A new study has provided deeper insight into the gravity of the world's current species extinction rates.
The study estimated that the pre-human rate was 10 times lower than scientists had thought, which means that the current level would be 10 times worse. Extinctions are about 1,000 times more frequent now than in the 60 million years before people came along.
Jurriaan de Vos, a Brown University postdoctoral researcher, said that this reinforces the urgency to conserve what was left and to try to reduce the impacts.
The paper calculated a "normal background rate" of extinction of 0.1 extinctions per million species per year. That revised the figure of one extinction per million species per year that Stuart Pimm estimated in prior work in the 1990s. By contrast, the current extinction rate was more on the order of 100 extinctions per million species per year.
Lucas Joppa, a scientist at Microsoft Research in Redmond, Wash, said that the total number of species on earth has not been declining in recent geological history, it was either constant or increasing, therefore, the average rate at which groups grew in their numbers of species must have been similar to or higher than the rate at which other groups lost species through extinction.
Pimm mentioned that it has been known for 20 years that current rates of species extinctions are exceptionally high but this new study came up with a better estimate of the normal background rate, how fast species would go extinct were it not for human actions and it's lower than they thought, meaning that the current extinction crisis was much worse by comparison.
The study is published in the journal Conservation Biology.