The Sixth Mass Extinction Is Coming, And Man Is To Blame

If the Pope's ominous warnings weren't enough for you, now scientists are chiming in to blame mankind for an imminent sixth mass extinction on Earth. The research, carried out by scientists at the National Autonomous University of Mexico, takes a conservative approach to extinction rates, but concludes that even then biodiversity is dwindling at a pace far greater than would be natural. Meanwhile, there's a possibility for a turnaround, but the window of opportunity is closing.

The researchers assumed a background rate of two mammal extinctions per 10,000 species per 100 years, something which the team says is "twice as high" as the more commonly used estimates.

That was compared with the current rate of extinctions of mammals and vertebrates, itself a conservative figure because of the difficulty in declaring conclusively that a species is no more.

"Even under our assumptions," Gerardo Ceballos and his fellow researchers point out, "which would tend to minimize evidence of an incipient mass extinction, the average rate of vertebrate species loss over the last century is up to 114 times higher than the background rate."

In fact, had extinction gone at the presumed background rate, it would've taken nature anywhere between 800 and 10,000 years to kill off the same number of species that have actually died out in the past century.

"These estimates reveal an exceptionally rapid loss of biodiversity over the last few centuries," the team concludes, "indicating that a sixth mass extinction is already under way."

Previous studies had blamed climate change alone for potentially wiping out 16-percent of species.

It's not all bad news, but our chance to take advantage of that fact won't be around forever.

"Averting a dramatic decay of biodiversity and the subsequent loss of ecosystem services is still possible through intensified conservation efforts," the University researchers say, "but that window of opportunity is rapidly closing."

Three factors are cited as being essential to address: habitat loss, overexploitation for economic gain, and climate change. Without that, the study predicts that it could take as little as three human lifetimes for a significant lack in biodiversity benefits that would be irreversible.

SOURCE Science Advances