Predictions of dire global warming are based on computer models. These
models are constructed from data bases. The data input consists of vast
numbers of climate variables. Those variables are of two major types, known
and unknown. (step one: Am I correct thus far?) The variables are weighted,
that is, they are assigned parameters. The assigned weights are determined by
the computer modeler or modeling team. (step two: OK so far?) The
weighting cannot possibly be 100% scientific, for several reasons: 1) The
huge volume of data has many imprecisely known inputs, and 2) the unknown
variables are by definition unknown, and thus are excluded, or  guessed.
Therefore, the data input is subjective. (step three: Any disagreement?)
   If I am correct in defining the inputs as subjective, then I ask: 1) Are any
computer modelers infallible? 2) Does each and every computer model use an
identical data base? I suspect both questions have the same answer.
   If you are still with me, this is the gist of my question. The winner of this
year?s pennant in MLB cannot be predicted today by any method because of
unknown variables.  If you believe otherwise, locate a computer
modeler who will predict this year's pennant winner correctly, and you
will both be multimillionaires in October.
Now I maintain MLB predictions are baby-simple compared to the
complexities of climate. I also maintain that any global warming computer
scenario can be tweaked to give any result you want. My conclusion is that
computer models of global warming are so much hooey. Prove me wrong

I think you are attacking a straw man here.  Rather than attempting to
predict the "pennant winners" in this season (which may not be as
difficult as you seem to think), a better analogy might be to try
predicting the number of games that will go into extra innings.

The distinction is whether a single outcome (pennant winner) or
cumulative statistic (number of games in extra innings) is to be
predicted.  With a larger number of observations the average behavior
of entities can be predicted with greater confidence than the behavior
of a single entity.

If a computer model of climate change were formulated with no regard
to the propagation of uncertainty within the calculations, then I'd
agree: it's hooey.  But in many cases the "law of large numbers"
allows a confidence interval to be computed, along with a predicted
value.  The combination of the predicted value and the range of
uncertainty around it is then a more meaningful claim.  Of course just
getting the form of the prediction right is no proof that the science
is valid.  To have an informed opinion requires study of the merits;
my ignorance is not proof that what I don't understand is nonsense.

regards, mathtalk-ga

Mathtalk-ga: OK, I agree I should not have chosen a single outcome
event as an example.(I had intended to use *World Series* rather than
*pennant* but let that be.) So: how about computer modelers predicting
the following for 100 years from now: 1) The global economy 2) % of
population with AIDS 3) How many fish in the oceans 4)Global insect
population. I could go on, but you get the idea. Very likely some or
all of those have been computer modeled, but how many have REAL
credibility?
  I was in industrial laboratory research for 30 years, which may
account for my cynicism. Prognostications with the ever-popular 95%
confidence level were a
standing joke.
  Recently I read an article from Carnegie-Mellon, no less, that
began: The principal greenhouse gases are: CO2, CH4, SO2. Evidently
the nerds at C-M never heard of water vapor, which accounts for up to
98% of atmospheric heat trapping.
(It is interesting that GW scaremongers rarely, if at all, consider
the role of water vapor. It's always CO2.)
  I stand by my contention that computerized predictions of disastrous
global warming are bogus science. They are political positions,
nothing else. Those models, if back extrapolated from today produce
bizarre data. And to repeat, the unknowns are truly unknown. How do
you weight a factor whose existence you are unaware of?
Regards, monroe22-ga

>>...I stand by my contention that computerized predictions of disastrous
global warming are bogus science...<<

What predictions are you talking about...?

Global climate models, whether you consider them plausible or
implausible, produce results along the lines of:  in the next 50 years
in Area X, average temperatures at sea level are expected to increase
0.8 degrees C...or something along those lines.  Global climate models
don't give results like:  "Warning, Will Robinson!  Danger!  Danger!"

Of course, people are free to explore what they see as the
implications of the predicted changes, and some of their explorations
are more convincing than others, I must admit.

But I'd still like to know which models you're taking some umbrage with.

pafalafa-ga: Well, for openers, much of the GW hysteria tells us:  X
group of scientists agree that global warming will etc. etc. Specific
computer models are not usually described in detail. I hope you will
forgive me for not having anticipated your question ten years ago and
havtng copious notes at my fingertips. But if you are unaware of the
GW hysteria, then you and I obviously are on different pages, and I am
not saying I'm right and you are wrong.
  Anyway, here is a sampling: 9/2002: BBC News: "UK faces global
warming disaster"...5 million people and most of best farmland at
risk.  1/2004: Guardian UK: "15 to 37% of animals and plants extinct
by 2050", quoting an article in *Nature*. (It goes on to tell us it's
Bush's fault. I guess the Brits don't like him. Fortunately, their
science is completely objective and non-political, except when it
isn't.)  1/2001: CNews Science: Global temperatures will rise 10 & 1/2
degrees, (presumably F). CO2 levels will be higher in 100 years than
in previous 420,00 years. (doesn't say how much higher... one is
tempted to say So what?). Sea levels will be up ten feet in 1000
years. (Man, can those dudes extrapolate or what?). Source:UN
sponsored Intergovernmental Panel on Climate. Again, it is Bush's
fault.  Coming to your local multiplex soon: The Global Warming
Disaster Movie "Day After Tomorrow". Undoubtedly it will be
non-sensational and 100% objective...something like a documentary. And
I doubt if anyone will derive an opinion from it.
  So, I wish the GW hystericals would indeed give us precise
identification of the computer modeling teams and where they are
based. Since they don't, forgive me for questioning the actual
existence of these nebulous researchers. If I get any details, you
will be the first to know.
Regards, monroe22-ga

Come now....do you really know anybody who's actually *hysterical*
about global climate change?  If you don't care for GW hyperbole,
perhaps you should tend to your own house as well.

I must admit though, from your description, it sounds a lot like the
GW scientists are relying on all the same models that were used to
identify weapons of mass destruction in Iraq!

palafala-ga: Do I personally know anyone who is literally hysterical about GW?
No, but I have crossed paths with some whom I would describe as
overwrought true believers in GW and who worship at the altar of what
they think is science. I use the term hysterical in the figurative
sense: behavior exhibiting overwhelming or unmanageable fear or
emotional excess, as in political hysteria (Merriam Webster, tenth
edition).
 I would hope readers have sufficient enlightenment to distinguish
forceful wording from carelessness or stupidity. If your intent was to
trip me up, it was pretty clumsy.
Best regards, monroe22-ga

Nope, nothing about tripping you up.  People just feel strongly about
different things.  For you, it's the science (or lack thereof) behind
the global warming issue.  For me, it's people invoking the public's
"hysteria" when, to my mind, there isn't any.

Best regards right back at ya!

paf

palafala-ga: Fair enough, and I agree that the general public, or at
least that very tiny slice of it that I am in contact with, is pretty
indifferent to global warming. (The heated discussions I have
participated in were in letter form.) Nonetheless, the media seem
obsessed by it. The overreaction, if that is the right word, lies
there, and I should have spelled that out in my writing.
Thanks, 
monroe22-ga

Well, the press and Hollywood at times seem to be "obsessed" about the
prospect of a big asteroid striking the Earth.  It could happen,
apparently has happened, and no doubt will happen again.  But how big
and how soon?

Perhaps if "global warming" concerns were based entirely on
hypothetical computer models, then your attacks would be more on
point.

We do know that climate can change, from historical records, and
presumably there is nothing inherently rediculous about asking what
the prospects for change in the next 50 years are, or for that matter
simply predicting that changes will continue to occur.  An important
question is what role human activities may be playing in the
measurable climate changes around us.

It reminds me of the scorn with which predictions of damage to the
ozone layer in the upper atmosphere were met 25 years ago.  Is it
valid to rebut empirical evidence of that with hand waving arguments
about how industry is valiantly pumping more ozone into the lower
atmosphere?  No, this is simply missing the point.

Likewise the evidence that the polar ice caps are melting and glaciers
disappearing is not merely an academic scare story based on picking
numbers at random.  Do the homework (or allow me to do it for you for
the list price offered!) and I predict you'll see that there's
substantial evidence for human effected climate change.  Not
incontrovertible perhaps, but deserving of unbiased consideration.

regards, mathtalk-ga

mathtalk-ga: There is no problem with debating anthropomorphic
influence on the atmosphere, other than neither of us will convince
the other. But try this for size: as much as 98%, repeat, 98% of
greenhouse gas global warming is caused by our old friend, water
vapor, AKA humidity. All other contributors are insignificant. Doubt
that? Look it up.
  Why should we destroy the economy of the world, not only the US,
because of a hypothesis? That's right, my friend, a hypothesis, not a
law of nature, nor is it absolutely PROVEN science. Melting ice? Prove
it is due to mankind. Go ahead, PROVE it. Of course, we could consider
covering the Pacific Ocean with a tarpaulin, or pass an act of
Congress forbidding volcanoes to emit CO2, or issue a judicial
restraint to stop the sun from fluctuating its radiation. It seems ,
based on historical evidence, that a new ice age is far more likely
than a drastic rise in global temperatures, and one hell of a lot more
difficult to deal with. But go ahead and believe whatever fluffs up
your skirts.
monroe22-ga

Some folks are predicting that global warming will havesome
destructive consequences, and you're taking issue with these
predictions.

Now you've made a prediction of your own --  that our policies to stem
global warming will "destroy the economy of the world".  Is this
prediction more reliable or less reliable than the predictions about
temperature change?  Is the underlying science more convincing or less
convincing?

pafalafa-ga:  
 I had previously posted a reply to your 4/23 comment but it didn't
appear for some reason. It was something like this:
   If every country were to sign onto the Kyoto Protocol and implemented every
regulation to the letter, there is a possibility that some countries
would experience a negative effect on their economiies as a result of
their participation.

Is that tepid enough to suit you?
monroe22-ga