WASHINGTON, D.C. – January 23, 2024 – The Doomsday Clock was reset at 90 seconds to midnight, still the closest the Clock has ever been to midnight, reflecting the continued state of unprecedented danger the world faces. The Bulletin of the Atomic Scientists, stewards of the Doomsday Clock, emphasized in their announcement that the Clock could be turned back, but governments and people needed to take urgent action.

A variety of global threats cast menacing shadows over the 2024 Clock deliberations, including: the Russia-Ukraine war and deterioration of nuclear arms reduction agreements; the Climate Crisis and 2023’s official designation as the hottest year on record; the increased sophistication of genetic engineering technologies; and the dramatic advance of generative AI which could magnify disinformation and corrupt the global information environment making it harder to solve the larger existential challenges.

Rachel Bronson, PhD, president and CEO, the Bulletin, said: “Make no mistake: resetting the Clock at 90 seconds to midnight is not an indication that the world is stable. Quite the opposite. It’s urgent for governments and communities around the world to act. And the Bulletin remains hopeful—and inspired—in seeing the younger generations leading the charge.”

The Doomsday Clock’s time is set by the Bulletin of the Atomic Scientists’ Science and Security Board (SASB) in consultation with its Board of Sponsors, which includes nine Nobel Laureates. Previously in January 2023, the Doomsday Clock was set at 90 seconds to midnight, the closest to midnight the Clock had ever been.

The Doomsday Clock statement states: “Ominous trends continue to point the world toward global catastrophe. The war in Ukraine and the widespread and growing reliance on nuclear weapons increase the risk of nuclear escalation. China, Russia, and the United States are all spending huge sums to expand or modernize their nuclear arsenals, adding to the ever-present danger of nuclear war through mistake or miscalculation. In 2023, Earth experienced its hottest year on record, and massive floods, wildfires, and other climate-related disasters affected millions of people around the world. Meanwhile, rapid and worrisome developments in the life sciences and other disruptive technologies accelerated, while governments made only feeble efforts to control them. . .. But the world can be made safer. The Clock can move away from midnight.”

Gov. Jerry Brown, executive chair of the Bulletin said: “As though on the Titanic, leaders are steering the world toward catastrophe–more nuclear bombs, vast carbon emissions, dangerous pathogens and artificial intelligence. Only the big powers like China, America and Russia can pull us back. Despite deep antagonisms, they must cooperate – or we are doomed.”

Bill Nye, who participated in the 2024 Doomsday Clock announcement, said: “For decades, scientists have been warning us of the dangers facing humankind. We could be facing catastrophe unless we better manage the technologies we’ve created. It’s time to act.”

The Many Dimensions of Nuclear Threat

• A durable end to Russia’s war in Ukraine seems distant, and the use of nuclear weapons by Russia in that conflict remains a serious possibility. In February 2023, Russian President Vladimir Putin announced his decision to “suspend” the New Strategic Arms Reduction Treaty (New START). In March, he announced the deployment of tactical nuclear weapons in Belarus. In June, Sergei Karaganov, an advisor to Russian President Vladimir Putin, urged Moscow to consider launching limited nuclear strikes on Western Europe as a way to bring the war in Ukraine to a favorable conclusion. In October, Russia’s Duma voted to withdraw Moscow's ratification of the Comprehensive Nuclear Test Ban Treaty, as the US Senate continued to refuse even to debate ratification.

• Nuclear spending programs in the three largest nuclear powers—China, Russia, and the United States—threaten to trigger a three-way nuclear arms race as the world’s arms control architecture collapses. Russia and China are expanding their nuclear capabilities, and pressure mounts in Washington for the United States to respond in kind.  

• Meanwhile, other potential nuclear crises fester. Iran continues to enrich uranium to close to weapons grade while stonewalling the International Atomic Energy Agency on key issues. Efforts to reinstate an Iran nuclear deal appear unlikely to succeed, and North Korea continues building nuclear weapons and long-range missiles. Nuclear expansion in Pakistan and India continues without pause or restraint.

• The candidates’ suitability to shoulder the immense presidential authority to launch nuclear weapons should be a central concern of the US election in fall. This is especially true given the concerns at the end of the previous administration, which prompted then Chairman of the Joint Chiefs of Staff Gen. Mark A. Milley to take steps to ensure that he would be consulted in the event the former president sought to launch nuclear weapons.

• And the war in Gaza between Israel and Hamas has the potential to escalate into a wider Middle Eastern conflict that could pose unpredictable threats, regionally and globally.

An Ominous Climate Change Outlook

• The world in 2023 entered into uncharted territory as it suffered its hottest year on record and global greenhouse gas emissions continued to rise. Both global and North Atlantic sea-surface temperatures broke records, and Antarctic sea ice reached its lowest daily extent since the advent of satellite data. The world already risks exceeding a goal of the Paris climate agreement—a temperature increase of no more than 1.5 degrees Celsius above pre-industrial levels—because of insufficient commitments to reduce greenhouse gas emissions and insufficient implementation of commitments already made. To halt further warming, the world must achieve net zero carbon dioxide emissions.

• The world invested a record-breaking $1.7 trillion in clean energy in 2023, and countries representing half the world’s gross domestic product pledged to triple their renewable energy capacity by 2030. Offsetting this, however, were fossil fuel investments of nearly $1 trillion. In short, current efforts to reduce greenhouse gas emissions are grossly insufficient to avoid dangerous human and economic impacts from climate change, which disproportionately affect the poorest people in the world. Barring a marked increase in efforts, the toll of human suffering from climate disruption will inexorably mount.

Evolving Biological Threats

• The revolution in life sciences and associated technologies continued to expand in scope last year, including, especially, the increased sophistication and efficiency of genetic engineering technologies. We highlight one issue of special concern: The convergence of emerging artificial intelligence tools and biological technologies may radically empower individuals to misuse biology.

• In October, US President Joe Biden signed an executive order on “safe, secure, and trustworthy AI” that calls for protection “against the risks of using AI to engineer dangerous biological materials by developing strong new standards for biological synthesis screening.” Though a useful step, the order is not legally binding. The concern is that large language models enable individuals who otherwise lack sufficient know-how to identify, acquire, and deploy biological agents that would harm large numbers of humans, animals, plants, and other elements of the environment. Reinvigorated efforts this past year in the United States to revise and strengthen oversight of risky life science research are useful, but much more is needed.

The Dangers of AI  

• One of the most significant technological developments in the last year involved the dramatic advance of generative artificial intelligence.  It is clear that AI is a paradigmatic disruptive technology and that recent efforts at the global governance of AI must be expanded.

• AI has great potential to magnify disinformation and corrupt the information environment required to solve large global issues and on which democracy depends. AI-enabled disinformation efforts could be a factor that prevents the world from dealing effectively with nuclear risks, pandemics, and climate change.

• Military uses of AI are accelerating. Extensive use of AI is already occurring in intelligence, surveillance, reconnaissance, simulation, and training. Of particular concern are lethal autonomous weapons, which identify and destroy targets without human intervention. Decisions to put AI in control of important physical systems—in particular, nuclear weapons—could indeed pose a direct existential threat to humanity.

• Fortunately, many countries are recognizing the importance of regulating AI and are beginning to take steps to reduce the potential for harm. These initial steps include a proposed regulatory framework by the European Union, an executive order by President Biden, an international declaration to address AI risks, and the formation of a new UN advisory body. But these are only tiny steps; much more must be done to institute effective rules and norms, despite the daunting challenges involved in governing artificial intelligence.

How To Turn Back the Clock

Everyone on Earth has an interest in reducing the likelihood of global catastrophe from nuclear weapons, climate change, advances in the life sciences, disruptive technologies, and the widespread corruption of the world’s information ecosystem. These threats, singularly and as they interact, are of such a character and magnitude that no one nation or leader can bring them under control. That is the task of leaders and nations working together in the shared belief that common threats demand common action.

As the first step, and despite their profound disagreements, three of the world’s leading powers—the United States, China, and Russia—should commence serious dialogue about each of the global threats outlined here. At the highest levels, these three countries need to take responsibility for the existential danger the world now faces. They have the capacity to pull the world back from the brink of catastrophe. They should do so, with clarity and courage, and without delay.

Founded in 1945 by Albert Einstein, J. Robert Oppenheimer, and University of Chicago scientists who helped develop the first atomic weapons in the Manhattan Project, the Bulletin of the Atomic Scientists created the Doomsday Clock two years later, using the imagery of apocalypse (midnight) and the contemporary idiom of nuclear explosion (countdown to zero) to convey threats to humanity and the planet. The Doomsday Clock is set every year by the Bulletin’s Science and Security Board in consultation with its Board of Sponsors, which includes nine Nobel laureates. The Clock has become a universally recognized indicator of the world’s vulnerability to global catastrophe caused by manmade technologies.