Extrapolation

[Kenelm Philip]

> Lomborg, in his recent book the Skeptical Environmentalist, argues that
> an extinction rate of 0.7% per 50 years is manageable and hardly worthy
> of hysteria. To me, this extinction rate will lead to 13% of the species
> on earth going extinct over the next 1000 years. (exp(-0.007*20 half-
> centuries)= 0.87). If this doesn't trouble you, consider the results of
> another 6000 years of human history.

	One point that Lomborg makes throughout his book is that some
environmentalists like to extrapolate from very short time series. To
extrapolate for 1000 (or 6000) years based on a 400 year record plus
a wild guess about the next 300 years is just the kind of thing that
Lomborg is talking about. Does anyone think that the extinction rate
will remain constant for the next 6000 years?

	As for Lomborg's lack of hysteria. here are quotes: "An extinction
rate of 0.7% over the next 50 years is not trivial. It is a rate about
1500 times higher than the natural background extinction. However, it is
a much smaller figure than the typically advanced 10-100% over the next
50 years (equal to some 20,000 to 200,000 times the background rate). More-
over, to assess the long-term impact, we must ask ourselves whether it is
likely that this extinction rate will reamin constant for many hundreds of
years (accumulating serious damage) or more likely will be alleviated as
population growth decelerates and the developing world gets rich enough
to afford to help the environment, reforest, and set aside parks..."

"Of course, losing 25-100% of all species would be a catastrophe by any
standards. However, losing 0.7% per 50 years over a limited time span is
not a catastrophe but a problem--one of many that mankind still needs to
solve."

							Ken Philip
fnkwp at uaf.edu




 
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