date: Tue, 09 Mar 2004 15:21:43 +0000 from: Tim Osborn subject: Fwd: Re: Anthropogenic forcing to: Keith Briffa So that's what's so interesting! Tim >Date: Tue, 09 Mar 2004 15:04:17 +0000 >From: Simon Tett >Subject: Re: Anthropogenic forcing >To: Tim Osborn >Reply-to: simon.tett@metoffice.com >Organization: Met Office >X-Accept-Language: en, en-us >User-Agent: Mozilla/5.0 (Windows; U; WinNT4.0; en-US; rv:1.4) Gecko/20030624 > Netscape/7.1 (ax) > >Hi Tim, > its the time development -- slow steady increase till 1970 or so > than massive and rapid increase beyond that. Forcing is linear so adding > should be OK. > >Simon > >Tim Osborn wrote: > >>Simon - sorry, you'll need to illuminate me here, as I'm not quite sure >>what it shows / what is interesting! Is it that the total anthropogenic >>forcing since 1750 is < 1 W/m^2, whereas IPCC give a best estimate >>somewhat higher than this (though with large aerosol-related uncertainty >>that means 1 W/m^2 is in the range of possibilities). >>Also, is it valid to add/subtract forcings likes this (anthro minus >>natural) - are they really additive, or do they have an interaction term? >>Tim >> >>At 10:58 09/03/2004, Simon Tett wrote: >> >>>Dear all, >>> I thought you might like to see this. Attached is total >>> global-mean anthropogenic adjusted forcing compates from ALL - >>> Natural. I think it shows something quite interesting.... >>> >>>Simon >>>-- >>>Dr Simon Tett Managing Scientist, Data development and applications. >>>Met Office Hadley Centre (Reading Unit) >>>Meteorology Building, University of Reading Reading RG6 6BB >>>Tel: +44 (0)118 378 5614 Fax +44 (0)118 378 5615 >>>Mobile: +44-(0)77 538 80696 >>>I work from home about 2 days/week. Tel: +44 (0)20 8874 2751 >>>E-mail: simon.tett@metoffice.com http://www.metoffice.com >>> >>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 > >-- >Dr Simon Tett Managing Scientist, Data development and applications. >Met Office Hadley Centre (Reading Unit) >Meteorology Building, University of Reading Reading RG6 6BB >Tel: +44 (0)118 378 5614 Fax +44 (0)118 378 5615 >Mobile: +44-(0)77 538 80696 >I work from home about 2 days/week. Tel: +44 (0)20 8874 2751 >E-mail: simon.tett@metoffice.com http://www.metoffice.com 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