cc: m.hulme@uea.ac.uk date: Fri, 30 Apr 1999 08:53:32 +0100 from: Merylyn McKenzie Hedger subject: RE: Fwd. re: US views on possible UK cooling- FYI to: "Jenkins, Geoff" Please tell Mike McCracken! It's not about evenhandeness though-it's about capturing all possibilities. Mike Hulme's new work on uncertainty does allow a way of this remote risk being accounted for despite it's non appearance in the GCMs. Where are my Buenos Aires photos? It will be Bonn soon. M > -----Original Message----- > From: Jenkins, Geoff [SMTP:gjjenkins@meto.gov.uk] > Sent: 29 April 1999 10:11 > To: 'Merylyn McKenzie Hedger' > Cc: Mitchell, John FB; 'penny_bramwell@detr.gsi.gov.uk' > Subject: RE: Fwd. re: US views on possible UK cooling- FYI > > Thanks for this info Merylyn - the ability to get HadCM2 widely used > in the > US Assessment came about through your meeting with Mike McCracken - so > thanks for the tip off. My personal view is that it would be a waste > of time > putting a cooling scenario in UKCIP - where would it come from? no > model > shows any cooling so it would have to be totally invented. Sounds like > the > usual even handedness in the US for political reasons gone made. > > Cheers > > Geoff > > > -----Original Message----- > > From: Merylyn McKenzie Hedger > > [SMTP:merylyn.hedger@environmental-change.oxford.ac.uk] > > Sent: 23 April 1999 13:06 > > To: 'penny_bramwell@detr.gsi.gov.uk'; > 'david_warrilow@detr.gsi.gov.uk'; > > 'gjjenkins@meto.gov.uk'; 'm.hulme@uea.ac.uk' > > Cc: 'cathy_johnson@detr.gsi.gov.uk' > > Subject: Fwd. re: US views on possible UK cooling- FYI > > > > Dear Colleague, > > > > This email arose from a discussion I first had with Granger Morgan > who > > has master-minded the US approach on socio-economic scenarios. When > > shown the material on the UKCIP98 sceanrios his first reaction was > what > > about cooling, and Mike McCracken jumped in too. The US National > > Assessment Synthesis team has gone for extremes on their economic > and > > demographic projections to capture all eventualities so I suppose > > that's a different philosophy, reflected here. > > > > By the way, most of the US National Assessment studies have used > HADCM2, > > (when I went to Washington last year they were only going with the > > Canadian model, so Geoff did good work there). In some places, this > has > > produced results in sharp contrast to the Canadian model causing > > problems. The NCAR model is just ready for use. > > > > I hope to do the overall report on the meeting next week. I am > telling > > Mike McCracken I have forwarded his thoughts! My response when we > spoke > > was that currently UKCIP was focusing on getting awareness and > action on > > the changes which were likely in the 'near' term. > > > > Merylyn > > ------------------------------------------- > > From Mike McCracken > > > > ------- > > > > Dear Merylyn--To follow-up on our discussion with Granger in > Atlanta, I > > went and looked at the plots I have. Both Granger and I would > interpret > > this as iimplying that there is indeed a chance of a cooling > scenario > > for > > the UK, even if not a full crash of the Atlantic circulation. > > > > Thanks again for coming to Atlanta, Mike > > > > >Date: Wed, 21 Apr 1999 13:43:20 -0400 > > >To: gmorgan > > >From: Mike MacCracken > > >Subject: North Atlantic overturning > > >Cc: > > >Bcc: > > >X-Attachments: > > > > > >Dear Granger--Following up on our discussion in Atlanta with > Merylyn > > >McKenzie Hedger and the risk of cooling in the UK and Europe, I > went > > back > > >and checked the figures for predictions for the North Atlantic > > circulation > > >changes from the GCDL and Hadley models: > > > > > >1. GFDL: > > > > > >Control--20 Sverdrups > > >up to 2 times CO2 at 1% per year and stabilize--drops to about 7 > and > > then > > >recovers over long time > > >up to 4 times CO2 at 1% per year and stabilize--drops to about 2 > and > > stays > > >there > > > > > >2. Hadley Centre model > > > > > >control--about 22-23 Sverdrups > > >IPCC BAU-drops to about 17 > > >up to 4 times CO2 at 2% per year--drops to about 14 and slwoly goes > up > > to > > >about 16 > > > > > >The dates on the Hadley figure are a bit strange--their BAU case > starts > > >dropping in about 1980-90. Their up to 4 times CO2 drops in about > 1890 > > >(yes, 110 years ago), so I assume they started their run in about > 1860 > > and > > >started the sharp CO2 increase then. > > > > > > > > >Thus, with respect to Merylyn's comments about the UK model not > showing > > a > > >collapse, true, but. Basically, the GFDL run does show a stronger > > >reduction, but the Hadley model does also show a significant > decrease > > as > > >well. I think I might worry about a potential cooling. > > > > > >Mike > > > > > > > > > > > > > Michael C. MacCracken, Ph.D. > > National Assessment Coordination Office > > Suite 750 > > 400 Virginia Avenue > > Washington DC 20024 > > > > Tel: (202) 314-2230 (Main number for NACO and for Robert Cherry, > Admin. > > Asst.) > > Tel: (202) 314-2233 (office and voicemail) > > Fax: (202) 488-8681 or (202) 488-8678 > > E-mail: mmaccracken@usgcrp.gov > > USGCRP Home Page: http://www.nacc.usgcrp.gov/ > > > > > > > >