[Prev][Next][Index][Thread]
Re: fHuman vs. natural influences on the environment
charliew@hal-pc.org (charliew) wrote:
>My discussion was intended to be more in the line of human
>influences on the environment rather than natural influences
>on it. At this point, I have been flogged by people who have
>come up with several possible scenarios that I accept as
>plausible. I wish I had been more explicit in my original
>comments. However, I still maintain that the human influence
>on the environment has been small (perhaps almost
>immeasureable) to date.
I'd say you need to continue trying to be more explicit, Charlie.
Your latest effort is still insupportable. If you are talking
only about the earth's climate, then say so. You say "human
influence on the environment has been small (perhaps almost
immeasurable) to date." But anyone can see this is not so. We
cut down most of the forests of North America. We nearly wiped
out the buffalo. Are these really changes that are too small to
be measured?
With respect to climate, you're right to some degree, there's
a scale question involved. 100 million people could probably
use coal and not think much about it. Now we are numerous
enough, and our demand for energy has grown enough, that we're
getting into the big leagues.
>The biggest problem here regards the
>fact that we don't have a good idea of what normal
>variability is, so it's difficult to know if humans have
>caused a measureable change. If there is someone out there
>who strongly disagrees, please provide a few statistics to
>indicate that we are seeing a statistically significant
>disturbance. In other words, if the standard deviation of
>the global average temperature is 1 deg F, a statistically
>significant disturbance should be approximately 2 standard
>deviations from the "norm" (approximately 2 deg F).
This presupposes that global average annual temperature is the
only important variable. It's easy to show significant changes
in other parameters. One good one is methane, another greenhouse
gas. Over the past 150,000 years, according to ice core data,
its concentration in the atmosphere has varied from 300 ppm to
650 ppm. Today it is around 1700 ppm.
Tom Gray
Director of Communications
American Wind Energy Association
PS Support renewable energy! Visit the Electronic Lobbyist For
Renewable Energy Web Site:
http://www.netcom.com/~stevie2/budget.html
Interested in energy and the environment? The free electronic
edition of _Wind Energy Weekly_ reports on energy-related
environmental issues, energy policy, and wind industry trade
news. The electronic edition normally runs about 10kb in length.
For a subscription, send me an e-mail request. Please include
information on your position, organization, and reason for
interest in the publication.
-----------------------------------------------------------------
Tom Gray <tomgray@econet.org>
References: