WASHINGTON ‒ Humanity is at its closest yet to destroying itself, according to Tuesday’s reset of the ominous “Doomsday Clock.” The symbolic clock now reads 89 seconds to midnight after advancing one second since last year’s reset.

It is now the closest to midnight since the introduction of the clock in 1947. It is updated by the Bulletin of the Atomic Scientists, which organizes the assessment of how close we are to a self-inflicted end of humanity.

The world is less safe and less stable than it was a year ago, said Dan Holz, chair of the Bulletin of the Atomic Scientists’ science and security board.

“Arms control treaties are in tatters, and there are active conflicts involving nuclear powers,” he said, and misinformation, disinformation and conspiracies are a “threat multiplier.”

The clock is meant as a metaphor for how close humanity is to self-annihilation, according to the Bulletin of the Atomic Scientists. The group was founded by University of Chicago scientists who had helped develop the first nuclear weapons for the Manhattan Project.

Nuclear, disease and AI fears factor into 2025 Doomsday Clock reset

The nuclear threat is especially concerning this year, said Manpreet Sethi, a member of the board and distinguished fellow at the Centre for Air Power Studies in New Delhi.

“We are in a situation where a slew of risks of arms racing, of loss of guard rails, the possibility of further proliferation, possibility of nuclear use, are all rising at the same time,” she said.

Too often, people think of nuclear weapons as if they were simply ordinary weapons but a bit more lethal. That is far from the case and is what worries members of the bulletin’s board.

“I fear we might be sleepwalking into nuclear disaster,” she said.

Another terrifying menace comes in the realm of disease, where biological threats, coupled with the increasing strength of artificial intelligence, are a major concern, said Suzet McKinney, a member of the bulletin’s Board of Science and Security and a director of Life Sciences for Sterling Bay

“How would it make you feel to know that rogue actors could employ AI technology to proliferate these diseases even more, or that entire nations have the power to unleash biological weapons within society’s due to war or just a menial disagreement?” she said.

Nations around the world, and even the U.S. government, are engaging in practices sure to encourage such behavior, which could not only launch new diseases but also cripple humanity’s ability to curb their spread, she said.

“We cannot hide our heads in the sand,” she said.

What is the Doomsday Clock?

Originally, the ominous clock measured the danger of nuclear disaster. In the past two decades, three other areas of concern have been added: climate change, artificial Intelligence and mis- and disinformation.

Each year, the members of the Science and Security Board are asked two questions:

• Is humanity safer or at greater risk this year than last year?
• Is humanity safer or at greater risk compared with the 78 years the clock has been set?

Their answers set the clock for the coming year.

What does 89 seconds to midnight mean in 2025?

Though the clock has moved only one second forward, it’s a significant indicator of the dangers the world faces, Holz said.

“When you’re at this precipice, the one thing you don’t want to do is take a step forward,” he said. “We’re saying that given what’s happened over the past year, we haven’t seen the sort of progress we need. And in some areas of our concern, things have gotten worse. Therefore, the clock is moving forward.”

All hope is not lost, but action must be taken soon, the group cautioned.

“There is a big chance that at this time next year we will be moving the hands back, not forward, but this will only happen if leaders engage in good-faith dialogue,” said Juan Manuel Santos, former president of Colombia and a member of The Elders, an independent group of global leaders founded by Nelson Mandela that works for peace, justice, human rights and a sustainable planet.

“We can only succeed if we act as one,” he said.

How did the Doomsday Clock start?

In 1945, on the anniversary of the bombing of Pearl Harbor, scientists who had worked on the Manhattan Project, which built the world’s first atomic bombs, began publishing a mimeographed newsletter called The Bulletin of the Atomic Scientists. 

Two years later, as those same scientists contemplated a world in which two atomic weapons had been used in Japan, they gathered to discuss the threat to humanity posed by nuclear war. 

“They were worried the public wasn’t really aware of how close we were to the end of life as we knew it,” said Rachel Bronson, president and CEO of the bulletin.

Martyl Langsdorf, an artist and wife of Manhattan Project physicist Alexander Langsdorf Jr., came up with the idea of a clock showing just how close things were.

They called it the Doomsday Clock.

“It gave the sense that if we did nothing, it would tick on toward midnight and we could experience the apocalypse,” Bronson said.

What does midnight represent on the Doomsday Clock?

The clock looks only at things humanity could do to itself. A meteor hurtling toward Earth wouldn’t count; tinkering with viruses to make them more dangerous would.

From the 1950s through the 1980s, the threat of nuclear war felt imminent. Though it feels less real now, the risk hasn’t gone away, said Robert Socolow, a environmental scientist, theoretical physicist and professor emeritus of Mechanical and Aerospace Engineering at Princeton University who is on the board.

“The nuclear threat is one that young people can’t believe their grandparents and parents lived with, but now their working assumption is ‘I don’t need to worry about it,'” he said. “But they do.”

Today’s dangers are somewhat different than they were when the threat was mainly from the Soviet Union, because we have nonstate actors such as terrorists and countries like North Korea that are not part of the global order and might have access to dangerous weapons and pathogens.

Where does the nuclear threat stand?

The original Doomsday Clock was all about the threat of nuclear annihilation. Little more than a week into President Donald Trump’s second term in office, the nuclear outlook is still unclear.

The world’s last remaining nuclear arms control pact – New START, which limits U.S. and Russian nuclear warhead deployments but not stockpile size – expires in early 2026.

The U.S. commander in chief told World Economic Forum attendees Thursday that he would “like to see denuclearization” and said he had discussed the idea with the leadership of Russia and China.

Yet the president’s appointees, including new Defense Secretary Pete Hegseth, are less bullish about future arms reductions. The Pentagon head, in written responses to lawmakers’ policy questions before his confirmation, said the country should “pursue arms control when it is in its interest to do so … Both China and Russian have rebuffed US efforts to engage in meaningful risk reduction talks since 2020.”

North Korea’s nuclear arsenal, a topic of significant concern in the U.S. and abroad during Trump’s first administration, poses a security and foreign relations challenge as well.

(This story has been updated to add new information.)

Davis Winkie’s role covering nuclear threats and national security at USA TODAY is funded by a grant from the Outrider Foundation. The Outrider Foundation does not provide editorial input. You can reach Davis via email at [email protected] or via the Signal encrypted messaging app at 770-539-3257.