For almost 75 years, the Doomsday Clock has monitored how close humankind is to global catastrophe. With the clock now closer to midnight than ever before, Rachel Brazil talks to physicists who say we must step up our efforts to prevent disaster
It is 100 seconds to midnight.
That’s according to the Doomsday Clock – a device created by the Bulletin of the Atomic Scientists in 1947 as a metaphor to indicate how near we are to a humanity-ending catastrophe. The clock started out at 11:53 p.m. and over the years has shifted backwards and forwards as the global situation has worsened or improved. But on 23 January 2020 the clock was moved closer to midnight than at any other time in its near 75-year lifetime.
This year’s historic decision was announced to “leaders and citizens of the world” at the National Press Club in Washington, DC by members of the Bulletin of the Atomic Scientists. In setting the clock to 100 seconds to midnight, they cited risks such as worsening nuclear threats, a lack of climate action, and the rise of “cyber-enabled disinformation campaigns that undermine society’s ability to act”.
The annual resetting of the Doomsday Clock is these days a major media event, providing grist for politicians, policy-makers and commentators around the world. But the clock actually emerged from the concerns of the physics community immediately after the Second World War, when two University of Chicago physicists – Eugene Rabinowitch and Hyman Goldsmith – started to think about the consequences of their work.
They were among the many scientists and engineers who had taken part in the Manhattan Project, which developed the atomic bombs that the US dropped on Hiroshima and Nagasaki in August 1945.
Chicago was where the Italian physicist Enrico Fermi had in 1942 designed and built the first reactor that could achieve a self-sustaining nuclear reaction and where much of the science of the Manhattan Project was incubated. “Within three or four months of the bombs being dropped, Rabinowitch and Goldsmith created a publication called the Bulletin of the Atomic Scientists,” says current Bulletin president and chief executive Rachel Bronson.
According to Bronson – who is not a physicist, but an expert in international relations – many of the Manhattan Project physicists were already politically conscious, but their main concern had been to acquire a nuclear bomb before Germany. In the event, the Germans never built such a weapon and it was only after the war that the Manhattan researchers began to debate nuclear risk and proliferation with the wider physics community.
“The Bulletin was established to set a flag and say here is where scientists should engage in political issues,” says Bronson. But the journal was also set up to consider future dangers or – as Rabinowitch poetically put it – “to manage the dangerous presents of Pandora’s box of modern science”. And it was a desire to communicate these risks to the public that led to the Doomsday Clock being set up in 1947, two years after the first edition of the Bulletin.
The idea of the clock emerged from the cover of the June 1947 edition of the Bulletin, created by the artist Martyl Langsdorf whose husband was a nuclear physicist. Langsdorf placed the first clock at seven minutes to midnight for purely aesthetic reasons but its subsequent position was decided by Rabinowitch, the Bulletin’s founding editor.
When he died in 1973, a science and security board took over that responsibility in consultation with the journal’s board of sponsors.
Originally set up by Albert Einstein with Robert Oppenheimer as its first chair, the board of sponsors currently includes 13 Nobel laureates – including the particle theorists Sheldon Glashow, Steven Weinberg and Frank Wilczek – as well as astronomer Martin Rees and theoretical physicist Lisa Randall. As for the science and security board, its composition has evolved over the years. It currently has 19 members and is chaired by Robert Rosner – a physicist and former head of the Argonne National Laboratory near Chicago.
“On the nuclear side we have physicists who know about all things nuclear, weapons and reactors, but also people who have been involved in negotiations with the government,” says Rosner, who has served on the board for a decade and currently leads the process to set the Doomsday Clock each year. “There’s a strong political aspect to it,” underlines Bronson, who points to the need for “people who understand the political process of different countries and how the science wraps up in what we’re doing”.
Closer and closer
Before 2020 the closest the Doomsday Clock had been to midnight was in 1953, when it was set to 11:58 p.m. after both the US and the Soviet Union carried out hydrogen-bomb tests the previous year (figure 1). Its furthest distance from midnight came in 1991 when the clock was moved back to 11:43 p.m. That heady moment followed the end of the Cold War and the signing of the Strategic Arms Reduction Treaty, which led to deep cuts in US and Soviet nuclear-weapon arsenals.
The nuclear threat is still with us, however. In 2019 there were almost 13,900 nuclear warheads in the world (albeit down from a high of more than 70,000 in the mid-1980s). And it was the continued existence of these arsenals – coupled with the lapse of several major arms-control treaties and America’s decision to quit the Iran nuclear deal – that shaped the Bulletin’s current risk assessment.
However, since 2007 the journal’s Doomsday Clock deliberations have also factored in the risks facing humanity from climate change. Bronson admits that adding climate change to its remit was “probably one of the most controversial decisions” her organization has made given its reputation as primarily an authority on the threat from nuclear weapons. “[But] if you believe that the Bulletin was founded to manage ‘the dangerous presents of Pandora’s box of modern science’, then the answer is, of course, you have to include climate change,” she says.
In recent years the Bulletin has also begun to focus on new disruptive technologies. “Take synthetic biology, for example, or gene editing,” says Steve Fetter, a physicist-turned-policy-expert from the University of Maryland, who serves on the Bulletin’s science and security board. “While this technology has tremendous promise for curing currently incurable diseases, you don’t have to have too much imagination to see how someone could misuse it.” The risks, Fetter adds, are compounded by how easy these technologies are to develop. “You needed a huge factory to make plutonium or highly enriched uranium, but gene editing, or artificial intelligence; these are things that can be done by an individual.”
Setting the Doomsday Clock is a process the Bulletin says it takes very seriously. “We pride ourselves in it being consultative,” says Bronson. “Our leaders and experts can come together with different perspectives and put them out on the table and have them examined.”
The formal process begins in November each year, when members of the science and security board meet in Chicago for a day and a half, with its deliberations centred on two fundamental questions.
First, is humanity safer or at greater risk this year compared to the year before? And second, is humanity safer or at greater risk this year than in all the years since the Bulletin began its deliberations in 1947? Rosner says discussions are not for the sensitive, with board members being “pretty hard-headed people who are vigorous in expressing their opinions”. With the calibre of minds involved, he says, “you can’t be a lazy thinker”.
To set the clock the closest it’s ever been to midnight, the Bulletin of the Atomic Scientists had to be convinced we are living in the most dangerous period since 1947
After the November meeting, board members start drafting a public statement that explains their decision, refining it with staff from the Bulletin in a process that lasts until the announcement of the clock’s new position in early January.
To set the clock the closest it’s ever been to midnight, Bronson insists that the board this year had to be convinced we are living in the most dangerous period since 1947. She cautions, though, that setting the clock is not an exact science. “You’re not shovelling data into a big algorithm that spits out a time; it’s really a judgement,” she says.
The annual clock-setting is intended to serve as a challenge to politicians to do better in the year ahead. However, members of the board are currently concerned that the world lacks the strong leadership and co-operation to deal with the risks they have flagged. “You can see it now playing out in the coronavirus pandemic,” says Fetter, who points out how many governments have ignored the results of their regular security and pandemic-readiness exercises.
Bronson denies accusations – mostly from the right wing – that its risk assessment is arbitrary and politically motivated, pointing out that the clock has been moved forward and back during both Democratic and Republican administrations in the US. “We take criticism on both sides, quite frankly, and we take that as a sign that we’re doing something correct.” If anything, Bronson feels that the clock provides many with a sense of sanity. “It’s empowering, if it helps people feel that they’re not crazy by noting that something is not right [and that] we’re not where we should be in 2020.” She also laughs off criticism that the clock is just a scare tactic. “That’s fair, it’s called the Doomsday Clock!”
Members of the Bulletin are also increasingly concerned by the rise of fake news and conspiracy theories, which have led to the anti-vaccination movement and other scare stories. Social media has allowed such disinformation to spread, making it much harder to address real risks. But could this move away from a pure focus on nuclear weapons and the arms race dilute the message behind the Doomsday Clock?
Stuart Parkinson, a physicist and executive director of the UK-based Scientists for Global Responsibility (SGR), thinks the Doomsday Clock may have become too simplistic given the variety of risks it now tries to encompass. “I’d like to see a more multi-dimensional risk-communication device, so maybe for each issue you have a traffic-light system or a five-point rating.” Bronson knows the clock is a blunt instrument but says that’s also its beauty, generating conversations at the highest levels of power and in the most local classrooms.
It’s true, though, that the issue of nuclear risk has suffered an overall decline in interest, including among physicists. “There was a very special period during the war and at least 20 years after, when physicists played a very important role in public policy,” says Rosner.
“That’s changed dramatically.” The policy agenda has become more crowded, with the climate crisis forcing the Bulletin to consult not just physicists, but chemists, biologists and risk-assessment experts too. Indeed, he feels many of today’s physicists shy away from public or political debate and are uncomfortable dealing with the uncertainties around climate risk.
One physicist who is unafraid to contemplate the risks posed by scientific advances is Anthony Aguirre, a cosmologist from the University of California, Santa Cruz. Together with Max Tegmark from the Massachusetts Institute of Technology, in 2014 he founded the Future of Life Institute – a non-profit centre that investigates how to safely develop new technologies. “[The institute addresses] questions that aren’t part of the regular academic day-to-day research discourse, and what can we tangibly do to increase the probability of things going well,” Aguirre says.
The COVID-19 pandemic has convinced Aguirre that scientists need to think even more seriously about risk. “It’s woken up a lot of people to the idea that risks are not purely theoretical. I’m even more concerned about the lack of effective national and international institutions to both prevent and deal with risks as they arise.” And although the Future of Life Institute does look at nuclear risk, its current focus is on transformative artificial intelligence (AI), which he feels could compound existing risks.
If used in weapons, for example, AI could rapidly and inadvertently escalate minor incidents into nuclear wars without humans being able to stop them. And that, he feels, is exactly the kind of problem physicists are well placed to examine. “Within the physics and cosmology community there is a tendency to think on bigger scales and longer timescales,” Aguirre points out, which he believes gives them an ability to understand how small risks can still become significant over time.
Aguirre cites the physicists on the Manhattan Project, who – even before they had built a bomb – worried that a nuclear explosion could create such extreme temperatures that hydrogen atoms in the air and water would fuse to form helium. Literally igniting the atmosphere and oceans, this process would – they feared – generate a runaway reaction that could engulf the globe. Fortunately, when this possibility was studied, it proved unfounded.
For its part, the Bulletin of Atomic Scientists is now looking to re-engage the physics community, given the nuclear threat posed by the current unravelling of Cold War agreements. The last remaining bilateral nuclear arms control treaty, New START, is scheduled to expire in February 2021, leaving nuclear weapons proliferation unconstrained for the first time in 50 years.
Those events prompted physicists at seven US universities to launch the Physicists Coalition for Nuclear Threat Reduction earlier this year, with support from the American Physical Society. Although the Bulletin is not directly involved with this initiative, it is supportive of these efforts according to Bronson.
As part of the initiative, Fetter and others are giving talks at university departments in the US and hoping to attract physicists to advocate for nuclear-threat reduction, through public engagement and lobbying their local Congressional representatives.
He points to the effective role that they played in disarmament policy well into the 1980s, including arguing against America’s proposed ballistic-missile defence systems, which had been touted as a solution to the nuclear threat. Physicists pointed out that in space all objects regardless of mass travel along the same trajectory of launch, meaning it would be very hard to distinguish warheads from decoys.
Over at SGR, Parkinson agrees that physicists have become complacent about nuclear risks and how their own work might endanger the world. That’s why his organization thinks ethics and responsibility must be embedded within scientific education. Physics, he feels, is not a pure, abstract exercise but has consequences that cannot just be ignored.
Indeed, he calls for more protection for scientists who speak out, and thinks professional institutions should debate the risks of new and existing technologies more openly with their members and with the public. Parkinson also thinks such organizations should end their links with fossil-fuel and defence firms.
Aguirre even feels better incentives and rewards are needed for individuals who help the world to avoid catastrophes, citing the case of Soviet air-defence officer Stanislav Petrov, who in 1983 was on duty in a command centre near Moscow when a radar screen on a satellite early-warning system seemed to suggest the US had launched five nuclear missiles. Petrov refused to alert the authorities, suspecting – correctly as it turned out – a malfunction. Despite having potentially saved the world from nuclear war, he was reprimanded by the Soviet authorities.
The current COVID-19 pandemic, while not a threat created by humans, is clearly a warning of what can happen when risks are ignored
The current COVID-19 pandemic, while not a threat created by humans, is clearly a warning of what can happen when risks are ignored, which Aguirre says is something we continue to do with existing and new technologies. Indeed, he feels the effort we put into planning for all risks is just not enough.
“We’ve all seen the catastrophic things that can in fact happen to us [with COVID-19],” he says, “[and] this is pretty minor in the spectrum of catastrophes.” For Aguirre, we need to put far more intellectual thought into other significant and potentially even more catastrophic risks.
Whether 2021 will bring us closer to midnight, we’ll find out soon.