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 18 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.

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

To: United Nations Secretary-General Ban Ki-Moon, members of the UN Security Council

Re: It is still five minutes to midnight

In 2013, the world made limited strides toward reducing the threat posed by nuclear weapons, most notable among them an interim agreement between the five permanent members of the UN Security Council and Germany (or P5 + 1) and Iran on a “joint plan of action” for reaching a long-term solution to international concern about the Iranian nuclear program. Also, in the last year a significant number of countries have taken steps to reduce their stocks of weapons-grade fissile material and to tighten security on the nuclear stores that remain.

Overall, however, in 2013 the international community dealt with the continuing, potentially civilization-ending threat of nuclear weapons in a business-as-usual manner, meaning that outsized nuclear arsenals remain in the United States and Russia, and the nuclear arsenals of some countries—notably India, Pakistan, and China—appear to be growing. The interim Iranian deal notwithstanding, the international community has not come to grips with an unfortunate reality: The spread of civilian nuclear power around the world—which continues apace, despite the disaster at Fukushima—also spreads the potential for new nuclear weapons states.

Meanwhile, even though there have been positive developments in the renewable energy field over the last year, worldwide efforts to limit the carbon dioxide emissions that cause climate change have largely stalled, with emission-reduction programs being used as political footballs in several industrialized countries. And beyond the nuclear and climate threats lies a spectrum of emerging dangers—from cyber weapons to killer robots—that are further challenging humanity’s ability to manage its most advanced technologies.

A careful review of these threats leads us to conclude that the risk of civilization-threatening technological catastrophe remains high, and that the hands of the Doomsday Clock should therefore remain at five minutes to midnight. We implore the Secretary-General and the Security Council to spur worldwide action in the following areas to reduce the danger that human technology will be humanity’s undoing.

Nuclear hope and danger. Last year provided some reason for guarded optimism in regard to nuclear weapons.

Speaking at Berlin’s historic Brandenburg Gate in mid-June, President Obama proposed a reduction in the limit on US and Russian deployed strategic nuclear warheads from the current New START level—1,550 warheads on each side—to 1,000.

Obama’s speech came just days after Iran elected a new president, Hassan Rouhani, who quickly changed the tone of the country’s foreign policy, clearing the path for the first direct talks between the United States and Iran in 35 years. Late in November, in talks with the P5 + 1, Iran agreed to, among other things, a six-month halt in enriching uranium beyond what is required for commercial nuclear power, in exchange for a limited suspension of some of the sanctions that have crippled the country's economy. If negotiations on a permanent accord are successful, they could calm a tense region and set important precedents for handling nuclear enrichment and nuclear energy around the world.

And in preparing for a third Nuclear Security Summit—to be held in The Hague late in March—many countries have pledged to reduce their stores of nuclear materials and improve the security of the fissile materials that remain, with the goal of preventing nuclear terrorism. According to a recent report by the Nuclear Threat Initiative, since 2012, seven countries have made significant progress in reducing their caches of weapons-usable material, and others have improved their security measures.

But these positive developments occurred within a business-as-usual context that threatens humanity’s future.

Around the world, much nuclear material remains unsecured.

Soon after Obama’s Brandenburg Gate speech, Russia offered political asylum to Edward Snowden, the former National Security Agency contractor who leaked US classified documents, creating an international media sensation, and Obama called off a planned summit with Russian leader Vladimir Putin. There appears to have been little movement since on nuclear agreements between the United States and Russia.

China is reported to be modernizing and quantitatively increasing its nuclear arsenal, albeit at a slow pace. India and Pakistan continue to expand their arsenals and stockpiles of fissile materials. Both countries are developing and testing new missiles, many nuclear-capable. India plans to build a nuclear submarine fleet and to develop a ballistic missile-defense system, the deployment of which could destabilize the subcontinent.

Despite authoritative reports that it has a nuclear weapons arsenal, Israel continues a policy of nuclear ambiguity while strenuously trying to scuttle talks on Iran’s nuclear efforts. In February 2013, North Korea conducted yet another nuclear weapon test, the first under its new leader, Kim Jong-un, and issued a series of military threats, some involving the use of nuclear weapons.

A climate of inaction. In a comprehensive report released in September 2013, the Intergovernmental Panel on Climate Change strengthened its unequivocal and alarming findings about climate change, stressing these conclusions:

It’s documented. Evidence of warming of the climate system is unequivocal. Since the 1950s, many of the observed changes are unprecedented, over times periods ranging from decades to millennia. The atmosphere and ocean have warmed, sea level has risen, and the amounts of heat-trapping gases have increased.

Evidence of warming of the climate system is unequivocal. Since the 1950s, many of the observed changes are unprecedented, over times periods ranging from decades to millennia. The atmosphere and ocean have warmed, sea level has risen, and the amounts of heat-trapping gases have increased. It’s us. Human activities have been the dominant cause of the observed warming since the mid-20th century.

It hasn’t stopped. Each of the last three decades has been successively warmer at the Earth’s surface than any preceding decade since 1850. In the Northern Hemisphere, 1983 to 2012 was probably the warmest 30-year period of the last 1,400 years.

Sea level is rising. The rate of sea level rise since the mid-1800s has been larger than the average rate during the previous 2,000 years.

Ice cover is shrinking. Over the last two decades, the Greenland and Antarctic ice sheets have been losing mass, glaciers have continued to retreat almost worldwide, and Arctic sea ice and Northern Hemisphere spring snow cover have continued to decrease in extent.

The ocean is more acidic. The ocean has absorbed about 30 percent of the carbon dioxide we have emitted into the atmosphere, making the ocean significantly more acidic and threatening ocean life.

Carbon dioxide is up. From analyzing air trapped in ice, we know the amount of carbon dioxide is 40 percent higher now than in the 1800s, due mainly to fossil fuel burning. The ice record shows that atmospheric carbon dioxide levels are now the highest in at least the last 800,000 years.

Dramatic emission reductions are needed. Limiting climate change to tolerable levels will require substantial and sustained global emissions reductions.

Climate change will be here for centuries. Most aspects of climate change will persist for many centuries even if emissions of carbon dioxide are stopped. Adaptation to inevitable climate change will be necessary. Like mitigation, adaptation deserves urgent attention.

This past year saw increased development and use of low-carbon renewable alternatives to fossil fuels. Costs of renewables—particularly solar and wind power—have continued to fall, and governments and private companies have continued significant investment in new renewable power facilities, with an especially strong upward trend in developing countries.

Despite the progress in low-carbon technologies, however, the world has failed to effectively curb emissions and adapt to a changing climate. Domestic politics have stalled efforts to cut emissions in several industrialized countries. This trend includes serious threats to renewable-energy support in the United States, the European Union, and Australia. It is clearly epitomized by Japan, which first withdrew from the Kyoto Protocol and then reneged on promises of voluntary emissions reductions.

The unlearned lessons of nuclear power. Following the March 11, 2011 disaster at the Fukushima Daiichi Nuclear Power Station—the third major catastrophe at a commercial nuclear power station since the dawn of the nuclear age—public opinion shifted strongly against deployment of nuclear power, in Japan and elsewhere. Germany and Switzerland decided to terminate their nuclear power programs; a number of other nations, including China and the United States, carried out safety re-assessments.

With the passage of time, however, it has become clear the world is not moving away from nuclear power on a wholesale basis. Indeed, there are distinct signs of a nuclear resurgence, especially in Southeast Asia and the Middle East, and especially among nations that have heretofore not engaged in its use. Abu Dhabi and Vietnam have pushed forward with the purchase of new nuclear power plants, and other nations in these regions are making nuclear plans. China has resumed construction of more than two dozen nuclear power plants it was building pre-Fukushima; the United Kingdom is evaluating a return to nuclear construction.

These developments make it ever more urgent that the lessons to be learned from three catastrophic civilian nuclear accidents—Three Mile Island, Chernobyl, and Fukushima Daiichi—are heeded. Among the most important of those lessons is the need for an independent nuclear regulatory body in every country with nuclear power, answerable only to the highest national authorities and open to public scrutiny. Without effective oversight of nuclear power, the world is likely to see more catastrophic accidents.

Nuclear power plant operators must also have clear and transparent command chains and emergency response systems that can be effectively tested under realistic (albeit artificial) emergency conditions. They should pay as much attention to the safety and security of used nuclear fuel stored on the grounds of a nuclear power plant as is paid to the safety and security of the plant itself, particularly as regards potentially catastrophic circumstances such as station blackout and external attack.

And when new nuclear power stations are constructed, older designs­—for example, the so-called Generation 2 plants—should no longer be adopted. Passive safety features—for example, cooling systems designed to operate even in the absence of electricity and new fuel types that withstand higher temperatures—should be part of all new nuclear power plants.

Beyond plant safety and security lies a more general danger: Civilian nuclear power can contribute to new nuclear weapons programs, as illustrated by the complexity of ongoing discussions with Iran. Also, the continued development of laser-based fuel enrichment is not encouraging from the proliferation perspective. This technology promises to provide a route to uranium enrichment that is less expensive and harder-to-constrain than the centrifuge enrichment pursued by Iran and North Korea.

Emerging technology, emerging threats. Headlines from 2013 only hinted at the speed and scope of technological change—from synthetic biology to three-dimensional printing to robotics and beyond—that is sweeping the globe. The positive aspects of this fast-moving technological advance mask a core problem: What happens when scientists create a technology with the best of intentions, but society cannot properly control it? Bioengineering, for example, might eradicate some diseases—but it might also put infectious weapons in the hands of terrorists. Sophisticated robots might help governments respond to disaster—or be programmed to hunt and kill humans with ruthless efficiency.

The challenge posed by advances in dual-use technologies is global and multidimensional in scope, fueled largely by advances in computation. Between 1965 and 2008, computer power increased a billion-fold. In 2010, the fastest computer reached a speed of just over one petaflop—a quadrillion calculations per second. In 2013, China’s Tianhe-2 became the fastest in the world, reaching a speed of 33.86 petaflops. And bulk data for computation is ever-more accessible; in one second, more data crosses the Internet today than existed on the Internet in the early 1990s.

Since the end of World War II, the Bulletin has focused on the interface between scientific discovery and self-governance. Humanity has been sorely tested during its attempts to control the implements of nuclear warfare. The difficulties of managing dangerous technology are perhaps even more challenging when the threat is not the fierce immediacy of atomic explosion, but slow, creeping dangers like rising carbon-dioxide levels or increased access to dual-use science.

In 2013, the world saw new evidence of a dangerous but familiar trend: Technology outpaced humanity’s capacity to understand or control it, even as many citizens continued—for a wide variety of reasons—to lose faith in the institutions upon which they must rely to make scientific innovation work for rather than against them. This is a trend that must be reversed if society is to gain control over the science it produces.

Managing technology for safety and survival. In the face of the continuing perils posed by nuclear weapons and greenhouse gases, as well as the potential threats from a variety of emerging technologies, particularly in the biological and cyber realms, we call on you and other leaders in the international community to create new and just ways to manage powerful and dangerous technologies, so as to enhance prosperity and peace. Preventing catastrophic damage requires the attention and concerted action of leaders and citizens around the globe. That’s why we appeal to you to take international actions that address existential dangers to humanity:

Demand that US and Russian leaders return to the negotiating table. Once there, they should take the courageous steps needed to further shrink their nuclear arsenals, to scrap their deployment of destabilizing missile defenses, and to reduce the alert levels of their nuclear weapons.

Once there, they should take the courageous steps needed to further shrink their nuclear arsenals, to scrap their deployment of destabilizing missile defenses, and to reduce the alert levels of their nuclear weapons. Support international discussions about the humanitarian effects of nuclear weapons. Talks begun at the Oslo conference in March brought developing countries to the table and increased knowledge about the danger posed by any nuclear exchange to countries around the world. We encourage the United States, Russia, France, the United Kingdom, and China to join these talks instead of boycotting them, as they did last spring.

Exercise political leadership on climate change. World leaders must curb carbon-emitting practices and support energy technologies—including wind, solar, and geothermal power generation and vigorous energy efficiency measures—that will mitigate further disastrous alteration of the climate. The science on climate change is clear, and many people around the world already are suffering from destructive storms, water and food insecurity, and extreme temperatures. It is no longer possible to prevent all climate change, but you can limit further suffering—if you act now.

Create new rules and institutions to manage emerging technology. The revolution in information technology is accelerating, and the consequences of such broad and fast-paced technological change cannot be foreseen. Some of the results of this revolution, such as military robotics and cyber warfare, will challenge international law and the norms of war, much as nuclear weapons do. These scientific advances require serious attention and policy action—before our newest technologies fuel another senseless and dangerous arms race.

Technological changes are outpacing humanity’s ability to manage them in ways that ensure our safety and security. As always, new technologies hold the promise of doing great good, supplying new sources of clean energy, curing disease, and otherwise enhancing our lives. From experience, however, we also know that new technologies can be used to diminish humanity and destroy societies. We can manage our technology, or become victims of it. The choice is ours, and the Clock is ticking.