date: Tue, 14 Mar 2000 10:55:15 +0100 from: Hans von Storch subject: revision 10.6. to: tar10@egs.uct.ac.za Folks, here is what I have agreed with Bruce about the revision of 10.6: Linda has promised to deal with the weather generators. I will try to shorten, but if I miss the 25% request, then we will live with it and ask the secretariat to complete this work. Neither Bruce nor I are aware of papers with significant new insights concerning uncertainty, methodology and comparison since completion of the zeroth draft. Thus, new material will mostly be brought into Appendix D, i.e. the list of applications. Time table: I will try to complete the revision, and shortening of 10.6 untilt the end of this week. A will offer 1-line, or so, responses to the reviewers; Bruce will incorporate them into his master document dealing with reviewers comments. After that I will go in some detail through my collection of "new papers" and prepare an extension of the list in Appendix D; also Bruce will do so. Eventually, Bruce will merge the original list with the two extensions prepared by himself and me. Linda, could you update the list as well? --- The "box"-debate: Filippo wrote: "We cannot invent information of course, but we can condense it in this box by including 1) the info relative to what AOGCMs sy for different continent, which is already there; 2) all possible other info from the techniques. If there is none or if we can say nothing we'll say we cannot do it for that specific region. but I think we need to do something because the way it is, the chapter does not address the right audience, which is not only made up only of scientists." The reason why the box may be be of interst for many people is what Mike says they are not suitable for: "yield the range of possible future regional climates that impacts studies should consider". First, continents are according to our definitions not "regional". Second, could we possibly discuss an example, namely the climate change information we think to have for, say, South Africa? An example: for the Mediterranean we (Cubasch et al.) made an intercomparison of AOGCM, high res (T106) time slices and regional emp. downscaling and found little convergence - for the same basic global scenario. This is the uncertainty problem, and I thought our asssessment would be that uncertainty is still too large, in particular because of lack of convergence on the side of the AOGCM information to be processed by regionalisation techniques. Mike wrote: "from the perspective John Houghton seems to be coming from there is also I think the very important question a lot of people ask about whether 'downscaling' fundamentally alters the basic GCM results for a region. Would it be possible to include in the Box therefore any examples of regional changes derived from GCMs directly and then derived using alternative downscaling methods driven by that GCM? Just to show the potential for divergence/convergence at a regional scale between downscaling methods rather than between different GCMs." That is the "added-value" problem brought forward by Filippo, which I consider essential for the entire chapter. We should have such an example. (I could provide a simple one for precip in Romania, but there may be better ones around.) We should be aware that it is our responsibility to assess the certainty and uncertainty of information on the regional scale.We should respond to critique concerning incomplete or incorrect analysis of what has been published, also concerning linguistic readability. But we must not respond positively to requests for information to be used in impact and policy analysis, which we do not consider sufficiently robust for this purpose. We should explain why we don't think the information robust yet. Climate research has become a postnormal science, with the intrusion of political demands and significant influence by activists driven by ideological (well meant) concerns. On the other hand, we have to defend the credibility of our science. Regards Hans Hans von Storch (until 31. March 2000) Institute for Marine and Atmospheric Research Utrecht (IMAU) Princetonplein 5, PO Box 80 005, NL 3508 TA Utrecht, The Netherlands http://w3g.gkss.de/staff/storch fax: + 31 30 254 3163, phone: +31 30 253 3182 private: Essenkamp 20, 3732 De Bilt, + 31 30 220 0863