The clock shows how close the world is to a global catastrophe as a number of minutes or seconds to midnight, changed in January of each year. When the clock hits midnight, it means that a global event that would harm humanity is near.[3]
On January 23, 2020, the Clock was moved further, to 100 seconds (1 minute 40 seconds) before midnight, meaning that the Clock's status today is the closest to midnight since the Clock's start in 1947. In 2021 and 2022, the clock's time was unchanged, staying at 100 seconds before midnight.
The Soviet Union tests its first atomic bomb, the RDS-1, officially starting the nuclear arms race.
1953
2
23:58
−1
The United States tests its first thermonuclear weapon in November 1952 with the Soviets doing a similar test. This was the clock's closest approach to midnight (tied in 2018) until 2020.
1960
7
23:53
+5
With scientists agreeing that a nuclear war would be fatal to humanity, both the United States and Soviet Union work to avoid a nuclear war
1963
12
23:48
+5
The United States and the Soviet Union sign the Partial Test Ban Treaty, limiting atmospheric nuclear testing.
Talks between American and Soviet leaders stop as the Soviet–Afghan War begins. As a result of the war, the U.S. Senate does not ratify the SALT II agreement.
Tensions between the United States and the Soviet Union grow, with the ongoing Soviet–Afghan War intensifying the Cold War.[5] Ronald Reagan pushes to win the Cold War by increasing the arms race between the superpowers. The Soviet Union and its allies (except Romania) boycott the 1984 Olympic Games in Los Angeles.
1988
6
23:54
+3
In December 1987, the Clock is moved back three minutes as the United States and the Soviet Union sign the Intermediate-Range Nuclear Forces Treaty, to stopping intermediate-range nuclear missiles, and their relations improve.[7]
Little progress on global nuclear disarmament. United States rejects a series of arms control treaties and announces its plans to withdraw from the Anti-Ballistic Missile Treaty.
2007
5
23:55
−2
North Korea tests a nuclear weapon in October 2006,[8] Iran's nuclear ambitions, a renewed American focus on the military utility of nuclear weapons, the failure to create secure nuclear materials, and the continued presence of some 26,000 nuclear weapons in the United States and Russia.[9] This is the first time climate change was added as a possible threat to mankind.[10]
2010
6
23:54
+1
Worldwide efforts to reduce nuclear weapons and limit effect of climate change.[2]New START agreement is ratified by both the United States and Russia, and more negotiations for reductions in the American and Russian nuclear weapons are already planned.
2012
5
23:55
−1
Lack of global political action to address global climate change, nuclear weapons stockpiles, the potential for regional nuclear conflict, and nuclear power safety.[11]
2015
3
23:57
−2
Concerns about a lack of global political action to stop global climate change, the modernization of nuclear weapons in the United States and Russia, and the problem of nuclear waste.[12]
2017
21⁄2
23:57:30
−1⁄2 (−30 s)
United States President Donald Trump's comments over nuclear weapons, the threat of a new arms race between the U.S. and Russia, and not believing in the effects of climate change by the Trump administration.[13][14][15][16][3]
Failure of world leaders to deal with the increased threats of nuclear war, such as the end of the Intermediate-Range Nuclear Forces Treaty (INF) between the United States and Russia as well as increased tensions between the US and Iran, along with the ignoring climate change. It is the first time the clock uses seconds instead of minutes, instead of minutes; this is the clock's closest approach to midnight, passing that of 1953 and 2018.[19] The Bulletin said that the current issues are "the most dangerous situation that humanity has ever faced." In 2021 and 2022, the Bulletin reused the "100 seconds to midnight" time setting.[20]
↑Science and Security Board Bulletin of the Atomic Scientists (August 9, 2011). "It is two and a half minutes to midnight"(PDF). Bulletin of the Atomic Scientists. Archived from the original(PDF) on January 26, 2017. Retrieved January 26, 2017.