The office of the Doomsday Clock resides in the Harris School of Public Policy. But it’s better known as the office of the Bulletin of the Atomic Scientists.

Every year since 1947, the Bulletin has released the Doomsday Clock, a figurative representation of the danger of humanity wiping itself out with its own technologies. The Bulletin focuses on the issues of nuclear weapons, nuclear energy, climate change, and emerging technologies such as bioengineering, artificial intelligence, and cybersecurity. The closer the minute hand is to midnight, the more imminent the threat to humanity.

The first Doomsday Clock was created in 1947 as a cover design for the Bulletin. It was meant to symbolize the urgency of informing the public about the nuclear threat, and was originally set to seven minutes to midnight. Martyl Langsdorf, its designer, said that seven minutes to midnight “looked good to [her] eye.”

Just this past week, after the Bulletin’s review of the events of 2015, they unveiled the clock set to three minutes to midnight, the same as it was last year.

The Bulletin’s Board of Science and Security decided to maintain the clock’s setting because, in general, the good of the past year balanced out the bad.

“There were two very important bright spots. But there was also dismay that so little had been done in other areas,” said Rachel Bronson, Executive Director and Publisher of the Bulletin.

The first bright spot was the Paris Agreement from December, a global agreement to reduce climate change. The second was the Iran nuclear agreement, which has lifted economic sanctions on Iran after confirmation that the country has restricted nuclear activity.

However, rising tensions between the United States and Russia, conflict in Syria and Ukraine, the modernization of nuclear weapons by multiple global powers, North Korea’s recent nuclear weapons test, and the current state of climate change have all offset those bright spots.

According to Robert Rosner, a professor in astronomy, astrophysics, and physics at the University and one of the co-chairs of the Board of Scientists and Security, three minutes to midnight means that the world needs to think seriously about the threat it presents to itself.

“It means that it’s not a great time. This is a time to sit back and realize that we have some problems, and that we need to fix things,” he said.

The Bulletin was founded in 1945 by scientists at the University of Chicago who had worked on the first atomic bomb. The publication, which has been published at varying intervals since its inception, is meant to inform the public and world leaders on the same issues that the Doomsday Clock decision encompasses.

According to Rosner, seeing those first tests of atomic bombs inspired the creation of the Bulletin.

“It was probably the very first time in all of human history…when it dawned on people that witnessed this explosion, that we’d mastered something that could basically wipe out human beings on the planet,” he said. “We started off with sticks and bones, beating each other up, but none of that would lead to the decimation of all of humanity.”

The Doomsday Clock itself was meant to convey that realization to the world at large, from everyday citizens to political leaders.

“So doomsday—they meant it literally, that we’ve mastered something technically, but may not have mastered it from the point of view of controlling it politically, socially,” Rosner said.

The closest the clock has ever been was one minute away from midnight in 1953, when the Soviet Union and the United States tested their first thermonuclear weapons within six months of each other. The farthest the clock has ever been from midnight is 17 minutes, after the United States and the Soviet Union signed the Strategic Arms Reduction Treaty in 1991.

The United States’ relationship with Russia did improve after that treaty, but as the Board cited in its clock decision for this year, the relationship has become strained once again.

“When the Soviet Union collapsed, the clock was moved way back. We like that. I would like to see that. We’d like to fix our relationship with the Russians. At this point, we can’t even have what people call ‘track two’ discussions, behind the scenes conversations, with the Russians,” Rosner said.

As an example of this relationship, Rosner pointed to a Christmas card from his friend Leonid Bolshov, the director of the Nuclear Safety Institute of the Russian Academy of Sciences.

“It’s like day and night… I met him probably 12 years ago, maybe a bit more, and we could talk about anything,” he said. “We send each other these things, because we’re still friends. But you can’t talk.” 

Public reactions to the Doomsday Clock announcement vary, according to Bronson. “It can go from the ridiculous to the sublime,” she said.

The clock trended on Twitter and Facebook even before its three-minute ruling was announced. Stephen Colbert talked about it on his show. The New Yorker and NPR ran stories about it.

Political leaders pay attention as well. Board members, based on pieces they write for the Bulletin, have been called in to give their expertise during congressional hearings. An interview between Ariane Tabatabai, one of the Bulletin’s columnists, and Iran’s deputy foreign minister Majid Takht-Ravanchi, was used as a resource by both the U.S. and Iran when working on the recent Iranian nuclear agreement. When North Korea completed its recent nuclear tests, the office of the Bulletin was flooded with calls from the media about how to tell whether a hydrogen bomb had actually been tested.

“Leaders do view the Bulletin as an important incredible source, and when they see pieces that make them think… they’ll call on us,” Bronson said.

No matter the reaction, Bronson said that the Doomsday Clock is all about creating conversation, especially regarding world issues. “For a moment every year, when the clock comes out, the world talks about nuclear security and disarmament and modernization programs and waste storage programs and climate change—and talks about whether, is it better than the scientists think, in their estimation, or worse? Where would they set the clock?” she said.

Though it’s the job of the Bulletin’s Science and Security Board to think about these issues all the time, Bronson acknowledges that the rest of the world can’t always do the same. But she believes that releasing the clock is an important reminder.

“Three minutes to midnight is very worrisome. This aspect of security is very fragile,” Bronson said. “We all have our lives to go about…everyone can’t think about these kind of existential threats all the time. But we can think about it sometimes.”