Saturday, May 06, 2006

How Many Species are Going Extinct?

Polar bears, hippos and many freshwater fish are among more than 16,000 species of animal, bird, fish and plants threatened with global extinction, the World Conservation Union said Tuesday.
Wow, 16,000 species are in serious danger of going extinct. Well except that this is only of the species that the IUCN is tracking.
The Red List classifies about 40,000 different species according to their risk of extinction and provides a searchable online database of the results. The total number of species on the planet is unknown, with 15 million being the most widely accepted estimate. Up to 1.8 million are known today.
They only classify 40,000 of 1.8 million known species (2.2%) and there could be over 13 million other still unknown species (or .26% of 15 million). Which really makes you wonder what about the species they aren't tracking?
These include one in three amphibians, a quarter of the world's coniferous trees and mammals and one in eight birds, according to a preview of the 2006 Red List.
Of the species they are tracking, this is dire. 16,000 of 40,000 is 40%. If that held for all species, we would be looking at 720,000 endangered known species and possibly 6 million of all species. Which raises the interesting zen koan like question: if a species goes extinct that was never known, did it really exist?

The 40% ratio might not hold. I have no idea how the 40,000 were selected. Maybe they are the most endangered of them all. Or maybe the easiest to track. But, I think it is clear to say that we don't have a good grasp at this point of how many total species are close to extinction.

For the species we do know about, the ICUN has registered very few extinctions:
Some 784 are listed as extinct - only a small increase from 2004 - while 65 are found only in captivity.
The impact of global warming is often predicted to wipe out many species. But, when I look at this report it shows how little we really know about the biodiversity on earth, and how any prediction must be taken with a grain of salt.

via The International Herald Tribune

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