Nuclear War Threat and Climate Crisis Move ‘Doomsday Clock’ 90 Seconds to ‘Midnight’

Interview with Robert Socolow, theoretical physicist and professor emeritus at Princeton University, conducted by Scott Harris

In the last week of January, The Bulletin of the Atomic Scientists’ “Doomsday Clock” was moved forward to 90 seconds before midnight, the closest the clock has ever been to midnight (a metaphor for global catastrophe) since the clock was launched in 1947.
The Doomsday Clock, used to alert humanity to imminent threats to human civilization and the planet, moved from 100 seconds to midnight — where it’s been set since 2020 — to 90 seconds this year. The decision to move the clock forward was due “largely, but not exclusively to the ongoing war in Ukraine and the increased risk of nuclear escalation. The new Clock time was also influenced by continuing threats posed by the climate crisis and the breakdown of global norms and institutions needed to mitigate risks associated with advancing technologies and biological threats such as COVID-19.”

Between The Lines’ Scott Harris spoke with Robert Socolow, theoretical physicist and professor emeritus at Princeton University, who serves as a member of the Bulletin’s Science and Security Board that, along with support from 10 Nobel Laureates, sets the Doomsday clock annually. Here, Socolow explains the unprecedented global dangers that led to the “Doomsday Clock” being moved forward to 90 seconds before midnight.

ROBERT SOCOLOW: This year, we announced a movement of 10 seconds from 100 to 90 toward midnight and with a clear conviction in our group — very little division among us — that the world was more dangerous this January, if you like, than last January. And the major reason for that was the introduction of the possibility of using nuclear weapons in the Ukraine war, which President Putin announced he could conceivably use them.

And he continues to do so. He continues to suggest that nuclear weapons are more usable than most of us would want to even begin to concede.

SCOTT HARRIS: As you talk about the horrifying specter of nuclear war as a result of the war in Ukraine, is it the concern of the scientists and others on the panel at the Doomsday Clock that it may not be a deliberate decision, that in war there is a lot of clouded judgment. There’s miscalculation and there’s accident.

ROBERT SOCOLOW: In my mind, those are absolutely central considerations. Things getting out of hand. Miscalculations. Misunderstandings.

One of the things that I learned, particularly this past year in our conversations among our group — which, by the way, is called the Science and Security Board of the Bulletin of Atomic Scientists, that’s the group I am part of — was that the people who know much more about nuclear weapons and nuclear weapons command and control than I did, simply did not have confidence that the world’s leaders could avoid an escalation. Low probability, but not zero probability.

If Putin were to use a single nuclear weapon, that would violate a 77-year taboo. And the terrible thing about nuclear weapons is they have a signature. You can’t have any doubt that that’s what’s set off with their uranium atoms’ fissions. There are telltale radioactive products that can’t come from any other place.

So, you know, a nuclear weapon has been used. You’ve crossed some kind of a threshold. And I would ask again and again with one of two metaphors: One, Are there some missing rungs on the ladder so we don’t worry about climbing straight up into oblivion? And the answer was no, we’re not sure there are any missing rungs on the ladder.

Is there any firebreak? Another image? We’re not sure there’s a firebreak.

So that’s why it is so provocative and so dangerous and so uncalled for for Putin to be doing what he’s doing. And it set us all back.

In past years, when we’ve moved the clock, there were multiple considerations that were on par. This year, we write a substantial essay on the movement of the clock, which is available on on the web.

We make clear this time that Ukraine was a dominant factor, not one of four or five equally important factors. And so that’s what comes across. I hope it comes across. I hope people will read those statements we have, which is about six or eight pages. And quite thorough.

SCOTT HARRIS: The issues cited in moving the clock forward, the Doomsday Clock forward that contribute to the rising threat of catastrophe are by and large created by humans in our systems. And by all accounts, these threats are within our power to mitigate and change. But the lack of leadership and political will are major obstacles. Are you optimistic that average people working together locally, nationally and internationally have the capacity to influence world events to avert future devastation?

ROBERT SOCOLOW: Well, first of all, I am optimistic. I do think we are driven to sort of towards survival. We have many checks and balances. Even the response to President Putin end of last year has been a contained response. It hasn’t gotten out of hand, at least so far. I think we’re dealing with climate change with international institutions, particularly. It’s going to take quite a while.

But we’ve got a global conversation, which we didn’t have for quite a long time. It was always that sense that the Europeans and Americans should solve the problems first. Now we have a global view. We have a lot of survival instinct built into us. That’s why we’re around, I suppose. So I’m an optimist.

I think first of all, human beings and voters and citizens influence their leaders. The leaders want to do things that are popular. The reason we’re doing this bulletin, central phrase is we want to raise awareness. Once people are aware that there are risks, they’re running into unnecessary risks. They push back on the politicians and they say, “Do something here.” And then they do something. Also, with private industry and finance and the NGO world, non-governmental organizations — all of these areas are areas of creativity.

For more information, visit Bulletin of the Atomic Scientists at

Listen to Scott Harris’ in-depth interview with Robert Sokolow (27:54) and see more articles and opinion pieces in the Related Links section of this page.

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