The path-breaking achievements of the past century offer grounds for cautious hope. Over the coming decades, economic and technological interdependence will continue to intensify, binding the interests of the world’s peoples even more tightly together than today. As nations and regions find themselves increasingly “in the same boat,” win-win solutions among them are likely to become more self-evidently attractive. To be sure, the possibility of failure is ever-present and very real. Building more effective instruments for planet-level governance will prove exceedingly hard, and we can expect plenty of disheartening setbacks along the way. But the evidence from the past, and the plausible trajectory of challenges and incentives that await us in the coming century, suggest that it can be done.

Over the coming decades, artificial intelligence and robotics will continue to grow rapidly in power and scope, exerting a transformative impact on our lives. Seven trends are likely: the machines will become progressively more versatile and multifunctional in their capabilities; they will be designed to improve their own software and hardware over time, as they interact with their environment; the line between AI and robots will gradually blur, as machines come to permeate our society at all levels; these machines will be entrusted with complex practical tasks that require them to develop sophisticated commonsense knowledge about the human social world; the machines will be interconnected in functional networks that multiply their powers; such machines will need to be able to refuse to obey certain kinds of human commands, raising fundamental questions about who controls their actions; and the logic of arms races will apply to such machines, impelling nations and corporations to develop increasingly powerful machines as quickly as possible, with only a secondary concern for caution and safety.

Engineered life forms are no longer science fiction: scientists, industrialists, and even college or high school students are now busily engaged in redesigning existing biological organisms or designing entirely new life forms from scratch. These bioengineered life forms offer humankind many potential benefits, from creating new forms of fuel to getting rid of oil spills to turning household waste into useful new materials. Nevertheless, leading scientists in the field are warning the public that the dangers inherent in this biotechnological undertaking need to be taken seriously. Our society urgently needs better instruments both for responding to the danger of naturally occurring pandemics, and for regulating the research and development of synthetic biology. Two areas of particular concern are secret military research and the rapid rise of unregulated Do-It-Yourself biohackers.

Four planet-level dangers loom over humankind in the coming hundred years, requiring solutions that can only be achieved through planet-level strategies and instruments. Reversing climate change requires a concerted effort among all the world’s peoples to decarbonize their economies and energy systems as swiftly as possible, while ramping up new technologies for removing accumulated carbon dioxide. Nuclear weapons will continue to pose an existential threat as long as nations vie with each other in a zero-sum competition for power and dominance. Naturally occurring or bioengineered pandemics threaten human well-being, and can only be mitigated via a comprehensive system of global regulation. Artificial intelligence proffers many tantalizing benefits, but will also create extreme risks unless humankind finds ways to control the development of these powerful machines. The historical track record suggests that these challenges, while daunting, can realistically be surmounted by concerted action.

This chapter sketches a potential architecture of global federal government, framing it as the end-goal of a century-long, incremental process of reforms and innovations in governance. Humankind, in this scenario, will be strongly motivated to undertake these innovations because of escalating dangers and crises that can only be handled effectively through stronger forms of global cooperation and coordination. The key challenges here are: revamping the UN Security Council so it more accurately reflects the realities of global economic and military power; replacing the Security Council veto system with a new principle of weighted voting in all UN institutions, so that key policies can be implemented effectively; creating a world constitution to lay out the basic rules and principles through which the system will operate, as well as a world court to adjudicate disputes among the players; and establishing a UN Office for Emerging Technologies, a more dynamic WHO, and a dedicated UN Office for Climate Change Mitigation.

This chapter surveys the rapid growth of globe-spanning organizations and institutions over the past 120 years – from the League of Nations to the UN to today’s International Criminal Court and European Union. Spurred by the world wars, economic crises, and environmental disasters of the twentieth century, humanity has already come much farther than most people realize in building innovative instruments of global concertation and crisis management. Therefore, the pathways of constructive change that lie ahead of us can best be understood as continuations and extensions of the remarkable gains already achieved. Four institutions – OECD, UN, NATO, and EU – exemplify distinct levels of rising integration across national boundaries. Institutions such as International Non-Governmental Organizations (INGOs) have offered powerful new pathways for citizens’ concerted action beyond borders. The recently-adopted UN doctrine of Responsibility to Protect (R2P) reflects a newfound legitimacy of cross-border ethical obligations and proactive interventions to halt large-scale humanitarian disasters.

Any government that wants to be taken seriously needs teeth. This chapter sketches a global security system in which national governments will still play a key role, but in which they have also worked together to create stable mechanisms of collective security. Since it is impossible to coerce nuclear-armed Great Powers through direct military action, the new global security system will need an especially robust regime of economic sanctions. If a Great Power transgresses international laws in egregious ways, such sanctions would aim to persuade the leaders of that nation that the costs of continued violations greatly exceed the benefits. In extreme cases, such sanctions could also aim to destabilize a transgressor nation’s economy so severely that its citizens would be impelled to bring about regime change from within. If such a global security system were in place for many decades, successfully keeping the peace, then incremental steps toward reductions in standing armies could be gradually undertaken. The resulting “peace dividend” could be used to further reduce global economic disparities, and to help fund the technologies for mitigating climate change.

Whereas today’s “narrow” AI machines can be easily controlled, the probable advent over the coming decades of machines endowed with Artificial General Intelligence (AGI) will pose a far more difficult control challenge – for such machines will function as agents endowed with many human-like capabilities. The AI expert Stuart Russell has proposed a radical new design for the motivational architecture of AI machines, which he calls “humble AI.” Rather than programming AI machines to pursue specific goals, he argues, it would be much safer to give them a single broad goal, namely, maximizing the realization of human preferences. The key innovation here lies in programming the machines so that they can never be 100 percent certain about what those human preferences are – a gambit that restores ultimate control over the machines’ behavior to their human overseers. Russell argues persuasively that fundamental safety research in the field of AI needs to be pursued as a much higher priority than it currently receives today.

The pragmatic partnership among West European nations that has emerged since 1945 exemplifies how “win-win” strategies can bring powerfully beneficial results over time. Yet the EU model cannot be straightforwardly applied at the global level, for five reasons. First, the cultural and political differences among the world’s nations are much greater than they are within Europe. Second, the obscene divide between “haves” and “have-nots” is much starker and more intractable at the global level than it is within Europe. Third, rapid globalization has caused a political backlash in many nations, bringing to power leaders who seek a defensive retrenchment behind national walls. Fourth, global institutions of cultural integration, such as UNESCO, remain relatively weak. And fifth, racist prejudice and nativist xenophobia are on the rise in many nations. Nevertheless, the historical precedent set by the EU demonstrates that national sovereignty can be incrementally dismantled, yielding new forms of institutionalized cooperation among formerly separate and mutually hostile peoples.

Wise governance for nuclear weaponry and synthetic biology requires humankind to move more swiftly than today in certain technological domains, while actively slowing down the pace in other areas. For example, advancing technologies for aerial and space-based surveillance, coupled with AI for interpreting the resulting high-resolution images, could allow nations to track in real time the location of other nations’ nuclear missile submarines. Such a development would remove one of the fundamental stabilizing factors in today’s military affairs: the guarantee of a second-strike capability, which lies at the heart of nuclear deterrence. These kinds of technological breakthroughs urgently need to be restrained via diplomatic agreements akin to the superpowers’ arms control treaties during the Cold War. Similarly, the existing “Wild West” in synthetic biology and AI requires swift governmental action to create effective regulatory frameworks for these fields, both within nations and among nations.

Harsh political polarization between Left and Right not only poses a serious threat to the viability of democracies, but also undermines the ability of governments to respond to planet-level challenges in an effective and timely manner. The politicization of science has been one unfortunate side effect of this broader trend toward political tribalism. The chapter surveys several strategies for mitigating, or dialing down, the political gridlock that afflicts many democratic countries: organizing citizens to elect politicians who seek pragmatic compromise rather than partisan advantage; pursuing trust-building initiatives across the Left-Right divide; and adopting the tools of deliberative democracy as a way to combat the “fake news” epidemic afflicting political debates. Individual citizens have many avenues for making a direct impact on these problems through their own behaviors and choices.