The below are part of a series of alleged emails from the Climate Research Unit at the University of East Anglia, released on 20 November 2009.
Original Filename: 972415204.txt | Return to the index page | Permalink | Earlier Emails | Later Emails
From: Phil Jones <p.jones@xxxxxxxxx.xxx>
To: Brendaw Morris <brendawmorris@xxxxxxxxx.xxx>
Subject: Re: JOC Review
Date: Tue Oct 24 15:20:xxx xxxx xxxx
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/xxx xxxx xxxx, 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
>
>
>
>
>
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From: Phil Jones <p.jones@xxxxxxxxx.xxx>
To: Ben Santer <santer1@xxxxxxxxx.xxx>
Subject: Re: Figures for revised version of paper
Date: Wed Oct 25 14:38:xxx xxxx xxxx
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/xxx xxxx xxxx, 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 coolingxxx xxxx xxxxwe 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: (9xxx xxxx xxxx
>FAX: (9xxx xxxx xxxx
>email: santer1@xxxxxxxxx.xxx
>----------------------------------------------------------------------------
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From: Phil Jones <p.jones@xxxxxxxxx.xxx>
To: Ben Santer <santer1@xxxxxxxxx.xxx>
Subject: Re: Text and Tables of draft JGR paper
Date: Fri Oct 27 08:31:xxx xxxx xxxx
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/xxx xxxx xxxx, 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 (xxx xxxx xxxx). 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: (9xxx xxxx xxxx
>FAX: (9xxx xxxx xxxx
>email: santer1@xxxxxxxxx.xxx
>----------------------------------------------------------------------------
>Attachment Converted: "c:eudoraattachvolcano_tables2.ps"
>
>Attachment Converted: "c:eudoraattachdriver_maintext.ps"
>
>Attachment Converted: "c:eudoraattachdriver_titlepage.ps"
>
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From: Mike Hulme <m.hulme@xxxxxxxxx.xxx>
To: barker,vira
Subject: Fwd: BP funding
Date: Sat Nov 4 16:45:xxx xxxx xxxx
Any idea who at Cambridge has been benefitting from this BP money?
Mike
From: "Simon J Shackley" <Mcysssjs@xxxxxxxxx.xxx>
Organization: umist
To: m.hulme@xxxxxxxxx.xxx
Date: Thu, 2 Nov 2000 14:44:09 GMT
Subject: BP funding
Reply-to: Simon.Shackley@xxxxxxxxx.xxx
CC: robin.smith@xxxxxxxxx.xxx,
brian.launder@xxxxxxxxx.xxx
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]http://www.auto.com/industry/iwirc26_20001026.htm
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. http://www.auto.com/industry/iwirc26_20001026.htm
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From: Eric.Steig@xxxxxxxxx.xxx (via the vacation program)
To: k.briffa@xxxxxxxxx.xxx
Subject: away from my mail
Date: Fri, 10 Nov 2000 09:53:xxx xxxx xxxx(EST)
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.
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From: Keith Briffa <k.briffa@xxxxxxxxx.xxx>
To: jjzeeberg <jzeebe1@xxxxxxxxx.xxx>
Subject: Re: temperature time series
Date: Mon Nov 20 09:41:xxx xxxx xxxx
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]http://www.cru.uea.ac.uk/cru/people/briffa/qsr1999/
At 03:56 PM 11/17/xxx xxxx xxxx, 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/xxx xxxx xxxx, 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. xxx xxxx xxxx(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]http://www2.uic.edu/~jzeebe1/news.htm
>>
>>845 W. Taylor Street MC186
>>Chicago, IL 60xxx xxxx xxxx, USA
>>
>>Phone: xxx xxxx xxxx
>>Fax: xxx xxxx xxxx
>>e-mail jzeebe1@xxxxxxxxx.xxx
>>
>>========================================
>
>--
>Dr. Keith Briffa, Climatic Research Unit, University of East Anglia,
>Norwich, NR4 7TJ, United Kingdom
>Phone: xxx xxxx xxxx Fax: xxx xxxx xxxx
>
>
--
Dr. Keith Briffa, Climatic Research Unit, University of East Anglia,
Norwich, NR4 7TJ, United Kingdom
Phone: xxx xxxx xxxx Fax: xxx xxxx xxxx
References
1. http://www.cru.uea.ac.uk/cru/people/briffa/qsr1999/
2. http://www2.uic.edu/~jzeebe1/news.htm
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From: "Michael E. Mann" <mann@xxxxxxxxx.xxx>
To: Tim Osborn <t.osborn@xxxxxxxxx.xxx>
Subject: Re: New tree-ring density data
Date: Fri, 01 Dec 2000 12:58:xxx xxxx xxxx
Cc: srutherford@xxxxxxxxx.xxx, mann@xxxxxxxxx.xxx
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
http://www.ngdc.noaa.gov/paleo/ei/ei_cover.html).
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@xxxxxxxxx.xxx Phone: (8xxx xxxx xxxxFAX: (8xxx xxxx xxxx
http://www.evsc.virginia.edu/faculty/people/mann.html
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From: Eric Steig <esteig@xxxxxxxxx.xxx>
To: <masson@xxxxxxxxx.xxx>, jouzel@xxxxxxxxx.xxx, ddj@xxxxxxxxx.xxx, fujii@xxxxxxxxx.xxx, tas.van.omnen@xxxxxxxxx.xxx, vimeux@xxxxxxxxx.xxx, <fisher@xxxxxxxxx.xxx>, <ethompso@xxxxxxxxx.xxx>, <Koerner@xxxxxxxxx.xxx>, edw@xxxxxxxxx.xxx, clow@xxxxxxxxx.xxx
Subject: No Subject
Date: Tue, 12 Dec 2000 11:55:xxx xxxx xxxx
Cc: <raynaud@xxxxxxxxx.xxx>, k.briffa@xxxxxxxxx.xxx, steig@xxxxxxxxx.xxx
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
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From: Eric Steig <steig@xxxxxxxxx.xxx>
To: Valerie Masson-Delmotte <masson@xxxxxxxxx.xxx>, Eric Steig <esteig@xxxxxxxxx.xxx>
Subject: Re: HILOL "optima"?
Date: Thu, 14 Dec 2000 10:30:xxx xxxx xxxx
Cc: jouzel@xxxxxxxxx.xxx, ddj@xxxxxxxxx.xxx, fujii@xxxxxxxxx.xxx, tas.van.ommen@xxxxxxxxx.xxx, vimeux@xxxxxxxxx.xxx, fisher@xxxxxxxxx.xxx, ethompso@xxxxxxxxx.xxx, Koerner@xxxxxxxxx.xxx, edw@xxxxxxxxx.xxx, clow@xxxxxxxxx.xxx, raynaud@xxxxxxxxx.xxx, k.briffa@xxxxxxxxx.xxx, Valerie Masson <masson@xxxxxxxxx.xxx>
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. (xxx xxxx xxxx xxx xxxx xxxxGif sur Yvette cedex
>Fax. (xxx xxxx xxxx France
>
Original Filename: 981068343.txt | Return to the index page | Permalink | Earlier Emails | Later Emails
From: Martin Welp <Martin.Welp@xxxxxxxxx.xxx>
To: gberz@xxxxxxxxx.xxx, juergen.engelhard@xxxxxxxxx.xxx, schlueter@xxxxxxxxx.xxx, gerd-rainer.weber@xxxxxxxxx.xxx, zimmermeyer@xxxxxxxxx.xxx, jan.rispens@xxxxxxxxx.xxx, guentherr@xxxxxxxxx.xxx, gretz@xxxxxxxxx.xxx, siegfried.jacke@xxxxxxxxx.xxx, paul.bergweiler@xxxxxxxxx.xxx, kohl.harald@xxxxxxxxx.xxx, klaus.hasselmann@xxxxxxxxx.xxx, schellnhuber@xxxxxxxxx.xxx, Carlo.Jaeger@xxxxxxxxx.xxx, tol@xxxxxxxxx.xxx, ccarraro@xxxxxxxxx.xxx, ola.johannessen@xxxxxxxxx.xxx, m.hulme@xxxxxxxxx.xxx, wokaun@xxxxxxxxx.xxx, f.gruber@xxxxxxxxx.xxx, baldur.eliasson@xxxxxxxxx.xxx, sengbusch@xxxxxxxxx.xxx, buchner.barbara@xxxxxxxxx.xxx, Ottmar.Edenhofer@xxxxxxxxx.xxx, Martin.Welp@xxxxxxxxx.xxx
Subject: ECF
Date: Thu, 01 Feb 2001 17:59:03 +0100
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
Original Filename: 981859677.txt | Return to the index page | Permalink | Earlier Emails | Later Emails
From: "John L. Daly" <daly@xxxxxxxxx.xxx>
To: Chick Keller <ckeller@xxxxxxxxx.xxx>
Subject: Re: Hockey Sticks again
Date: Sat, 10 Feb 2001 21:47:57 +1100
Reply-to: daly@xxxxxxxxx.xxx
Cc: "P. Dietze" <p_dietze@xxxxxxxxx.xxx>, mmaccrac@xxxxxxxxx.xxx, Michael E Mann <mann@xxxxxxxxx.xxx>, rbradley@xxxxxxxxx.xxx, wallace@xxxxxxxxx.xxx, Thomas Crowley <tom@xxxxxxxxx.xxx>, Phil Jones <p.jones@xxxxxxxxx.xxx>, sfbtett@xxxxxxxxx.xxx, daly@xxxxxxxxx.xxx, onar@xxxxxxxxx.xxx, jarl.ahlbeck@xxxxxxxxx.xxx, richard@xxxxxxxxx.xxx, McKitrick <rmckit@xxxxxxxxx.xxx>, Bjarnason <agust@xxxxxxxxx.xxx>, Harry Priem <priem@xxxxxxxxx.xxx>, vinmary.gray@xxxxxxxxx.xxx, balberts@xxxxxxxxx.xxx, Martin Manning <m.manning@xxxxxxxxx.xxx>, Albert Arking <arking@xxxxxxxxx.xxx>, Sallie Baliunas <baliunas@xxxxxxxxx.xxx>, Jack Barrett <100436.3604@xxxxxxxxx.xxx>, Sonja Boehmer-Cristianse <sonja.b-c@xxxxxxxxx.xxx>, Nigel Calder <nc@xxxxxxxxx.xxx>, John Christy <christy@xxxxxxxxx.xxx>, cpaynter@xxxxxxxxx.xxx, driessen@xxxxxxxxx.xxx, dwojick@xxxxxxxxx.xxx, Myron Ebell <mebell@xxxxxxxxx.xxx>, Ellsaesser <hughel@xxxxxxxxx.xxx>, John Emsley <j.emsley@xxxxxxxxx.xxx>, Jim Goodridge <jdg@xxxxxxxxx.xxx>, gsharp@xxxxxxxxx.xxx, Peter Holle <cog@xxxxxxxxx.xxx>, Douglas V Hoyt <dhoyt1@xxxxxxxxx.xxx>, "W. S. Hughes" <wsh@xxxxxxxxx.xxx>, Wibj
Original Filename: 983196231.txt | Return to the index page | Permalink | Earlier Emails | Later Emails
From: "Michael E. Mann" <mann@xxxxxxxxx.xxx>
To: Phil Jones <p.jones@xxxxxxxxx.xxx>
Subject: Re: Wally
Date: Mon, 26 Feb 2001 09:03:xxx xxxx xxxx
Cc: mhughes@xxxxxxxxx.xxx, tom crowley <tom@xxxxxxxxx.xxx>, rbradley@xxxxxxxxx.xxx, tom@xxxxxxxxx.xxx, k.briffa@xxxxxxxxx.xxx, t.osborn@xxxxxxxxx.xxx, mann@xxxxxxxxx.xxx
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
Original Filename: 983204299.txt | Return to the index page | Permalink | Earlier Emails | Later Emails
From: tom crowley <tom@xxxxxxxxx.xxx>
To: "Michael E. Mann" <mann@xxxxxxxxx.xxx>
Subject: Re: Wally
Date: Mon, 26 Feb 2001 11:18:xxx xxxx xxxx
Cc: mhughes@xxxxxxxxx.xxx, rbradley@xxxxxxxxx.xxx, k.briffa@xxxxxxxxx.xxx, p.jones@xxxxxxxxx.xxx, t.osborn@xxxxxxxxx.xxx
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/xxx xxxx xxxx, 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 xxx xxxx xxxx
>>>>School of Environmental Sciences Fax +44 xxx xxxx xxxx
>>>>University of East Anglia
>>>>Norwich Email p.jones@xxxxxxxxx.xxx
>>>>NR4 7TJ
>>>>UK
>>>>---------------------------------------------------------------------------
>>>-
>>>
>>>>
>>>>
>>>>
>>>_______________________________________________________________________
>>> Professor Michael E. Mann
>>> Department of Environmental Sciences, Clark Hall
>>> University of Virginia
>>> Charlottesville, VA 22903
>>>_______________________________________________________________________
>>>e-mail: mann@xxxxxxxxx.xxx Phone: (8xxx xxxx xxxxFAX: (8xxx xxxx xxxx
>>> http://www.evsc.virginia.edu/faculty/people/mann.html
>>
>>
>>
>>
>>Thomas J. Crowley
>>Dept. of Oceanography
>>Texas A&M University
>>College Station, TX 77xxx xxxx xxxx
>>xxx xxxx xxxx
>>xxx xxxx xxxx(fax)
>>xxx xxxx xxxx(alternate fax)
>>
>>
>>
>>
>_______________________________________________________________________
> Professor Michael E. Mann
> Department of Environmental Sciences, Clark Hall
> University of Virginia
> Charlottesville, VA 22903
>_______________________________________________________________________
>e-mail: mann@xxxxxxxxx.xxx Phone: (8xxx xxxx xxxxFAX: (8xxx xxxx xxxx
> http://www.evsc.virginia.edu/faculty/people/mann.html
Thomas J. Crowley
Dept. of Oceanography
Texas A&M University
College Station, TX 77xxx xxxx xxxx
xxx xxxx xxxx
xxx xxxx xxxx(fax)
xxx xxxx xxxx(alternate fax)
Original Filename: 983207072.txt | Return to the index page | Permalink | Earlier Emails | Later Emails
From: Phil Jones <p.jones@xxxxxxxxx.xxx>
To: mhughes@xxxxxxxxx.xxx,"Michael E. Mann" <mann@xxxxxxxxx.xxx>
Subject: Re: Wally
Date: Mon, 26 Feb 2001 12:04:32 +0000
Cc: <mhughes@xxxxxxxxx.xxx>,"Michael E. Mann" <mann@xxxxxxxxx.xxx>, tom crowley <tom@xxxxxxxxx.xxx>, "Michael E. Mann" <mann@xxxxxxxxx.xxx>, <rbradley@xxxxxxxxx.xxx>,<tom@xxxxxxxxx.xxx>, <mhughes@xxxxxxxxx.xxx>,k.briffa@xxxxxxxxx.xxx,t.osborn@xxxxxxxxx.xxx
<x-flowed>
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/xxx xxxx xxxx, mhughes@xxxxxxxxx.xxx 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" <mann@xxxxxxxxx.xxx>:
>
> > 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/xxx xxxx xxxx, mhughes@xxxxxxxxx.xxx 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" <mann@xxxxxxxxx.xxx>:
> > >
> > >> 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/xxx xxxx xxxx, 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 xxx xxxx xxxx: 1xxx xxxx xxxx. [Summary] [Full Text]
> > >> >>
> > >> >>http://www.sciencemag.org/cgi/content/full/291/5508/1497
> > >> >>
> > >> >>While my previous perspective piece is here:
> > >> >> CLIMATE CHANGE:
> > >> >> Lessons for a New Millennium
> > >> >> Michael E. Mann
> > >> >> Science 2000 July 14; 289: xxx xxxx xxxx. (in Perspectives) [Summary]
> > >> [Full
> > >> >>Text]
> > >> >>URL:
> > >>
> > >>http://www.sciencemag.org/cgi/content/full/289/5477/253?maxtoshow=&HIT
> 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: 1xxx xxxx xxxx. (in Perspectives) [Summary]
> > >> [Full
> > >> >>Text]
> > >> >>
> > >> >>URL:
> > >>
> > >>http://www.sciencemag.org/cgi/content/full/288/5470/1353?maxtoshow=&HI
> 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.
> > >> >>>
> > >> >>><http://www.insightmag.com/archive/200103143.shtml>
> > >> >>>
> > >> >>>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
> > >> >>><http://www.greeningearthsociety.org>, as well as Undereditor of
> > the
> > >> >>>Washington Pest <http://www.WashingtonPest.com>
> > >> >>>
> > >> >>>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.
> > >> >>>
> > >> >>><http://www.eco.freedom.org/el/20010202/wojick.shtml>
> > >> >>>
> > >> >>>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@xxxxxxxxx.xxx)
> > >> >>>
> > >> >>>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
> > >> http://www.climatechangedebate.org
> > >> >>>Non subscribers can follow the debate at
> > >> >>>http://www.eScribe.com/science/ClimateChangeDebate/
> > >> >>>
> > >> >>>
> > >> >>>
> > >> >>>
> > >>
> > >>_______________________________________________________________________
> > >> >> Professor Michael E. Mann
> > >> >> Department of Environmental Sciences, Clark Hall
> > >> >> University of Virginia
> > >> >> Charlottesville, VA 22903
> > >>
> > >>_______________________________________________________________________
> > >> >>e-mail: mann@xxxxxxxxx.xxx Phone: (8xxx xxxx xxxxFAX: (804)
> > >> xxx xxxx xxxx
> > >> >> http://www.evsc.virginia.edu/faculty/people/mann.html
> > >> >
> > >> >
> > >> >
> > >> >
> > >> >Thomas J. Crowley
> > >> >Dept. of Oceanography
> > >> >Texas A&M University
> > >> >College Station, TX 77xxx xxxx xxxx
> > >> >xxx xxxx xxxx
> > >> >xxx xxxx xxxx(fax)
> > >> >xxx xxxx xxxx(alternate fax)
> > >> >
> > >> >
> > >> >
> > >> >
> > >>
> > _______________________________________________________________________
> > >> Professor Michael E. Mann
> > >> Department of Environmental Sciences, Clark Hall
> > >> University of Virginia
> > >> Charlottesville, VA 22903
> > >>
> > _______________________________________________________________________
> > >> e-mail: mann@xxxxxxxxx.xxx Phone: (8xxx xxxx xxxxFAX: (804)
> > xxx xxxx xxxx
> > >> http://www.evsc.virginia.edu/faculty/people/mann.html
> >
> > >>
> > >>
> > >>
> > >
> > >
> > >
> > >
> > >
> > >
> > _______________________________________________________________________
> > Professor Michael E. Mann
> > Department of Environmental Sciences, Clark Hall
> > University of Virginia
> > Charlottesville, VA 22903
> > _______________________________________________________________________
> > e-mail: mann@xxxxxxxxx.xxx Phone: (8xxx xxxx xxxxFAX: (8xxx xxxx xxxx
> > http://www.evsc.virginia.edu/faculty/people/mann.html
> >
> >
> >
Prof. Phil Jones
Climatic Research Unit Telephone +44 xxx xxxx xxxx
School of Environmental Sciences Fax +44 xxx xxxx xxxx
University of East Anglia
Norwich Email p.jones@xxxxxxxxx.xxx
NR4 7TJ
UK
----------------------------------------------------------------------------
</x-flowed>
Original Filename: 983280741.txt | Return to the index page | Permalink | Earlier Emails | Later Emails
From: PARRYML@xxxxxxxxx.xxx
To: tgcia@xxxxxxxxx.xxx
Subject: Proposed TGCIA meeting: 30th Mayto 1st June, Amsterdam
Date: Tue, 27 Feb 2001 08:32:xxx xxxx xxxx(EST)
Dear TGCIAers:
A proposed date/place for the next TGCIA meeting is: 9.00 on Wednesday 30th
May to 14.00 on Friday 1st June at Shell International Bldg, Amsterdam. Rob
Swart and colleagues at WGIII TSU have kindly agreed to be local hosts.
I suggest this date after consulting with 9 TGCIA members present at WGII
plenary at Geneva last week. The window is narrow between IPCC and SUBSTA
meetings (the latter is now almost certainly delayed until mid June).
Please put this date in your diary, but also let me know of any major
conflict with IPCC/UNFCC-type schedules.
Unless I hear to the contrary( *let us say by Monday 5th March*), the
proposal is that this dates stands .
This meeting is particularly because top of the agenda from our last meeting
is consideration of developing a 'one-stop-shop' for data and guidance for
scenario-based climate impacts assessment, which would lay the foundations
for compatible research for the next IPCC assessment (whatever form it may
take). We might well also consider what recommendations to make concerning
the form of the next assessment (a subject probably on the agenda of the IPCC
London Plenary in September).
More follows next week, assuming these dates hold, about agenda and
arrangements.
Kind regards,
Martin parry
Prof. Martin L. Parry
Jackson Environment Institute
University of East Anglia
Norwich
NR4 7TJ
Tel: +44 xxx xxxx xxxx
Fax: +44 xxx xxxx xxxx
E-mail: parryml@xxxxxxxxx.xxx
Web: http://www.uea.ac.uk/env/jei
Original Filename: 983286849.txt | Return to the index page | Permalink | Earlier Emails | Later Emails
From: Phil Jones <p.jones@xxxxxxxxx.xxx>
To: mann@xxxxxxxxx.xxx
Subject: Fwd: RE: Science issue Feb 22/23
Date: Tue, 27 Feb 2001 10:14:09 +0000
Cc: mhughes@xxxxxxxxx.xxx,rbradley@xxxxxxxxx.xxx,tom@xxxxxxxxx.xxx, k.briffa@xxxxxxxxx.xxx,t.osborn@xxxxxxxxx.xxx
<x-flowed>
Mike et al,
Sorry about the multiple sendings. I've forgotten my glasses and
couldn't see I'd
missed a comma.
Another thing to point to is the special issue of Climatic Change by
Astrid Ogilbie
and Trausti Jonsson. They point to the LIA not being very appropriate in
Iceland.
Cheers
Phil
Mike,
So Julia handled it. Even she thought it was handwaving, but it
passed the usual
Science review process. Obviously this isn't great as none of us got to
review it. Odd
that she didn't send it to one of us here as she knew we were writing the
article she
asked us to ! Anyway that is water under the bridge.
As for authorship we have this article coming out so this rules us
out. Tom isn't
keen and he's away. Wally told me he didn't reckon Tom, so Tom has got
the right
vibes. Julia is asking us to go ahead and hinting at a joint response.
One possibility is
either you or Macolm taking the lead. Malcom and Henry wrote the MWP
piece in
Climate Change in 94. Keith and I think something pointed about the MWP
is the way
to go. Could add in that even the two warming periods in the 20th century
don't show
warming everywhere - especially the early 20th century.
Remember that we are all basically averaging long series together and
if one site
shows a big warming/cooling then the average will to a lesser extent.
Also bring in
a few of the papers where people have compared tree based reconstructions
with
glacial advances/retreats (eg Raper et al in J. Glaciology and Luckman et
al in the
Holocene. Also there are more in that Interhemispheric Linkages Book of
Vera amd
work by Ricardo Villalba and others).
Basically need to point to a load of literature that we would expect
someone writing
an article of this type to be aware of. Also the North Atlantic isn't the
last word in NH
and global averages. Clearly said in Hughes and Diaz and papers therein.
Also the latest IPCC report will use and reference the latest curves,
but from
1400 they are not that different from Bradley and Jones (1993), so why
the fuss now.
Clearly the MWP is the issue that has got a few worked up, but we have
concluded
nothing that couldn't have been gleaned in 1994. Maybe we're stating it
more clearly
now, but the recent warmth of the 1990s is a factor as well.
Cheers
Phil
>From: "Julia Uppenbrink" <Juppenbrink@xxxxxxxxx.xxx>
>To: "Phil Jones" <p.jones@xxxxxxxxx.xxx>
>Subject: RE: Science issue Feb 22/23
>Date: Mon, 26 Feb 2001 17:05:xxx xxxx xxxx
>X-Mailer: Microsoft Outlook IMO, Build 9.0.2416 (9.0.2910.0)
>Importance: Normal
>
>Dear Phil
>
>Thanks for your message regarding Wally Broecker's Perspective. I am of
>course aware of this Perspective coming out - I did handle it - I realized
>that it was perhaps a bit handwaving in parts but I thought the message was
>interesting and the article passed the usual screening. But we are always
>open to criticism! So please do send a letter to us; you can send it
>directly to me, and you may cowrite it with Tom Crowley and Mike Mann or you
>can send separate letters (if the concerns overlap a lot then one letter is
>perhaps better than several). The letter will be handled through our letters
>department, and we will get a response from Wally plus possibly outside
>review before we make a decision to publish.
>
>I look forward to receiving your letter.
>
>Best wishes
>
> Julia
>
>-----Original Message-----
>From: Phil Jones [mailto:p.jones@xxxxxxxxx.xxx]
>Sent: 26 February 2001 14:40
>To: Julia Uppenbrink
>Subject: Science issue Feb 22/23
>
>
>
> >
> > Dear Julia,
> I don't know if you have seen the Perspectives piece in last
>week's issue of
> Science by Wally Broecker. I guess it was nothing to do with you and it
>contains
> several inaccuracies and sweeping statements. I accept it is a personal
>view
> and I've not seen the issue yet , only a copy that I was ironically given
>by Wally
> Broecker as we were both guest speakers at a meeting at Bowdoin College,
>ME
> on Saturday. I got back this morning to Norwich.
> I talked to Wally about it over the weekend and will send him a few
>reprints
> pointing out a few of the things he should have read. Some things he
>states are just
> wrong.
> I don't want to change the article already accepted, but what are
>the possibilities
> of writing a response to Wally's piece in a later issue. I've been
>contacted by a couple
> of people in the US about Broecker's piece (Mike Mann and Tom Crowley),
>who are
> quite unhappy about it and would like to respond. They both know about
>the invited
> piece and wanted me to comment, hence my email to you. The invited piece
>does
> address some of the issues, but not the link between high and low
>frequency
> proxy series.
>
> Best Regards
> Phil
>
>
>
>
>
>Prof. Phil Jones
>Climatic Research Unit Telephone +44 xxx xxxx xxxx
>School of Environmental Sciences Fax +44 xxx xxxx xxxx
>University of East Anglia
>Norwich Email p.jones@xxxxxxxxx.xxx
>NR4 7TJ
>UK
>----------------------------------------------------------------------------
Prof. Phil Jones
Climatic Research Unit Telephone +44 xxx xxxx xxxx
School of Environmental Sciences Fax +44 xxx xxxx xxxx
University of East Anglia
Norwich Email p.jones@xxxxxxxxx.xxx
NR4 7TJ
UK
----------------------------------------------------------------------------
</x-flowed>
Original Filename: 983452785.txt | Return to the index page | Permalink | Earlier Emails | Later Emails
From: "Thomas L. Delworth" <td@xxxxxxxxx.xxx>
To: "Michael E. Mann" <mann@xxxxxxxxx.xxx>
Subject: Re: letter to Science
Date: Thu, 01 Mar 2001 08:19:xxx xxxx xxxx
Cc: tom@xxxxxxxxx.xxx, hpollack@xxxxxxxxx.xxx, mhughes@xxxxxxxxx.xxx, rbradley@xxxxxxxxx.xxx, p.jones@xxxxxxxxx.xxx, k.briffa@xxxxxxxxx.xxx
Dear Mike et al,
I offer the following comments on your letter
for your consideration.
It seems to me there are 2 primary issues to
address:
(A) what does proxy evidence say about whether
the Medieval Warm period was global
(B) what do we know about potential mechanisms
for the Medieval Warm period
(i) evidence for a forced phenomenon
(ii) evidence for internal variability
Issue (A) is currently dealt with in your sections (1) and
(2). One point that could be perhaps conveyed more
clearly is the necessity of using the spatial information
conveyed in (multi) proxy reconstructions, rather than
overly interpreting sets of local proxy evidence. I
felt this point could have been stressed more, and is one
which the casual reader may not appreciate.
Issue (B, Bi) is in your section (3). I suggest a more
explicit mention of conclusions with regard to the
Medieval Warm period in recent work on this topic.
The first statement in this section doesn't provide
(I don't think) explicit evidence to back itself up. The
sentence starting "These results ..." could be more
explicit about what those studies show with respect to
the Medieval Warm period, in addition to the more general
statement about the partitionng between forced and internal
variability. A reader could ask "Ok, if 50% of the variability
is explained by volcanic and solar forcing, that doesn't
exclude the other 50% playing a strong role for events such as
the Medieval Warming." Such a question could be dealt with
in advance by stating what role these studies suggest for
radiative forcing in the Medieval Warm period.
For issue (Bii), I would suggest being explicit that
it is incumbent upon authors to provide some evidence to
support their speculation. What evidence can the author
provide to support his speculation concerning the role of
the THC in the Medieval Warm period? Rather than explicitly
stating this is not a likely mechanism, I would contrast the
speculation he has offered on this topic to the stronger
(in my opinion) evidence provided by modeling studies to
support the idea of the importance of radiative forcing.
... a few more minor comments
(1) I agree with the overall message you are conveying, but
might choose somewhat differing wording in a place or
two. The statement is made "(1) It cannot reasonably be
argued that the Middle Ages were as warm as the
20th century at global or hemispheric scales." This
might be a bit strong ... I would think one can have
a reasoned discussion on this topic. Perhaps something
like "We strongly disagree with the assertion that the
Middle Ages were as warm as the 20th century at global
or hemispheric scales."
(2) In the second to last sentence, I would add the
qualifying phrase "on planetary scales" after the
text "... responsible for centennial-millenial changes ...".
Regards,
Tom Delworth
ps The central issue is one that I have not been heavily
involved in, and thus don't think it's appropriate for
me to sign on as an author. Good luck, and please
send me a copy of your final submission.
pps I previously provided to Tom correlations between the
THC and global/hemispheric temperature based on a 900 year
run of our R30 coupled model. These correlations were
relatively low (0.27), but probably significant. The
applicability of those correlations to the issue of the
Medieval Warming may not be strong. If the Medieval Warming
is a multi-century event, then I should really be looking at
the correlations of low frequency (>50 years) filtered model
output from a run of several millenia duration. Thus, the
900 year run may not be applicable. I will revisit this
topic using a multi-millenial R15 coupled run, but probably
won't have any results today. I don't think that would
change the essential conclusions, however. I recall that
experiments with the R15 model in which the THC was substantially
weakened through the addition of fresh water to the North
Atlantic provided strong regional temperature anomalies, but
their global expression was small. These experiments are
being repeated with the higher resolution model.
In light of these issues, I suggest that the focus be
not so much on saying the THC cannot be responsible for the
Medieval Warming, but rather on saying (1) there is strong
evidence for a substantial role of radiative forcing, and (2) the
burden is on the author to provide evidence for the role of
the THC.
?
"Michael E. Mann" wrote:
> Dear Colleagues,
>
> Below is a draft of a short letter to Science that Tom Crowley and I
> have put together, after discussing w/ Phil, Ray, and Malcolm. We
> feel that a reply to Broecker's recent "Perspectives" piece is
> warranted to correct several misconceptions that Wally unfortunately
> chose to perpetuate (attached as an html file FYI). We have been given
> encouragement to submit this by Julia Uppenbrink at Science.
>
> We are working under a very tight timeline owing to Tom's travel
> schedule (leaves on an extended travel on friday) so we would greatly
> appreciate it if you could respond ASAP w/ comments, suggestions, etc.
> Please note that we are currently near the length limitations (and
> probably shouldn't include more than 15 references) so we're looking
> to sharpen and hone, but not lengthen the piece at this point.
>
> Thanks in advance for your feedback,
>
> mike
>
> _________________________________________
>
> Medieval Warming Redux
> In a recent "Perspectives" opinion piece, W. Broecker suggests that
> the
> "hockey stick" reconstruction of climate change over the past 1000
> years -
> with extreme warming only in the late 20th century - is incorrect, and
> that
> the so-called "Medieval Warm Period" was at least as warm as the 20th
> century and due to oscillations in the thermohaline circulation. To
> reach
> this conclusion, Dr. Broecker rejects traditional empirical "proxy"
> climate
> indicators of past climate (e.g. tree ring, ice core, coral, and long
> historical documentary records) that are the foundation of a number of
>
> hemispheric reconstructions, as well as our current best physical
> understanding of the factors controlling climate at
> century-to-millennial
> timescales. We disagree with Broecker on several major points:
> (1) It cannot reasonably be argued that the Middle Ages were as warm
> as the
> 20th century at global or hemispheric scales. Although regional warmth
>
> during the Middle Ages may have sometimes been significantly greater
> than
> present, four different hemispheric-scale reconstructions (Jones,
> Mann,
> Briffa, Crowley) have been completed for the last 1000 years -- all of
> them
> showing warmth in the Middle Ages that is either no warmer or
> significantly
> less than mid-20th century warmth. This is because it has been known
> for a
> quarter of a century that the timing of warmth during the Middle Ages
> was
> significantly different in different regions (Lamb, Dansgaard,
> Hughes).
> Failure to take this observation into account can lead to serious
> errors in
> the inference of hemispheric temperature trends. Although one analysis
> of
> heat flow measurements suggests warmer temperatures than the surface
> proxies during the Middle Ages (Huang and Pollack, GRL. 1997), the
> considerable sensitivity of the resulting trends to a priori
> statistical
> assumptions has lead borehole researchers to restrict their attention
> to
> the more reliably interpretable temperature fluctuations during the
> past
> five centuries (Huang and Pollack, Nature). Our conclusion is also
> supported by measurements from tropical glaciers indicating an
> unprecedented level of recent warming with respect to the last
> 1,000-2,000
> years (Thompson).
> (2) High-resolution proxy climate records which form the foundation of
>
> recent hemispheric temperature reconstructions are far more reliable
> indicators of century-to-millennial scale climate variability than is
> implied by Broecker. The potential limitations in interpreting
> long-term
> climate change from proxy indicators such as tree rings, have been
> long
> recognized by dendroclimatologists (e.g., Cook "segment curse" paper)
> and
> are almost always taken into account in framing interpretations of
> long-term trends. For example, Mann et al (1999) verified that a
> significant subset of multiple-millennial length tree ring and ice
> core
> proxy climate indicators used to reconstruct the trend over the past
> millennium passed rigorous statistical tests for fidelity at the
> millennial
> timescale, and that the basic attributes of the hemispheric
> reconstruction
> using more recent non-tree ring proxies available over the past few
> centuries yielded essentially the same result as that based on both
> tree
> ring and non-tree ring based information (Mann et al, Earth
> Interactions,
> 2000). Several independent reconstructions (Jones et al and Crowley
> and
> Lowery ), using a wide variety of proxy climate indicators and
> different
> statistical approaches, yield similar hemispheric temperature trends.
> Even
> the centennial-scale changes within the so-called "Little Ice Age" of
> the
> 15th-19th centuries are largely in agreement. Furthermore these
> centennial
> changes have been shown to be in "agreement" , rather than "in
> opposition"
> (as argued by Broecker) with evidence from alpine glacial advances
> (Raper
> reference).
> (3) Physical considerations show that external forcing, not internal
> variability, played the dominant role in the transition from the
> "Medieval
> Warm Period" to "Little Ice Age" (these terms are used loosely and
> are, in
> fact, ill advised in the context of hemispheric or global temperature
> changes -see e.g. Bradley and Jones, 1993; Hughes and Diaz, 1994). One
> of
> the major points of Broecker's argument is that changes in the
> thermohaline circulation are a primary driver of climate change on
> this
> time scale. These results do not consider recent modeling studies
> (Free,
> Crowley) that demonstrate at a high significance level (>99%) that
> about
> 50% of the pre-anthropogenic (pre-1850) variance can be explained by
> changes in volcanism and low frequency solar irradiance. Although the
> latter term is still not well constrained from observational studies,
> there
> are a number of independent lines of evidence suggesting such changes
> (Hoyt, Lean, Lockwood).
> (4) It is not justifiable to argue that changes in the thermohaline
> circulation cause significant hemispheric or global changes in
> temperature.
> Although changes in the conveyor play a major role in the Atlantic
> Basin,
> to a first approximation changes in ocean circulation simply
> redistribute
> heat on the planet without significantly raising global temperature,
> or
> even hemispheric temperature. This conclusion is born out by very low
> correlations between warmth in the Greenland sector and the
> hemispheric
> indices over the last 1000 years (Crowley footnote ref.), a low
> correlation
> that is shared by coupled model experiments (Delworth citation)? In
> fact,
> sediment core data from the subtropical North Atlantic often cited as
> indicative of a distinct "Medieval Warm Period" and "Little Ice Age"
> (Keigwin Sargasso Sea), has recently been shown to be more consistent
> with
> changes in the North Atlantic Oscillation (Keigwin and Pickart),
> implying a
> zero sum pattern of regionally alternating warm and cold superimposed
> on
> far more modest hemispheric variations over the past 1000 years. This
> pattern itself may be forced, rather than internal in nature, and
> would
> explain the limited evidence for more dramatic cold and warm periods
> in
> regions such as Europe (see Mann, Sci Perspective, 2000).
> The above arguments lead us to conclude that, although the conveyor
> may be
> changing, radiative forcing perturbations were primarily responsible
> for
> centennial-millennial changes in the last 1000 years, with attendant
> implications for interpretation of earlier Holocene oscillations (e.g,
>
> Denton and Karlen). Furthermore, the weight of evidence indicates that
> the
> late 20th century hemispheric warming is significantly greater than
> the
> Middle Ages.
>
> Michael E. Mann
> Thomas J. Crowley
> WHO ELSE???
>
> ___________
> ___________________________________________________________
> Professor Michael E. Mann
> Department of Environmental Sciences, Clark Hall
> University of Virginia
> Charlottesville, VA 22903
>
> ______________________________________________________________________
>
> e-mail: mann@xxxxxxxxx.xxx Phone: (8xxx xxxx xxxxFAX: (804)
> xxx xxxx xxxx
> http://www.evsc.virginia.edu/faculty/people/mann.html
--
Thomas L. Delworth
GFDL/NOAA e-mail: td@xxxxxxxxx.xxx
P.O. Box xxx xxxx xxxx Phone: xxx xxxx xxxx
Princeton, NJ 08542 USA FAX: xxx xxxx xxxx
Original Filename: 983552403.txt | Return to the index page | Permalink | Earlier Emails | Later Emails
From: "Michael E. Mann" <mann@xxxxxxxxx.xxx>
To: tom crowley <tom@xxxxxxxxx.xxx>
Subject: Re: Science letter
Date: Fri, 02 Mar 2001 12:00:xxx xxxx xxxx
Cc: "Raymond S. Bradley" <rbradley@xxxxxxxxx.xxx>, mhughes@xxxxxxxxx.xxx, k.briffa@xxxxxxxxx.xxx, tom@xxxxxxxxx.xxx, p.jones@xxxxxxxxx.xxx, td@xxxxxxxxx.xxx, hpollack@xxxxxxxxx.xxx
<x-flowed>
Thanks for clarifying Tom,
Yes, these are my sentiments as well, and I would conditionally sign-on to
this effort. In the meantime, I think there is a lot of good science to be
done!
mike
At 10:53 AM 3/2/xxx xxxx xxxx, tom crowley wrote:
>Dear All,
>
>A few more comments re Mikes note - Mike and I thought that if we cannot
>make a case to our colleagues, why muddy the waters further (as either
>Keith, Malcolm, or Ray said)?
>
>That said, I don't think this has been wasted time. I still think a
>thoughtful short paper on the subject of Holocene climate change wold be
>useful, this time stating it from OUR perspective (i.e., not focusing
>exculsively on Broeckers message). By broadening this it may be more
>interesting; we could also include a couple of figures and maybe add some
>input from Tom Delworth and Henry Pollack. I would be willing to take a
>crack at this, and if anyone wants to CONDITIONALLY sign on, I would be
>more than happy to include you.
>
>I probably would not begin this until late April, after our trip to Germany
>and the meeting in Virginia.
>
>Tom
>
>ps fyi I counted the average spacing between the warm and cold
>oscillations in the iron oscillations illustrated by Broecker. Regardless
>of whether warm or cold are used, the mean spacing is indeed 1.5 k,
>although the s.d. is 0.4k HOWEVER, the mean spacing between the four main
>warm phases illustrated by Broecker on the same figure is, believe it or
>not, 2.15! much closer to the solar peak. This calls to mind the
>interesting (and clever) Wigley and Raper paper in Proc. Roy. Soc. (1990)
>indicating that, given the uncertainties in chronology, solar forcing plays
>a role i n Holocenn climate change. It therefore seems that the conveyor
>is indeed oscillating but the time scale of the larger scale CLIMATE shifts
>may be more regulated by solar, with volcanism adding some stochastic
>contribution. Something like this is worth adding to the proposed Eos
>piece.
>
>Tom
>
>
>
>Thomas J. Crowley
>Dept. of Oceanography
>Texas A&M University
>College Station, TX 77xxx xxxx xxxx
>xxx xxxx xxxx
>xxx xxxx xxxx(fax)
>xxx xxxx xxxx(alternate fax)
_______________________________________________________________________
Professor Michael E. Mann
Department of Environmental Sciences, Clark Hall
University of Virginia
Charlottesville, VA 22903
_______________________________________________________________________
e-mail: mann@xxxxxxxxx.xxx Phone: (8xxx xxxx xxxxFAX: (8xxx xxxx xxxx
http://www.evsc.virginia.edu/faculty/people/mann.shtml
</x-flowed>
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From: Chick Keller <ckeller@xxxxxxxxx.xxx>
To: "Michael E Mann" <mann@xxxxxxxxx.xxx>, <rbradley@xxxxxxxxx.xxx>, "Phil Jones" <p.jones@xxxxxxxxx.xxx>, <k.briffa@xxxxxxxxx.xxx>, tom crowley <tom@xxxxxxxxx.xxx>, "Jonathan Overpeck"<jto@u.arizona.edu>, Tom Wigley <wigley@xxxxxxxxx.xxx>, Mike MacCracken <mmaccrac@xxxxxxxxx.xxx>
Subject: Some thoughts on climate change proxy temperatures in the last 1,000 yrs
Date: Fri, 2 Mar 2001 15:54:xxx xxxx xxxx
<x-rich>Folks,
Two points here:
1. I read with some consternation Wally Broecker's latest piece in
Science (23Feb. 2001). First you can all take up some other topic
since Wally says only Boreholes and treeline changes are accurate
enough to do low frequency trends. What does he mean by "only two
proxies can yield temperatures that are accurate to 0.5
Original Filename: 984598451.txt | Return to the index page | Permalink | Earlier Emails | Later Emails
From: "Michael E. Mann" <mann@xxxxxxxxx.xxx>
To: Tim Osborn <t.osborn@xxxxxxxxx.xxx>
Subject: Re: verification results
Date: Wed, 14 Mar 2001 14:34:xxx xxxx xxxx
Cc: srutherford@xxxxxxxxx.xxx, mann@xxxxxxxxx.xxx
HIi Tim,
That all sounds great, and indeed, the 19th century will be a *hot* topic
(pun intended) as we try to rectify Tom's model response w/ the
instrumental record and proxy reconstructions. Ironically, the 19th century
is one in most dispute over the past millennium, it seems!
You accurately summarize what my understanding is of the breakdown of lead
roles. I don't see any reason for changing that. I think Scott and I will
have our hands full w/ the other items, so if you can take the lead role on
the MXD paper (comparing the two methods, etc.) that would be great.
My intention is to give you and Scott full credit for anything I show at
meetings that is a result of mutual collaboration. Of course, both of your
are co-authors of my EGS talk.
So all sounds great! Scott: when Tim sends revised plots, can you prepare
some revised ppt files and let me know when they are available to download?
Hope to get all this straightened away next week after I return from the
frozen north (Michigan)...
mike
That soundsAt 07:05 PM 3/14/01 +0000, Tim Osborn wrote:
> >Thanks alot, these look good. I think we're really making some good
> >progress now.
> >
> >Just to confirm, my understanding is that you're next working on a similar
> >plot showing the
> >comparison of the REG-EM results w/ the straight gridbox age-banded
> >estimates you and Keith have produced over the longer period (ie, back to
> >1600 or so?). It would be great to be able to show those at EGS.
>
>Mike, you're welcome to show these results at EGS. I had to leave early
>today (Wednesday) as my wife was ill, but I'll be back at work tomorrow.
>What I'll do first is just to modify the figures I've already sent to you,
>comparing the verification REG-EM run with instrumental data over the
>1xxx xxxx xxxxperiod. What I want to do is to modify the final map so that the
>grid boxes that actually have tree-ring sites in them are highlighted in
>some way. Then we can visualise more clearly whether the 'local'
>information is much better than the 'non-local' information. I was in a bit
>of a hurry with my e-mail earlier, I didn't mention that the map is based on
>all those grid boxes with at least 20 years of instrumental data during the
>1xxx xxxx xxxxperiod. I found the year-by-year pattern correlations quite
>informative too, and was particularly impressed by the fact that there were
>no really poor years! (at least that's my recollection, not having the plots
>in front of me at home).
>
>Having modified the map as described, I'll repeat the analysis but comparing
>the 1xxx xxxx xxxxperiod of the full reconstruction from REG-EM with our
>existing year-by-year maps and quasi-hemispheric averages. I shall compare
>them against our "traditionally-standardised" version, since it would be
>unfair to compare them with the age-banded version. The year-by-year maps
>we have already got are calibrated on a grid-box by grid-box basis
>(individually) using simple linear regression between the density series and
>the instrumental temperature. This gives us coverage for those grid boxes
>with density data in them. We throw away those that do not correlate
>significantly with their local grid box temperature. That leaves around 100
>boxes, with fewer further back in time. We then try to reconstruct all
>remaining northern hemisphere grid boxes, using principal component
>regression (PCs of the calibrated density used as predictors on a grid box
>by grid box basis), but only actually retain those that have significant
>correlations during an independent verification period. So we gain quite a
>few more grid boxes, again time-varying. So we have this (perhaps rather
>odd!) combination of local regression plus principal component regression
>producing our maps. I shall use this set of year-by-year maps for the
>comparison with REG-EM, though as with the instrumental temperatures, I'll
>sometimes highlight or subsample just those with trees in (i.e. those
>locally-calibrated).
>
>Our original plan for carving up the analysis/papers was for me to take the
>lead on the comparison of methods with the same data set, Scott on the
>comparison of data sets with the same method, and Mike to concentrate on the
>19th century stuff including verification against the instrumental data etc.
> I saw Tom Crowley last week and he showed some results indicating how
>critical the 19th century is for getting a good match between his forced
>model results and the various proxy reconstructions - so the 19th century
>could certainly be a hot topic. Phil Jones would be useful here as he may
>know of more early instrumental data from Europe that might help (depending
>upon homogeneity!). Anyway, I'm refreshing our minds about the 3-way split
>of work because: (i) this might be an appropriate point to confirm that such
>a split is still the best way to go (I'm still happy with it); and (ii) to
>point out that the REG-EM comparisons with our existing density-based maps
>falls into the bit that I'm to take the lead on - so while I'm completely
>happy for you to show these at EGS or other meetings, I'd still like to
>write the comparisons up for a journal paper.
>
> >p.s. Tim: are you going to be at EGS? I know Phil will...Also, I'm hoping
> >that one of the 3 of you can make it to the Charlottesville workshop in
> >April. You and Phil have both indicated you can't go, I think? At present,
> >Keith hasn't yet confirmed. It would be a shame not to have him, you, or
> >Phil present. Can you suggest some sort of "alternate" (Schweingruber?) the
> >Europeans might invite if Keith can't make it. Thanks...
>
>I can't make it to EGS, as I have work to prepare for my 3 talks I'm giving
>at NCAR in the first week in April! For the Charlottesville workshop, I
>spoke to Keith yesterday and I think he has now booked his flights - so I'd
>take that as confirmation. He's in touch with Julie Jones at GKSS about it.
> I put in a good word about how pleasant Charlottesville was!
>
>Best regards to you both,
>
>Tim
>
>
>Dr. Timothy J. Osborn
>Climatic Research Unit
>University of East Anglia
>Norwich NR4 7TJ, UK.
>Telephone: 01xxx xxxx xxxx
>Fax: 01xxx xxxx xxxx
>e-mail: t.osborn@xxxxxxxxx.xxx
>homepage: http://www.cru.uea.ac.uk/~timo
_______________________________________________________________________
Professor Michael E. Mann
Department of Environmental Sciences, Clark Hall
University of Virginia
Charlottesville, VA 22903
_______________________________________________________________________
e-mail: mann@xxxxxxxxx.xxx Phone: (8xxx xxxx xxxxFAX: (8xxx xxxx xxxx
http://www.evsc.virginia.edu/faculty/people/mann.shtml
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From: Tim Osborn <t.osborn@xxxxxxxxx.xxx>
To: mann@xxxxxxxxx.xxx, srutherford@xxxxxxxxx.xxx
Subject: Re: verification results
Date: Thu Mar 15 16:38:xxx xxxx xxxx
Mike & Scott,
I've redone the verification against instrumental temperatures for 1xxx xxxx xxxx. Previously I'd used 1xxx xxxx xxxx, but I've now realised that 1900 is not part of the verification period (the pattern correlation = 1 gave it away!). So I've now stopped in 1899. It makes virtually no difference to the quasi-hemispheric series and their correlations. What it does affect is the grid-box by grid-box temporal correlations, since I was previously using one perfect value at the end of each series. So the correlations are mostly a bit lower now, though still fairly good I think. There's a reasonable area with r > 0.3. Signal to noise should increase fairly dramatically if some kind of regional averaging were done. I've outlined the boxes that actually have chronologies in them. There's not enough instrumental data to verify the more northern ones, but the European and USA ones do well (r in range 0.5 to 0.9). The more distant oceanic regions are a bit poorer, excep the northern Indian Ocean. So that's it for the verification, for the moment.
I've compared the 1xxx xxxx xxxx(i.e., pre-instrumental) reconstruction with the Briffa et al. and Osborn et al. reconstructions. Correlations are all quite high (0.7 to 0.85) for the quasi-hemispheric series, while the pattern correlations average around 0.6. The box-by-box temporal correlations show many boxes with r in the range 0.6 to 1.0, indicating little sensitivity to the method used. One notable feature of the latter results is that there's less agreement in the boxes that actually have trees than those don't! There's two different interpretations of this that I'm working on, which seem equally possible. More later. I was going to send the time series and maps from this comparison, but I've just realised that I'm using anomalies from two different baselines (1xxx xxxx xxxxfor ours, 1xxx xxxx xxxxfor REG-EM) so the % variance explained and the time series aren't right - that'll have to wait till Friday now.
Tim
Original Filename: 984770757.txt | Return to the index page | Permalink | Earlier Emails | Later Emails
From: "Michael E. Mann" <mann@xxxxxxxxx.xxx>
To: Tim Osborn <t.osborn@xxxxxxxxx.xxx>
Subject: Re: comparison with our existing reconstructions
Date: Fri, 16 Mar 2001 14:25:xxx xxxx xxxx(EST)
Cc: Scott Rutherford <srutherford@xxxxxxxxx.xxx>, Mike Mann <mann@xxxxxxxxx.xxx>
Dear Tim, Scott
On the road w/ tenous email connection so have to be brief. This sounds
good. Hoping we can have age-banded connections by the end of tnext week
so I can show in Nice! Scott: can you rectify the comparisons that Scott
is
producing w/ your own comparisons that show more of a discpreapancy ?
Thanks,
mike
Fri, 16 Mar 2001, Tim Osborn wrote:
> Dear Mike & Scott,
>
> Attached is "traditional.ps", comparing the 1xxx xxxx xxxx(i.e.
> pre-instrumental) REG-EM reconstruction with our existing Osborn et al.
> maps and Briffa et al. quasi-hemispheric series (see refs below). Neither
> the REG-EM nor the existing reconstructions use the age-banded trees, so
> low frequencies are suppressed. [Scott - thanks for the new age-banded
> results, but I probably won't get to them till next week due to other
> commitments.]
>
> The time series comparisons are, as you see, quite good - thought you'd
> expect this as we're comparing two methods but identical data! Red is
> REG-EM, black is from the Osborn et al. existing reconstructions (then
> averaged into quasi-hemispheric means), while blue is from Briffa et al.
> (where we average the tree-density into regions/hemisphere *before*
> calibrating against regional/hemispheric temperature). Blue & black agree
> quite closely, so all correlations and % var explained are between red and
> black.
>
> Timeseries are:
>
> '0-90' = full spatial average over each of our existing maps.
> '0-70' = full spatial average over each of the REG-EM maps.
> 'masked' indicates REG-EM maps are masked by the time-dependent coverage of
> our existing maps.
> 'land20-90' or 'land20-70' indicates only land grid boxes north of 20N are
> averaged.
> 'treeboxes' indicates only those grid boxes that contain tree-ring sites
> are averaged together.
>
> The pattern correlations range from 0.2 to 0.8, with a mean of 0.6
> (approx). Fairly consistent then. The pattern of temporal correlations is
> reasonable, ranging from 0.0 to 0.9, with a mean of 0.6 (approx).
>
> Comments:
> (1) Time series generally have less variance in REG-EM, especially early
> on, though masking of data brings them closer to our time series.
> (2) Getting the mean level correct (I've converted REG-EM to behave like
> anomalies from 1xxx xxxx xxxxmean) helps with the %variance explained considerably.
> (3) The temporal correlations are poorer for boxes containing trees than
> those that do not!
>
> The decreased variance early in the REG-EM [comment (1)] is, I guess,
> because the fewer the records with data, the earlier the
> truncation/weighting function kicks in etc. and therefore the less the
> variance that is reconstructed. As the 'skill' of REG-EM decreases, the
> more the values are filled in with something near to their mean, I seem to
> recall. This raises the question that the early values might be biased
> towards the observational mean? If so, it might be better to replace box
> values by missing values when their expected 'skill' becomes fairly low.
>
> Comment (3) can be explained two ways. In the non-tree boxes our two
> methods (REG-EM and principal component regression) have similarities, and
> given the common input data, one would expect similar reconstructions -
> which the high correlations indicate. In the tree boxes, however, the
> difference is our approach uses only local information, while REG-EM still
> uses non-local information too. So, either (i) our reconstructions are
> poorer *because* we're ignoring non-local information, or (ii) REG-EM
> reconstructions are poorer *because* real local variations are partly
> masked by regional-scale variations. It might be possible to choose either
> (i) or (ii) as a preferred explanation, using verification or other
> consideration, but I'd prefer to stick with (i) and (ii) as being equally
> possible and therefore justifying both approaches. This is politically
> better too! What I get out of the comparison is that the REG-EM is
> producing variability that is highly correlated with our method, given the
> same input data. The main concern is the difference in variance and hence
> absolute anomalies. We should look at this again when I've compared the
> age-banded stuff too.
>
> Another long e-mail, but I hope that this is useful (especially for EGS)
> and will form the basis of a comparion of methods paper.
>
> Have a good weekend!
>
> Tim
>
>
>
>
>
>
>
> Briffa KR, Osborn TJ, Schweingruber FH, Harris IC, Jones PD, Shiyatov SG
> and Vaganov EA (2001) Low-frequency temperature variations from a northern
> tree-ring-density network. Journal of Geophysical Research 106, 2xxx xxxx xxxx.
>
> Osborn TJ, Briffa KR, Schweingruber FH and Jones PD (2001)
> Annually-resolved patterns of summer temperatures over the Northern
> Hemisphere since AD 1400 from a tree-ring-density network. In preparation.
>
_______________________________________________________________________
Professor Michael E. Mann
Department of Environmental Sciences, Clark Hall
University of Virginia
Charlottesville, VA 22903
_______________________________________________________________________
e-mail: mann@xxxxxxxxx.xxx Phone: (8xxx xxxx xxxxFAX: (8xxx xxxx xxxx
http://www.evsc.virginia.edu/faculty/people/mann.html
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From: Wolfgang Cramer <Wolfgang.Cramer@xxxxxxxxx.xxx>
To: "F. Ian Woodward" <F.I.Woodward@xxxxxxxxx.xxx>, "Nigel W. Arnell" <N.W.Arnell@xxxxxxxxx.xxx>, Alberte Bondeau <Alberte.Bondeau@xxxxxxxxx.xxx>, Almut Arneth <Aarneth@xxxxxxxxx.xxx>, Anabel Sanchez <a.sanchez@xxxxxxxxx.xxx>, Andreas Schuck <andreas.schuck@xxxxxxxxx.xxx>, Anne de la Vega-Leinert <a.vega-leinert@xxxxxxxxx.xxx>, Ari Pussinen <ari.pussinen@xxxxxxxxx.xxx>, B
Original Filename: 986407807.txt | Return to the index page | Permalink | Earlier Emails | Later Emails
From: "Michael E. Mann" <mann@xxxxxxxxx.xxx>
To: p.jones@xxxxxxxxx.xxx, k.briffa@xxxxxxxxx.xxx, t.osborn@xxxxxxxxx.xxx
Subject: problem
Date: Wed, 04 Apr 2001 14:10:xxx xxxx xxxx
Cc: mann@xxxxxxxxx.xxx, rbradley@xxxxxxxxx.xxx
<x-flowed>
Phil et al,
There is a problem w/ figure 4 (and discussion thereof) in your paper to
appear in Science. Unfortunately, I didn't catch this until I re-read the
paper just now. You haven't shown the right Mann et al NINO3
reconstruction. Are you sure you have used the *cold-season* NINO3
reconstruction, as discussed (and available) in the Mann et al Earth
Interactions paper, and not the annual mean reconstruction!!
http://www.ngdc.noaa.gov/paleo/ei/ei_reconsb.html
I don't believe that has the trend that the series you show does. That
NINO3 series agrees closely (r=0.63) w/ the Stahle et al series (once
the sign has been flipped on that series, and the off-by-one-year date
convention is taken into account), far closer than
what you have shown. I'm pretty sure you've used the wrong series.
Moreover, it is inappropriate to refer (as you do) the Nino3 reconstruction
as an SOI reconstruction, no matter whether it has been
renormalized, sign-switched, etc. There are fundamennal differences between
the low-frequency behavior of NINO3 and SOI, (consider
for example the 20th century!) and they aren't dynamically equivalent! To
say there is a "long-term trend" in our "SOI reconstruction"
is extremely misleading. There is a long-term trend in our *NINO3*
reconstruciton. Only Stahle produced an SOI reconstruction, and it is only
meaningful to correlate the two at annual timescales where they should
similarly reflect largely interannual ENSO variability.
Moreover, I don't think this is true (or as true) of our colld-season NINO3
series, which is the right one to use. Hopefully, you still
have a chance to change this in the galleys, etc.
Thanks in advance for your attention to this,
mike
_______________________________________________________________________
Professor Michael E. Mann
Department of Environmental Sciences, Clark Hall
University of Virginia
Charlottesville, VA 22903
_______________________________________________________________________
e-mail: mann@xxxxxxxxx.xxx Phone: (8xxx xxxx xxxxFAX: (8xxx xxxx xxxx
http://www.evsc.virginia.edu/faculty/people/mann.shtml
</x-flowed>
Original Filename: 986486371.txt | Return to the index page | Permalink | Earlier Emails | Later Emails
From: Mike Hulme <m.hulme@xxxxxxxxx.xxx>
To: s.torok
Subject: Fwd: RE: kyoto survey - press inquiry from the THES
Date: Thu Apr 5 11:59:xxx xxxx xxxx
Simon,
Could you - or Vanessa - buy a THES today from the paper shop and check this out. I would
quite like to draft a short letter to THES as suggested by Steve. But I need to see how
the issue was presented in this week's issue.
Thanks,
Mike
From: "Farrar, Steve" <steve.farrar@xxxxxxxxx.xxx>
To: 'Mike Hulme' <m.hulme@xxxxxxxxx.xxx>
Subject: RE: kyoto survey - press inquiry from the THES
Date: Thu, 5 Apr 2001 09:45:33 +0100
X-Mailer: Internet Mail Service (5.5.2653.19)
Dear Mike,
thanks for that. I feel terrible but despite the pain it cost to reply to the survey,
the deadline has now passed. We had such a high response rate that we decided to run the
piece in this week's paper while the issue of the US withdrawl from the protocol was
still high in everyone's mind. So I cannot include your responses. However, you make a
number of very significant points, not least your reply to question 2 on the strength of
the evidence and the political framework outlined in your final sentences. I wonder -
and I know this is pushing it - whether you might consider rearranging some of these
sentences to form a brief letter to the editor for the following week's paper? I would
like this issue to stay alive in the THES and allow the paper to play a small role in
persuading as many scientists as possible to take part in a scientific/political debate
that may contribute to influencing those people who *can* change things. Not an original
objective, I know, but the THES does have a fairly unique position within the academic
community and hence a responsibility. Anyhow, sorry for the bad news
best wishes
Steve
***********************
Steve Farrar
Science Reporter
Times Higher Education Supplement
xxx xxxx xxxxEast Smithfield
London E1W 1BX
United Kingdom
[1]www.thes.co.uk
Tel: (xxx xxxx xxxx
Fax: (xxx xxxx xxxx
-----Original Message-----
From: Mike Hulme [[2]mailto:m.hulme@xxxxxxxxx.xxx]
Sent: 04 April 2001 19:57
To: Farrar, Steve
Subject: Re: kyoto survey - press inquiry from the THES
Steve,
I hate these sort of questionnaires since Y or N answers are barely
adequate. However, I've given it a go with some other comments .............
(by the way, Prof. Trevor Davies is Head of my School here at UEA - I am
only Director of a Centre within the School, albeit a highly relevant one!).
You can quote me if appropriate, but let me know before hand.
Mike
At 12:30 02/04/01 +0100, you wrote:
>Dear Mike,
>
>hope you're well. I am conducting a survey of heads of UK university
>departments of environmental science for the Times Higher Education
>Supplement. I am keen to explore views concerning the United States and
>the Kyoto agreement. I wonder if you could answer the following Yes/No
>questions when you get a moment. Note, I will not identify you unless you
>specifically state that you do not mind being quoted.
>
>I do hope you can help
>
>all the bets
>
>Steve
>
>1: Do you believe human activities are at least in part responsible for
>driving global climate change?
YES
>2: Do you feel the evidence for this is sufficiently strong to start
>reducing emissions?
NO - to reduce emissions requires more evidence than that humans are
altering climate. We need to know something about the potential risks
associated with future climate change, whether these risks can be minimised
through adaptive action and then have some socially negotiated basis for
deciding about the necessity and extent of desirable emissions
reductions. On none of these issues do we have a good basis to work
from. The precautionary principle, if chosen, would imply start reducing
emissions now - but I am not convinced a blind application of the
precautionary principle in this case is the most appropriate instrument.
>3: Do you think the measures proposed at Kyoto were too weak, correct, or
>too strong?
The 5.2% emissions reduction by 2010 by Annex I countries were not driven
by science but by real-politik. By definition they were the best
achievable. The real issue however is not about target setting - it's
about the dynamics of change worldwide in energy technologies, investment
strategies, consumer and community behaviour and aspirations, etc. It is
*these* things that in the end will deliver a safer climate - not the
Protocol per se. More attention should be directed at the diverse and
myriad set of actions needed to decarbonise our societies.
>4: Are you disappointed that George Bush has abandoned the Kyoto agreement?
YES - but it is too early to say that Kyoto is dead. The USA does not have
the power of veto - and Bush will have to propose some climate management
strategy of his own. We wait and see.
>5: Should the rest of the world press on with the agreement without the
>United States?
Probably YES. This can be achieved and should provide valuable lessons in
global climate management which we can learn from in the long-term.
>6: Do you feel the US should be allowed to count carbon sequestration
>measures such as planting new forests towards any carbon emissions
>reduction target?
YES. The UK are doing it in their national climate change programme so why
not the USA?
>7: Are you optimistic that there will be a new emissions control agreement
>within the next 12 months?
A 'new' one? We haven't got one yet. I would think maybe not in the next
12 months, but the critical issues about global climate management will be
clearer.
>8: Should the Kyoto preliminary targets be watered down to gain the
>Americans' support?
NO. If the USA don't like them, let them not ratify or propose a strategy
of their own.
>If you would like to add any comments to this survey as to the
>implications of the US's rejection of Kyoto for the planet, what UK can do
>about it or what role scientists can play in this debacle, please do so.
In a literal sense the implications for global climate are trivial - what
will affect the course of global climate (and only then climate beyond
about 2030 - up until then climate is pretty much pre-determined by inertia
in the system) in the long-run are the effects of cumulative decisions
taken by many, many people/governments/businesses over the next 10-20
years. Let's not kid ourselves that the USA President is more powerful
than he would like to think. The planetary system is much bigger than one
4-year term of a US president.
The UK is playing a key role both within the negotiating machinery of the
FCCC, in pioneering new scientific analyses, and in working out new forms
of adapting to climate change. This momentum in the UK is not going to be
halted by Bush.
Scientists need to be there to point out the long-term nature of the
problem - it is not a classic political issue where a one-term government
can solve or worsen the problem. Scientists need to point out that for
long-term planetary management we need new analytical tools, new criteria
for investment decisions, a new appreciation of the concept of global
citizenship. What climate change forces us to do is to think about the
influence we are having on the quality of life for the next generation but
one - not our own generation or even our children's
generation. Conventional politics is not a system geared up for this
challenge.
>***********************
>Steve Farrar
>Science Reporter
>Times Higher Education Supplement
>xxx xxxx xxxxEast Smithfield
>London E1W 1BX
>United Kingdom
>[3]www.thes.co.uk
>Tel: (xxx xxxx xxxx
>Fax: (xxx xxxx xxxx
>
>
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Dr Mike Hulme
Executive Director
Tyndall Centre for Climate Change Research
School of Environmental Sciences
University of East Anglia
Norwich NR4 7TJ
UK
tel: +44 (0)1xxx xxxx xxxx(or 593900)
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The Tyndall Centre for Climate Change Research
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The Tyndall Centre is a new research initiative funded by three UK
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References
1. http://www.thes.co.uk/
2. mailto:m.hulme@xxxxxxxxx.xxx
3. http://www.thes.co.uk/
4. http://www.tyndall.uea.ac.uk/