Conservative populist government is an existential risk.

In the chapters that follow, I’ll outline the biggest risks facing humanity. I’ll begin in chapter 2 with pandemics, such as the possibility that the next virus might combine the infectiousness of COVID-19 with the deadliness of Ebola. What can we do to shut down exotic animal markets, speed up vaccine develop- ment, and create surge capacity in hospitals? I’ll then delve into bioterrorism, and the danger of extremists developing their own versions of smallpox or the bubonic plague. How difficult is it for them to create these devilish diseases, and what can we do to prevent it?

In chapter 3, I’ll then explore climate change—perhaps the in- tergenerational issue that has received the most public attention in recent years. While much of the modeling looks at how global warming could be bad, my focus is on the chances that it’s catastrophic. This isn’t about climate change shortening the ski season; it’s about the possibility of temperatures rising by 18°F (10°C), rendering large sections of the planet uninhabitable. What does the risk of cataclysmic climate change mean for energy policy?

Next, I’ll turn to nukes. As a child in the 1980s, I vividly re- member watching The Day After. My classmates and I agreed that a nuclear war was inevitable. When the Cold War ended, the world seemed safer, but in the three decades since, the threat from new nuclear powers has made the problem less predictable. As I discuss in chapter 4, what we used to call an arms race now looks more like a bar fight, with hazards coming from unexpected directions, including terrorist groups. Yet just as there are practical ways to avoid pub brawls (don’t drink past midnight, avoid the stairs, look out for the glass), so too are there sensible strategies that can reduce the odds of nuclear catastrophe (adopt a “no first use" policy, reduce the stockpiles, control loose nukes).

A superintelligence has been dubbed the “last invention” we’ll ever make. An artificial intelligence machine whose abilities exceed our own could turbocharge productivity and living stan- dards. But it could also spell disaster. If we program our artificial intelligence to maximize human happiness, it could fulfill our wishes literally by immobilizing everyone and attaching electrodes to the pleasure centers of our brains. As chapter 5 notes, what makes artificial intelligence different from every other risky technology is its runaway potential. Once a superintelligence can improve itself, it is unstoppable. So we need to build the guardrails before the highway.

What are the odds? In chapter 6,1 complete the discussion of catastrophic danger by examining less risky risks, including asteroids and supervolcanoes. I also consider the prospect of “unknown unknowns.” For example, prior to the first atomic bomb test, some scientists thought there was a chance it could set the atmosphere on fire, destroying the planet. When the Large Hadron Collider was being built, critics warned that the particle collisions inside it could create micro black holes. Although neither situation eventuated, they raise the question of what other doomsday scenarios could be lurking around the corner. How should the prospect of these unexpected risks change our approach to cutting-edge science? Drawing together these dangers with the major hazards, I report the likely probability of each, benchmarking existential risks such as nuclear war and pandemics against individual risks such as being struck by lightning or dying on the battlefield.

Ultimately, tackling existential risks is a political problem. Private citizens can achieve many things, but preventing nuclear war, averting bioterrorism, and curbing greenhouse emissions are fundamentally problems of government. Governments control the military, levy taxes, and provide public goods. So the values of those who run the country will determine how much of a priority the nation places on averting catastrophe.

That’s why the rise of populists is crucial to humanity’s long- term survival. In chapter 7,1 discuss the factors that have led to the electoral success of populists during recent decades, and why populists tend to be uninterested in dealing with long-term threats. Populists’ focus on the short term means that—like a driver distracted by a back seat squabble—we’re in danger of missing the threats that could kill us. I’ll explore why populists around the world struggled to respond to COVID-19, and what this says about the dangers that populism poses to our species. Most critics of populism have concentrated on the present day. They’re missing the bigger picture. Populists are primarily endangering the unborn.

Bad politics doesn’t just exacerbate other dangers; it represents a risk factor in itself through the possibility of a totalitarian turn —in which democracy is replaced by an enduring autocracy. The road to democracy is not a one-way street. Over the centuries, dozens of countries have backslid from democracy into autocracy—abandoning the institutions of fair elections, protection for minorities, and free expression. Such an outcome could be deadly for dissenters and miserable for the multitudes. Chapter 8 explores why democracy dies and identifies the signs that institutions are being undermined. Chapter 9 suggests how we might strengthen democracies to allow citizens to have a greater say, and lower the chances of the few taking over from the many. Chapter 10 concludes the book.