1870.
So in these files I've patched on the 1856-1869 data on the front so they
are the same length. This early data is the same as the original
version (HadCRUT). For the global series I still think the best way
of producing this is by averaging the two hemispheres. HadCRUT is what
you all probably have - it is on the CRU web page. Again I would
produce the globe by averaging the hemispheres so what Chris Folland has
for the globe may differ slightly as the HadC produce this as one domain.
The way the variance correction is achieved is by reducing the high-freq
variance of each grid-box series. This means that when I update the series
for 2000 some values for the last few years (1995-9) will be altered
slightly.
I don't know much about Chapter 2, but I don't recollect there being
any power spectrum diagrams. Probably left for the detection chapter.
Do make sure the axes and units are well explained. Don't leave anything
for the skeptics to cling to !
Cheers
Phil
At 05:16 PM 10/3/00 +0100, Myles Allen wrote:
>Hi Phil,
>
>If you could send me the latest version that chapter 2 are using, that
>would be great -- I certainly won't pass it on nor use it for anything
>else.  Subtle differences in processing do make a difference to the visual
>appearence of the plot, and even though these differences are inside the
>noise indicated by the error bar, you can bet potential critics will
>ignore that.
>
>Do you show a power spectrum of global temperatures in chapter 2, and if
>so, how was it computed?  It would certainly be tidy to make sure both are
>processed in the same way.
>
>Myles
>----------------------------------------------------------------------
>Myles R. Allen				Phone (RAL):	44-1235-446480
>Space Science & Technology Department	Ph (Oxford):	44-1865-272085
>Rutherford Appleton Laboratory		Fax:		44-1235-445848
>Chilton, Didcot, OX11 0QX		e-mail:	    m.r.allen@rl.ac.uk
>United Kingdom
>----------------------------------------------------------------------
>
>On Tue, 3 Oct 2000, Phil Jones wrote:
>
>>
>>  Curt, Myles and anyone else,
>>     As the data on the web site has an end date of 1994, I suspect you
>>  may have an earlier version of the surface data (different form of
>>  gridding and maybe a few other differences in data usage), so I suggest
>>  you use the latest one, which can be got from the CRU web site.
>>     If this relates to IPCC work, then Chapter 2 on the Observations is
>>  going to go with a variance corrected version (corrects for changing
>>  station numbers within individual grid boxes), but the effect of this
>>  on the hemispheric and global temp series is small.
>>    If anyone wants this new version (HadCRUTv) then I can send the hemispheric
>>  and global series by email. The 'normal' version (HadCRUT) is on the
>>  CRU website. This naming and the variance correction procedures are
>>  discussed in a paper which has been accepted by JGR. It will not be out for
>>  a while, as I've not yet sent the camera ready columns to the AGU.
>>
>>  Cheers
>>  Phil
>>
>>
>>
>> At 03:45 PM 10/2/00 -0700, Curtis Covey wrote:
>> >  Myles Allen wrote: Dear Curt, Can you give me the ancestry of the "ObsJ"
>> >global mean temperature series
>> >  We need the source, start date (I think I can work it
>> >out by matching bumps, but it would be better to be sure) and how it's
>> >been detrended for the figure caption.
>> >
>> >>
>> >>> sent you, the data is
>> >>>the "Jones" set used by the IPCC for its Second (1995)
>> >>>  It's
>> >>> processed this particular data that
>> >>> don't remember exactly who gave it to me: either Phil
>> >>>   should invite Phil's latest
>> >>>(including error bars) now that I'm updating our Web
>> >>>site     See attached
>> >>>PostScript graphic. Regards,
>> >>>Curt
>> >>>
>> >>
>> >   Attachment Converted: "c:\eudora\attach\tseries_obsJ.ps"
>> Prof. Phil Jones
>> Climatic Research Unit        Telephone +44 (0) 1603 592090
>> School of Environmental Sciences    Fax +44 (0) 1603 507784
>> University of East Anglia
>> Norwich                          Email    p.jones@uea.ac.uk
>> NR4 7TJ
>> UK
>>
>> ----------------------------------------------------------------------------
>>
>>
>>
>
>


Stepan and Eugene
I have asked INTAS for an extension on the report period. Stepan some problem has now arisen regarding your final payment . I have asked Janet to sort this out and contact you directly.
I have to give an up to date report on chronology development and tree-line changes at the PAGES meeting in Avignon on October 24-26 and I would really appreciate some Figures that demonstrate the latest state-of-the-art in the Yamal and Taimyr (and any other good Russian evidence ) . The focus of the meeting is High-resolution variability of the Holocene , and the long records and evidence of tree-line changes is particularly valuable. Later there will be some large review papers (with many authors) summarising the information from high latitudes, mid latitudes, the tropics etc. The form of these papers is not yet decided but you would be contributing authors. I am also (with Ray Bradley,Julie Cole and Malcolm Hughes) writing a Chapter on the last 10000 years (with a major emphasis on the last 1000) for the PAGES Synthesis book and I intend to include a summary Figure that includes your work - I hope this is O.K
Malcolm has just asked for a letter of support from me for a project he is submitting to NSF , in which I believe you are both involved. I have sent it to him. I am still exploring when we can resubmit our own proposal to the EC, and I will write an application to The Leverhulme trust before the end of this year. I am still discussing the Holocene ADVANCE-10K issue and I will be in touch about your papers.
best wishes
Keith


Dear Keith,
Stepan Shiyatov tell me that you need some figures concerning
Yamal chronology and tree line dynamics to show somewhere in
France.
Attached are archived files contained some figures.
File MAP - the map of region of research. Red dots - subfossil
wood sites, green marks - recent northern border of larch along
river valleys.
File FIGURES - in Excel format, contains several figures.
Sheet "Values-10" - data on northernmost position of trees and
number of trees dated for corresponding year (decadal step)
Sheet "Treeline" - dynamics of treeline in Yamal during last 7000
years reconstructed using about 1000 subfossil wood remains.
Recent treeline position is about 67°34’.
One year ago we supposed (C-14 data, Hantemirov, Shiyatov
1999) that significant drop of treeline (the transition from
"middle" to "late" Holocene) was about 1700-1600 AD. According
new data it was earlier (about 2550 BC). May be it is because
of lack of data from region northward of 68°N (only 25
datings)?
Sheet "Treeline and Nu" - treeline dynamics and number of dated
trees. May be number of trees reflects the long scale climate
fluctuations as well.
Sheet "2600-all" - for last 4600 years: treeline dynamics,
number of trees, 11 most cold summers for last 7000 years
(according our version of reconstruction), most expressed
frosts in July (reconstructed using junipers from Polar Urals,
see file PATHOL, frost in 1626 BC - based on subfossil larch -
you can put away it), summer temperatures reconstruction
smoothed with 20- and 100-year filters (our version of
reconstruction).
Sheet "Values-2" - values for preceding figures, in 2-years
step.
Sheet "Yam-Ur-fig" - comparing of treeline data for Yamal and
Polar Urals upper treeline dynamics (data by S.G.Shiyatov)
Sheet "Yamal-Ural" - values for preceding figure, in 2-years
step.
Sheet "Treeline-std" - treeline dynamics and 50-year standard
deviations of summer temperatures (our version of
reconstruction). This figure shows surprising high negative
correlation. However may be both of them just reflect long
scale climate fluctuations?
Sheet "Std" - 50-year standard deviations of summer
temperatures (our version of reconstruction) .
File PATHOL - in Excel format, contains data and figure on
pathological structures in tree rings of Siberian juniper
(Juniperus sibirica Burgsd.). According our data (Hantemirov et
al., 2000) the presence of frost rings provides evidence for
frosts that occurred in late June or first days of July (frost
rings in earlywood) and in the first half of July (frost rings in
late wood). Long term and pronounced temperature drop in the
middle of very warm period in the second half of July is the
factor responsible for wood density fluctuations (false rings).
Please let me know when you receive this. Some time large
messages get lost.
P.S. We (Eugene Vaganov, Stepan Shiyatov, Leonid Agafonov and I)
will be in Birmensdorf from 23 till 29 October. Are you going to
Switzerland after your meeting? We would be happy to see you
there.
Best regards,
Rashit M. Hantemirov
Lab. of Dendrochronology
Institute of Plant and Animal Ecology
8 Marta St., 202
Ekaterinburg, 620144, Russia
e-mail: rashit@ipae.uran.ru
Fax: +7 (3432) 29 41 61; phone: +7 (3432) 29 40 92
Attachment Converted: "c:\eudora\attach\Map.zip"
Attachment Converted: "c:\eudora\attach\Figures1.zip"
Attachment Converted: "c:\eudora\attach\Pathol.zip"


I am just having to go so I will think about the "should we?" . The answer to the "can we?"
is yes. I have spoken to the person organising the editorial review and she has promised me
she will get it to us in the next week or so. If we can get it back immediattely she says
we can make the December issue. Therefore it is possible to do the edits if it means very
little change to the text. I have also confirmed that we will pay 1500 dollars for the
colour and they say they are working on these now. I really want to get this into the 2000
so I can include it in the RAE. Ed is here now and has some great looking extended PDSI
reconstructions (1000 years) for the western US.
I am suspicious as to whether the negative trend in Mike's Hockey stick prior to the 20th
century is not at least partly the result of a trend in the long  high elevation western US
trees he uses . Malcolm sent me some figures for the HIHOL meeting and in this work he cuts
off the juvenile growth sections of the long tree data but does no detrending on the
remainder. This might leave a linear age trend in these data. I remember that Mike in his
long reconstruction , stated that the pc representing the western US stuff was essential
for getting a verifiable result. Interesting , but only a diversion. We can discuss the JGR
and other stuff in Avignon. Hope your weekend was a god one. I tend to agree a
bout the NAO meeting- you could use the money (and perhaps time) to better effect.
At 04:24 PM 10/19/00 +0100, you wrote:
Keith,
have you had to produce the camera-ready copy for the age-banded JGR paper
yet?  If not, then is it possible to make some minor changes to it?  For the
comparison with the Mann et al. reconstruction, I had previously just taken
their land&marine full northern hemisphere mean annual temperature time series
and re-calibrated it against the instrumental land north of 20N Apr-Sep mean
temperature time series.  Well, I have not taken the Mann et al. spatial
temperature field reconstructions, and computed a land north of 20N area mean.
I still have to re-calibrate it against the instrumental series because it is
an annual rather than Apr-Sep mean.  After doing all this, you'll be pleased
to know that the final figure is only slightly different (the Mann et al.
curve is very slightly more of an outlier during the 1500-1700 period, and is
cooler and closer to observations post-1950, but not much different
elsewhere).  What does change, however, are the correlations.  The
correlations with instrumental data are slightly worse (from 0.76 to 0.73, and
from 0.92 to 0.89 decadal), but I'm not sure that we show these anyway.  But
the cross-correlations between the Mann et al. and the other reconstructions
(which we do show) are all stronger than previously - which now seems a little
unfair on them.
Cross-correlations between unfiltered series:
Mann versus:  Jones, Briffa (ABD), Briffa (Torn+Tai+Yam)
before: 0.47, 0.36, 0.33
now:    0.50, 0.37, 0.34
Cross-correlations between 50-yr smoothed series:
Mann versus:  Jones, Briffa (ABD), Briffa (T+T+Y), Overpeck, Crowley
before: 0.78, 0.43, 0.50, 0.86, 0.76
now:    0.81, 0.51, 0.55, 0.86, 0.78
I don't have a copy of the paper in front of me, but the 'before' values
should match those in one of the tables.  Some of the 50-yr smoothed new
values are noticeably stronger.
Can we make these changes still, or is it too late?  And do you think we
should?
Cheers
Tim


Dear Brendaw,
My review of the paper JCL 3435 is attached. My recommendation is
to accept the paper subject to minor changes. I don't wish to see it
again. If there are any problems with the attachment, let me know and
I can fax the 2 pages.
Cheers
Phil Jones
At 06:58 PM 10/7/00 -0400, you wrote:
>Professor Michael Mann, Editor of Journal of Climate, has suggested you as a
>possible reviewer of a paper entitled "Differential ENSO and volcanic
>effects on surface and tropospheric temperatures" (JCL-3435 by T. M. L.
>Wigley and B. D. Santer.
>
>Would you please let me know whether or not you will be able to do this
>review?  If you accept, we ask that you complete your review by 11/24/00 (if
>possible).  Hard copy or e-mail copies of reviews are very acceptable.
>
>Also, if you accept, please send your complete address including telephone
>and fax numbers for our files.  Thank you so much.
>
>If you are unable to do this review, suggestions of other potential
>reviewers (and their e-mail addresses) for this paper would be greatly
>appreciated.
>
>Brenda W. Morris
>Editorial Assistant
>Journal of Climate
>
>
>
>
>


Ben,
I hope the surgery next week goes OK. Ruth and I are going away next
week for a short break to Coldstream on the River Tweed. This was the
holiday cottage Matthew had planned to go to for his honeymoon, but the
fuel crisis around his wedding time precluded this. We were able to
negotiate the cottage for a later date, as we could get a refund or
claim on the insurance as a national emergency wasn't declared. So on
Nov 1 we will think about you !
I've listed off the diagrams and will take the text when it comes, but
I won't be able to send you any comments until the week of Nov 6.
Also just sent back comments to Mike Mann on the paper by Tom and
you factoring out ENSO and Volcanoes. Felt like writing red ink all over
it, but sent back a short publish suject to minor revision to Mike. This
is the first time I've ever reviewed one of Tom's or your papers !
Copy of what I sent is attached. I forgot to sign it before sending it !
Again hope all is well later next week !
Cheers
Phil
At 06:37 PM 10/24/00 -0700, you wrote:
>Dear All,
>
>Sorry that it has taken me so long to revise our paper. As I mentioned in a
>previous email, I've had to repeat most of the calculations using an improved
>estimate of the pre-eruption reference level temperature (Tref). I've also had
>to look at the sensitivity of our results to uncertainties in Tref. I'd like to
>thank Tom for prompting me to take a critical look at this issue - it's an
>important one. I'd also like to thank the rest of you for all the comments that
>you've sent me. I hope I've addressed them adequately in the revised paper.
>
>Another major change is that, rather than giving results are based on a variety
>of different filtering options -- e.g., estimation of volcano parameters from
>unfiltered data (too noisy) and highly smoothed data (13-term Gaussian filter
>leads to underestimate of volcanically-induced cooling) -- we now only give
>results for our "best guess" filtering option,
>a five-term binomial filter. We still discuss sensitivities to tau (the volcanic
>signal decay time) and choice of ENSO index. Restricting attention to one
>filtering option reduces the length of Tables, and hopefully improves the
>clarity of the paper.
>
>I've rewritten the discussion of the iterative method, and we now make it clear
>that although this approach is automated, its implementation still involves a
>number of subjective decisions (filter choice, choice of averaging period for
>estimating pre-eruption reference temperature, choice of tau, etc.) Many of the
>changes made here attempt to address useful comments that I received from Tom.
>
>Lennart and Erich kindly provided me with the SLP data from the GSOP, GSO1 and
>GSO2 integrations. Recall that we did not have this data previously, and so our
>estimation of ENSO signals in GSO1 and GSO2 and of ENSO/volcano signals in GSOP
>was based on simulated Nino 3.4 SSTs only. We've now also used the (simulated)
>SOI to perform ENSO/volcano signal estimation.
>
>Section 5 (discussion of ECHAM4/OPYC results) has been completely rewritten,
>and the ordering of individual subsections should now be more logical. We
>discuss the simulated Pinatubo signal first, then the "ENSO component" of
>simulated temperature trends, and finally residual trends after the removal of
>volcano and ENSO effects.
>
>Today I'm sending you, as postscript attachments, the revised Figures for the
>paper. To simplify things I've encoded the Figure number at the top of the
>postscript file. I don't want to overload your mailboxes, so I'm sending the
>Figures in two separate mail messages. There should be 11 Figures in total.
>Tomorrow I'll send you the revised text of the paper and the Tables. Please let
>me know if you have any problems printing these files. Note that all Figures
>except Figure 7 are in color. Color is not essential for some of the Figures,
>and in the next day or two I'll prepare black-and-white versions of Figues 3, 5,
>6, 8, 9, 10 and 11. But for now I thought you might find it easier working with
>the color versions.
>
>I will be going in for surgery on November 1st, and am not sure how long it will
>be until I get back to my office. I realize that it may not be feasible to
>submit the paper before November 1st. But I'd really appreciate it if you could
>send me comments before November 1st. These will keep me occupied while I'm
>trying to get back on my feet!
>
>With best regards,
>
>Ben
>--
>----------------------------------------------------------------------------
>Benjamin D. Santer
>Program for Climate Model Diagnosis and Intercomparison
>Lawrence Livermore National Laboratory
>P.O. Box 808, Mail Stop L-264
>Livermore, CA 94550, U.S.A.
>Tel:   (925) 422-7638
>FAX:   (925) 422-7675
>email: santer1@llnl.gov
>----------------------------------------------------------------------------


Ben,
All received and printed. The weather forecast for the next few days
is cold and windy, so I'll read this at the cottage in Coldstream.
Hope everything goes OK later next week. I will email comments, hopefully
on Nov 6, maybe Nov 7 if there is a lot of urgent things to do when I
get back.
Cheers
Phil
At 05:18 PM 10/26/00 -0700, you wrote:
>Dear All,
>
>Here are the three postscript files with the title page, main text, and Tables
>for our draft JGR paper. Sorry it took me a bit longer to get these to you.
>Please let me know if you have any problems printing these files. You should
>already have all the Figures that I sent on Tuesday.
>
>I'll be in my office tomorrow and Monday and Tuesday of next week. After Tuesday
>the best way of getting in touch with me is by contacting PCMDI's secretary,
>Harriet Moxley (925-422-7638). I hope to be out of hospital and back in my
>office by November 10th. It would be nice if we could submit this paper shortly
>thereafter!
>
>With best regards, and thanks again for all your help,
>
>Ben
>--
>----------------------------------------------------------------------------
>Benjamin D. Santer
>Program for Climate Model Diagnosis and Intercomparison
>Lawrence Livermore National Laboratory
>P.O. Box 808, Mail Stop L-264
>Livermore, CA 94550, U.S.A.
>Tel:   (925) 422-7638
>FAX:   (925) 422-7675
>email: santer1@llnl.gov
>----------------------------------------------------------------------------
>Attachment Converted: "c:\eudora\attach\volcano_tables2.ps"
>
>Attachment Converted: "c:\eudora\attach\driver_maintext.ps"
>
>Attachment Converted: "c:\eudora\attach\driver_titlepage.ps"
>


Any idea who at Cambridge has been benefitting from this BP money?
Mike
From: "Simon J Shackley"
Organization: umist
To: m.hulme@uea.ac.uk
Date: Thu, 2 Nov 2000 14:44:09 GMT
Subject: BP funding
Reply-to: Simon.Shackley@umist.ac.uk
CC: robin.smith@umist.ac.uk,
brian.launder@umist.ac.uk
Priority: normal
X-mailer: Pegasus Mail for Win32 (v3.12a)
dear TC colleagues
looks like BP have their cheque books out!   How can TC benefit from
this largesse?  I wonder who has received this money within Cambridge
University?
Cheers, Simon
17) BP, FORD GIVE $20 MILLION FOR PRINCETON UNIVERSITY
EMISSIONS
STUDY
Auto.com/Bloomberg News
October 26, 2000
Internet: [1]
LONDON -- BP Amoco Plc, the world's No. 3 publicly traded oil
company, and Ford Motor Co. said they will give Princeton
University $20 million over 10 years to study ways to reduce
carbon-dioxide emissions from fossil fuels. BP said it will give
$15 million. Ford, the world's second-biggest automaker, is
donating $5 million. The gift is part of a partnership between the
companies aimed at addressing concerns about climate change.
Carbon dioxide is the most common of the greenhouse gases believed
to contribute to global warming.
London-based BP said it plans to give $85 million in the next
decade to universities in the U.S. and U.K. to study environmental
and energy issues. In the past two years, the company has pledged
$40 million to Cambridge University, $20 million to the University
of California at Berkeley and $10 million to the University of
Colorado at Boulder.
References
1.


I am away for a couple of days.  This is an automatic reply.  I will reply
to your mail regarding "reminder" when I return on Sunday.


Hi Jap
please see the following - I have had the data put on my web site and I will slowly put
other data and Figures and Abstracts on there also. Let me know if you have a problem
downloading the data. Good luck
Keith
The data you want are included in those listed under -
[1]
At 03:56 PM 11/17/00 -0600, you wrote:
Dear Mr Briffa,
I remind you to send me your temperature reconstructions for northern
Scandinavia and the Polar Urals.
JaapJan Zeeberg
At 02:55 PM 11/14/2000 +0000, you wrote:
>Dear Jap
>I am sorry , but your earlier message must have slipped through the net .
>I will try to look out the data and send them to you in the next couple of
>days or so. Please remind me on thursday if they have not arrived.Best wishes
>Keith
>
>At 02:14 PM 11/13/00 -0600, you wrote:
>
>>Dear Dr Briffa,
>>
>>You may not have received this message the first time I sent it (30/10);
>>
>>I am a PhD-student at the University of Illinois, Chicago. I study the
>>effect of North Atlantic modulated inputs of precipitation and summer warmth
>>on the glacier mass balance of Novaya Zemlya. Results will appear in the
>>January or March-issue of The Holocene.
>>
>>I would like to use your temperature reconstructions for the northern Urals
>>and northern Fennoscandia published in Nature 376,  p. 156-159 (1995). I
>>plan to compare the temperature time series with grain size distributions of
>>three sediment cores obtained from Russkaya Gavan', a fjord at north Novaya
>>Zemlya. These cores span the past ~4 centuries.
>>
>>I could not find the requested time series in the NOAA data base and would
>>be grateful if you could provide them.
>>
>>Sincerely
>>
>>JaapJan Zeeberg
>>
>>
>>=======================================
>>JaapJan Zeeberg
>>
>>[2]~jzeebe1/news.htm
>>
>>845 W. Taylor Street MC186
>>Chicago, IL 60607-7059, USA
>>
>>Phone: 312-996-3154
>>Fax: 312-413-2279
>>e-mail jzeebe1@uic.edu
>>
>>========================================
>
>--
>Dr. Keith Briffa, Climatic Research Unit, University of East Anglia,
>Norwich, NR4 7TJ, United Kingdom
>Phone: +44-1603-592090    Fax: +44-1603-507784
>
>
--
Dr. Keith Briffa, Climatic Research Unit, University of East Anglia,
Norwich, NR4 7TJ, United Kingdom
Phone: +44-1603-592090    Fax: +44-1603-507784
References
1.
2. ~jzeebe1/news.htm


Scott, Tim,
Here's the abstract.
If the results pan out, then several us us may want to be discussing this
work on the talk circuit.
This is the first stab! Notice how safe (a very results-insensitive abstract!)
mike
XXVI General Assembly, Spring EGS Meeting
Comparison of Large-Scale Proxy-Based Temperature Reconstructions Over the
Past Few Centuries
MANN, M.E.; RUTHERFORD, S; OSBORN, T.J.
OA28.0  Study of past climates: Climate of the past millennium
JOUZEL, J.; (co-conveners: JONES, P.D.; MANN, M.E.)
Comparison of Large-Scale Proxy-Based Temperature Reconstructions Over the
Past Few Centuries
M.E. Mann(1), S. Rutherford(1), and T.J. Osborn(2)
(1) Univ. of Virginia, USA, (2) Climate Research Unit, Univ. East Anglia, UK
A  promising approach to the problem of reconstructing patterns of past
climate variability
involves the application of spatial climate field reconstruction (CFR)
techniques to networks of proxy
climate indicators (e.g., Mann et al 1998;2000--see

This approach seeks to exploit the complimentary information in a diverse
network of proxy indicators by determining the most consistent
relationships between these
networks of data and  the leading spatial patterns of climate variability
during a recent "calibration" period of overlap with the modern
instrumental record.
The calibrated relationship is then used to estimate large-scale patterns
of climate variability
in the past from the proxy data. This method makes no  assumptions regarding
the relationship between a given proxy indicator and specific local
annual/seasonal climate variable, but
does assume that the proxy indicator is tied to some combination of
large-scale patterns of climate variability.
Alternatively,  it is possible to  estimate large-scale temperature
patterns from a relatively homogenous network
of proxy climate indicators (e.g., tree-ring density data--see Briffa et
al, 1998) by invoking
a local calibration between each climate indicator and the climate variable
(e.g., summer temperature)
of interest. This approach is more conservative in the amount of
information it seeks to
extract from the proxy data network, but it is free from assumptions
regarding the large-scale
patterns of past climate variability. Recent reconstructions of Northern
Hemisphere annual-mean and
warm-season temperature patterns using these respective approaches and data
show some similarities,
but also some important differences. Here we investigate these differences
more closely, examining
the sensitivity of Northern Hemisphere temperature pattern reconstructions
to (a) the underlying
proxy data used, (b) the particular method used to estimate large-scale
patterns from these data,
and (c) the target  seasonality of the reconstruction. By controlling
independently for each of these
three factors, we gain insight into the reasons for differences between
various proxy-based estimates
of past large-scale temperature variability.
_______________________________________________________________________
Professor Michael E. Mann
Department of Environmental Sciences, Clark Hall
University of Virginia
Charlottesville, VA 22903
_______________________________________________________________________
e-mail: mann@virginia.edu   Phone: (804) 924-7770   FAX: (804) 982-2137


Dear Colleagues
At the HIHOL meeting in Avignon in October, several of us (Steig, van
Ommen, Dahl-Jensen, Vimeux) agreed to write a review paper addressing
Holocene climate change as viewed from polar ice core records.  The main
task of writing and organizing this paper has fallen upon Tas and Eric, and
we are writing to solicit your interest, support, and contribution.  We
would appreciate hearing from each of you with comments on our proposed
plan, requests for clarification and (hopefully) data sets.  We hope you
will be interested in working with us on this project.  Note that the
deadline for completion is the end of March, 2001.
Although the question of Holocene climate change has obviously been
addressed in numerous papers on individual ice core records (and most
recently in the Masson et al. review of Antarctic records in QR), we
believe that
it would be valuable to select the best-understood, best dated, polar ice core
data from both hemispheres and put them in a single paper.  We also think
that the paper should be limited only to
1) data that address directly the TEMPERATURE history at high latitudes --
the information
we get from isotopes and from borehole reconstructions -- as opposed e.g.
to atmospheric circulation changes that one gets from the chemistry record,
and
2) discussion of the long-term variations, as opposed to short term
variations such as the Little Ice Age.
The intention here is not to be exclusive of either people or ideas, but to
limit the scope of the paper so that it is as definitive a document as
possible.  Of particular interest is the "simple" question of the timing
and magnitude of the "thermal maximum", the subsequent Holocene cooling,
and their relationship to insolation forcing.  This was a major question at
the HIHOL meeting and we do not believe it was adequately resolved there.
Our vision is a summary paper that not only reproduces already-published
work, but that carefully quantifies the uncertainties inherent in each of
the reconstructions.  Of particular interest are the possible affects of
elevation change on the records, and uncertainties in the timescales.  We
cannot say a priori what the conclusions of this paper will be.  An example
might be that the "thermal maximum" was actually warmer than present - a
major issue of contention in the popular literature - and was more-or-less
simultaneous in both polar regions.  If this is correct, it will be a
useful service to the paleoclimate community to demonstrate it.
Alternatively, we may find after carefully looking at the data that we
CANNOT reach such a conclusion.  This would be an equally important result.
How should we proceed?  Our suggestion is that those who are willing to
participate send their favorite ice-core based temperature reconstructions
to us, providing the best available timescales and a brief description of
the uncertainties you ascribe to the reconstruction.  We will compile the
data and produce both 1) a single file containing all the data, and 2) a
PDF figure comparing all the independent temperature reconstructions.  We
can then intitiate discussion around a common figure, so that everyone is
looking at exactly the same information.  The last 11,000 years would be
considered the appropriate time interval to consider.  We do not wish to
confuse matters by including the glacial-interglacial transition!
Data sets that we think would be particularly important include the
following.  Note that we will probably need to include other authors.
This is just a preliminary list and is not intended to exclude anyone.
We are also aware that some of these data are so far unpublished but we
hope that they could be included anyway, perhaps in "smoothed" form (?).
1) Isotope profiles from Vostok, Byrd (and EPICA, if possible), on the
most-accepted timescales (Francoise).
2) Isotope profiles from Taylor Dome and Siple Dome, Dye 3 and GISP2 (Eric).
3) Isotope profile from Dome Fuji (Fujii)
3) Isotope profiles and borehole temperatures from Law Dome core(s) (Tas,
Vin).*
4) Isotope data from GRIP (and from N-GRIP if possible) (Dorthe)
4) Borehole data from Taylor Dome, GISP2, Dye 3 (Gary, Ed).*
5) Borehole data from GRIP (and N-GRIP if possible) (Dorethe)
6) Isotope, meltlayer frequency, and borehole T data from the Canadian ice
caps (David, Fritz)
7) Meltlayer data from other sites (GISP2 - Alley?)
*The Law and Taylor Dome records only go to mid Holocene but would still be
very useful here!
Other suggestions for data sets and people to contact?
Again, please reply to this email with your comments, criticisms concerns,
request for clarification and (hopefully) data sets!
Thanks!
Warm regards to all,
Eric Steig & Tas van Ommen


Valerie, Francoise et al.
We also were suprised by the "conclusion" that there was a 9-7 ka optimum.
This probably arose from a statement by Greg Zielinski regarding the Arctic
records.  In any case, the article by Dominique and Kieth was just a rough
draft -- we have pointed out the mistake to them and I expect we will all
see a final version anyway!
Regarding the subject of the HIHOL paper, we agree that there are already
many papers published that dicuss the temperature interpretation of
isotopic records during the Holocene.  What has not been done, however, is
to include the best Holocene records from both polar regions in a single
paper, nor to make a specific comparison of the timing and magnitude of the
optimum (or optima).  For example, the elevation effect on the long-term
trends for East Antartica has been discussed (Masson et al., 2000) but not
quantified.  Of course quantifying this effect is difficult but our paper
could put useful error estimates, for example, on the amount of cooling in
the late Holocene.  We do not of course wish to compete with Sigfus, but
his paper will be more limited in geographic focus than ours and will
include new data that we will not use.  It would be good to include NGRIP
borehole temperatures if we can, but this is not necessary.  Even the GRIP
and GISP2 records show very clearly the Holocene optimum.  Our suggestion
would be to let Dorethe decide on that, in consultation with Sigfus.
In our vision, one of the key features of the Holocene article will be its
deliberately limited scope and confinement to observation rather than
speculation about causes of climate change.  We think that to involve
modelers and oceanographers makes it difficult to keep the focus and is
rather beyond the intended purposes of the Holocene volume.  Keep in mind
that modelling was looked at separately at the HIHOL meeting and we believe
that the modelers at the meeting are planning their own contribution to the
volume.
As mentioned earlier, we think the best way to get the paper going is to
begin soon the process of simply collating data sets and putting them all
on one graph.  We can then discuss the details of the paper with the same
image in front of each of us.
We hope that you can agree more-or-less with the above, and that others on
our email list will also provide some input.  We are of course open to
further discussion!
Further comments?
Eric and Tas
At 12:07 PM 12/13/00 +0100, Valerie Masson-Delmotte wrote:
>
>Dear Eric and Tas, dear collegues,
>
>First, thank you for your initiative in motivating a comparison of ice
>isotope and borehole temperature records from both hemispheres from the
>Holocene. We think that it is important to position this work with respect
>to other related studies. There are in particular several papers already
>discussing the temperature interpretation of isotopic records during the
>Holocene (see below for Greenland; correcting the isotopic profiles in
>Antarctica from trends due to SST or ocean isotopic composition changes,
>based on the deuterium excess).
>
>As Dorthe will probably confirm, there is an ongoing work conducted by
>Sigfus Johnsen to be submitted to Journal of Quaternary Sciences next
>year, aiming at comparing all the Greenland Holocene temperature and
>isotopic profiles (including North GRIP).
>
>Therefore we think that it important to better define the scope of the
>HILOL possible paper (comparing north and south Holocene isotopic records
>and discussing the climate mechanisms involved) more than discussing the
>temperature imprint on water isotope records for instance.
>
>Second, we are still under the shock of the HILOL conclusions, mentionning
>a widespread Antarctic temperature optimum supposely seen in all ice cores
>between 9 and 7 ka BP! In our paper published in Quaternary Research in
>november 2000 (data presented by Francoise at HILOL), we had a careful
>comparison of 11 existing Holocene Antarctic isotopic records (but
>without Dome F, so without ice cores in the Atlantic sector). Although we
>had no control on the independent time scales of these ice cores, they are
>all precisely dated during the transition and there is no doubt from the
>simple view of the raw isotopic (deuterium or oxygen 18) data, that they
>all exhibit a clear optimum from 11.5 to 9 ka BP, followed by a relative
>minimum at around 8 ka BP. Now, the sites located around the Ross Sea show
>a mid Holocene optimum (8 to 6 ka BP), whereas in East Antarctica (apart
>from Dome C and Taylor Dome) a third "warm" interval can be seen later (6
>to 3 ka BP). This is why we were quite surprised to hear about an optimum
>between 9 and 7 ka BP in Antarctica.
>
>Last, if the HILOL possible paper is supposed to discuss the different
>timing of the major optima in the north and the south high latitudes,
>then it would greatly benefit from including climate modellers using
>intermediate complexity models (such as CLIMBER) and oceanographers (to
>discuss the possible role of changes in the north Atlantic circulation in
>the first half of the Holocene).
>
>In such a framework, we are obviously willing to participate in the
>climate mechanisms discussion and of course provide the isotopic data
>measured at LSCE (e.g. Dome B, Vostok, "old" Dome C and EPICA Dome C). For
>Byrd, you need to contact the Danish group.
>
>Sincerely,
>
>			Valerie and Francoise.
>
>_______________________________________________________________________
>Laboratoire des Sciences 		LSCE UMR CEA/CNRS 1572 Bat 709
>du Climat et de l'Environnement		L'Orme des Merisiers CEA Saclay
>Tel. (33) 1 69 08 77 15			91 191 Gif sur Yvette cedex
>Fax. (33) 1 69 08 77 16			France
>


Dear friends of the ECF,
Attached I send you:
- An executive summary of the ECF (to be revised anytime on the basis of
your suggestions),
- The current version of the ECF "Manifesto" (to be revised anytime on the
basis…),
- The minutes of the Amsterdam preparatory meeting of last November.
We do have an URL by now:
. We will
gradually develop it, please feel free to make suggestions. We also have an
internal section, see:
.
Her at PIK, Dr. Martin Welp will take care of ECF logistics for the time
being. His e-mail address is: Martin.Welp@pik-potsdam.de.
As for the Logo search, I like these things very much, although I am really
not knowledgeable at all. We might make a pre-selection and run a
competition on our web-site, inviting cyber-visitors to give their opinion
- we will still be free to choose what we like best. Perhaps rather than
looking for the single best Logo right now it is more fruitful to identify
which proposals find enough appreciation to become part of the web
competition.
And let us enjoy these more playful moments without neglecting the key
challenge we are faced with: Defining first joint projects and reaching
agreements with relevant stakeholders to actually carry them out.
As for the foundation technicalities, we are preparing a background
document that we will send out soon.
A final remark on e-mail etiquette: Could we put the string "ECF" in the
subject line of all e-mails dealing with ECF, in order to enable our
various browser to filter these pearls out of the ocean of e-mails we have
begun to live in?
Best regards,
Carlo Jaeger
and Martin Welp
Attachment Converted: "c:\eudora\attach\ECF executive summary.rtf"
Attachment Converted: "c:\eudora\attach\ECF_Jan_01.rtf"
Attachment Converted: "c:\eudora\attach\ECF minutes Amsterdam.rtf"


Dear Chick & all
> the first is Keith Briffa's rather comprehensive treatment of getting
> climate variations from tree rings:  Annual climate variability in
> the Holocene: "interpreting the message of ancient trees", Quaternary
> Science Reviews, 19 (2000) 87-105.  It should deal with many of the
> questions people raise about using them to determine temperatures.
Take this from first principles.
A tree only grows on land.  That excludes 70% of the earth covered by
water. A tree does no grow on ice. A tree does not grow in a desert.  A
tree does not grow on grassland-savannahs.  A tree does not grow in
alpine areas.  A tree does not grow in the tundra
We are left with perhaps 15% of the planet upon which forests
grow/grew.  That does not make any studies from tree rings global, or
even hemispheric.
The width and density of tree rings is dependent upon the following
variables which cannot be reliably separated from each other.
sunlight - if the sun varies, the ring will vary. But not at night of
course.
cloudiness - more clouds, less sun, less ring.
pests/disease - a caterpillar or locust plague will reduce
photosynthesis
access to sunlight - competition within a forest can disadvantage or
advantage some trees.
moisture/rainfall - a key variable. Trees do not prosper in a drought
even if there's a heat wave.
snow packing in spring around the base of the trees retards growth
temperature - finally!
The tree ring is a composite of all these variables, not merely of
temperature.  Therefore on the 15% of the planet covered by trees, their
rings do not and cannot accurately record temperature in isolation from
the other environmental variables.
In my article on Greening Earth Society on the Hockey Stick, I point to
other evidence which contradicts Mann's theory. The Idso's have produced
more of that evidence, and a new article on Greening Earth has
`unearthed' even more.
Mann's theory simply does not stack up. But that was not the key issue.
Anyone can put up a dud theory from time to time.  What is at issue is
the uncritical zeal with which the industry siezed on the theory before
its scientific value had been properly tested. In one go, they tossed
aside dozens of studies which confirmed the existence of the MWE and LIA
as global events, and all on the basis of tree rings - a proxy which has
all the deficiencies I have stated above.
The worst thing I can say about any paper such as his is that it is `bad
science'. Legal restraint prevents me going further.  But in his case,
only those restraints prevent me going *much* further.
Cheers
John Daly
--
John L. Daly
`Still Waiting For Greenhouse'

replies to:  daly@microtech.com.au
PLEASE NOTE:
WEBSITE URL HAS BEEN CHANGED TO
EMAIL ADDRESS HAS BEEN CHANGED TO  daly@microtech.com.au
BOOKMARKS AND ADDRESS ENTRIES, IF ANY, SHOULD BE AMENDED ACCORDINGLY.


Dear Phil,
Thanks for your response. I agree that I think these folks just don't quite
seem to get it! Anyways, I've pasted in the text of Broecker's piece below
(everything there but the figure. Trust me, the figure isn't worth looking
at anyways). Will be very interested to hear your thoughts after reading
this...
mike
PALEOCLIMATE:
Was the Medieval Warm Period Global?
Wallace S. Broecker*
The reconstruction of global temperatures during the last millennium can
provide important clues for how
climate may change in the future. A recent, widely cited reconstruction
(1) leaves the impression that the
20th century warming was unique during the last millennium. It shows no
hint of the Medieval Warm
Period (from around 800 to 1200 A.D.) during which the Vikings colonized
Greenland (2), suggesting
that this warm event was regional rather than global. It also remains
unclear why just at the dawn of the
Industrial Revolution and before the emission of substantial amounts of
anthropogenic greenhouse gases,
Earth's temperature began to rise steeply.
Was it a coincidence? I do not think so. Rather, I suspect that the
post-1860 natural warming was the
most recent in a series of similar warmings spaced at roughly 1500-year
intervals throughout the present
interglacial, the Holocene. Bond et al. have argued, on the basis of the
ratio of iron-stained to clean
grains in ice-rafted debris in North Atlantic sediments, that climatic
conditions have oscillated steadily
over the past 100,000 years (3), with an average period close to 1500
years. They also find evidence for
the Little Ice Age (from about 1350 to 1860) (3). I agree with the authors
that the swing from the
Medieval Warm Period to the Little Ice Age was the penultimate of these
oscillations and will try to
make the case that the Medieval Warm Period was global rather than regional.
One difficulty encountered when trying to reconstruct Holocene temperature
fluctuations is that they were probably less than 1°C. In my
estimation, at least for time scales greater than a century or two, only
two proxies can yield temperatures that are accurate to 0.5°C: the
reconstruction of temperatures from the elevation of mountain snowlines
and borehole thermometry. Tree ring records are useful for measuring
temperature fluctuations over short time periods but cannot pick up
long-term trends because there is no way to establish the long-term
evolution in ring thickness were temperatures to have remained constant.
Corals also are not accurate enough, especially because few records
extend back a thousand years. The accuracy of the temperature estimates
based on floral or faunal remains from lake and bog sediments is
likely no better than ±1.3°C (4) and hence not sufficiently sensitive for
Holocene thermometry.
The Mountain Glaciation Record
At the Last Glacial Maximum, mountain snowlines throughout the world were
on average about 900 m lower than today (5). On the basis of
today's rates of temperature change with elevation, this required an air
temperature cooling at the elevation of the glacier of about 5°C (and a
corresponding tropical sea surface temperature cooling of about 3°C).
During the Younger Dryas--a cold "spell" of about 1200 years during the
last deglaciation--snowlines in the Swiss and New Zealand Alps dropped to
about 300 m below the lowest levels reached in the subsequent
Holocene.
Since their 1860 maximum at the end of the Little Ice Age, the retreat of
Swiss glaciers represents a rise in snowline of about 90 m (6). If this
rise could be attributed entirely to air temperature, the required warming
would be between 0.5° and 0.6°C. However, simple considerations
suggest that precipitation changes result in a negative feedback of about
20% (7). The warming required to account for the post-1860 retreat of
Alpine snowlines would then be between 0.6° and 0.7°C.
The post-1860 glacier retreat is not confined to Switzerland. With the
exception of Antarctica, it has been well documented everywhere on
Earth where ice-covered mountains are present (2). There is no doubt that
the Little Ice Age was global in extent and that the post-1860
warming was also global. In this regard, the Mann et al. (1)
reconstruction is consistent with the mountain snowline record.
The Medieval Warm Period has also left its traces in the Swiss Alps.
Holzhauser has reconstructed the history of a larchwood aqueduct
constructed by medieval farmers (8). It ran from a small mountain lake
along the valley occupied by the Grosser Aletsch Glacier, supplying
water to an Alpine village. The aqueduct was first constructed around 1200
A.D. (toward the end of the Medieval Warm Period). It was
partially destroyed when the glacier advanced in 1240 A.D. and had to be
totally rerouted after a further advance in 1370 A.D.
Swiss geologists and geomorphologists agree that the large moraines
marking the maximum glacier extent during the Little Ice Age are a
composite of debris left behind by a series of Holocene advances (9). For
example, soils separating individual advance episodes have been
found within the moraines. Precise dating has proven difficult, however,
and the chronology of these prior advances remains uncertain.
Two recent studies of Holocene climate cycles in the Swiss Alps have
greatly improved this situation. Both focus on establishing the times of
glacial retreats rather than advances. Holzhauser (8), on the basis of
radiocarbon dating of larchwood stumps exposed by the ongoing retreat of
the Grosser Aletsch Glacier, finds warm episodes 2400 ± 300 and 1500 ± 200
calendar years ago. Hormes and Schlüchter (10-12) have dated
wood and peat fragments that are being disgorged from beneath a number of
Swiss glaciers. Radiocarbon dates of a large number of these
samples cluster in three major groups centered at 8700, 6600, and 4300
calendar years before present. The correlation between these Alpine
warm phases and the warm phases of Bond's North Atlantic ice-rafting
record, although imperfect, is encouraging (see the figure).
Climatic oscillations during the Holocene. Circles show the ratios of
iron-stained to total grains (for grains with diameters >63 mm) in a
North Atlantic core (3). The chronology is taken from (22). The green
(10-12) and yellow (8) boxes are based on radiocarbon dating on wood
and peat formed when the glaciers had retreated to positions similar to or
up-valley from those at present (see text).
CREDIT: FIGURE PREPARED BY AUTHOR FOR THIS PUBLICATION
Borehole Thermometry
Geothermal heat is produced deep inside Earth, and the shape of the
vertical temperature profile measured in a borehole from any point on
Earth's surface thus reflects the depth dependence of the thermal
conductivity of the crustal material. The temperature at the surface does not
remain constant, however, and the thermal profiles therefore have kinks
that reflect past air temperature fluctuations. Mathematical
deconvolutions are used to reconstruct these fluctuations from the
temperature profile, but because of smoothing due to diffusive spreading of
past thermal anomalies, many different time histories fit the observed
downhole temperature record. The modeler selects from these
possibilities the temperature history with the least complicated shape.
The details are thus lost, and only the broad features of the time history
are captured.
Deconvolutions of thermal records from holes drilled through the polar ice
caps reveal broad maxima that reflect the colder temperatures during
glacial times. In Greenland boreholes, this broad glacial feature is
preceded by a narrower one, which requires a temperature oscillation to have
occurred in the late Holocene. The timing of this swing broadly matches
that of the Medieval Warm Period to Little Ice Age oscillation. Its
magnitude is about 2°C (13). The borehole temperature record for Greenland
thus appears to reflect the climate changes thought to have led to
the establishment and eventual abandonment of the Viking colonies in
southern Greenland (2). It is also consistent with records in the Swiss
Alps.
Far Field Evidence
Evidence for the Medieval Warm Period from other parts of the world exists
but is spotty and/or circumstantial. From an analysis of 6000
continental borehole thermal records from around the world (14), Huang et
al. conclude that 500 to 1000 years ago, temperatures were warmer
than today, but that about 200 years ago, they cooled to a minimum some
0.2° to 0.7°C below present. However, as is the case for the thermal
profiles in ice, those for continental boreholes are highly smoothed.
Although suggestive, the fluctuation postulated by Huang et al. does not
prove that the Medieval Warm Period was global in extent.
Evidence that climate during the latter part of the Medieval Warm Period
was much different from today's comes from moisture records for
the western United States. Stine has studied lodgepole pine trees rooted
at 8 to 19 m depth in Lake Tenaya in the high Sierra Nevada (15). For
the trees to have grown, the lake must have been nearly dry. In contrast,
only once during the past 50 years has the lake not overflown during
snowmelt. Using radiocarbon dating and ring counting, Stine has shown that
for 70 years before 1093 A.D., the lake stood at least 13 m below
its outflow spillway, and for 141 years before 1333 A.D., it stood at
least 11 m below its spillway (16). Stine has documented similar events at
Mono Lake and the Walker River (17). He concludes that late in the
Medieval Warm Period, California experienced several decade-long
periods of profound drought.
If, as Bond et al. (3) suggest, the cyclic changes in ice-rafted debris
composition reflect oscillations in the strength of the Atlantic's conveyor
circulation, one might expect temperature changes in Antarctica to have
been opposite in phase to those in the North Atlantic, as was the case
during the last deglaciation (18). Clow has carried out a deconvolution of
the temperature record at the Antarctic Taylor Dome site (19). His
reconstruction shows that the air temperature was 3°C colder during the
time of the Medieval Warm Period than during that of the Little Ice
Age. This record suggests that conditions in Antarctica underwent an
antiphased oscillation during the Medieval Warm Period-Little Ice Age
period.
The Case for a Global Event
The case for a global Medieval Warm Period admittedly remains
inconclusive. But keeping in mind that most proxies do not have adequate
sensitivity, it is interesting that those capable of resolving temperature
changes of less than 1°C yield results consistent with a global Medieval
Warm Period. To test whether this is indeed the case, we require Holocene
snowline fluctuation records for tropical and Southern Hemisphere
sites and continued studies of wood and peat exposed by the continuing
retreat of Northern Hemisphere glaciers. As the world's mountain
glaciers continue to retreat, ever more evidence for past Holocene warm
episodes will be exposed.
One might ask why the strength of the Atlantic's conveyor circulation
oscillates on a time scale of one cycle per 1000 to 2000 years. I suspect
that it has to do with the export through the atmosphere of water vapor
from the Atlantic to the Pacific Ocean. The magnitude of this export
has been estimated to be (0.25 ± 0.10) x 106 m3/s (20). If this freshwater
loss were not balanced by the export of salt from the Atlantic, the
latter's salt content would rise at the rate of about one gram per liter
each 1500 years. Such an increase in salt content would densify cold
surface water by an amount equivalent to a 4 to 5 K cooling, thereby
strongly altering the buoyancy of surface waters in the North Atlantic and
hence their ability to sink to the abyss.
I believe that this salt export is not continuous but episodic. The salt
content of the Atlantic periodically builds up until a strong conveyor
circulation mode is turned on, causing the salt content to drain down.
Eventually, a weak circulation mode kicks in, allowing the salt content to
build up again. I have suggested previously (21) that an apparent mismatch
between radiocarbon and chlorofluorocarbon-based estimates of the
rate of deep-water formation in the Southern Ocean may reflect a change in
circulation after the Little Ice Age.
The geographic pattern of Holocene climate fluctuations remains murky, but
several things are clear. The Little Ice Age and the subsequent
warming were global in extent. Several Holocene fluctuations in snowline,
comparable in magnitude to that of the post-Little Ice Age warming,
occurred in the Swiss Alps. Borehole records both in polar ice and in
wells from all continents suggest the existence of a Medieval Warm
Period. Finally, two multidecade-duration droughts plagued the western
United States during the latter part of the Medieval Warm Period. I
consider this evidence sufficiently convincing to merit an intensification
of studies aimed at elucidating Holocene climate fluctuations, upon
which the warming due to greenhouse gases is superimposed.
References and Notes
1.M. E. Mann, R. S. Bradley, M. K. Hughes, Geophys. Res. Lett. 26, 759
(1999) [ADS].
2.J. M. Grove, The Little Ice Age (Methuen, New York, 1988), pp. 1-198.
3.G. C. Bond et al., Mechanisms of Global Climate Change at Millennial
Time Scales, Geophysical Monograph Series, vol. 112
(American Geophysical Union, Washington, DC, 1999), pp. 35-58
[publisher's information].
4.A. Lotter et al., Palaeogeogr. Palaeoclimatol. Palaeoecol. 159, 349
(2000) [GEOREF].
5.S. C. Porter, Quat. Sci. Rev., in press.
6.M. Maisch et al., Die Gletscher der Schweizer Alpen (Hochschulverlag
AG an der ETH Zürich, Zürich, 1999), pp. 221-256.
7.M. Greene, W. S. Broecker, D. Rind, Geophys. Res. Lett. 26, 1909
(1999) [ADS].
8.H. Holzhauser, in Paläoklimaforschung Palaeoclimate Research 24,
Special Issue: ESF Project "European Palaeoclimate and Man
16," B. Frenzel et al., Eds. (Verlag, Stuttgart, 1997), pp. 35-58.
9.F. Rothlisberger et al., Geogr. Helv. 35/5, 21 (1980).
10.A. Hormes, The 14C Perspective of Glacier Recessions in the Swiss
Alps and New Zealand (Verlag, Osnabrück, Germany, 2001),
p. 176.
11.A. Hormes, C. Schlüchter, T. F. Stocker, Radicarbon 40, 809 (1998).
12.A. Hormes, B. U. Müller, C. Schlüchter, Holocene, in press.
13.E. J. Steig et al., Science 282, 92 (1998).
14.S. Huang, H. N. Pollack, P. O. Snen, Geophys. Res. Lett. 24, 1947
(1997) [ADS].
15.S. Stine, in Water, Environment and Society in Times of Climatic
Change, A. S. Issar, N. Brown, Eds. (Kluwer Academic,
Amsterdam, Netherlands, 1998), pp. 43-67 [publisher's information].
16.The level that would have existed had there been an annual
snowmelt-induced overflow.
17.S. Stine, Nature 369, 546 (1994) [GEOREF].
18.W. S. Broecker, Paleoceanography 13, 119 (1998) [ADS].
19.G. Clow, personal communication.
20.F. Zaucker, W. S. Broecker, J. Geophys. Res. 97, 2765 (1992) [ADS].
21.W. S. Broecker, S. Sutherland, T.-H. Peng, Science 286, 1132 (1999).
22.M. Stuiver et al., Radiocarbon 40, 1041 (1998).
The author is at Lamont-Doherty Earth Observatory, Columbia University,
Palisades, NY 10964, USA. E-mail: broecker@ldeo.columbia.edu
At 12:04 PM 2/26/01 +0000, Phil Jones wrote:
>
>  Dear All,
>       I was away over the weekend at Bowdoin College in Maine, giving a
>talk about the
>  last 1000 years. There were three others as well on other paleo aspects,
>Richard Alley,
>  Gary Clow and Wally Broecker !  The latter briefly mentioned to me that
>he had had
>  something in last Friday's Science, which was getting at the Mann et al.
>series. He
>  didn't have a copy so we've not seen it here yet.  I tried to get a copy
>of Science on
>  the bookstand at Logan airport last night - I guess it's not sold that
way !
>      Wally was going on about this 1500 yr cycle of Bond's, which seemed
>pretty flimsy.
>  I was showing all the various series in a general talk - and I used some
>of the overheads
>  from the upcoming Science paper. This is due to appear in the issue for
>the last week
>  of April. It is all accepted now.  I will forward if you'll all abide by
>the Science rules. Both
>  Wally and Alley seem convinced that the climate of Greenland changed by
>10 C in
>  the space of 2-3 years at times in the past (Y Dryas etc).  I had long
>talks with both
>  and they don't seem to have got their heads around spatial scales (local
>changes
>  and hemispheric). Also they don't seem to realise where we are coming
>from.  He
>  has a downer on trees (believes all the multiproxy series depend
>exclusively on
>  trees) but he thinks Ed Cook is a great scientist. The latter is true,
>but he might
>  just think that because he's at Lamont. I did tell him that Keith's paper
>on the age
>  banding is out in JGR. I should send him a reprint and maybe ask that great
>  scientist to go and explain it to him ! Ed's in NZ at the moment. Also
>Wally believes
>  much more in glacier advances/retreats. I'll get Keith to send him
>Sarah's paper
>  where the long Tornetrask reconstruction is shown to agree with
Storglaciaren
>  advance/retreat dates from moraine evidence. Also Sarah's been working on
>similar
>  glaciers in the Swiss Alps with long tree-ring reconstructions.  One
>interesting
>  thing was he didn't seem to realise that a lot of the tree-ring
>reconstructions use
>  density. Seemed to think they were all ring widths and there had to be
>moisture
>  changes we were not accounting for.
>        It is easy to respond to a Perspectives piece. Some of you did it
>with respect to
>  one of mine. I'm not sure it will achieve much - it won't come out before
>the paper
>  in the last week of April.  I need to wait to se what he says. Our paper
>(me, Tim and
>  Keith) clearly says that the MWP couldn't have been warmer (for the NH
>average)
>  than the late 20th century.
>       Another possible reason for not doing anything is that the IPCC
>report will be out
>  soon. The summary is written in pretty clear language.
>      The above is my first thoughts, not having read the piece and just
>got off the
>  flight back.
>
>      Best to ignore Woijcek. All he seems to want to do is deflect us into
>responding.
>
>  Cheers
>  Phil
>
>
>
>At 11:47 25/02/01 -0700, mhughes@ltrr.arizona.edu wrote:
>>Dear all,
>>WHat mechanism does "Science" have for repsonding to Perspective pieces?
Most
>>of the answer to Wally is contained within his own piece - he comments on
the
>>ambiguity of the record, which, in various ways, we have all done. What he
>>doesn't offer, however, is anything other than an anecdotal alternative. As
>>always, he seeks to damn ( in this case with faint praise) the records or
>>work
>>that don't serve his purpose , and to elevate any scrap of evidence that
does
>>serve it. I think it will be important for us to stick closely to what we
>>have
>>written in published papers. CHeers, MAlcolm
>>
>>Quoting "Michael E. Mann"
:
>>
>> > Dear Phil, Ray,
>> >
>> > What do you guys think. If we're all on board, than an appropriately
>> > toned,
>> > "high road" response here might be appropriate. We don't want to engage
>> > Wally in a personal battle, but simply should correct the record where
>> > Wally has muddied it. Again, Phil et al do have a Science article in
>> > press
>> > that serves this purpose to some extent, so I'm especially interested in
>> > what
>> > Phil thinks (Phil?)...
>> >
>> > mike
>> >
>> > At 02:52 PM 2/24/01 -0700, mhughes@ltrr.arizona.edu wrote:
>> > >Dear Mike et al., I think we should definitely let Wojick stew in his
>> > own
>> > >juice - as Mike pointed out to me the other day he, and his like, have
>> > a
>> > >specific agenda, and anything we write will be pressed into the service
>> > of
>> > that
>> > >agenda. I'm not so sure about Wally. I share Tom's disinclination to
>> > get
>> > into a
>> > >street fight with Wally - generally I take the view that life's too
>> > short and
>> > >uncertain for such activities. On the other hand, would we let such a
>> > shoddy
>> > >piece of work(and editing) go by if it were from another author? There
>> > are so
>> > >many holes in Wally's argument, and such a selective choice of evidence
>> > that it
>> > >should beggar belief. One of the more obvious holes is that he writes
>> > of the
>> > >Great Basin droughts of the 10th through 14th centuries as proof of
>> > warmer
>> > >conditions then, but doesn't explain why we don't have such conditions
>> > now.
>> > >Interestingly, Larry Benson, Dave Meko and others have good evidence
>> > that
>> > these
>> > >same multidecadal periods were marked by a great excess of
>> > precipitation
>> > just a
>> > >few hundred miles north in northern Nevada and California and southern
>> > Oregon.
>> > >He just hasn't grasped that the methods that are appropriate for
>> > tracking the
>> > >consequences of major changes in boundary conditions don't work in the
>> > late
>> > >Holocene. I've been trying to figure out the issue of "Was there a
>> > Medieval
>> > >Warm Period, and if so where and when" for a decade or so, and still
>> > have the
>> > >impression that the records for the 9th through 14th centuries are
>> > extremely
>> > >mixed. But then, I didn't come to the investigation with a certain
>> > knowledge of
>> > >the absolute truth, and have had to 'misfortune' to work with people
>> > who let
>> > >careful analysis get in the way - Henry Diaz, Ray and Mike, and others.
>> >
>> > >Anyway, the point of this rant is that I think we should give careful
>> > >consideration to making a measured response to Wally. Cheers, Malcolm
>> > >
>> > >
>> > >
>> > >
>> > >Quoting "Michael E. Mann"
:
>> > >
>> > >> Hi Tom,
>> > >>
>> > >> Thanks for your quick reply. I agree with you entirely. I think its
>> > very
>> > >> unfortunate he's chosen to disinform the community rather than engage
>> > in
>> > >> a
>> > >> constructive dialogue (we tried the latter w/ him in a series of
>> > emails
>> > >> last
>> > >> year, but clearly to no avail).
>> > >>
>> > >> On the other hand, think that a war of words w/ Broecker would be
>> > >> exploited
>> > >> by the skeptics, and perhaps we should just try to let this thing
>> > die...
>> > >>
>> > >> I'm not sure. I'd appreciate knowing what others think?
>> > >>
>> > >> mike
>> > >>
>> > >> At 10:25 AM 2/24/01 -0600, tom crowley wrote:
>> > >> >Mike,
>> > >> >
>> > >> >I was not aware of the Broecker piece - I am dismayed but not
>> > >> surprised.  I
>> > >> >do not know what to do - I personally cannot stand the combative
>> > >> personal
>> > >> >approach Broecker relishes but it does seem as if some rebuttal is
>> > >> called
>> > >> >for.  Maybe you Ray Phil I and Malcolm could pen a response - we are
>> > >> >heading to Germany in a week, for a month, so I am not sure how much
>> > I
>> > >> can
>> > >> >keep up on this but it seems as if some response is called for.
>> > >> >
>> > >> >What think ye?
>> > >> >
>> > >> >Tom
>> > >> >
>> > >> >
>> > >> >>Dear Mike,
>> > >> >>
>> > >> >>Thanks for passing this along.
>> > >> >>
>> > >> >>Wojick of course completely misrepresents Broecker, and puts his
>> > >> >>conventional intellectually dishonest spin on this.
>> > >> >>
>> > >> >>That having been said, it is a bit disappointing that Wally
>> > continues
>> > >> to
>> > >> >>cling to some of his flawed beliefs which aren't supported from
>> > either
>> > >> our
>> > >> >>best current understanding of the observations or of the results of
>> > >> careful
>> > >> >>modeling experiments. My own perception is that the climate
>> > community,
>> > >> >>modelers as well as observationalists, simply don't take seriously
>> > >> anymore
>> > >> >>the idea that the history of climate change over the past 1000
>> > years
>> > >> is
>> > >> >>part of an internal oscillation. The sediment core evidence oft
>> > cited
>> > >> by
>> > >> >>Broecker (e.g. Bond et al) for this is tremendously weak, and I, as
>> > >> well as
>> > >> >>the vast majority of my colleagues, simply don't buy it for even a
>> > >> second.
>> > >> >>But people don't like to challenge Broecker publically. He can and
>> > >> will
>> > >> >>play hardball.
>> > >> >>
>> > >> >>There is an odd irony. Broecker refused to accept the modeling
>> > >> evidence
>> > >> >>that the 100 kyr ice age Pleistocene variations were part of an
>> > >> internal
>> > >> >>oscillation paced by insolation variations, favoring instead the
>> > >> >>discredited notion that they were a direct response to (too weak)
>> > >> >>eccentricity forcing, until the evidence became insurmountable
>> > (from
>> > >> my
>> > >> >>adviser, Barry Saltzman, may he rest in piece, and people like Dick
>> > >> >>Peltier). Ironically, Broecker then took credit for the very
>> > >> proposition he
>> > >> >>had fought w/ tooth and nail.
>> > >> >>
>> > >> >>Broecker is even more wrong, and unfortunately equally stubborn, in
>> > >> this case.
>> > >> >>And, again, the reason: because his pet theory, that climate
>> > >> variability is
>> > >> >>a simple millennial oscillation, is finally being challenged w/
>> > hard
>> > >> data
>> > >> >>and hard facts.
>> > >> >>
>> > >> >>Broecker misrepresents the nature of that data that we and others
>> > have
>> > >> >>used, and misunderstands the source of the muted hemispheric trends
>> > >> (there
>> > >> >>*is* a hemispheric "medieval warm period" and "little ice age",
>> > just
>> > >> not of
>> > >> >>the magnitude or the distinctiveness that Broecker imagines).
>> > >> Individual
>> > >> >>regions in our reconstructions, and Phils, and others, vary by
>> > several
>> > >> >>degrees C, ie, the proxies we use have no problem whatsoever in
>> > >> resolving
>> > >> >>high-amplitude temperature variations in the past. The problem is
>> > that
>> > >> when
>> > >> >>we look at  the different regions we find that periods of cold and
>> > >> warm
>> > >> >>often occur at very different times in different regions, and so in
>> > a
>> > >> >>hemispheric or global average, a lot of purely regional variability
>> > >> cancels
>> > >> >>out. The resulting trends are somewhat smaller. I remained
>> > befuddled
>> > >> as to
>> > >> >>why Wally doesn't understand this point. Its been explained to him
>> > >> time and
>> > >> >>time again. Maybe he's just not listening, or doesn't want to
>> > >> listen...
>> > >> >>
>> > >> >>In fact, Tom Crowley has clearly shown that the observed millennial
>> > >> >>temperature reconstruction is precisely consistent w/ our
>> > >> understanding of
>> > >> >>*forced* climate change over the past 1000 years (solar changes,
>> > >> volcancic
>> > >> >>output, and recent greenhouse gas concentrations). There is, simply
>> > >> put, no
>> > >> >>room for a global millennial internal oscillation. Regionally, such
>> > >> types
>> > >> >>of climate phenomena, associated for example with changes in the
>> > North
>> > >> >>Atlantic ocean circulation, are supported by the observations. This
>> > >> >>explains why, for example, European temperature variations are
>> > >> somewhat
>> > >> >>larger than those in other regions not effected so strongly by such
>> > >> climate
>> > >> >>processes.
>> > >> >>
>> > >> >>Other recent perspectives, by Ray Bradley and myself provide a far
>> > >> more
>> > >> >>balanced and nuanced (and less dogmatic or defensive) viewpoint.
>> > I'm
>> > >> not
>> > >> >>sure a written response to Broecker is worthwhile (this is,
>> > afterall,
>> > >> a
>> > >> >>"perspective" and everyone understands that a scientist may have a
>> > >> flawed
>> > >> >>perspective). If Wally wants this to be his legacy, so be it...
>> > >> >>
>> > >> >>Phil and others have a review article coming out in the near future
>> > >> which
>> > >> >>also provides a much more balanced perspective on the climate
>> > changes
>> > >> of
>> > >> >>the past millennium, and will set the record straight once again
>> > (good
>> > >> >>timing Phil!). Science's embargo policy prevents me from saying
>> > much
>> > >> more
>> > >> >>at this time, but if Phil or anyone else wishes to comment further,
>> > >> I'd
>> > >> >>encourage it.
>> > >> >>
>> > >> >>Well, I've still got some snow to shovel here in Charlottesville!
>> > >> Happy
>> > >> >>weekend to all,
>> > >> >>
>> > >> >>mike
>> > >> >>
>> > >> >>p.s. For those with electronic subscriptions, Broecker's latest
>> > piece
>> > >> can
>> > >> >>be found here:
>> > >> >>
>> > >> >> PALEOCLIMATE:
>> > >> >>        Was the Medieval Warm Period Global?
>> > >> >>        Wallace S. Broecker
>> > >> >>        Science Feb 23 2001: 1497-1499. [Summary] [Full Text]
>> > >> >>
>> > >> >>
>> > >> >>
>> > >> >>While my previous perspective piece is here:
>> > >> >>   CLIMATE CHANGE:
>> > >> >>   Lessons for a New Millennium
>> > >> >>   Michael E. Mann
>> > >> >>   Science 2000 July 14; 289: 253-254. (in Perspectives) [Summary]
>> > >> [Full
>> > >> >>Text]
>> > >> >>URL:
>> > >>
>> > >>
>> S=10&h
>> > >>
>> > >>its=10&RESULTFORMAT=&author1=Mann&searchid=QID_NOT_SET&stored_search=&
>> FIRSTI
>> > >> >>NDEX=&fdate=10/1/1995&tdate=2/28/2001
>> > >> >>
>> > >> >>and Bradley's is here:
>> > >> >>
>> > >> >>   PALEOCLIMATE: Enhanced: 1000 Years of Climate Change
>> > >> >>   Ray Bradley
>> > >> >>   Science 2000 May 26; 288: 1353-1355. (in Perspectives) [Summary]
>> > >> [Full
>> > >> >>Text]
>> > >> >>
>> > >> >>URL:
>> > >>
>> > >>
>> TS=10&
>> > >>
>> > >>hits=10&RESULTFORMAT=&author1=Bradley&searchid=QID_NOT_SET&stored_sear
>> ch=&FI
>> > >> >>RSTINDEX=&fdate=10/1/1995&tdate=2/28/2001
>> > >> >>
>> > >> >>>Dear Michael--The third point below has comments on the
>> > controversy
>> > >> >>>betweenyou and Broecker--I'd be interested in your response (did
>> > >> Wally not
>> > >> >>>just understand what your data show?).
>> > >> >>>
>> > >> >>>Mike
>> > >> >>>
>> > >> >>>Three Wojick Pieces on Climate Change.
>> > >> >>>I've been busy busy.
>> > >> >>>
>> > >> >>>David
>> > >> >>>
>> > >> >>>FIRST, the latest issue of Insight Magazine includes a
>> > >> point-counterpoint
>> > >> >>>between measly old me and the great Robert Watson. Boy has he got
>> > >> >>>credentials! Too bad he's wrong.
>> > >> >>>
>> > >> >>>
>> > >> >>>
>> > >> >>>Symposium: Do scientists have compelling evidence of global
>> > warming?
>> > >> >>>
>> > >> >>>Yes: Rising sea levels worldwide and retreating Arctic glaciers
>> > are
>> > >> ominous
>> > >> >>>signs.
>> > >> >>>
>> > >> >>>By Robert T. Watson -- chairman of the UN Intergovernmental Panel
>> > on
>> > >> >>>Climate Change, chief scientist at the World Bank and former chief
>> > >> science
>> > >> >>>advisor to the Clinton White House.
>> > >> >>>
>> > >> >>>No: Despite the overheated rhetoric, there is no new evidence of
>> > >> warming
>> > >> >>>
>> > >> >>>By David E. Wojick -- covers climate policy for Electricity Daily
>> > and
>> > >> is a
>> > >> >>>science adviser to the Greening Earth Society
>> > >> >>>
, as well as Undereditor of
>> > the
>> > >> >>>Washington Pest
>> > >> >>>
>> > >> >>>SECOND, the February 15 Eco-logic on-line has published "The Black
>> > >> Hole of
>> > >> >>>Global Climate Government" by David Wojick, my detailed attack on
>> > the
>> > >> >>>Framework Convention on Climate Change. It includes a lot of the
>> > >> actual
>> > >> >>>treaty language.
>> > >> >>>
>> > >> >>>
>> > >> >>>
>> > >> >>>THIRD, here is a draft Electricity Daily article of mine. Seems
>> > I'm
>> > >> not the
>> > >> >>>only one who thinks the IPCC is nuts.
>> > >> >>>
>> > >> >>>Climate Guru Kicks The Hockey Stick
>> > >> >>>by David Wojick (dwojick@shentel.net)
>> > >> >>>
>> > >> >>>Global warming is natural and the recent warming is probably no
>> > >> exception.
>> > >> >>>This is the controversial argument made by prominent climatologist
>> > >> Wallace
>> > >> >>>S. Broecker in today's issue of Science.
>> > >> >>>
>> > >> >>>Broecker's bombshell bears the seemingly innocent title "Was the
>> > >> Medieval
>> > >> >>>Warm Period Global?" It may seem esoteric, but whether the
>> > apparent
>> > >> warmth
>> > >> >>>reported in Europe about 1000 years ago was global or simply local
>> > is
>> > >> >>>becoming a central issue in climate science. What makes it
>> > >> contentious is
>> > >> >>>the recent claims by the United Nations Intergovernmental Panel on
>> > >> Climate
>> > >> >>>Change that the earth is warmer now than it has been for
>> > millennia,
>> > >> and
>> > >> >>>that therefore human carbon dioxide emissions are to blame.
>> > Broecker,
>> > >> a
>> > >> >>>leading figure at Lamont-Doherty Earth Observatory, Columbia
>> > >> University,
>> > >> >>>questions both IPCC claims.
>> > >> >>>
>> > >> >>>The focus of the debate is a 1000-year temperature reconstruction
>> > >> known in
>> > >> >>>climate circles as the "hockey stick". Produced in 1999 by M. E.
>> > >> Mann, R.
>> > >> >>>S. Bradley, M. K. Hughes, the long handle of the hockey stick
>> > shows
>> > >> global
>> > >> >>>temperatures for the first 8 centuries as basically unchanging,
>> > >> followed by
>> > >> >>>the sharply up-tilting blade of the last 150 years or so. The Mann
>> > et
>> > >> al
>> > >> >>>hockey stick is the central feature of the recently released IPCC
>> > >> working
>> > >> >>>group one Summary for Policy makers, which claims to embody the
>> > best
>> > >> of
>> > >> >>>climate science.
>> > >> >>>
>> > >> >>>Broecker does not like the hockey stick, nor the conclusions the
>> > IPCC
>> > >> draws
>> > >> >>>from it. He says " A recent, widely cited reconstruction (Mann's)
>> > >> leaves
>> > >> >>>the impression that the 20th century warming was unique during the
>> > >> last
>> > >> >>>millennium. It shows no hint of the Medieval Warm Period (from
>> > around
>> > >> 800
>> > >> >>>to 1200 A.D.) during which the Vikings colonized Greenland,
>> > >> suggesting that
>> > >> >>>this warm event was regional rather than global. It also remains
>> > >> unclear
>> > >> >>>why just at the dawn of the Industrial Revolution and before the
>> > >> emission
>> > >> >>>of substantial amounts of anthropogenic greenhouse gases, Earth's
>> > >> >>>temperature began to rise steeply. Was it a coincidence? I do not
>> > >> think so.
>> > >> >>>Rather, I suspect that the post-1860 natural warming was the most
>> > >> recent in
>> > >> >>>a series of similar warmings spaced at roughly 1500-year intervals
>> > >> >>>throughout the present inter-glacial, the Holocene."
>> > >> >>>
>> > >> >>>Broecker presents the evidence for a global Medieval Warm Period,
>> > as
>> > >> well
>> > >> >>>as for a Little Ice Age from around 1300 to 1860, when the present
>> > >> >>>temperature rise begins. He also argues that the "proxy" evidence
>> > >> used by
>> > >> >>>Mann et al, such as tree ring data, is ill suited to the time
>> > period
>> > >> and
>> > >> >>>temperature variation -- less than one degree C -- in question.
>> > >> >>>
>> > >> >>>As he puts it, "In my estimation, at least for time scales greater
>> > >> than a
>> > >> >>>century or two, only two proxies can yield temperatures that are
>> > >> accurate
>> > >> >>>to 0.5 C: the reconstruction of temperatures from the elevation of
>> > >> mountain
>> > >> >>>snowlines and borehole thermometry. Tree ring records are useful
>> > for
>> > >> >>>measuring temperature fluctuations over short time periods but
>> > cannot
>> > >> pick
>> > >> >>>up long-term trends because there is no way to establish the
>> > >> long-term
>> > >> >>>evolution in ring thickness were temperatures to have remained
>> > >> constant."
>> > >> >>>
>> > >> >>>Broecker acknowledges that the proxy evidence is necessarily
>> > somewhat
>> > >> >>>"murky", but his conclusion is that "climatic conditions have
>> > >> oscillated
>> > >> >>>steadily over the past 100,000 years, with an average period close
>> > to
>> > >> 1500
>> > >> >>>years... The swing from the Medieval Warm Period to the Little Ice
>> > >> Age was
>> > >> >>>the penultimate of these oscillations." The implication being that
>> > >> some, if
>> > >> >>>not all, of the present warming is the natural swing out of the
>> > >> Little Ice
>> > >> >>>Age, and that Mann et al, as well as the IPCC, are mistaken.
>> > >> >>>
>> > >> >>>
>> > >> >>>--
>> > >> >>>
>> > >> >>>
>> > >> >>>Dr. David E. Wojick
>> > >> >>>President
>> > >> >>>Climatechangedebate.org
>> > >> >>>Subscribe to the free debate listserv at
>> > >>
>> > >> >>>Non subscribers can follow the debate at
>> > >> >>>
>> > >> >>>
>> > >> >>>
>> > >> >>>
>> > >> >>>
>> > >>
>> > >>_______________________________________________________________________
>> > >> >>                     Professor Michael E. Mann
>> > >> >>          Department of Environmental Sciences, Clark Hall
>> > >> >>                      University of Virginia
>> > >> >>                     Charlottesville, VA 22903
>> > >>
>> > >>_______________________________________________________________________
>> > >> >>e-mail: mann@virginia.edu   Phone: (804) 924-7770   FAX: (804)
>> > >> 982-2137
>> > >> >>
>> > >> >
>> > >> >
>> > >> >
>> > >> >
>> > >> >Thomas J.  Crowley
>> > >> >Dept. of Oceanography
>> > >> >Texas A&M University
>> > >> >College Station, TX  77843-3146
>> > >> >979-845-0795
>> > >> >979-847-8879 (fax)
>> > >> >979-845-6331 (alternate fax)
>> > >> >
>> > >> >
>> > >> >
>> > >> >
>> > >>
>> > _______________________________________________________________________
>> > >>                     Professor Michael E. Mann
>> > >>            Department of Environmental Sciences, Clark Hall
>> > >>                       University of Virginia
>> > >>                      Charlottesville, VA 22903
>> > >>
>> > _______________________________________________________________________
>> > >> e-mail: mann@virginia.edu   Phone: (804) 924-7770   FAX: (804)
>> > 982-2137
>> > >>
>> >
>> > >>
>> > >>
>> > >>
>> > >
>> > >
>> > >
>> > >
>> > >
>> > >
>> > _______________________________________________________________________
>> >                     Professor Michael E. Mann
>> >            Department of Environmental Sciences, Clark Hall
>> >                       University of Virginia
>> >                      Charlottesville, VA 22903
>> > _______________________________________________________________________
>> > e-mail: mann@virginia.edu   Phone: (804) 924-7770   FAX: (804) 982-2137
>> >
>> >
>> >
>> >
>
>Prof. Phil Jones
>Climatic Research Unit        Telephone +44 (0) 1603 592090
>School of Environmental Sciences    Fax +44 (0) 1603 507784
>University of East Anglia
>Norwich                          Email    p.jones@uea.ac.uk
>NR4 7TJ
>UK
>---------------------------------------------------------------------------
-
>
>
>
_______________________________________________________________________
Professor Michael E. Mann
Department of Environmental Sciences, Clark Hall
University of Virginia
Charlottesville, VA 22903
_______________________________________________________________________
e-mail: mann@virginia.edu   Phone: (804) 924-7770   FAX: (804) 982-2137


Mike,
you are really the most appropriate person to be the lead author on this -
I was just volunteering myself as the unfortunate soul who has to bear the
brunt of Wallys wrath
Tom
ps  Peck would be fine of course but I don't know whether we want to get
him tangled up in the acrimony - we could of course ask for his comments
beforehand
>HI Tom,
>
>Thanks--I was thinking this too. Ray held out a real olive branch to Wally
>by the extremely balanced piece he wrote in Science last year (some of us
>thought he caved in a bit too much!). So there was absolutely no reason for
>Wally to write this piece.
>
>If Julie Uppenbrink gives us the go-ahead, I say lets do as Tom suggests. I
>think this has a lot more cachet if all on this list are willing to sign on
>as co-authors.
>
>Regarding primary authorship: On the one hand, it would be appropriate for
>me tsince it is primarily Mann et al that is explicitly under attack here,
>though all of us are implicitly under attack. However, I think the piece
>carries a lot more weight if it is authored by someone of Wally's stature,
>and I think Tom far better fits the bill in this regard. So if Tom  is
>willing to bear the brunt of this, I would definitely endorse him being
>primary author.
>
>I would argue to include Peck too, but I think this would be a conflict for
>him, as he is pretty close to Wally. So best to leave it w/ the current
>group in my opinion. Lets pursue this further once Phil hears back from J.U...
>
>mike
>
>At 09:16 AM 2/26/01 -0600, tom crowley wrote:
>>Hi all,
>>
>>I vote for a response - quick and to the point - itemized in fact.
>>
>>The only problem is somehow has to volunteer to be the sacrificial lamb as
>>first author - that person will almost certainly be badgered by Wally and
>>probably charged with some trumped up unethical piece - he will also
>>probably try to subvert the review process by contacting the Editor of
>>Science.  This is not paranoia - Wally did exactly this when some people
>>(some at Lamont!) questioned his conveyor explanation for the LIA that came
>>out in Science a year or so ago.  He was actually screaming at some of
>>these people in the Lamont lunch room.
>>
>>That said, I say we must bite the bullet and do it - Wally doesn't like me
>>anyway so it wouldnt make as much a difference to me if I volunteered to go
>>to the slaughter but if there is anyone else who wants to take the lead,
>>thats fine with me!!
>>
>>Tom
>>
>>ps  as I indicated the other day I will be in only until this Friday after
>>which I am out for a month - I could write enough to get us going and then
>>hand it over to someone else to deal with the submission business (MIke?)
>>
>>
>>>Thanks a bunch Phil,
>>>
>>>Will look forward to hearing back w/ more info. I talked to Dick Kerr last
>>>week about related stuff (an IPCC article he's writing) and he made no
>>>mention of this at all! I wonder who did commission this, and why?
>>>
>>>mike
>>>
>>>At 02:51 PM 2/26/01 +0000, Phil Jones wrote:
>>>>A
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>   Mike,
>>>>     I've had a quick read and sent an email to Julia Uppenbrink to get her
>>>>views as
>>>>  she commissioned our piece. Also asked about a response, particularly on
>>>the
>>>>  high and low frequency indicators.  I was going to send Wally two papers
>>>>  (Sarah Raper's on linking trees and glaciers in J. Glaciol. and Brian
>>>>Luckman's
>>>>  in The Holocene, where the two are also linked but only in a qualitative
>>>>way).
>>>>  From the weekend it was clear he had no ideas about these. His lack of
>>>>knowledge
>>>>  of density data in trees come through in the article as well.
>>>>     In Maine he also went on at length about the Stine work. and seems to
>>>>in this
>>>>  piece as well.  Malcolm should know all about this.
>>>>     I'm going to go home soon as I'm getting knackered, but I'll email you
>>>>Julia's
>>>>  response.  I think she'll find out who asked Wally to do it, as he
>>>>implied to me it
>>>>  was.
>>>>
>>>>  Cheers
>>>>  Phil
>>>>
>>>>  PS Meant to say at the start that I see your points. Thanks for pasting
>>>>it to us.
>>>>
>>>>
>>>>
>>>>Prof. Phil Jones
>>>>Climatic Research Unit        Telephone +44 (0) 1603 592090
>>>>School of Environmental Sciences    Fax +44 (0) 1603 507784
>>>>University of East Anglia
>>>>Norwich                          Email    p.jones@uea.ac.uk
>>>>NR4 7TJ
>>>>UK
>>>>---------------------------------------------------------------------------
>>>-
>>>
>>>>
>>>>
>>>>
>>>_______________________________________________________________________
>>>                     Professor Michael E. Mann
>>>          Department of Environmental Sciences, Clark Hall
>>>                      University of Virginia
>>>                     Charlottesville, VA 22903
>>>_______________________________________________________________________
>>>e-mail: mann@virginia.edu   Phone: (804) 924-7770   FAX: (804) 982-2137
>>>
>>
>>
>>
>>
>>Thomas J.  Crowley
>>Dept. of Oceanography
>>Texas A&M University
>>College Station, TX  77843-3146
>>979-845-0795
>>979-847-8879 (fax)
>>979-845-6331 (alternate fax)
>>
>>
>>
>>
>_______________________________________________________________________
>                     Professor Michael E. Mann
>          Department of Environmental Sciences, Clark Hall
>                      University of Virginia
>                     Charlottesville, VA 22903
>_______________________________________________________________________
>e-mail: mann@virginia.edu   Phone: (804) 924-7770   FAX: (804) 982-2137
>
Thomas J.  Crowley
Dept. of Oceanography
Texas A&M University
College Station, TX  77843-3146
979-845-0795
979-847-8879 (fax)
979-845-6331 (alternate fax)