Re: [asa] Creation Care

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.

More to the point, I've also studied chaos theory fairly extensively. The
Lorenz attractor came from an attempt to model weather. It's probably a
woefully simple model of weather, but it demonstrates why weather is difficult
to predict. Small changes in initial conditions cause large changes in outcome.
Of course Lorenz's system showed what happens on a relatively short time scale,
had only a few inputs, and low order dynamics (I believe it was third order --
I'm too lazy to step over to the bookcase and look it up just now) But I would
be cautious about making predictions on any system with embedded chaotic
dynamics.

This doesn't mean we're stuck with no visibility into the future. I'm glad to
see that most of the climate models predict ranges of temperature variation.
And those ranges and the resulting increases in sea level are certainly a cause
for concern. But in choosing policy initiatives to deal with global warming it
seems to me we ought to select low-cost changes over high-cost changes:
1) As one individual has already suggested, eliminate the federal subsidy on
flood insurance
2) Encourage countries to eliminate "slash and burn" agriculture. Here we can
point to our example: The U.S. and Canada both dump more oxygen into the
atmosphere on the east than they take in on the west because of their heavy
forestation (S. Fan, M. Gloor, J. Mahlman, S. Pacala, J. Sarmiento,
T. Takahashi, P. Tans, "A Large Terrestrial Carbon Sink in North America
Implied by Atmospheric and Oceanic Carbon Dioxide Data and Models" SCIENCE 16
OCTOBER 1998 VOL 282. For those of you who don't have free access to Science on
line, I have a pdf of the article which I'll be glad to email to those
interested)
3) Continue efforts to reduce CO2 emissions. I got an email from an
environmental organization the other day that included a quiz. The first
question was something like "The average 4 member family home has more
environmental impact than a car" True or false. The correct answer was true.
Not that the automakers can't do more, but cars have received a great deal of
attention since 1965, and something like 98% of their nonCO2 emissions have
been eliminated. Probably CO2 emissions can be significantly reduced by going
to hybrids or fuel cells or even burning ethanol, which just recycles carbon
taken out of the atmosphere by the crops that are used as feedstock. But some
effort needs to be put into other sources of emissions, where it may be easier
to reduce emissions.
4) And I second what Don says re Janice. I certainly disagree with her much of
the time, but it's worthwhile to have someone digging up dissenting data and
views.

--- Don Winterstein <dfwinterstein@msn.com> wrote:

> Thanks for pointing to Hansen's presentation. Lots of interesting pictures
> and graphs.
>
> I acknowledge my ignorance of climate modeling, but I've been involved in one
> way or another with geophysical modeling for most of my career as a
> scientist. This experience makes me skeptical of climate modeling.
>
> Geophysical modeling as I knew it concerned primarily the evaluation of
> seismic wave behavior in sedimentary rocks. Geophysicists are usually able
> to come up with impressive models of subsurface rocks from seismic data; but
> when you look closely at the details, you often find they did a little
> stretching here, a little bending there, and a little tweaking over here.
> The scientists of course had perfectly "reasonable" explanations for all
> their manipulations, but still the manipulations were necessary to make the
> fit impressive. If you look even more closely, you find cases where the fits
> really aren't good at all. Sometimes the impressive models turn out to
> correspond well with reality, sometimes poorly. Earth is messy.
>
> Is climate less messy than subsurface rocks? Superficially it seems likely
> to be rather messier.
>
> Seismologists fit literally thousands of different models to thousands of
> different data sets involving millions of seismic traces. Climatologists
> really have only a single data set to fit: the historical record. I suspect
> many geophysical modelers of seismic data would consider the task of fitting
> such a single trace to be relatively straightforward: You just tweak what you
> think are all the relevant parameters until you get a good match. This
> doesn't mean that your calculations have considered all the relevant
> parameters, it just means that, for the parameters you chose, you could get
> an impressive match. If the history had been different, the match might not
> have been as good. The good match also does not necessarily mean your model
> can give good predictions.
>
> Were I to seriously investigate climate modeling, one of the first things I'd
> want to do is invite the graduate students who're doing the work to the local
> bar long enough to get them to tell me how they work and what they think!
>
> Many of Janice's posts on this topic seem to go over poorly with the
> majority, but I think it's important when dealing with Earth science
> predictions for someone to vociferously take the minority view. With
> something so messy, there are many ways to go wrong. It's good to be a bit
> skeptical of "beautiful fits to data." Earth science is not physics.
>
> Getting back to seismology: Everyone in the West bases seismic models on
> acoustic impedance changes. There's essentially complete consensus. Halfway
> through my career a Russian scientist (aided by his beautiful and intelligent
> daughter, who's fluent in English) came on the scene with models based on
> radically different assumptions. We were unable to find fault with his
> assumptions or models. I eventually concluded that both kinds of models may
> be relevant, some more so in certain environments than others; and some of
> our unexplained results might be better explained in terms of the Russian's
> model. Recently his daughter (now married to Werner Herzog) informed me that
> her father had been given a lifetime achievement award by Vladimir Putin. Yet
> to this day he's had very little influence in the West.
>
> How about having two radically different models that can explain your data?
> Who would have guessed?
>
> Don
>
> ----- Original Message -----
> From: Randy Isaac<mailto:randyisaac@comcast.net>
> To: asa@calvin.edu<mailto:asa@calvin.edu>
> Sent: Tuesday, January 23, 2007 8:09 AM
> Subject: Re: [asa] Creation Care
>
>
> Yes, Don, there's been a lot of progress lately. See the correlations of
> models, temperature, and sea level in
>
http://www.columbia.edu/~jeh1/SierraStorm.09Jan2007.pdf<http://www.columbia.edu/~jeh1/SierraStorm.09Jan2007.pdf>
>
> I also wanted to follow up on a comment someone made recently but I can't
> find that post right now. I think it was Rich, but I'm not sure, who
> mentioned the few thousand year mismatch in temperature cycles between
> climate models and historical data. Last week Jim Hansen told me a story
> about how this was recently resolved. One of the inputs to the model is the
> Mankovitch cycle and the 21,000 year cycle of the perihelion vs the direction
> of tilt of the earth's axis. The assumption in the model was reasonable, it
> seemed, that the maximum solar energy absorbed in the northern hemisphere
> coincided with the time when the perihelion occurred in summer (for the
> northern hemisphere). For a long time, the paleoclimatologists puzzled over
> the timelag of the models with respect to the data. Finally, they realized
> that the maximum solar energy absorption was actually when the perihelion
> occurred in the springtime. That shortened the snowcover, changed the albedo,
> and maximized the solar energy flux for the entire season until the next
> winter. This was confirmed with more detailed modeling of that specific
> effect. When the modified assumption was changed in the global model, the
> discrepancy disappeared and the match is now remarkable!
>
> Beautiful example of science at work.
>
> Randy
> ----- Original Message -----
> From: Don Winterstein<mailto:dfwinterstein@msn.com>
> To: asa@calvin.edu<mailto:asa@calvin.edu> ; Randy
> Isaac<mailto:randyisaac@adelphia.net>
> Sent: Tuesday, January 23, 2007 4:19 AM
> Subject: Re: [asa] Creation Care
>
>
> Randy wrote: "I learned that there were no competing models and that the
> basic climate model, complex though it was, fit the data well enough to be
> considered the right model. That is, the community is not in the uncertainty
> phase since there is a framework of understanding that explains the key
> features of climate for the last 420,000 years."
>
> I need clarification on this. Wikipedia says, "The causes of ice ages
> remain controversial for both the large-scale ice age periods and the smaller
> ebb and flow of glacial/interglacial periods within an ice age." This
> Wikipedia statement is consistent what I heard throughout my 25-year career
> as an Earth scientist. Ice ages are certainly key features of climate,
> they've occurred within 420 000 years, and there is no agreement on causes
> despite multiple possible or likely mechanisms. This implies there are
> competing models.
>
> Don
>
>

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 08:53:11 2007