cc: m.hulme@uea.ac.uk, wagner@thames.iiasa.ac.at, kuszko@thames.iiasa.ac.at,  Peter Whetton <peter.whetton@dar.csiro.au>,  Chris Mitchell <chris.mitchell@dar.csiro.au>
date: Fri, 12 Feb 1999 12:02:02 +1100
from: Barrie Pittock <barrie.pittock@dar.csiro.au>
subject: RE: Stabilization/mitigation scenarios workshop
to: 'Nebojsa NAKICENOVIC' <naki@iiasa.ac.at>,  Timothy Carter <tim.carter@vyh.fi>, shaheen@sdpi.org, emilio@ppe.ufrj.br,  rik.leemans@rivm.nl, lindam@ucar.edu,  Barrie Pittock <barrie.pittock@dar.csiro.au>, semenov@glas.apc.org,  j.skea@psi.org.uk

Dear Tim, Naki, et al.,

The description of the Workshop on stabilization/mitigation scenarios
makes clear its WG3 focus on mitigation. Our concern in WG2 must surely
be on climate and SL rise impacts of such scenarios. This is the key to
answering my and Bob Watson's concern that we address the FCCC objective
which requires identifcation of safe levels of GH gases. Of course, what
this requires is that such stabilization scenarios actually be run in
GCMs and the results evaluated as regards impacts.

So, either the Workshop should re recommending running GCMs with
stabilisation scenarios ASAP, or else looking at those few stabilisation
scenarios that have actually already been run in GCMs, such as several
we have done in CSIRO. What we need are a survey of what stabilisation
runs have been run, and what results are available especially regarding
global and regional patterns of climate change and SL rise beyond
stabilisation of concentrations. It is probably too much to expect
detailed impact assessments from them in time for TAR, but some broad
inferences could be drawn based on climate and SL sensitivity studies.
For example, what are the implications of  a latent 1 or 2 extra metres
of SL rise after 2100? - given economic discounting, technological
adaptation, etc., does the international community care, and if so why?
Maybe that is a key question for WG3 also?! It is certainly relevant to
international and inter-generational equity.

I suggest that irrespective of what comes out of said Workshop, the
above is one of the tasks that we Chapter 3 authors will need to
address. I will try to address this in outline at least in my
contribution to the zero-order draft, but any suggestions of other
existing stabilisation simulations which can be looked at would be
welcome. A technical question is whether we have only
upwelling-diffusion models to apply to long-term SL rise beyond 2100, or
some more physically based model results - we really need some vertical
integrations of  the deep oceans from detailed ocean models to put these
estimates on a sounder footing - although maybe the actual SL rise is
not the issue, but more the principle that a lot of latent rise will be
in the system.

Obviously Naki or others from Chapter 3 attending the Workshop in
Copenhagen should convey this concern, and see that it is transmitted to
WG1. I am already doing that via my colleague Peter Whetton in the
adjoining office, but there is other overlapping membership of WGs 1 and
2.

Does that make sense to everyone?

Regards,

Barrie.
Dr A. Barrie Pittock
Leader, Climate Impact Group
CSIRO Atmospheric Research
PMB 1, Aspendale 3195, Australia
Tel +61 3 9239 4527, Fax +61 3 9239 4688
email barrie.pittock@dar.csiro.au
WWW: http://www.dar.csiro.au/res/cm/impact.htm

"Far better an approximate answer to the right question which is often
vague, than an exact answer to the wrong question which can always be
made precise." J.W. Tukey as cited by R. Lewin, Science 221,636-639.

> -----Original Message-----
> From:	Nebojsa NAKICENOVIC [SMTP:naki@iiasa.ac.at]
> Sent:	Thursday, 11 February 1999 21:35
> To:	Timothy Carter; shaheen@sdpi.org; emilio@ppe.ufrj.br;
> rik.leemans@rivm.nl; lindam@ucar.edu; barrie.pittock@dar.csiro.au;
> semenov@glas.apc.org; j.skea@psi.org.uk
> Cc:	m.hulme@uea.ac.uk; wagner@thames.iiasa.ac.at;
> kuszko@thames.iiasa.ac.at
> Subject:	Re: Stabilization/mitigation scenarios workshop
> Importance:	High
> 
> Dear Tim and colleagues,
> 
> I just wanted to inform you that I am planning to attend this workshop
> and
> hopefully make a presentation about SRES scenarios in the context of
> mitigation. 
> 
> Regards,  Naki
> 
> At 10:25 AM 2/11/99 +0200, Timothy Carter wrote:
> >Dear colleagues,
> >
> >I am forwarding a message from Neil Leary about a workshop that has
> some
> >relevance for Chapter 3 (especially recalling Bob Watson's comments
> in
> >Geneva that we should address stabilization scenarios). I would be
> grateful
> >if you could read this through and let me know if you are already
> planning
> >to attend the workshop.
> >
> >The enquiry from Neil (and Rob Swart of WG III) includes a suggestion
> that 
> >WG I/WG II has a representative at the workshop who could describe
> the
> >relevance for/linkages to the needs of these two WGs. Clearly, issues
> that
> >might need to be pursued include:
> >
> >1. How do stabilization scenarios affect projections of future
> climate and
> >sea-level change?
> >
> >2. How do the socio-economic and environmental assumptions underlying
> these
> >scenarios differ from the SRES scenarios we are already working with?
> A
> >multiple century, post-2100 time horizon is obviously one aspect that
> will
> >be different.
> >
> >To Linda Mearns and Mike Hulme (Chapter 13, WG I CLAs): Perhaps one
> member
> >of our teams needs to attend to provide some insights into the
> climatic
> >implications of stabilization.
> >
> >Best wishes,
> >
> >Tim
> >
