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

What is the Doomsday Clock? It's 2025 and scientists have reset the clock closer to midnight and global catastrophe. Here's what it all means.