What Is the Doomsday Clock?
A comprehensive guide to the Bulletin of the Atomic Scientists' Doomsday Clock — its history, meaning, and relevance today.
What Is the Doomsday Clock?
The Doomsday Clock is a symbol that represents the likelihood of a human-made global catastrophe. Maintained by the Bulletin of the Atomic Scientists since 1947, the clock uses the imagery of midnight to convey how close humanity is to destroying itself.
A Brief History
The clock was created by scientists who had worked on the Manhattan Project. Originally focused solely on the threat of nuclear war, its scope has expanded over the decades to include climate change, disruptive technologies, and biosecurity threats.
Key Moments
- 1947: Clock created, set at 7 minutes to midnight
- 1953: Closest setting at the time — 2 minutes to midnight — after the US and Soviet Union test thermonuclear devices
- 1991: Furthest from midnight — 17 minutes — following the end of the Cold War
- 2023: Moved to 90 seconds to midnight, the closest ever at the time
- 2025: Moved to 89 seconds to midnight, a new record
How Is the Clock Set?
The clock is set annually by the Bulletin's Science and Security Board in consultation with its Board of Sponsors, which includes Nobel laureates. The board evaluates:
- Nuclear threats: Arsenal sizes, modernization programs, rhetoric, near-misses
- Climate change: Emissions trajectories, policy commitments, tipping points
- Disruptive technologies: AI, biotech, cyber weapons
- Biosecurity: Pandemic preparedness, gain-of-function research
What NukeClock Adds
NukeClock uses the official Doomsday Clock as its baseline. The NukeClock Live indicator is a separate, dynamic tool that adjusts more frequently based on current events. It is educational and meant to make nuclear risk more tangible — it is not an alternative to the official clock.