The Doomsday Clock now stands at 89 seconds to midnight, the closest to catastrophe in its nearly eight-decade history.
The closer it moves to midnight, the closer humanity is to the end of the world. Apocalyptic threats could arise from political tensions, weapons, technology, climate change or pandemics.
The clock was its farthest from midnight — a sizable 17 minutes — in 1991, with the end of the Cold War and the signing of the Strategic Arms Reduction Treaty between the U.S. and Soviet Union.