(CNN) 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. 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. Often, scientists who study crisis in the natural world focus on species that are at high and short-term risk for extinction. And currently, scientists say that species are going extinct at roughly 100 times what would be considered normal -- perhaps considerably more. The window of opportunity is small, but we can still do something to save species and populations."

Source: CNN July 11, 2017 04:18 UTC