date: Mon Feb 18 16:15:08 2002 from: Keith Briffa subject: Re: conclusion to: "Raymond S. Bradley" Fine Ray - see typo as caps below. My only suggestion is the possibility of repeating that we have only explored selected regional evidence and that the high-res spatial coverage is markedly reduced before the 17th century. I am here and working on the annotated version now. I could do with seeing the latest version of the Figure legends please. Keith At 10:43 AM 2/18/02 -0500, you wrote: Tom Pedersen requested a concluding "wrap-up" to our chapter. Here's what I wrote. Any comments/additions/changes? ray Conclusion A wide range of proxies for past climate provide an invaluable long-term perspective on global climate variability, and proxies of past forcing allow natural factors affecting climate to be evaluated. Together, these records indicate that recent warming is both unusual and not explicable in terms of natural factors alone. By combining model simulations with paleoclimatic data, a better understanding of climate sensitivity and the climate system response to forcing is emerging. Nevertheless, many uncertainties remain. Paleoclimate research has had a strong northern hemisphere, extra-tropical focus; there are very few high resolution paleoclimatic records from the tropics or from the extra-tropical southern hemisphere. Variability of major climate systems, such as the monsoons, is poorly documented. Our understanding OF regional responses to forcing and how one part of the climate system may lead, or lag, another remains poor. Much more work on these topics remains to be done. Climate variability over the last millennium provides the essential context for assessing future changes, even as anthropogenic effects become increasingly dominant. It is over the last millennium that modern societies have developed, coping with a wide range of climatic vicissitudes. Much of the world still lives at a subsistence level, very much affected by both inter-annual and inter-decadal climate variability. As we confront a world whose population is expected to increase from 6 billion people today to ~9-10 billion by 2060, paleoclimatic research can shed an important light on mechanisms of climate variability at these societally-relevant timescales. Raymond S. Bradley Distinguished Professor and Head of Department Department of Geosciences University of Massachusetts Amherst, MA 01003-5820 Tel: 413-545-2120 Fax: 413-545-1200 Climate System Research Center: 413-545-0659 Climate System Research Center Web Page: <[1]http://www.geo.umass.edu/climate/climate.html> Paleoclimatology Book Web Site (1999): [2]http://www.geo.umass.edu/climate/paleo/html -- Professor Keith Briffa, Climatic Research Unit University of East Anglia Norwich, NR4 7TJ, U.K. Phone: +44-1603-593909 Fax: +44-1603-507784 [3]http://www.cru.uea.ac.uk/cru/people/briffa[4]/