Monday, June 11, 2012


cc: Eystein Jansen <>, Gabi Hegerl <>,, Fortunat Joos <>, joos <>, "Ricardo Villalba" <>,
date: Wed Jan 5 17:41:56 2005
from: Keith Briffa <>
subject: Re: Fwd: Re: [Wg1-ar4-ch06] IPCC last 2000 years data
to: Jonathan Overpeck <>

Hi Peck (et al)
I am considering comments (including David's) re last 2000 years - some are valid = some are not . Will try to chop out bits but we need this consensus re the forcing and responses bit - I am for keeping the forcings in as much as they relate to the specific model runs done - and results for last 1000 years as I suspect that they will not be covered in the same way elsewhere . David makes couple good points - but extent to which forcings different (or implementation) perhaps need addressing here. The basic agreement I mean is that the recent warming is generally unprecedented in these simulations.
It will take time and input from the tropical ice core /coral people to do the regional stuff well . I think the glaciological stuff is a real problem - other than just showing recent glacial states (also covered elsewhere) - of course difficult to interpret any past records without modelling responses (as in borehole data), but this requires considerable space . My executive decision would be to ask Olga to try to write a couple of papragraphs on limits of interpretation for inferring precisely timed global temperature changes? What do others think? I only heaved Olga's stuff in at last moment rather than not include it - but of course it needs considerable shortening. The discussion of tree-ring stuff is problematic because it requires papers to be published eg direct criticism of Esper et al. We surely do not want to waste space HERE going into this esoteric topic? All points on seasonality , I agree with , but the explicit stuff on M+M re hockey stick - where is this? ie the bit about normalisation base affecting redness in reconstructions - sounds nonsense to me ?

I have to consider the comments in detail but am happy for hard direction re space and focus. If concensus is no forcings and model results here fine with me - Peck and Eystein to rule

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