The Doomsday Clock has been set at 100 seconds to midnight—as close to total destruction as we were in 2020. But after a year of increasingly dangerous weather and wildfires, not to mention the COVID-19 pandemic, why didn’t the clock move?

Rachel Bronson is the president and CEO of the Bulletin of The Atomic Scientists, the organization that sets the clock. We sit down with her to talk about the thinking behind this year’s clock, climate change, pandemics and the ever-increasing threat of nuclear war.