The Bulletin of Atomic Scientists has announced that the Doomsday clock is now at 90 seconds to midnight, the closest it has been since its creation more than 75 years ago. This is a warning of the potential for global catastrophe due to threats from nuclear weapons, climate change and infectious diseases such as Covid-19. The organization has called for urgent action to reduce the risks of global catastrophe, urging world leaders to take immediate steps to address these threats.