cc: wg1-ar4-ch06@joss.ucar.edu
date: Wed, 20 Jul 2005 09:41:07 -0400
from: David Rind <drind@giss.nasa.gov>
subject: Re: [Wg1-ar4-ch06] Comments on Section 6.3
to: Stefan Rahmstorf <rahmstorf@ozean-klima.de>

   Sorry, Stefan. In the interest of maintaining a constructive working atmosphere, perhaps I
   should have used the term "conceptual" model, which  I would use for any model  (not just
   CLIMBER-2) that parameterizes the water vapor feedback with a functional relationship, that
   has a one layer cloud model, that parameterizes the dynamic transports, etc. These are all
   zeroth or first order processes, which GCMs, with all their flaws (which I'm the first to
   admit) at least try to calculate.  I apologize if the comment was taken personally as
   applying only to this one model. Unlike others, I believe conceptual models do have their
   use, which is why I have included without argument the comment in Section 6.2 that models
   of various complexity are useful for paleoclimate studies due to the long time periods that
   need to be simulated.  I believe such models can suggest possible mechanisms, and, by using
   appropriate tuning procedures, can suggest orders of magnitude of various terms. But
   "suggest" is as far as I would go, due to the highly parameterized nature of the primary
   processes and climate feedbacks - and I should say that if you think this is just coming
   from the GCM community, this comment comes straight from Peter Stone, who as you know runs
   an EMIC and has published numerous papers with one. Given that opinion, or even regardless
   of it, the reference is overused - it shows up four times in five paragraphs.

   As for your comment about GCMs, if they were used to address questions that depended
   heavily on highly parameterized representations of the processes you mention, I would call
   their approach "simplistic" (conceptual) in those cases as well.

   David

   At 12:39 PM +0200 7/20/05, Stefan Rahmstorf wrote:

      have a request on procedure. In the interest of a good and constructive working
     atmosphere, I would suggest that all of us focus on sober scientific arguments and
     refrain from unneccessarily derogatory comments about the work of colleagues. I'm
     referring in this case to David's comment

     - this reference is overused, especially for such a simplistic model

     It would never occur to me to call David's model "simplistic" because it does not
     include an interactive continental ice sheet model, vegetation model, carbon cycle
     model, sediment model and isotope model.

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