Doomsday Clock

Symbolic timepiece created and maintained by the Bulletin of the Atomic Scientists since 1947 to represent humanity’s proximity to global catastrophe, expressed as minutes or seconds remaining before metaphorical “midnight” representing civilization-ending disaster from nuclear war, climate change, and emerging technologies.

The clock originated during the early Cold War as scientists involved in the Manhattan Project sought to communicate nuclear dangers to the public, initially set at seven minutes to midnight. The board of scientists meets regularly to assess global threats and adjust the clock’s time based on nuclear proliferation, climate change, cyber threats, and biosecurity risks.

The clock’s settings have ranged from two minutes to midnight (1953, when the U.S. and Soviet Union developed hydrogen bombs, and 2018-2019, due to nuclear modernization and climate change) to seventeen minutes to midnight (1991, following the end of the Cold War and signing of the Strategic Arms Reduction Treaty).

Recent assessments have incorporated climate change as an existential threat equal to nuclear war, reflecting scientific consensus about anthropogenic global warming’s potential for civilizational collapse. The clock has also begun considering cyber warfare, artificial intelligence risks, and biological weapons as factors in humanity’s survival prospects.

Critics argue the clock’s settings reflect political bias rather than objective scientific assessment, noting inconsistencies in how different threats are weighted and the subjective nature of catastrophic risk evaluation. Supporters maintain it serves an important educational function in communicating complex global risks to public audiences and policymakers.