The Doomsday Clock is closer to midnight than ever before. What does it mean? How is this determined? Can the clock be wound back?

The Doomsday Clock now stands at 89 seconds to midnight reflecting unprecedented global risks including nuclear proliferation and climate change.

Doomsday Clock' Moves Closer to Midnight Amid Threats of Climate Change, Nuclear War, Pandemics, AI Earth is moving closer to destruction, a science-oriented advocacy group said Tuesday as it advanced its famous “Doomsday Clock” to 89 seconds till midnight,