cc: Simon Tett , Chris Turney , Rob Allan , Catherine Bass , Keith Briffa , Matt Collins , Peter Cox , Pierre Friedlingstein , Pete Hodges , Chris Jones , Phil Jones , "Richard, Sharon, Rowan and Nathan Jones" , Tom Melvin , Tim Osborn , "Sime, Louise C" , Sandy Tudhope , Rob Wilson date: Wed, 28 Oct 2009 15:03:28 +0000 from: Gabi Hegerl subject: Re: Model/data WP to: "Wolff, Eric W" The time coverage question is a good one. I would advocate to at least cover the LIttle Ice Age, as this is a period with very interesting changes, will help better constrain the emerging ghg signal if you cover the solar low period in the LIA (so you can try separate ghg from solar, volcanism etc) and would be interesting from a carbon cycle point of view. The medieval warm period would be interesting due to its lack of CO2 response (so may produce an upper constraint on CO2response), and also the question of what caused it.... so in my view, is of secondary interest to our goals but not of zero. Can we do a 'largely period from LIA to now but with some reduced effort in the time since, say, 800AD'? Gabi Wolff, Eric W wrote: > Dear Simon > Great to read this text. I can start to see how the different parts fit together, though there is still a lot of work to do. I just want to raise a couple of high level issues we will need to decide very fast on Monday before we go further: > > 1. Timescale covered by this project. Your text, on the second page, mentions three different timescales: "1750 to 2000", 500 years and 1000 years. We must settle on one. If we do scale back to 1750 then we miss the LIA (mentioned in the same paragraph as 1750) - however you define it was almost over by 1750. > 2. You question whether we can also use CH4. CH4 does show some variation in the pre-1800 period. However, based on CH4 and 13CH4, authors tend to ascribe this to fire and agriculture, ie human influenced. While I am convinced Ruddiman is wrong for CO2, methane has probably been under human influence for too long for us to use it. I would avoid this. > > See you next week. > Eric > > Eric Wolff > British Antarctic Survey > High Cross > Madingley Road > Cambridge CB3 0ET > United Kingdom > > E-mail: ewwo@bas.ac.uk > Phone: +44 (0)1223 221491 > Fax: +44 (0)1223 221279 > > British Antarctic Survey: www.antarctica.ac.uk > IGBP/Past Global Changes (PAGES): www.pages-igbp.org > International Partnerships in Ice Core Sciences (IPICS): www.pages-igbp.org/ipics/ > > > -----Original Message----- > From: Simon Tett [mailto:simon.tett@ed.ac.uk] > Sent: 27 October 2009 22:19 > To: Chris Turney > Cc: Rob Allan; Catherine Bass; Keith Briffa; Matt Collins; Peter Cox; Pierre Friedlingstein; Gabi Hegerl; Pete Hodges; Chris Jones; Phil Jones; Richard, Sharon, Rowan and Nathan Jones; Tom Melvin; Tim Osborn; Sime, Louise C; Sandy Tudhope; Rob Wilson; Wolff, Eric W > Subject: Re: Agenda for 2-3 November > > and rather late here is the current draft text that Gabi and I have. It > is still far from complete but will give us something to discuss. > > Sorry -- neither Gabi nor I have had much time to work on it and we > won't have any more this week. Have yet to figure out resource > requirements. > > If this is the way we want to go then I think our current structure will > need some radical changes.... > > Simon > > Chris Turney wrote: > >> Hi guys, >> >> Please find attached the agenda for the 2-3 November. If you haven't >> yet sent me any outstanding documents for the application (as listed in >> my previous email), please do so by the close of today. I'm away next >> week but will spend the time making a first pass at weaving the >> application together to send round to everyone for next Friday so we >> have something to butcher for the residential! >> >> All the best, >> >> Chris >> >> **************************************************** >> *Professor Chris Turney FRSA FGS FRGS* >> >> Director of Carbonscape , /Fixing carbon the >> way nature intended/ >> // >> >> Author of Ice, Mud and Blood: Lessons from Climates Past >> >> Popular science website: >> www.christurney.com >> Journal of Quaternary Science >> Asian and Australasian >> Regional Editor >> >> School of Geography >> The University of Exeter >> Exeter >> Devon >> EX4 4RJ >> UK >> >> Home page: >> http://geography.exeter.ac.uk/geography/people/staff/c_turney/main.shtml >> E-mail: c.turney@exeter.ac.uk >> Office Tel.: +44 (0)1392 263331 >> Fax.: +44 (0)1392 263342 >> >> **************************************************** >> >> *Slartibartfast: * Science has achieved some wonderful things of course, >> but I'd far rather be happy than right any day. >> *Arthur Dent:* And are you? >> *Slartibartfast:* No. Thats where it all falls down of course. >> *Arthur Dent:* Pity. It sounded like quite a good lifestyle otherwise. >> >> /The Hitchhikers Guide to the Galaxy/, Douglas Adams >> >> **************************************************** >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> ------------------------------------------------------------------------ >> >> > > -- ------------------------------------------------------------------------------ Gabriele Hegerl Chair of Climate System Science School of GeoSciences, University of Edinburgh Grant Institute, The King's Buildings, West Mains Road EDINBURGH EH9 3JW Phone: +44 (0) 131 6519092, FAX: +44 (0) 131 668 3184 http://www.geos.ed.ac.uk/people/person.html?indv=1613 Email: Gabi.Hegerl@ed.ac.uk ------------------------------------------------------------------------------ The University of Edinburgh is a charitable body, registered in Scotland, with registration number SC005336.