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.

Therefore, we are moving the clock forward," said Daniel Holz, chair of the Science and Security Board of the Bulletin of the Atomic Scientists, according to CBS News."The war in Ukraine remains a source of nuclear risk,

Iconic Doomsday Clock moves one second closer to midnight as global existential threats rage. Clock factors include nuclear weapons, climate crisis, artificial intelligence, infectious diseases, and conflicts in Ukraine and the Middle East.