cc: oyvind.paasche@geo.uib.no date: Tue, 5 Sep 2006 22:27:20 +0200 from: Eystein Jansen subject: Re: urgent IPCC need to: Keith Briffa OK, but please not later than Monday! Cheers, Eystein >eystein >i have to leave for austria now for a week - on >monday next will send result of consultation for >text change regrading the von storch paragraph >of our chapter, after discussion with Stefan and >john Mitchell - please wait til then >keith > >At 16:13 01/09/2006, you wrote: >>dear All, thanks for being alert. >>I think we have an agreement that Martin´s >>comments are useful, but that we should change >>only those sentences where they clarify. >>Otherwise i agree with Stefan and Keith´s >>statements below. >> >>Eystein >> >>At 15:45 +0100 01-09-06, Keith Briffa wrote: >>>I forgot to say that I too disagree with >>>removing the first sentence re simulations >>>being consistent with reconstructed NH temps. >>>As Sefan says we need the context , and our >>>results are independent of Chapter 9 in this >>>regard. >>>Keith >>> >>>At 15:37 01/09/2006, Stefan Rahmstorf wrote: >>>>Hi Peck, >>>> >>>>Martin as in Manning? I have found his >>>>feedback very useful so far, so we should >>>>definitely look at what he suggests - he >>>>mostly tends to look for whether our >>>>sentences are clear. Obviously, he cannot >>>>suggest real changes in meaning, only issues >>>>of clarity, but the latter I would take very >>>>seriously. Mostly I find his small rewordings >>>>good, I comment on the larger points and >>>>exceptions below. >>>> >>>>- I am against deleting the bullet on speed >>>>of deglacial change. This point is extremely >>>>effective. Just two days ago an oil industry >>>>person told me that there have been big >>>>natural climate changes like ice ages in the >>>>past, hence we need not worry. I responded >>>>that the biggest warming in recent climate >>>>history was the end of the last Ice Age - but >>>>that warming by about 5 ºC took about 5,000 >>>>years, not a hundred. "Oh" he said, "Really >>>>so long? I didn't know that." I think it is a >>>>very important point, we need to make it. >>>>Maybe not in term of "average rate", may we >>>>should just say: the warming of 4-7 ºC took >>>>about 5,000 years, as compared to a future >>>>change of up to the same magnitude within a >>>>century. >>>> >>>>- Next ice age bullet in 30k seems fine to me. >>>> >>>>- exceptional warmth: the SPM said: >>>>20th C T increase likely the largest in a >>>>millennium - that is strengthened (perhaps >>>>very likely now?) >>>>1990s likely the warmest decade in a >>>>millennium - that again is strengthened >>>>1998 likely the warmest year - I'd say this >>>>is unchanged (except for 2005 challenging >>>>it), likely is only 66%! Even though the >>>>annual proxy data may be uncertain, as a >>>>physicist I would find it unlikely that there >>>>is a mechanism to cause a big warm outlier >>>>year that beats 1998 from a much cooler >>>>background state. How would that work - where >>>>would the heat come from? >>>>So in my view we could actually say that >>>>these past SPM statements held up or were >>>>strengthened - but in fact I also like the >>>>bullet as it is. >>>> >>>>- Paleoclimate model simulations are broadly >>>>consistent with the reconstructed NH >>>>temperatures over the past 1000 years. The >>>>rise in surface temperatures since 1950 very >>>>likely cannot be reproduced without including >>>>anthropogenic greenhouse gases in the model >>>>forcings, and it is very unlikely that this >>>>warming was merely a recovery from the >>>>pre-20th century cold period. >>>>On this I disagree with deleting the first >>>>sentence, as the second one needs it to >>>>follow logically. And why should the paleo >>>>chapter suddenly make a statement on >>>>post-1950 warming, if it is not in the >>>>context of the past millennium? >>>> >>>>Cheers, Stefan >>>> >>>> >>>> >>>> >>>>-- >>>>To reach me directly please use: >>>>rahmstorf@ozean-klima.de >>>>(My former addresses @pik-potsdam.de are read by my assistant Brigitta.) >>>> >>>>Stefan Rahmstorf >>>>www.ozean-klima.de >>>>www.realclimate.org >>> >>>-- >>>Professor Keith Briffa, >>>Climatic Research Unit >>>University of East Anglia >>>Norwich, NR4 7TJ, U.K. >>> >>>Phone: +44-1603-593909 >>>Fax: +44-1603-507784 >>> >>>http://www.cru.uea.ac.uk/cru/people/briffa/ >> >> >>-- >>______________________________________________________________ >>Eystein Jansen >>Professor/Director >>Bjerknes Centre for Climate Research and >>Dep. of Earth Science, Univ. of Bergen >>Allégaten 55 >>N-5007 Bergen >>NORWAY >>e-mail: eystein.jansen@geo.uib.no >>Phone: +47-55-583491 - Home: +47-55-910661 >>Fax: +47-55-584330 > >-- >Professor Keith Briffa, >Climatic Research Unit >University of East Anglia >Norwich, NR4 7TJ, U.K. > >Phone: +44-1603-593909 >Fax: +44-1603-507784 > >http://www.cru.uea.ac.uk/cru/people/briffa/ -- ______________________________________________________________ Eystein Jansen Professor/Director Bjerknes Centre for Climate Research and Dep. of Earth Science, Univ. of Bergen Allégaten 55 N-5007 Bergen NORWAY e-mail: eystein.jansen@geo.uib.no Phone: +47-55-583491 - Home: +47-55-910661 Fax: +47-55-584330