cc: Eystein Jansen date: Wed, 1 Mar 2006 09:11:15 -0700 from: Jonathan Overpeck subject: Fwd: Re: latest draft of 2000-year section text to: Keith Briffa , TBaumgar@CICESE.MX, TRBaumgartner@UCSD.Edu Just to you - seems you could go a little further and be more clear as Stefan suggests. Not a major change. Your call, though. Thanks, Peck X-Sieve: CMU Sieve 2.2 Date: Wed, 01 Mar 2006 15:55:41 +0100 From: Stefan Rahmstorf X-Accept-Language: en-us, en To: Fortunat Joos Cc: Jonathan Overpeck , Tim Osborn , Keith Briffa , cddhr@giss.nasa.gov, Eystein Jansen Subject: Re: latest draft of 2000-year section text X-Provags-ID: kundenserver.de abuse@kundenserver.de login:a55186a74a9492274b66220889845b72 Hi all, let me add to Fortunat that I feel Keith and Tim have done a tremendous job in very thorny terrain. And I agree with Peck - science has moved way past the "hockey stick" debate, and it is great how our chapter shows that. Nevertheless, we should remember that the Von Storch et al. (2004) critique was a fundamental methodological critique that applies to *all* (or at least most) proxy reconstructions - it is not just a Storch vs. Mann quarrel (although it is that as well, of course). Hence it is worth mentioning their error, else this could still call the entirety of our conclusions from that section into question. Currently, our draft just says: At present, the extent of any such bias in specific reconstructions is uncertain This is true, but leaves in my view slightly too much room for interpretation - like, it would still encompass the interpretation that the bias of all reconstructions is desastrous, so they are all "nonsense" in Von Storch's words. What about saying something along the lines: "At present, the extent of any such bias in specific reconstructions is uncertain, although probably not as large as suggested by Von Storch et al. (2004), whose work was affected by a calibration error (Wahl, Ritson and Amman, 2006)." Regards, Stefan p.s. Tim: Are you convinced the more recent papers by the VS group use the correct calibration? In those curves that are intended to show the pseudoproxies perform poorly even when calibrated correctly, as long as you add a lot more noise, I wonder why the pseudoproxies perform poorly even within the calibration interval, where they now should be calibrated to properly reproduce the 20th C warming trend, and they don't? -- Jonathan T. Overpeck Director, Institute for the Study of Planet Earth Professor, Department of Geosciences Professor, Department of Atmospheric Sciences Mail and Fedex Address: Institute for the Study of Planet Earth 715 N. Park Ave. 2nd Floor University of Arizona Tucson, AZ 85721 direct tel: +1 520 622-9065 fax: +1 520 792-8795 http://www.geo.arizona.edu/ http://www.ispe.arizona.edu/