Steven wrote:
> And, while models such as you mention can be validated by
> ground checks, most of the models for global weather and global warming
> cannot be verified against actual data. That is my problem with models.
> Steven
The General Circulation Model can be validated. But this would require an
'independent data set'...which is that another 'earth like' ecosystem would
have to supply the data. Barring that, the data set would have to be an
actual data set from earth. This means that the model would only prove true
or false after the date was reached when the predictions were initially
predicted.
From an ethical stand point thus if the sources of the problem which are the
high per capita emitters of green house gases do not take the predictions in
stance, then they are morally blameworthy. Sure little countries like
Senegal or Bhutan may be worse off, but it is the countries like the US,
Canada and Australia that are to blame. Note that if something is done to
reduce fossil fuel emissions, and to reduce 'deforestation' then the
countries such as the US, Canada and Australia will be morally
'praiseworthy'.
Afterall fossil fuels are finite. So it makes extra sense to conserve and
find non-polluting alternatives. There are many advantages to finding
substitutes for wood and coal.....
chao
john foster
>
> -----Original Message-----
> From: Discussion forum for environmental ethics.
> [mailto:[log in to unmask]]On Behalf Of Ray Lanier
> Sent: Wednesday, July 25, 2001 11:42 AM
> To: [log in to unmask]
> Subject: Re: more on global warming models
>
>
> Hello Steven,
>
> It seems to me that your comments are not well-grounded, perhaps I am
wrong.
> Let me offer my experience in an effort to clarify for us both. I'm
> obviously biased! :-)
>
> All models that I have been involved with - on agriculture water & land
use
> issues - have begun with many trial runs to test validity of the data and
> assumptions used in model construction. These analyses were then analyzed
> by professionals in the several fields involved: agr production and yield
> assumptions, current and over time, technology, water available, costs &
> prices, land available and productivity, environmental factors, etc. For
> example, I remember particularly one model 35 years ago. When I presented
> it for review by the several specialists one old agricultural specialist
> sorta drawled: "Well, I see you have projected a move of the dairy
industry
> from Wisconsin to Iowa!" For various institutional reasons that was not a
> valid outcome in the time-frame involved. So go back to the drawing board
> to see where the data and/or assumptions were not acceptable.
>
> Once the model was judged "reasonable" in data and basic assumptions the
> analysis could begin. First we would evaluate the situation based on the
> assumption that there would be no change in poliicy/program. This is
> extremely important because it establishes a baseline that suggests the
> magnitude of, for example, the potential water supply problems, if any.
> Then it offers a baseline against which the several proposals to alleviate
> any water supply problems that might be proposed. These programs offer us
> an opportunity to evaluate, relatively easily, many policy/program options
> to enable us to better select those that are most helpful and least
> damaging.
>
> None of these analyses were "predictions" - implying factual accuracy.
They
> were *projections*, implying best estimates of the relative consequences
> that could be expected under the assumptions and the data available at the
> time of study.
>
> Those models were extremely important because they enabled us to
incorporate
> interrelationships among many activities in a way that the old hand
> calculators could not provide. And, in today's modelling world, they were
> very primitive. The model outlined above was a matrix of about 200+/-
> columns and about 100+/- rows with a large percentage of empty cells. Yet
> it still took over 12 hours to run on an IBM computer complex taking up
most
> of a building at U. Illinois Champaign-Urbana - and that was just to see
if
> we had a potential feasible solution. And we ran the problem on the
> weekends to save money - it would take a weekend to get to a feasible
> solution. Today, I could run that problem on my little old desktop in
> minutes.
>
> Now the analytical capabilities are far in advance of the little work we
> did. But for me, the significance of the great expansion in computer
power
> is, first, the savings in time & money; second, the opportunity to
> incorporate more of the complexity of the environmental problems in the
> analysis.
>
> The important ethical issues for me are whether the data and assumptions
are
> valid in the eyes of the professionals reviewing the work and whether the
> problem is appropriate to the particular computer complex used. In
today's
> world, I think that the organization and review of data and assumptions in
> such large problems must be horrendous. We should expect errors; the
test -
> whether there is adequate review by competent professionals of the base
> program and the analyses.
>
> And these are only projections to help society visualize the potential
> problems and to get some understanding of the *relative* worthwhileness of
> proposed policies/programs.
>
> I think it would be unethical not to use the newest computer technology as
> it becomes tested and available.
>
> Steven, and all, I would appreciate any comments.
>
> Ray
> -------------
>
> ----- Original Message -----
> From: "Steven Bissell" <[log in to unmask]>
> To: <[log in to unmask]>
> Sent: Wednesday, July 25, 2001 10:16 AM
> Subject: more on global warming models
>
>
> > Here is another article (I haven't seen the cited article in _Science_)
> that
> > seems to me to be based on the use of models. This is not new evidence,
it
> > is just more modeling of old data and, worse, it is based on assumption
> > about policy. I'm not sure this serves anyone very well.
> >
> > Steven
> >
>
http://www.enn.com/news/enn-stories/2001/07/07242001/warming_44399.asp?site=
> > email
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