As of 2023 the Doomsday Clock moved to 90 seconds to midnight, 10 seconds closer than it has been for the past three years. This is the closest the Doomsday Clock has ever been to midnight.
The Doomsday Clock is a symbol that represents how close humanity is to destroying the world with dangerous technologies. It is set every year by the Bulletin of Atomic Scientists to warn the public and inspire action. The hands of the clock are moved closer to or further away from midnight based on the scientists' reading of existential threats at a particular time.
When the Doomsday Clock hits midnight, it means that the Bulletin of Atomic Scientists believe a global catastrophe has occurred. This could be a nuclear war, an uncontrollable threat to global bio- or cybersecurity, or irreversible and destructive climate change.