But what does that actually mean?
The "Doomsday Clock" is a symbolic timepiece showing how close the world is to ending.
Midnight marks the theoretical point of annihilation.
Every year scientists move the hands of the clock closer to or further away from midnight, based on their reading of existential threats at that time.
Cambridge University’s expert on existential threat Paul Ingram:
"It emerged at the beginning of the Cold War to give a sense of the urgency to achieve nuclear disarmament and to climb out of the abyss that we were facing in the early 1950s. And in more recent times, it has taken on climate change and emerging disruptive technology to give a sense of the the risks, the catastrophic risks that we face as a planet largely through our own deliberate activities."
Albert Einstein was among a group of atomic scientists who created the clock back in 1947.
These days, a Chicago-based NGO called the Bulletin of the Atomic Scientists updates the time annually.
A board of scientists and other experts in nuclear technology and climate science, including 13 Nobel laureates, discuss world events and determine where to place the hands of the clock each year.
At 90 seconds to midnight, the "Doomsday Clock" is now the closest it has ever been to midnight.
Another of the Bulletin of Atomic Scientists experts, Steve Fetter from the University of Maryland, says Russia's invasion of Ukraine is causing deep concerns.
Nuclear risks increased significantly last year due largely to Russia's unprovoked invasion of Ukraine. Putin (Russian President Vladimir) has repeatedly raised the specter of nuclear use. In launching the invasion, he warned that 'whoever tries to hinder us should know that Russia's response will be immediate and will lead to consequences you have never faced in your history.' A few days later, he ordered Russia's nuclear forces to special combat duty. In announcing the annexation of Ukrainian territories in September, Putin declared that he would defend them with all weapons systems available to us. This is not a bluff. And in case anyone missed the reference to nuclear weapons, he mentioned that Hiroshima and Nagasaki had set a precedent."
When the clock first started ticking, more than 75 years ago, it sat at seven minutes to midnight.
