Atomic scientists on Tuesday moved their "Doomsday Clock" closer to midnight than ever before, citing Russian nuclear threats amid its invasion of Ukraine, tensions in other world hot spots, military applications of artificial intelligence and climate change as factors underlying the risks of global catastrophe.

The Doomsday Clock, which has been used to examine the world’s vulnerability to global catastrophe for nearly a century, has moved one second closer to midnight. On Jan. 28, the Bulletin of the Atomic Scientists announced that the Doomsday Clock was set at 89 seconds to midnight,

The Bulletin of Atomic Scientists announced Tuesday that the "Doomsday Clock" is now set to 89 seconds to midnight.