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Re: Global warming - was Re: Michael Crichton dies
> > Predicting short-term fluctuations and long-term trends are two
> > different pair of shoes entirely. I cannot predict next week's weather,
> > but I can rather confidently predict that it will be colder than the
> > weather we had in summer.
> ...which is making a prediction based on a yearly pattern, in which
> you exclude all other variables having an effect on the weather, for
> example solar activity. You are actually just approximating the truth.
That's a given in science, you always approximate the truth. If the
sun explodes, it will be warmer next week for sure... But, under
normal circumstances, it is easily possible to make long-term
predictions in systems where short-term detailed predictions are not
possible, that's all I wanted to say.
> Although I would not call next week's weather long-term, I agree that
> predicting the two are completely different.
That was my whole point - I only wanted to criticise your "We cannot
even predict the weather"-argument because it is simply not relevant
to this discussion.
> However, climate
> predictions are extremely controversial. There isn't even complete
> certainty about ice age patterns, patterns in paleomagnetism or
> volcano behavior. Certainly what climatologists are trying to predict
> using global warming models is not less complicated. Predicted
> temperatures vary incredibly. We are making predictions for over a
> hundred years into the future based on 150 years of "accurate" weather
> data. How could we honestly have confidence in our predictions?
Because we understand the basic science? Because we do things like
parameter variation, look at error bars, etc.? Surely we cannot
predict exactly how warm the earth will be in 100 years, but if all
high-level calculations agree that it will be warmer and that adding
CO2 to the atmosphere raises global temperatures, then this is good
evidence. The fact that there are error bars to our calculations does
not mean that they are meaningless.
Priv.-Doz. Dr. Martin BÃker
Institut fÃr Werkstoffe
Technische UniversitÃt Braunschweig
Langer Kamp 8