Species extinction rate `overestimated`: Study

Earth`s biodiversity continues to dwindle due to deforestation, climate change and over-exploitation.

Paris: The pace at which humans are
driving animal and plant species toward extinction through
habitat destruction is at least twice as slow as previously
thought, according to a study released today.

Earth`s biodiversity continues to dwindle due to
deforestation, climate change, over-exploitation and chemical
runoff into rivers and oceans, said the study, published in

"The evidence is in -- humans really are causing
extreme extinction rates," said co-author Stephen Hubbell, a
professor of ecology and evolutionary biology at the
University of California at Los Angeles.

But key measures of species loss in the 2005 UN
Millennium Ecosystem Assessment and the 2007 Intergovernmental
Panel on Climate Change (IPCC) report are based on
"fundamentally flawed" methods that exaggerate the threat of
extinction, the researchers said.

The International Union for the Conservation of Nature
(IUCN) "Red List" of endangered species -- likewise a
benchmark for policy makers -- is now also subject to review,
they said.

"Based on a mathematical proof and empirical data, we
show that previous estimates should be divided roughly by
2.5," Hubbell told journalists by phone.

"This is welcome news in that we have bought a little
time for saving species. But it is unwelcome news because we
have to redo a whole lot of research that was done

Up to now, scientists have asserted that species are
currently dying out at 100 to 1,000 times the so-called
"background rate," the average pace of extinctions over the
history of life on Earth.

UN reports have predicted these rates will accelerate
tenfold in the coming centuries.

The new study challenges these estimates. "The method
has got to be revised. It is not right," said Hubbell.


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