[Committee] exxon woman

Thu Feb 15 14:32:10 UTC 2007

---------- Forwarded message ----------
Subject: Re: Fwd: Re: [Committee] suphur dioxide
To: "A.L. Stephenson" <als53 at cam.ac.uk>
Cc: "A.L. Stephenson" <als53 at hermes.cam.ac.uk>,
        Oliver Crease <oc222 at cam.ac.uk>,
        Steve Stretton <steve at zerocarbonnow.org>
From: olivia.gwynn at exxonmobil.com
Date: Thu, 15 Feb 2007 14:19:29 +0000

Anna/Steve,

Thanks for setting me correct on that point and apologies for the mistake
on my part.  I thought I remembered from old chemistry lessons that it was
the other way around, but clearly that is not the case.

Kind regards,

Olivia

Olivia Gwynn
ExxonMobil International Limited
St. Catherines House, 2 Kingsway, London, WC2B 6WG

Tel:    +44 (0) 207 412 4474
Fax:   +44 (0) 207 412 2470
E-mail:   olivia.gwynn at exxonmobil.com

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             "A.L.                                                         
             Stephenson"                                                   
             <als53 at cam.ac.                                             To 
             uk>                      olivia.gwynn at exxonmobil.com          
             Sent by: "A.L.                                             cc 
             Stephenson"              Oliver Crease <oc222 at cam.ac.uk>,     
             <als53 at hermes.           Steve Stretton                       
             cam.ac.uk>               <steve at zerocarbonnow.org>            
                                                                   Subject 
                                      Fwd: Re: [Committee] suphur dioxide  
             15/02/07 14:05                                                

Dear Olivia,

I thought I should send this information on to you from Stephen Stretton,
an expert in Climate Change who is a member of the Cambridge University
Zero Carbon Society.

Best regards,

Anna Stephenson
Cambridge Zero Carbon Society

I was very disturbed to hear the speaker today suggested that Sulphur
Dioxide is a greenhouse gas. In fact the opposite is true: it is an aerosol
which cools the earth [1] and may well have had a significant effect in
masking the impact of much of the Carbon Dioxide that we have already
produced. [2] [3]

Please find enclosed a graphic which shows the past effect of SO2 (the main
aerosol) in masking global warming. The area below the x axis is the
negative impact of the gas, offsetting increased CO2 in the twentieth
century. The y axis (Radiative forcing) is a measure of the warming effect
of the greenhouse gases. It measures the degree of committed climate
change,
depending on stabilisation scenarios. All the scenarios require very strong
action to be taken.

*Further information:* [1] FROM IPCC (2001) "Aerosols are liquid or solid
particles suspended in the air. " "Aerosols have most likely made a
significant negative contribution to the overall radiative forcing. An
important characteristic of aerosols is that they have short atmospheric
lifetimes and therefore cannot be considered simply as a long-term offset
to the warming influence of greenhouse gases." "Sulphate aerosols are
produced by chemical reactions in the atmosphere from gaseous precursors
(with the exception of sea salt sulphate and gypsum dust particles)." "The
two main sulphate precursors are SO2 from anthropogenic sources and
volcanoes, and DMS from biogenic sources, especially marine plankton (Table

5.2 <http://www.grida.no/climate/ipcc_tar/wg1/167.htm#tab52>). Since SO2
emissions are mostly related to fossil fuel burning, the source
distribution and magnitude for this trace gas are fairly well-known, and
recent estimates differ by no more than about 20 to 30%"

[2] Also see: http://www.zerocarbonnow.org/GHG.xls

[3] Furthermore, James Lovelock has proposed production of Di-methyl
Sulphide by cool-water algae which decomposes to sulphates as being the
main
mechanism behind the biological regulation of climate: why we live on a
living planet (in thermodynamic dis-equilibrium) rather than a dead one.

[attachment "stabilisation.PNG" deleted by Olivia Gwynn/UK/ExxonMobil]