The Bulletin of the Atomic Scientists said in January that the hand of the Doomsday Clock had moved 30 seconds closer to midnight. The clock now sits at 2 minutes and 30 seconds to Doomsday. Since its creation in 1945, the hand of the clock has moved several times, but it has only been less than three minutes to midnight at one other point in history: 1953, the start of the Cold War.

According to the statement released by the Bulletin, this change was made to reflect threats by North Korea, as well as conflict between Pakistan and India and the statements regarding nuclear weapons by President Donald Trump.

The Bullentin’s change is increasingly relevant as North Korea has fired multiple missiles over Japan in recent months, according to CNN.

Sara Koopman, an assistant professor in the School of Peace and Conflict Management who grew up in Seattle, anticipated the city to be the first hit during nuclear threats as a child. Her school treated nuclear strike drills the same way they treated fire drills.

“From about age nine and after, I was really scared,” Koopman said. “It created a lot of tension and worry among all of us.”

The first nuclear weapons used nuclear fission, a process of splitting heavy atoms in uranium or plutonium to create energy. The U.S. developed these weapons and used them against Japan in 1945.

“That was the only type that was known until around 1950,” said Declan Keane, a physics professor at Kent State. 

Since the bombings of Hiroshima and Nagasaki, the first and only nuclear strikes in world history, research into nuclear weapons has persisted. The Soviet Union and the United States both developed the hydrogen bomb around the same time in 1950, Keane said. 

Despite posturing on both sides, neither country fired. Keane said this posturing as reflective of the current conflict between the United States and North Korea.

Hydrogen bombs like the one the North Korean government claims to have developed are far more powerful than the bombs dropped on Japan.

This is because hydrogen bombs use a different process to release energy at the atomic level. Hydrogen is a lighter element, and the energy created in hydrogen weapons is from fusion, where two hydrogen atoms combine.

It was the creation of the hydrogen bomb that drove the hand of the Doomsday Clock to two minutes to midnight in 1953.

Koopman’s concerns are about nuclear weapons influencing the community surrounding testing sites. She said that various cancers are associated with living and working near radiation, and that these diseases are discussed less than the possibility of a nuclear strike.

She said that the difference in cultural perception of nuclear weapons is interesting. Even though the Doomsday Clock was at three minutes to midnight in 1984, farther than where scientists placed it this year, nuclear threats don’t seem to be as prominent as they were at the time.

“There’s so much to be anxious about in the world right now,” Koopman said. “Not thinking about nuclear war is a coping mechanism.”

Keane said there is some science behind nuclear preparations like fallout shelters, but they may not be a priority.

“The North Koreans have quite a small number of nuclear weapons and it’s not clear that they have the capability to attack the mainland U.S.,” Keane said. “The chances of this being a really serious threat to your life is miniscule compared to a zillion other things that are of concern to you.”

The Bulletin called for leaders and civilians to act on their recommendations for avoiding both nuclear disaster and climate change progression.

“Wise public officials should act immediately, guiding humanity away from the brink,” the Bulletin wrote. “If they do not, wise citizens must step forward and lead the way.”

Carlyle Addy is the politics reporter. Contact her at [email protected].