Editor’s note: Founded in 1945 by University of Chicago scientists who had 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 decision to move (or to leave in place) the minute hand of the Doomsday Clock is made every year by the Bulletin‘s Science and Security Board in consultation with its Board of Sponsors, which includes 15 Nobel laureates. The Clock has become a universally recognized indicator of the world’s vulnerability to catastrophe from nuclear weapons, climate change, and new technologies emerging in other domains. A printable PDF of this statement, complete with the executive director’s statement and Science and Security Board biographies, is available here.

From: The Bulletin of the Atomic Scientists Science and Security Board

To: Leaders and citizens of the world

Re: It is 30 seconds closer to midnight

Over the course of 2016, the global security landscape darkened as the international community failed to come effectively to grips with humanity’s most pressing existential threats, nuclear weapons and climate change.

The United States and Russia—which together possess more than 90 percent of the world’s nuclear weapons—remained at odds in a variety of theaters, from Syria to Ukraine to the borders of NATO; both countries continued wide-ranging modernizations of their nuclear forces, and serious arms control negotiations were nowhere to be seen. North Korea conducted its fourth and fifth underground nuclear tests and gave every indication it would continue to develop nuclear weapons delivery capabilities. Threats of nuclear warfare hung in the background as Pakistan and India faced each other warily across the Line of Control in Kashmir after militants attacked two Indian army bases.

The climate change outlook was somewhat less dismal—but only somewhat. In the wake of the landmark Paris climate accord, the nations of the world have taken some actions to combat climate change, and global carbon dioxide emissions were essentially flat in 2016, compared to the previous year. Still, they have not yet started to decrease; the world continues to warm. Keeping future temperatures at less-than-catastrophic levels requires reductions in greenhouse gas emissions far beyond those agreed to in Paris—yet little appetite for additional cuts was in evidence at the November climate conference in Marrakech.

This already-threatening world situation was the backdrop for a rise in strident nationalism worldwide in 2016, including in a US presidential campaign during which the eventual victor, Donald Trump, made disturbing comments about the use and proliferation of nuclear weapons and expressed disbelief in the overwhelming scientific consensus on climate change.

The Bulletin of the Atomic Scientists Science and Security Board takes a broad and international view of existential threats to humanity, focusing on long-term trends. Because of that perspective, the statements of a single person—particularly one not yet in office—have not historically influenced the board’s decision on the setting of the Doomsday Clock.

But wavering public confidence in the democratic institutions required to deal with major world threats do affect the board’s decisions. And this year, events surrounding the US presidential campaign—including cyber offensives and deception campaigns apparently directed by the Russian government and aimed at disrupting the US election—have brought American democracy and Russian intentions into question and thereby made the world more dangerous than was the case a year ago.

For these reasons, the Science and Security Board of the Bulletin of the Atomic Scientists has decided to move the minute hand of the Doomsday Clock 30 seconds closer to catastrophe. It is now two minutes and 30 seconds to midnight.

The board’s decision to move the clock less than a full minute—something it has never before done—reflects a simple reality: As this statement is issued, Donald Trump has been the US president only a matter of days. Many of his cabinet nominations are not yet confirmed by the Senate or installed in government, and he has had little time to take official action.

Just the same, words matter, and President Trump has had plenty to say over the last year. Both his statements and his actions as president-elect have broken with historical precedent in unsettling ways. He has made ill-considered comments about expanding the US nuclear arsenal. He has shown a troubling propensity to discount or outright reject expert advice related to international security, including the conclusions of intelligence experts. And his nominees to head the Energy Department and the Environmental Protection Agency have disputed the basics of climate science.

In short, even though he has just now taken office, the president’s intemperate statements, lack of openness to expert advice, and questionable cabinet nominations have already made a bad international security situation worse.

Last year, and the year before, we warned that world leaders were failing to act with the speed and on the scale required to protect citizens from the extreme danger posed by climate change and nuclear war. During the past year, the need for leadership only intensified—yet inaction and brinksmanship have continued, endangering every person, everywhere on Earth.

Who will lead humanity away from global disaster?

A dangerous nuclear situation on multiple fronts. Predictability and continuity are often prized when it comes to nuclear weapons policy, because the results of miscommunication or miscalculation could be so catastrophic. Last year, however, the nuclear weapons continuity most in evidence was negative: North Korea’s continuing nuclear weapons development, the steady march of arsenal modernization programs in the nuclear weapon states, simmering tension between nuclear-armed India and Pakistan, and stagnation in arms control.

North Korea conducted two more nuclear weapons tests, the second, in September, yielding about twice the explosive power of the first, in January. Pyongyang also relentlessly tested missiles, achieving a rate of about two launches per month in 2016. In his 2017 New Year’s statement, Kim Jong-un declared he would soon test a missile with an intercontinental range. The UN Security Council passed new sanctions against North Korea in November 2016 in an effort to further limit the country’s access to cash, but there is no guarantee those sanctions will succeed where others have failed.

Meanwhile, Russia is building new silo-based missiles, the new Borei class of nuclear ballistic missile submarines, and new rail-mobile missiles as it revamps other intercontinental ballistic missiles. The United States forges ahead with plans to modernize each part of its triad (bombers, land-based missiles, and missile-carrying submarines), adding new capabilities, such as cruise missiles with increased ranges. As it improves the survivability of its own nuclear forces, China is helping Pakistan build submarine platforms. And Pakistan and India continue to expand the number of weapons in and the sophistication of their nuclear arsenals.

Elsewhere, nuclear volatility has been (and remains) the order of the day. While the US president-elect engaged in casual talk about nuclear weapons, suggesting South Korea and Japan acquire their own nuclear weapons to compete with North Korea, other countries voted in the United Nations to move forward toward a treaty to ban nuclear weapons, passing Resolution L41. In 2017, those states will convene to consider a nuclear weapons ban, presumably without the 38 countries—including the United States and a number of its allies—that voted against the ban. A ban would be merely symbolic without the participation or input of countries that have nuclear weapons. But this approach—which circumvents traditional, often glacial efforts like the Conference on Disarmament—reflects long-held frustration with the slow pace of progress toward nuclear disarmament. The world saw the 20th anniversary of the first signature on the Comprehensive Nuclear Test Ban Treaty pass in 2016; the treaty still awaits its entry into force.

The Iran nuclear deal has been successful in accomplishing its goals during its first year, but its future is in doubt under the Trump administration. No firm plans have been made to extend the nuclear security summit process. Disputes over Ukraine, Syria, ballistic missile defenses in Europe, and election interference have the United States and Russia at loggerheads, with little if any prospect that nuclear arms reduction negotiations will resume.

Progress in reducing the overall threat of nuclear war has stalled—and in many ways, gone into reverse. This state of affairs poses a clear and urgent threat to civilization, and citizens around the world should demand that their leaders quickly address and lessen the danger.

The clear need for climate action. Global efforts to limit climate change have produced mixed results over the last year. The Paris Agreement went into effect in 2016, and countries are taking some actions to bring down emissions of greenhouse gases. There are encouraging signs that global annual emissions were flat this past year, though there is no assurance this heralds a break point. If the global economy has weaned itself from exponentially growing emissions rates, that would indeed be a major accomplishment.

But because carbon dioxide persists in the atmosphere for centuries, net emissions must eventually be put on a trajectory to reach zero if global warming is to be stemmed. The longer it takes to shift toward that trajectory, the greater the warming—and consequences—that current and future generations will face. The true success of the Paris Agreement should be measured against a strict criterion: Do the next steps in its implementation bring about the reductions of carbon dioxide emissions necessary to keep world temperatures from reaching levels that: threaten catastrophic sea level rise; change rainfall patterns and therefore threaten agriculture; increase storm severity; reduce biodiversity; and alter ocean chemistry (among the many negative impacts that unchecked global warming will cause)?

The continued warming of the world measured in 2016 underscores one clear fact: Nothing is fundamentally amiss with the scientific understanding of climate physics. The burning of fossil fuels adds carbon dioxide to the atmosphere; carbon dioxide is a greenhouse gas, inhibiting the radiation of heat into space. The relationship between increased atmospheric carbon dioxide levels and increased terrestrial temperature has been researched for decades, and national science academies around the world agree: Human activity is the primary cause of climate change, and unless carbon dioxide emissions are dramatically reduced, global warming will threaten the future of humanity.

In 2016, however, the international community did not take the steps needed to begin the path toward a net zero-carbon-emissions world. The Marrakech Climate Change Conference, for instance, produced little progress beyond the emissions goals pledged under the Paris Accord.

The political situation in the United States is of particular concern. The Trump transition team has put forward candidates for cabinet-level positions (especially the Environmental Protection Agency and Energy Department) who foreshadow the possibility that the new administration will be openly hostile to progress toward even the most modest efforts to avert catastrophic climate disruption.

Climate change should not be a partisan political issue. The well-established physics of Earth’s carbon cycle is neither liberal nor conservative in character. The planet will continue to warm to dangerous levels so long as carbon dioxide continues to be pumped into the atmosphere—regardless of who is chosen to lead the United States or any other country.

International leaders need to refocus their attention on achieving the additional carbon emission reductions that are needed to capitalize on the promise of the Paris Accord. In the United States, as a very first step, the Trump administration needs to make a clear, unequivocal statement that it accepts climate change, caused by human activity, as a scientific reality. No problem can be solved, unless its existence is recognized.

Nuclear power: An option worth careful consideration. During the last half of the 20th century, the most profound existential threat facing the world was the prospect of global nuclear holocaust, sparked by decisions made under the pressure of the very short time required for intercontinental ballistic missiles to reach their targets. In the 21st century, another existential threat looms: global warming caused by greenhouse gas emissions from more than 100 years of fossil fuel use.

Ironically, the nuclear forces used in weapons of mass destruction can also be harnessed as a carbon-free source of energy. Splitting the atom provides a million-fold increase in energy over the simple chemical reactions that convert fossil fuels to carbon dioxide and energy. The scale of the energy potential of nuclear fission—and its capacity to reduce the greenhouse gas emissions that cause global warming—make nuclear power a tempting part of the solution to the climate change problem. Some 440 nuclear power plants already generate 11 percent of the world’s electricity.

In addition to its promise, however, nuclear power has safety, cost, waste, and proliferation challenges. One can argue that the number of deaths and adverse health effects caused by nuclear power has been minimal, even when major accidents have occurred. But a single accident can change governmental policy and public attitudes toward nuclear power. That single accident can also affect multiple countries and produce effects that stretch over decades—as the Chernobyl and Fukushima disasters have shown.

Although new nuclear power plants are being built, mainly in Asia, the scale of the effort does not match the need for clean energy. Today’s 400-plus nuclear power plants are, on average, 30 years old. They displace some 0.5 to 0.7 gigatons of carbon each year, as compared to the 10 gigatons discharged annually from the use of fossil fuels.

To achieve just 6 percent of needed reductions in greenhouse gas emissions, nuclear power would have to increase in capacity at least threefold during the next 50 years. This would mean adding 2,000 megawatts of capacity per month, the equivalent of a new 1 gigawatt-electric nuclear power plant every several weeks. Such growth in the use of nuclear power would also require concomitant commitments to nuclear safety, security, and waste management that are politically, technically, and intergenerationally responsible.

In the short and medium terms, governments will need to discourage the premature closure of existing reactors that are—as determined on a case-by-case basis—safe and economically viable. In the longer term, entrepreneurs will have to design and test new types of reactors that can be built quickly, and they will then have to prove to regulators that those new reactors are at least as safe as the commercial nuclear plants now operating.

It is likely that leaders in different parts of the world will make different decisions on whether their countries will or will not include nuclear power in their efforts to combat climate change. Where nuclear power is used, at a very minimum, leaders must ensure that truly independent regulatory systems and safe geological disposal repositories are created.

Potential threats from emerging technologies. In December, US intelligence agencies concluded that Russia had intervened in the 2016 US presidential campaign to help Donald Trump in ways that highlight the vulnerability of critical information systems in cyberspace. Information monocultures, fake news, and the hacking and release of politically sensitive emails may have had an illegitimate impact on the US presidential election, threatening the fabric of democracy, which relies on an informed electorate to decide the direction of public policy—including policy relating to existential threats such as nuclear weapons and climate change. If not controlled, these types of electoral attacks could be launched against democracies around the world, undermining belief in representative government and thereby endangering humanity as a whole.

Such attacks on the democratic process, however, represent just one threat associated with the modern world’s increased reliance on the internet and information technology. Sophisticated hacking—whether by private groups or governmental entities—has the potential to create grave and large impacts, threatening financial activities and national electrical power grids and plants (including nuclear power plants) and the personal freedoms that are based on the privacy at the core of democracy.

Beyond cybersecurity, the increasing potential of autonomous machine systems—which could, for example, allow the development of efficient, self-driving cars—also opens up a new set of risks that require thoughtful management. Without good governance, including appropriate regulation, these threats could emerge in coming decades as existential—that is, dangerous to the whole of humanity or to modern civilization as we know it. Lethal autonomous weapons systems that make “kill” decisions without human input or supervision, for example, would be particularly worrisome. Advances in synthetic biology, including the Crispr gene-editing tool, also have great positive potential—and a dark side that includes the possible creation of bioweapons and other dangerous manipulations of genetic material.

Technological innovation is occurring at a speed that challenges society’s ability to keep pace. While limited at the current time, potentially existential threats posed by a host of emerging technologies need to be monitored, and to the extent possible anticipated, as the 21st century unfolds.

Reducing risk: Expert advice and citizen action. Technology continues to outpace humanity’s capacity to control it, even as many citizens lose faith in the institutions upon which they must rely to make scientific innovation work for rather than against them. Expert advice is crucial if governments are to effectively deal with complex global threats. The Science and Security Board is extremely concerned about the willingness of governments around the world—including the incoming US administration—to ignore or discount sound science and considered expertise during their decision-making processes.

Wise men and women have said that public policy is never made in the absence of politics. But in this unusual political year, we offer a corollary: Good policy takes account of politics but is never made in the absence of expertise. Facts are indeed stubborn things, and they must be taken into account if the future of humanity is to be preserved, long term.

Nuclear weapons and climate change are precisely the sort of complex existential threats that cannot be properly managed without access to and reliance on expert knowledge. In 2016, world leaders not only failed to deal adequately with those threats; they actually increased the risk of nuclear war and unchecked climate change through a variety of provocative statements and actions, including careless rhetoric about the use of nuclear weapons and the wanton defiance of scientific truths. We call on these leaders—particularly in Russia and the United States—to refocus in the coming year on reducing existential risks and preserving humanity, in no small part by consulting with top-level experts and taking scientific research and observed reality into account.

Because we know from experience that governmental leaders respond to public pressure, we also call on citizens of the world to express themselves in all the ways available to them—including through use of the powerful new tools of social media—to demand that:

US and Russian leaders return to the negotiating table to seek further reductions in nuclear arms and to limit nuclear modernization programs that threaten to create a new nuclear arms race.The world can be more secure with much, much smaller nuclear arsenals than now exist—if political leaders are truly interested in protecting their citizens from harm.

The United States and Russia reduce the alert levels of their nuclear weapons and use existing crisis stability mechanisms to avoid inadvertent escalation of conflict. Provocative military exercises increase the possibilities for accidental war and should cease.

Governments around the world sharply reduce their countries’ greenhouse gas emissions and fulfill the Paris Accord promise of keeping warming to 2 degrees Celsius above preindustrial levels, or less. This temperature target is consistent with consensus views on climate science and is eminently achievable and economically viable, provided that poorer countries are given the support they need to make the post-carbon transition.

The Trump administration acknowledge climate change as a science-backed reality and redouble US efforts to limit carbon dioxide emissions and support carbon-free energy sources, including, when economically reasonable and safe over the long term, nuclear energy. It is well past time to move beyond arguments over the reality of climate change and on to solutions, including fiscal measures—such as carbon markets and carbon taxes or fees—that encourage efficiency and put a price on carbon emissions.

The United States, China, Russia, and other concerned nations engage with North Korea to reduce nuclear risks. Neighbors in Asia face the most urgent threat, but as North Korea improves its nuclear and missile arsenals, the threat will rapidly become global. As we said last year and repeat here: Now is not the time to tighten North Korea’s isolation but to engage seriously in dialogue.

Leaders of countries with commercial nuclear power programs deal responsibly with safety issues and with the commercial nuclear waste problem. Top experts disagree on whether an expansion of nuclear-powered electricity generation can become a major component of the effort to limit climate change. Regardless of the trajectory of the global nuclear industry, there will be a continuing need for safe and secure interim and permanent nuclear waste storage facilities and for ever-safer nuclear power plants.

The countries of the world collaborate on creating institutions specifically assigned to explore and address potentially malign or catastrophic misuses of new technologies. Scientific advance can provide society with great benefits. But as events surrounding the recent US presidential election show, the potential for misuse of potent new technologies is real. Governmental, scientific, and business leaders need to take appropriate steps to address possibly devastating consequences of these technologies.

For the last two years, the minute hand of the Doomsday Clock stayed set at three minutes before the hour, the closest it had been to midnight since the early 1980s. In its two most recent annual announcements on the Clock, the Science and Security Board warned: “The probability of global catastrophe is very high, and the actions needed to reduce the risks of disaster must be taken very soon.” In 2017, we find the danger to be even greater, the need for action more urgent. It is two and a half minutes to midnight, the Clock is ticking, global danger looms. Wise public officials should act immediately, guiding humanity away from the brink. If they do not, wise citizens must step forward and lead the way.