SOURCE: CNN and PNAS

DATE: July 11, 2017

SNIP: Many scientists say it’s abundantly clear that Earth is entering its sixth mass-extinction event, meaning three-quarters of all species could disappear in the coming centuries.

That’s terrifying, especially since humans are contributing to this shift.But that’s not even the full picture of the “biological annihilation” people are inflicting on the natural world, according to a study published Monday in the Proceedings of the National Academy of Sciences.

Their key findings: Nearly one-third of the 27,600 land-based mammal, bird, amphibian and reptile species studied are shrinking in terms of their numbers and territorial range. The researchers called that an “extremely high degree of population decay.”

Looking at the extinction crisis not only in terms of species that are on the brink but also those whose populations and ranges are shrinking helps show that “Earth’s sixth mass extinction is more severe” than previously thought, the authors write. They say a major extinction event is “ongoing.”