cc: Keith Briffa date: Tue, 14 Feb 2006 11:54:44 +0000 from: Tim Osborn subject: Re: your paper today to: peter.stott@metoffice.gov.uk Hi Peter - thanks for your interesting question. I don't think we can rule out systematic bias in the proxies in the most recent decades, but random noise in the proxies is also capable of producing such a deviation, given that the noise could be autocorrelated and anyway we are working with 20-year smoothed results and the number of proxy records drops from 14 to 5 over the final few decades through to 1995 (the instrumental data are also included up to 2004, covering more of the warmest period). There's still more work to be done, but we really need more long proxies and more brought up to date. Cheers, Tim At 18:40 10/02/2006, you wrote: >Hi Tim, > >I enjoyed reading your paper in Science today. One issue I was >interested in was the separation in fig 3D between the instrumental data >and the proxy data. You comment in the paper that this could be expected >consequence of noise in the proxy records but naively it looks like >there might be something more systematic in the last few decades. Are >you able to rule out systematic non temperature effects on the proxies >in recent decades then ? > >Thanks ! >Peter > >-- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > Dr. Peter Stott Climate Scientist Met Office > Hadley Centre for Climate Prediction and Research (Reading Unit) > Meteorology Building, University of Reading, Reading RG6 6BB > Tel: +44 (0)118 378 5613 Fax: +44 (0)118 378 5615 > Mobile: 07753880683 > E-mail:peter.stott@metoffice.gov.uk http://www.metoffice.gov.uk > NOTE WILL ALSO BE AT EXETER PART OF EACH WEEK >~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Dr Timothy J Osborn Climatic Research Unit School of Environmental Sciences, University of East Anglia Norwich NR4 7TJ, UK e-mail: t.osborn@uea.ac.uk phone: +44 1603 592089 fax: +44 1603 507784 web: http://www.cru.uea.ac.uk/~timo/ sunclock: http://www.cru.uea.ac.uk/~timo/sunclock.htm