cc: "Phil Jones"
date: Tue, 16 Oct 2007 13:43:11 +0100
from: "Jenkins, Geoff"
subject: RE: Romans in Britain
to: "Stott, Peter"
Thanks. I think I will say: "Anecdotal evidence, for example the growing
of grapes in the medieval period, has been used to imply that current
warm temperatures in England have not been influenced by human
activities. However, the popularity of grape growing is related to many
other factors apart from temperature, and the longest temperature record
in existence (that for the Low Countries (van Engelen, refernce??))
indicates a medieval warm period that was cooler than current
temperatures". OK?
I am not very convinced by it myself, but it's the best I can think of.
Realclimate points out that "attribution doesn't depend on previous
climates changes", which I have used myself, but doesnt seem to apply
here, does it, because you use the lack of any natural warming from
obs/model as the way to rule out natural causes for the last 50 years.
van Engelen (Fig 6 in UKCIP02) seems to show sustained warmings as big
as 1970-2000 in the 1300s.
Change of subject. In K&S you say "....it is likely that there has been
a sig human influence on the recent warming of CET...". I is the word
"likely" meant to have IPCC connotations ie GT 66%?
BTW I didn't think much of the 9 errors article on realclimate,
particularly the points on SLR and on Kilimanjaro. Much too defensive of
Gore.
Geoff
-----Original Message-----
From: Stott, Peter
Sent: 16 October 2007 13:10
To: Jenkins, Geoff
Cc: Jones, Gareth S
Subject: Re: Romans in Britain
Geoff,
http://www.realclimate.org/index.php?p=322
has an extensive discussion of English wine growing.
Also
http://www.realclimate.org/index.php/archives/2006/11/english-vineyards-
again/
Socio economic factors are more important than climate.
Phil Jones can tell you all about Vine Street in London which isn't
anything to do with vineyards I gather.
The observed variability on the 200 years we looked at in Karoly and
Stott agreed with the modelled variability - in fact the unforced
control model had about the same variability as the (presumably
naturally forced) observed variability, indicating the model had too
much (not too little) variability.
If there was greater unforced variability pre 1700 than post 1700 than
that could I suppose invalidate our conclusions but I don't know any
evidence there was, during the last 2000 years or so.
A whole industry of bloggers out there are debating the 9 "errors" and
now realclimate has weighed in.
http://www.realclimate.org/
Peter
On Tue, 2007-10-16 at 11:09 +0100, Jenkins, Geoff wrote:
> Peter
>
> What is the line to take, please, on "It was warmer in England in
> Roman times - grapes etc - so the Karoly & Stott attribution of recent
> CET warming to man is rubbish".
>
> Thanks
>
> Geoff
>
> Dr Geoff Jenkins
> Manager, Climate Change Scenarios
> Hadley Centre
> Met Office
> FitzRoy Road, EXETER, EX1 3PB, UK
> tel: +44 (0) 787 966 1136
> geoff.jenkins@metoffice.gov.uk
> www.metoffice.gov.uk
>