Viktor Vasnetsov’s 1887 painting Four Horsemen of the Apocalypse depicts the Christian vision of the end of the world: Death, Famine, War and Conquest
riding out to herald the Day of Judgment.
At first glance, one might think that the more thought we give to existential risks, the
better. The stakes, quite literally, could not be higher. What harm could there be in
getting people to think about these terrible risks? The worst that could happen is that we would take some precautions that turn out in retrospect to have been unnecessary.
But apocalyptic thinking has serious downsides. One is that false alarms to catastrophic risks can themselves be catastrophic. The nuclear arms race of the 1960s, for example, was set off by fears of a mythical “missile gap” with the Soviet Union.
The 2003 invasion of Iraq was justified by the uncertain but catastrophic possibility that Saddam Hussein was developing nuclear weapons and planning to use them against the United States.
(As George W. Bush put it, “We cannot wait for the final proof – the smoking gun – that could come in the form of a mushroom cloud.”) And one of the reasons the great powers refuse to take the common-sense pledge that they won’t be the first to use nuclear weapons is that they want to reserve the right to use them against other supposed existential threats such as bioterror and cyberattacks.
Sowing fear about hypothetical disasters, far from safeguarding the future of humanity, can endanger it.
A second hazard of enumerating doomsday scenarios is that humanity has a finite budget of resources, brainpower and anxiety. You can’t worry about everything. Some of the threats facing us, such as climate change and nuclear war, are unmistakable, and will require immense effort and ingenuity to mitigate.
Folding them into a list of exotic scenarios with minuscule or unknown probabilities can only dilute the sense of urgency. Cognitive psychologists have shown that people are poor at assessing probabilities, especially small ones, and instead play out scenarios in their mind’s eye. If two scenarios are equally