Re: [asa] Creation Care

--- Rich Blinne <rich.blinne@gmail.com> wrote:

> On 1/24/07, Bill Hamilton <williamehamiltonjr@yahoo.com> wrote:
>
> > Don makes some good points. I've been involved with engineering projects
> > for
> > the past 35 years, and seldom have I seen an engineering project
> > correspond
> > exactly to the frequently extensive modeling that was done in the design
> > phases. When we could presumably control all aspects of the design, we
> > still
> > had to tweak and modify to account for circumstances that loomed larger in
> > practice than in the models.
>
>
> Like you I have 25 years of experience in engineering modelling. In my case,
> it is semiconductor device simulation. One thing I have seen in either Don's
> or your post is how modelling has changed recently. 25 or 35 years ago we
> made numerous simpifying assumptions just because it would take FOREVER to
> simulate. Now we have machines that are 5-10 order of magnitude faster than
> when we started our careers. This means we can remove the heuristics -- a
> fancy scientific word for guess -- decrease our mesh size and time steps and
> get really good results. Why do I have confidence about this? Well, we are
> communicating through devices that have been extensively simulated where the
> measured results match extremely well with the modelled behavior. As time
> went on we modelled more and more effects, e.g. resistance, crosstalk, short
> channel effects, etc. None of these were a great surprise from a physics
> perspective but they required more iron to do the simulations. The same
> holds true with climate modelling. When I look at the climate models I see
> the same well-formed models. In fact, I would have killed to get such good
> correlations at so many corners as these models (and I would like access to
> their computers too :-) ).

I agree that the hardware -- and the software -- for modeling have improved
significantly. And that allows us to model more effects that we used heuristics
for before. But climate models are still complex enough that if we miss
anything, all the increased capability will do will be to enable us to produce
garbage much faster. And I suspect that it's easy to miss effects in
climatological models. Since the models are validated by comparison with
historical data, an effect that shows up outside the time baseline may be
missed. And given the chaotic nature of weather, _any_ omission -- dynamical or
boundary condition -- is likely to cause significant departure from the true
behavior.
>
> One item specific to climate modelling also gives me confidence. The
> satellite data was not meshing with the models in that the high altitude
> temperatures were not as predicted. An error in the data collection was
> fixed and then the models matched. This discrepency caused a literal act of
> Congress to determine why the models were not so good. Since then much has
> been done to make these models much, much better. There is still work to do
> in order to more accurately predict the small-scale implications of global
> warming because these are important for good public policy. But, the models
> are accurate enough now for the upcoming IPCC AR4 to have a 90% confidence
> that we are experiencing global warming and that it's primarily caused by
> anthropogenic greenhouse gases.
>
> Models matching the current (and now extensive) climate data are a necessary
> condition for any alternative hypotheses now. None of Janice's skeptics have
> put forth their own computer model (you can check for this youself by doing
> a Google scholar search for the author) and show that matches either the
> current or paleoclimate data better. It's not that these individuals have
> presented research results that got poo-pooed by the mainstream they have
> offered literally NOTHING. If I was Pim I would call it vacuous. :-) From

Fair enough

> now on, Janice will need to reference papers that have these models in them.
> For example, she needs to show that a model that has solar forcing more than
> 5X smaller than GHG forcing fits the curve better than the current model.
> Climate science is now quantitative and a qualitative hand waving no longer
> cuts it.
>

Bill Hamilton
William E. Hamilton, Jr., Ph.D.
248.652.4148 (home) 248.821.8156 (mobile)
"...If God is for us, who is against us?" Rom 8:31

 
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Received on Wed Jan 24 22:37:25 2007