Saturday, May 19, 2012


cc: Mike Hulme <>
date: Thu, 22 Jan 1998 19:49:21 -0700 (MST)
from: Tom Wigley <>
subject: COSMIC
to: Philip Newton <>

Dear Philip,

Michael Schlesinger mentioned to me that you had expressed an interest in
his software package "COSMIC". You may not realize that my colleagues and
I in CRU (notably Mike Hulme, Mike Salmon, Sarah Raper and Ogla Brown)
developed similar user-friendly software some years ago. It comes in two
integrated components, MAGICC and SCENGEN. MAGICC does the global-mean
calculations that are used to drive the regional climate-change pattern
algorithms in SCENGEN. It is widely used; and has been integrated into a
more complex Integrated Assessment package by Jae Edmonds, Hugh Pitcher
and others at Battelle.

The principle used by our software is the same as used by Schlesinger in
COSMIC. The method was invented by Ben Santer and me almost 10 years ago.
MAGICC employs the same models that I used in doing the latest IPCC
global-mean temperature and sea level projections. Michael uses similar
models, but they are not "the" IPCC models. SCENGEN employs a large
database of GCM results, overlapping the database that Michael uses.
SCENGEN also includes regionally-specific SO2 emissions scenarios, using a
compositing method that I invented some years ago. Michael uses the same
method; but I don't think he has implemented this part of his code yet.
SCENGEN can give global maps of climate change, or higher-resolution maps
for a number of selected regions. SCENGEN uses a better observed climate
database than COSMIC, drawing on 20 years of work in this area in CRU. I
believe SCENGEN also gives output for a wider range of climate variables
than COSMIC.

In my view, COSMIC simply re-invents the wheel that we developed some time
ago. Michael tends to be rather cavalier in giving credit to others. He
has known about MAGICC/SCENGEN for some time; but I doubt that he has ever
bothered to look at the software.

If you want to know more, contact Mike Hulme (details below). The latest
version of MAGICC/SCENGEN was developed largely under his direction. It
is available on a CD-ROM to run under Windows. It is easy, educational
and fun to use.


cc: Mike Hulme
Climatic Research Unit
University of East Anglia
Norwich NR4 7TJ, United Kingdom
Tel: 1603-593162
Fax: 1603-507784

*Tom M.L. Wigley *
*Senior Scientist *
*National Center for Atmospheric Research *
*P.O. Box 3000 *
*Boulder, CO 80307-3000 *
*USA *
*Phone: 303-497-2690 *
*Fax: 303-497-2699 *
*E-mail: *

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