Doomsday Clock at 100 Seconds to Midnight: What the 2020 Move Meant

First published May 7, 2020.

On 23 January 2020 the Bulletin of the Atomic Scientists moved the hands of its Doomsday Clock to 100 seconds to midnight. It was the first time the warning had ever been expressed in seconds rather than minutes, and it put the symbolic clock closer to "midnight", the Bulletin's shorthand for a civilisation-ending catastrophe, than at any point since it was created in 1947, including the worst years of the Cold War.

The short answer to why: the Bulletin's experts judged that nuclear risks, an accelerating climate crisis and a flood of online disinformation were all getting worse at the same time, while the treaties and institutions meant to manage them were being weakened. Below is how the clock works, why the 2020 setting mattered, how it has moved since, and what critics say about it.

What the Doomsday Clock is, and what it is not

The Doomsday Clock is a graphic, not a machine. It first appeared on the cover of the June 1947 issue of the Bulletin of the Atomic Scientists, a magazine founded in 1945 by researchers who had worked on the Manhattan Project and wanted the public to understand the weapon they had helped build. The artist Martyl Langsdorf drew a clock face with the minute hand set at seven minutes to midnight, and the image stuck.

Today the setting is decided each year by the Bulletin's Science and Security Board, a group of specialists in nuclear policy, climate science and emerging technology, who consult the organisation's sponsors, a panel that has included many Nobel laureates. They look at the state of the world and ask a single question: compared with last year, is humanity safer or in greater danger?

Two common misunderstandings are worth clearing up early:

• It is not a countdown. The clock does not predict that disaster will happen in 100 seconds, 100 days or 100 years. It is a way of expressing an expert judgement about risk in a form anyone can grasp.
• It is not a formula. There is no published equation behind the hands. The board weighs evidence and argues it out, then explains its reasoning in a written statement.

A short history of the hands

Looking at the clock's past settings helps put 2020 in perspective. A few key moments:

• 1947: seven minutes. The original setting, two years after Hiroshima and Nagasaki.
• 1949: three minutes. The Soviet Union tested its first atomic bomb, ending the American monopoly.
• 1953: two minutes. Both superpowers had now tested hydrogen bombs, weapons hundreds of times more powerful than those used in 1945.
• 1963: twelve minutes. The hands moved away from midnight after the Partial Test Ban Treaty ended atmospheric nuclear testing by the US, UK and USSR.
• 1984: three minutes. US–Soviet talks had stalled and new nuclear missiles were being deployed in Europe.
• 1991: seventeen minutes. The furthest from midnight the clock has ever been, after the Cold War ended and the START I arms reduction treaty was signed.
• 2018 and 2019: two minutes. Matching the 1953 low, now citing climate change alongside nuclear weapons.

One detail often gets muddled in older write-ups: the 1962 Cuban Missile Crisis, probably the closest the world has come to nuclear war, happened between two of the Bulletin's announcements and never produced a setting of its own. The clock stood at seven minutes then, and the next change, in 1963, was a move back from midnight. Critics have pointed to this as evidence that the clock does not always track short, sharp emergencies.

The 2019 setting is the one USA Today was reporting in the post below, a year before the hands moved again.

It's still 2 minutes to midnight because of nuclear weapons and climate change. https://t.co/DYbeNB3Lxg #DoomsdayClock pic.twitter.com/BRfFPlvvHm

— USA TODAY (@USATODAY) January 24, 2019

Why the Bulletin moved to 100 seconds in 2020

The 2020 announcement was made in Washington, with two members of The Elders, the group of former world leaders founded by Nelson Mandela, on stage: Mary Robinson, the former president of Ireland, and Ban Ki-moon, the former UN Secretary-General. Robinson summed up the board's view by calling it "the most dangerous situation that humanity has ever faced".

The board pointed to three broad problems feeding into each other.

Nuclear weapons and broken agreements

In 2019 the United States and Russia had let the Intermediate-Range Nuclear Forces (INF) Treaty collapse, removing one of the main pillars of Cold War arms control. The US had already pulled out of the 2015 Iran nuclear deal in 2018, talks with North Korea had stalled, and the remaining big US–Russia treaty, New START, was due to expire in 2021 with no clear plan to replace it. Both countries were also investing in new kinds of weapons. The board's statement urged governments to open talks on cyber warfare, missile defence, weapons in space, hypersonic missiles and short-range "battlefield" nuclear arms.

Climate change

The Bulletin has counted climate change as a core threat since 2007. In 2020 it noted that global emissions were still rising despite the Paris Agreement, and it criticised the United States in particular for starting its withdrawal from that agreement and for backing coal and other fossil fuels.

Disinformation as a "threat multiplier"

New for 2020 was a strong emphasis on information warfare. The board argued that disinformation campaigns and the erosion of trust in science were making it harder for societies to respond rationally to either nuclear or climate dangers.

“At a time when world leaders should be focused on...nuclear escalation & the climate emergency, we are instead witnessing denial, disregard & dangerous brinkmanship,” — Ban Ki-moon, Deputy Chair of @TheElders, former UN Secretary-General #DoomsdayClockhttps://t.co/On5ctRjelk pic.twitter.com/FOK1BO3o5o

— Bulletin of the Atomic Scientists (@BulletinAtomic) January 23, 2020

Rachel Bronson, then the Bulletin's president and CEO, described the setting as "the closest to Doomsday we have ever been in the history of the Doomsday Clock", and framed the moment as a "new abnormal" in which several dangers were rising together rather than one at a time.

Where the clock has stood since 2020

The 100-second setting turned out not to be the low point. The hands stayed at 100 seconds in 2021 and 2022, through the pandemic. In January 2023, less than a year after Russia's full-scale invasion of Ukraine raised fears of nuclear escalation, the board moved them to 90 seconds, and kept them there in 2024. In 2025 they edged to 89 seconds, with the board adding concern about artificial intelligence in warfare.

In January 2026 the clock was set at 85 seconds to midnight, again the closest in its history, with the Bulletin pointing to what it called a failure of leadership. Each of these settings is a judgement about that year, so a figure quoted from 2020 should not be read as the current one.

“As long as nuclear weapons remain in existence, it is inevitable that they will one day be used, whether by accident, miscalculation or design,” —Mary Robinson, Chair of @TheElders, former President of Ireland#DoomsdayClock pic.twitter.com/IzHZDRFvOs

— Bulletin of the Atomic Scientists (@BulletinAtomic) January 23, 2020

The case against the clock

The clock has always had critics, and their points are worth knowing if you want to read it sensibly:

• Method. Journalists writing in Slate and the New Statesman have complained that the Bulletin never explains in measurable terms how it weighs one threat against another.
• Consistency. The psychologist Steven Pinker has argued that the clock is not tied to objective indicators, noting that it was set further from midnight during the Cuban Missile Crisis than in 2007.
• Paralysis. Anders Sandberg, formerly of Oxford's Future of Humanity Institute, has warned that bundling many threats together can leave people feeling helpless rather than motivated.
• Politics. Some conservative commentators see the board's statements as advocacy for particular policies, such as arms control and climate action.

The Bulletin's answer is that the clock was never meant to be a scientific instrument. It is a public warning, written by experts, designed to start conversations and push leaders to act. Read that way, the most useful part of each announcement is not the number but the statement that explains it.

How to read Doomsday Clock news without panic

Headlines about the clock tend to arrive every January, usually with words like "apocalypse" attached. A few habits help keep them in proportion:

• Read the statement, not just the setting. The Bulletin publishes a full explanation each year, listing the specific developments that worried the board and the steps it thinks would help.
• Separate risk from prediction. A higher risk does not make a catastrophe certain. Nuclear war has been avoided for eight decades, often because of deliberate diplomacy, hotlines, inspections and treaties.
• Notice what can change it. The clock has moved away from midnight repeatedly, most notably after arms control agreements in 1963, 1972, 1988 and 1991. Those moves were the result of political choices, which means today's settings can be reversed by choices too.
• Focus on practical levers. For most people that means paying attention to arms control and climate policy at election time, supporting reliable journalism and science, and being careful about sharing unverified claims online, the disinformation problem the board highlighted in 2020.

The clock's enduring value is that it reminds us the biggest risks to humanity are made by humans, and so can be reduced by humans. Further background on the climate side of that picture is in our piece on climate change and the long-term risk to civilisation.

Sources: Bulletin of the Atomic Scientists: Doomsday Clock statement; Bulletin of the Atomic Scientists: past statements; Wikipedia: Doomsday Clock; Common Dreams, 23 January 2020.