New Delhi: Humanity is responsible for speeding up the natural rate of extinction for animal and plant species by up to 10,000 times, as the planet is on the brink of a dinosaur-scale sixth mass extinction, a new study has warned.
Species are disappearing around 10 times faster than is widely believed in the scientific community, while in pre-human times extinction rates were slower than previously thought, researchers from Duke University in the US said.
The study looks at past and present rates of extinction and finds a lower rate in the past than scientists had thought. Species are now disappearing from Earth about 10 times faster than biologists had believed, said study lead author noted biologist Stuart Pimm of Duke University.
The work, published Thursday by the journal Science, was hailed as a landmark study by outside experts.
Pimm's study focused on the rate, not the number, of species disappearing from Earth. It calculated a "death rate" of how many species become extinct each year out of 1 million species.
In 1995, Pimm found that the pre-human rate of extinctions on Earth was about 1. But taking into account new research, Pimm and his colleagues refined that background rate to about 0.1.
Now, that death rate is about 100 to 1,000, Pimm said.
Numerous factors are combining to make species disappear much faster than before, said Pimm and co-author Clinton Jenkins of the Institute of Ecological Research in Brazil. But the No. 1 issue is habitat loss. Species are finding no place to live as more places are built up and altered by humans.
Add to that invasive species crowding out native species, climate change affecting where species can survive, and overfishing, Pimm said.