The Doomsday Clock, a symbolic timekeeper that tracks how close the world is to ending, is now 90 seconds away from striking midnight.
The scientists responsible for the clock cited the “unprecedented danger” of the Russia-Ukraine war for their decision.
"As UN secretary-general Antonio Guterres warned this past August, the world has entered a time of nuclear danger not seen since the height of the Cold War," said Chief Executive of the Bulletin of the Atomic Scientists Rachel Bronson on Tuesday.
"There is no clear pathway for forging a just peace. The US government, its NATO allies, and Ukraine have a multitude of channels for dialogue; we urge leaders to explore all of them to their fullest ability."
In a statement, the Bulletin of the Atomic Scientists said Russia's invasion of Ukraine eroded norms of international conduct and raised "profound questions about how states interact."
"And worst of all, Russia’s thinly veiled threats to use nuclear weapons remind the world that escalation of the conflict — by accident, intention, or miscalculation — is a terrible risk," they said.
In addition to rising tensions between the West and Russia, the incoming 2026 expiration of the last remaining nuclear weapons treaty between Russia and the United States, New START, was cited as a reason for the clock's change. North Korea's launching of an intermediate-range ballistic missile test over Japan was also mentioned as a justification.
"The invasion of Ukraine opened up a geopolitical fissure, weakening the global will to cooperate," said Science and Security Board Member Sivan Kartha.
The Bulletin of the Atomic Scientists, based out of Chicago, IL., regularly updates the clock's time based on risks to the planet and humanity. The time is determined by a board of scientists, including experts in nuclear technology and climate, who regularly meet to discuss world events.
The clock was first created in 1947 by a group atomic scientists who worked on the Manhattan Project to invent nuclear weapons during the Second World War.
Before 2022, the lowest point for the Doomsday clock was two minutes to midnight in 1953, after the United States and Soviet Union started testing powerful hydrogen bombs. The furthest the clock was ever away from midnight was in 1991, when the Soviet Union dissolved after signing the first Strategic Arms Reduction Treaty with the United States.
However, the clock has been slowly inching towards midnight ever since global military spending increased in 1995. Events such as North Korea's testing of nuclear weapons, US President Donald Trump's comments over nuclear weapons, and the failure to address the growing threats of nuclear weapons and climate change brought the clock to 100 seconds to midnight in 2020.
While the Doomsday Clock has been heralded by many as a easily recognizable and important metaphor for the threats humanity faces, some accused the clock of unnecessarily fearmongering and being too subjective. Cognitive psychologist Steven Pinker said the clock was a political stunt that is inconsistent, while the National Review once wrote that the clock overestimates the effects of developments in the areas of nuclear testing and formal arms control.
The National Post's Tristin Hopper once wrote that while there are "plenty of things to worry about regarding climate change," climate change is not in the same league as nuclear annihilation.