Earth is on the brink of a sixth mass extinction, scientists say, and it’s humans’ fault

By Sarah Kaplan June 22 at 3:41 AM, WashPost

A vast chunk of space rock crashes into the Yucatan Peninsula, darkening the sky with debris and condemning three quarters of Earth’s species to extinction. A convergence of continents disrupts the circulation of the oceans, rendering them stagnant and toxic to everything that lives there. Vast volcanic plateaus erupt, filling the air with poison gas. Glaciers subsume the land and lock up the oceans in acres of ice.

Five times in the past, the Earth has been struck by these kinds of cataclysmic events, ones so severe and swift (in geological terms) they obliterated most kinds of living things before they ever had a chance to adapt.

Now, scientists say, the Earth is on the brink of a sixth such “mass extinction event.” Only this time, the culprit isn’t a massive asteroid impact or volcanic explosions or the inexorable drifting of continents. It’s us.

(More here.)