Mankind may have unleashed the sixth known mass extinction in Earth’s history, according to a paper released on Wednesday by the science journal Nature.
Over the past 540 million years, five mega-wipeouts of species have occurred through naturally-induced events.
But the new threat is man-made, inflicted by habitation loss, over-hunting, over-fishing, the spread of germs and viruses and introduced species and by climate change caused by fossil-fuel greenhouse gases, says the study.
Evidence from fossils suggests that in the “Big Five” extinctions, at least 75% of all animal species were destroyed.
On the assumption that these species are wiped out and biodiversity loss continues unchecked, “the sixth mass extinction could arrive within as little as three to 22 centuries,” said researcher Anthony Barnosky of the University of California at Berkeley.