The Doomsday Clock now stands at 89 seconds to midnight, the closest to catastrophe in its nearly eight-decade history. Here's a look at how — and why — it's moved.

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

On Tuesday morning, the Doomsday Clock was set at 89 seconds to midnight, which is the closest it has ever been to midnight in the 78 years since it started running. So what has set off the historic change? Essentially everything, according to the 2025 Doomsday Clock statement.

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.