Re: [asa] Level of certainty in science

You are correct that skepticism about models is good. However, models
do not exist in a vacuum but rather take existing data from the past
and use hindcasts as well as forecasts to validate the performance. In
addition, climate models are based on laws of physics and while they
may miss relevant processes, climate models are well founded in
science.
Sure, all these models may be wrong and the earth may end up cooling
and the scientists may look foolish, on the other hand the earth may
actually follow the predictions and who would look foolish then?
Science is never certain and global warming is no exception but there
are good or even strong reasons to believe that these predictions are
quite valid.

<quote>For example, the Program for Climate Model Diagnosis and
Intercomparison at Lawrence Livermore National Laboratory has been
conducting model comparison and validation tests since 1989 (including
the climate models used by the IPCC), and published a publicly
available report of its research in the summer of 2004. [see
http://www-pcmdi.llnl.gov/ ]</quote>

IPCC is also involved in validation of models and I believe that most
scientists understand that models are supplementary to other
scientific data and cannot stand alone.

http://www.grida.no/climate/ipcc_tar/wg1/308.htm

AR4 draft also shows the hard work done here:
http://www.junkscience.com/draft_AR4/
    * Executive Summary
    * Advances in Modeling
    * Evaluation of Contemporary Climate as Simulated by Coupled Global Models
    * Evaluation of Large Scale Climate Variability as Simulated by
Coupled Global Models
    * Evaluation of the Key Relevant Processes as Simulated by Coupled
Global Models
    * Model Simulations of Extremes
    * Climate Sensitivity
    * Evaluation of Model Simulations of Thresholds and Abrupt Events
    * Representing the Global System With Simpler Models

<quote>There is considerable confidence that climate models provide
plausible quantitative estimates of future climate change,
particularly at continental scales and above. Confidence in these
estimates is higher for some climate variables (e.g. temperature)
than for others (e.g. precipitation). This confidence comes from the
foundation of the models in accepted physical principles and from
their ability to reproduce observed features of recent climate (see
Chapters 8, 9) and past climate changes (see Chapter 6). In this
summary we highlight areas of progress since the TAR:
</quote>

On 2/6/07, Don Winterstein <dfwinterstein@msn.com> wrote:
>
>
>
> Pim Van Meurs wrote: "What is so scary about science being correct once
> again? If one
> believes this to be scary, imagine how scary it could be when
> Christians, as Augustine pointed out, are observed spouting scientific
> nonsense?"
>
> Who's got more to lose here? The climate data may be fairly firm, but the
> models, from which scientists make predictions, are likely much less
> trustworthy. They're Earth science models, after all. If Earth starts
> cooling within a few decades--as it's been known to do, climate scientists
> and other scientists by association will lose credibility for a long time to
> come.

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Received on Tue Feb 6 23:49:18 2007