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Continued ...
Q: Give me a sample of how complicated
just one little thing can be.
A: The most complicated thing about the atmosphere that the models
cannot capture is clouds. First of all, clouds are small. The
resolution of the computer models is about 200 miles; clouds
are much smaller than that. Secondly, they don't know when clouds
form. They have to guess what humidity is necessary for a cloud
to form. And of course, humidity is not the only factor. You
have to have nuclei -- little particles -- on which the water
vapor can condense to form droplets. They don't know that either.
And they don't know at what point the cloud begins to rain out.
And they don't know at what point -- it goes on like this.
Q: Is this debate a scientific fight or
a political fight?
A: Both. I much support a scientific fight, because I'm pretty
sure we'll win that -- because the data support us; they don't
support the climate models. Basically it's a fight of people
who believe in data, or who believe in the atmosphere, versus
people who believe in models.
Q: Is it not true that CO2 levels have
gone up by about a third in the last 100 years?
A: A little more than a third, yes. I accept that.
Q: Do you say that's irrelevant?
A: It's relevant, but the effects cannot be clearly seen. The
models predict huge effects from this, but we don't see them.
Q: Why is it important that global warming
be studied in a balanced, scientific, depoliticized way?
A: It's a scientific problem. The climate is something we live
with, and we need to know what effect human activities are having
on climate. I don't deny that there's some effect of human activities
on climate. We need to learn how important they are.
Q: Why is it important that global warming
be studied in a balanced, scientific, depoliticized way?
A: It's a scientific problem. The climate is something we live
with and we need to know what effect human activities are having
on climate. I don't deny that there's some affect of human activities
on climate. Cities are warmer now than they used to be. We have
changed forests into agricultural fields. That has some affect
on climate. We irrigate much of the Earth. That affects climate.
And so on. We are having some influence on climate, at least
on a small scale. So we need to know these things. We need to
how important they are.
Q: And global warming is something we should
study but not get panicky about?
A: The thing to keep in mind always is that the natural fluctuations
of climate are very much larger than anything we can ascribe
so far to any human activity. Much larger. We lived
through a Little Ice Age just a few hundred years ago. During
the Middle Ages the climate was much warmer than it is today.
So the climate does change all the time. We need to understand
the scientific reasons for natural climate change. Most of us
now think it's the sun that is the real driver of climate. It
has something to do with sun spots, but the mechanism is not
quite clear. That's what's being studied now.
Bill Steigerwald is a columnist
at the Pittsburgh Tribune-Review. E-mail Bill at bsteigerwald@tribweb.com.
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