Scientists have changed the time on what’s known as the Doomsday Clock, which uses various predictors to gauge how close humanity might be to extinction. The Science and Security Board (SASB) of the Bulletin of the Atomic Scientists moved the clock to 89 seconds to midnight at a press conference on Tuesday (Jan.

The Doomsday Clock now stands at 89 seconds to midnight, the closest to catastrophe in its nearly eight-decade history. Here's a look at how — and why — it's moved.

"This is a bleak picture. But it is not yet irreversible."