Brad Plumer in Vox:
The world's plant and animal species are going extinct at a rate 1,000 to 10,000 times faster than they did before humans came along. If that continues, we could lose one-third to half of all species by the end of the century. A variety of birds, frogs, fish, mammals — gone.
Those grim statistics come from a big recent study inScience, led by Duke University biologist Stuart Pimm. The paper was the most comprehensive attempt yet to calculate a “death rate” for the world's species — an update on work first begun in 1995.
It's not an easy calculation to make: We still haven't fully tallied all the current species on Earth, for instance. So the researchers had to make estimates on how many species there are likely to be, how many are dying off, and what that “death rate” likely was before humans ever arrived on the scene.
Based on updated research, Pimm and his colleagues estimated that roughly 0.1 out of 1 million species went extinct each year before humans showed up. That's the “background rate.” But nowadays, thanks to deforestation, habitat loss, and other factors, the “death rate” has increased to an estimated 100 to 1,000 extinctions per million species-years.
That's a big deal. And, not surprisingly, many of the media reports on Pimm's paper underscored that the Earth is now facing a “sixth extinction” comparable to the five earlier mass extinctions in history.