From: "Michael E. Mann" <mann@meteo.psu.edu>
To: Tom Crowley <tcrowley@duke.edu>
Subject: Re: not so fast
Date: Tue, 02 Jan 2007 11:18:45 -0500
Reply-to: mann@psu.edu
Cc: "raymond s. bradley" <rbradley@geo.umass.edu>, rahmstorf@ozean-klima.de, Eric Steig <steig@ess.washington.edu>, gschmidt@giss.nasa.gov, rasmus.benestad@physics.org, garidel@marine.rutgers.edu, Caspar Ammann <ammann@ucar.edu>, William Connelley <wmconnolley@gmail.com>, d-archer@uchicago.edu, rtp1@geosci.uchicago.edu, p.jones@uea.ac.uk

   for those who are interested, there is a paper by Goosse et al (I'm a co-author) explaining
   why parts of Europe such as central england would have experienced warmer summer conditions
   relative to present than other regions, related to early land-use change:
   Goosse, H., Arzel, O., Luterbacher, J., Mann, M.E., Renssen, H., Riedwyl, N., Timmermann,
   A., Xoplaki, E., Wanner, H., [1]The origin of the European "Medieval Warm Period", Climate
   of the Past, 2, 99-113, 2006.
   paper available as pdf here:
   [2]http://www.meteo.psu.edu/~mann/shared/articles/Goosseetal-CP06.pdf
   meanwhile, winter warmth could have been due to a strong AO/NAO pattern associated with
   decreased volcanism and high solar, as discussed in the various Shindell et al paper.
   this simply underscores the point that we all often make, that one needs to take into
   account regional factors when interpreting regional records. This is especially relevant to
   the extrapolation of a long record from England to the entire NH (which appears to have
   been tacitly done by Jack Eddy?),
   mike
   Tom Crowley wrote:

   we still don't have an adequat explanation as to how Jack "cooked up" that figure - I do
   not believe it was purely out of thin air - look at the attached - which I used in the
   Crowley-Lowery composite just because it was "out there" - I made no claim that it was the
   record of record, but just that it had been used beforer.  the Lamb ref. is his book dated
   1966.  I will have to dig up the page ref later.  Dansgaard et al. 1975 Nature paper on
   Norsemen...etc used that figure when comparing what must have been their Camp Century
   record - have to check that too - where the main point of that paper was that the timing of
   Medieval warmth was different in Greenlandn and England!
   25 years later my provocation for writing the CL paper came from a strong statement on the
   MWP by Claus Hammer that the canonical idea of the MWP being warming than the present was
   correct and that the 1999 Mann et al was wrong.  he kept going on like that I reminded him
   that he was a co-author on the 1975 paper!  that is also what motivated to do my "bonehead"
   sampling of whatever was out there just to see what happened when you added them all
   together - the amazing result was that it looked pretty much like Mann et al.  ther rest is
   history -- much ignored and forgotten.
   I might also pointn out that in a 1996 Consequences article I wrote - and that Fred Singer
   loves to cite -- Jack (who was the editor of the journal) basically shoehorned me into
   re-reproducing that figure even though I didn't like it - there was not an alternative.  in
   the figure caption it has a similar one to Zielinski except that it states "compiled by
   R.S. Bradley and J.A. Eddy based on J.T. Houghton....so that puts a further twist on this
   because it point to Houghton not Bradley/Eddy as the source.  Jack must have written that
   part of the figure caption because I don't think I knew those details.
   but we still don't know where the details of the figure came from - the MWP is clearly more
   schematic than the LIA (actually the detailsl about timing of the samll wiggles in the LIA
   are pretty good) - maybe there was a meshing of the Greenland and the England records to do
   the MWP part - note that the English part gets cooler.  they may also have thrown in the
   old LaMarche record - which I also have.  maybe I can schlep something together using only
   those old three records.
   tom
   Michael E. Mann wrote:

   Ray, happy holidays and thanks for the (quite fascinating) background on this. It would be
   good material for a Realclimate article. would be even better if someone could get Chris on
   record confirming that this is indeed the history of this graphic...
   mike
   raymond s. bradley wrote:

     I believe this graph originated in a (literally) grey piece of literature that Jack Eddy
     used to publish called "Earth Quest".  It was designed for, and distributed to, high
     school teachers.  In one issue, he had a fold-out that showed different timelines,
     Cenozoic, Quaternary, last 100ka, Holocene, last millennium, last century etc.  The idea
     was to give non-specialists a perspective on the earth's climate history.  I think this
     idea evolved from the old NRC publication edited by L. Gates, then further elaborated on
     by Tom Webb in the book I edited for UCAR, Global Changes of the Past.  (This was an
     outcome of the wonderful Snowmass meeting Jack master-minded around 1990).

     I may have inadvertently had a hand in this millennium graph!  I recall getting a fax
     from Jack with a hand-drawn graph, that he asked me to review.  Where he got his version
     from, I don't know.  I think I scribbled out part of the line and amended it in some
     way, but have no recollection of exactly what I did to it.  And whether he edited it
     further, I don't know.  But as it was purely schematic (& appears to go through ~1950)
     perhaps it's not so bad.  I note, however, that in the more colourful version of the
     much embellished graph that Stefan circulated ([3]
     http://www.politicallyincorrect.de/2006/11/klimakatastrophe_was_ist_wirkl_1.html
     the end-point has been changed to 2000, which puts quite a different spin on things.
     They also seem to have fabricated a scale for the purported temperature changes.  In any
     case, the graph has no objective basis whatsoever; it is purely a "visual guess" at what
     happened, like something we might sketch on a napkin at a party for some overly
     persistent inquisitor..... (so make sure you don't leave such things on the table...).
     What made the last millennium graph famous (notorious!) was that Chris Folland must have
     seen it and reproduced it in the 1995 IPCC chapter he was editing.  I don't think he
     gave a citation and it thus appeared to have the imprimatur of the IPCC. Having
     submitted a great deal of text for that chapter, I remember being really pissed off that
     Chris essentially ignored all the input, and wrote his own version of the paleoclimate
     record in that volume.

     There are other examples of how Jack Eddy's grey literature publication was misused.  In
     a paper in Science by Zielinski et al. (1994) [v.264, p.448-452]--attached-- they
     reproduced [in Figure 1c] a similarly schematic version of Holocene temperatures giving
     the following citation, "Taken from J. A. Eddy and R. S. Bradley, Earth-quest 5 (insert)
     (1991), as modified from J. T. Houghton, G. J. Jenkins, J. J. Ephraums, Climate Change,
     The IPCC Scientific Assessment (Cambridge Univ. Press, Cambridge, 1990)."
     But I had nothing to do with that one!
     So, that's how a crude fax from Jack Eddy became the definitive IPCC record on the last
     millennium!
     Happy New Year to everyone
     Ray

     Raymond S. Bradley
     Director, Climate System Research Center*
     Department of Geosciences, University of Massachusetts
     Morrill Science Center
     611 North Pleasant Street
     AMHERST, MA 01003-9297
     Tel: 413-545-2120
     Fax: 413-545-1200
     *Climate System Research Center: 413-545-0659
              <[4] http://www.paleoclimate.org>
     Paleoclimatology Book Web Site: [5]http://www.geo.umass.edu/climate/paleo/html
     Publications (download .pdf files):
     [6]http://www.geo.umass.edu/faculty/bradley/bradleypub.html

--
Michael E. Mann
Associate Professor
Director, Earth System Science Center (ESSC)

Department of Meteorology              Phone: (814) 863-4075
503 Walker Building                    FAX:   (814) 865-3663
The Pennsylvania State University      email:  [7]mann@psu.edu
University Park, PA 16802-5013

[8]http://www.met.psu.edu/dept/faculty/mann.htm


--
Michael E. Mann
Associate Professor
Director, Earth System Science Center (ESSC)

Department of Meteorology              Phone: (814) 863-4075
503 Walker Building                    FAX:   (814) 865-3663
The Pennsylvania State University      email:  [9]mann@psu.edu
University Park, PA 16802-5013

[10]http://www.met.psu.edu/dept/faculty/mann.htm

References

   1. file://localhost/tmp/Goosseetal-CP06.pdf
   2. http://www.meteo.psu.edu/~mann/shared/articles/Goosseetal-CP06.pdf
   3. http://www.politicallyincorrect.de/2006/11/klimakatastrophe_was_ist_wirkl_1.html
   4. http://www.paleoclimate.org/
   5. http://www.geo.umass.edu/climate/paleo/html
   6. http://www.geo.umass.edu/faculty/bradley/bradleypub.html
   7. mailto:mann@psu.edu
   8. http://www.met.psu.edu/dept/faculty/mann.htm
   9. mailto:mann@psu.edu
  10. http://www.met.psu.edu/dept/faculty/mann.htm

