In its annual announcement, the Bulletin of the Atomic Scientists moved the Doomsday Clock ahead to 100 seconds to midnight.

The clock was introduced in 1947 and is a symbolic representation of how close humanity is to destroying civilization. Typically, the hands are moved forward or back depending on how vulnerable the world is. Midnight represents a catastrophe.

While the hands of the clock typically move a minute at a time, the Bulletin of the Atomic Scientists moved it forward by 30 seconds in 2017 and 2018, stopping at two minutes to midnight. It remained unchanged in 2019.

"It is 100 seconds to midnight. We are now expressing how close the world is to catastrophe in seconds — not hours, or even minutes," said Rachel Bronson, president and CEO of the Bulletin of the Atomic Scientists. "It is the closest to Doomsday we have ever been in the history of the Doomsday Clock. We now face a true emergency — an absolutely unacceptable state of world affairs that has eliminated any margin for error or further delay."

(Kevin Kirk)

In making the announcement, Bronson said the clock needed to be recalibrated — which is why it was moved 20 seconds — due to new concerns not taken into account in the past, including climate change.

The farthest the clock's hands have been from midnight was 17 minutes in 1991, at the end of the Cold War.

"What we called the new abnormal last year … now has become apparently an enduring reality," said Robert Rosner, chair of the bulletin's science and security board.

In reaching their decision — which was made in November — the scientists said they took into account three concerning issues: nuclear weapons, climate change and cyber-based disinformation.

"As long as nuclear weapons remain in existence, it is inevitable that they will one day be used, whether by accident, miscalculation or design," said Mary Robinson, former president of Ireland and chair of The Elders, a group of world leaders working to promote human rights and other important world issues.

'We have indeed normalized a very dangerous world,' says Bulletin of The Atomic Scientists. 1:06

Sivan Kartha, a member of the bulletin's science and security board and senior scientist at the Stockholm Environmental Institute, said the state of the world demands an emergency response, citing the record-breaking heat waves and floods in India, recent hurricanes and the wildfires that raged from the Arctic to Australia in 2019.

"If the Earth warms by what we tend to think of just a few degrees … we have no reason to be confident that such a world will remain hospitable to human civilization," said Kartha, who was also the author of the fifth and sixth assessment reports of the Intergovernmental Panel on Climate Change.

Former California governor Jerry Brown, who is the bulletin's executive chair, gave a fiery speech. He said while he's not a scientist, he recognizes the importance of the symbolic clock and that it's the only way to let the world know the threats to civilization.

"We're on the Titanic ready to hit an iceberg," Brown said. "But we have have an incredible opportunity to reverse."