by Bryan Walsh
For all our fear of what would come after, for all our bleak stories, collapse and conflict aren’t givens after a disaster. Sociologists who study postcatastrophe societies report that communities often grow tighter, like the scar tissue that forms following a wound, even as they endure what seems to be unendurable. Human beings help each other, including in those times when it doesn’t seem to be in their interest. That’s likely how Homo sapiens survived its closest brush with extinction—the Toba supereruption—and it’s the only way we would survive the next one.
Survival, though, will require the triumph of more than just the human spirit. An existential catastrophe will be like no disaster we have ever faced, an emergency with no end in sight and no safe haven. We will need preparation—one of the most important acts we can undertake now is to fully research and ready plans for alternative foods like the kind Denkenberger has studied. Most of all, we will need leadership, because without it, a terrible disaster could turn terminal.
Given our current politics, that might be the biggest existential risk of all. We’ve become paralyzed as a country in the face of what would surely seem like insignificant differences after an existential catastrophe. Washington can’t plan a budget for an entire year, let alone devise and implement a strategy to save the world. Global politics are no better. But the survival of humanity is more important than anything else, not just for today but for all our tomorrows. And so we will need to take even more drastic preventative measures, to ensure that the future of the human race doesn’t die out with the present.
The survivalist shelters you can buy on the internet won’t save you from an existential catastrophe. The human race as a whole, though, would benefit from the insurance of a refuge. Not a shelter or a bunker but a true refuge that could withstand any catastrophe. It would save the individuals who find protection there, but it wouldn’t be for them—not exactly. It would be an investment in the future of the species, to ensure that there will be living human beings left to restart some form of civilization. To keep the future going.
A proper refuge is to a commercial doomsday shelter as an aircraft carrier is to a tugboat. Robin Hanson—the economist we met in the last chapter—has suggested the proactive construction of one or more subterranean refuges, perhaps deep inside a mine shaft and completely independent of the surface, stocked with enough food and supplies to last for years. It would need to be isolated, and it would probably need to be secret, to keep it safe from survivors on the outside desperate for protection. That might seem cruel, but if such refuges came into play, any survivors left outside its doors would be sacrificed. The refuge’s purpose would be to maintain a suitable and varied group of human beings capable of repopulating the Earth once the worst had passed.
If all of this—mine shafts, refuges, repopulating the Earth—is giving you a Cold War shiver, don’t be surprised. Both the Soviet Union and the United States built elaborate, deeply protected bunkers for civilian and military leaders to survive a nuclear attack. One of them, the Mount Weather bunker in Virginia, is still operational, and it’s where America’s top civilian and military leaders would be relocated in the event of a nuclear attack or similar global catastrophe. There’s also the Cheyenne Mountain Complex in Colorado, where hundreds of military staff protected by 2,500 feet of granite man the nation’s missile surveillance system.26 These are the closest examples the United States has to doomsday refuges, though they’re both designed to help the world keep going, not survive its end.
What Hanson entertains is something different, better thought of as a bank, but for human beings. The closest existing analogue is a vault built to hold the world’s agricultural resources. The Norwegian government constructed the $9 million Global Seed Vault on the remote island of Svalbard, far north of the Arctic Circle. Also known as the “Doomsday” vault, it serves as a backup to the world’s 1,700 national seed banks, each of which holds a collection of native seeds that contain that country’s agricultural inheritance. Seeds are the foundation of human civilization, and Svalbard holds more than 930,000 varieties.27 If a line of seed is lost—and they can be lost through war, through drought, through disease—that plant is lost forever. Seed banks are an insurance against that loss.
In the event of an actual doomsday, of course, there may not be anyone left to make a withdrawal from the Seed Vault. (And the Seed Vault itself is far from indestructible—in 2017 the vault flooded because of unusually warm weather, although no seeds were lost.28) But if we could create a similar refuge that would safeguard a selection of the global population, the human world could be restarted after its end, just as we might use Svalbard to restart global agriculture.
It wouldn’t be easy. If the refuges were kept empty, people would have to be moved into them once a disaster was already under way, or even afterward. That might be possible in the event of pandemic, or something that can be predicted in advance, like a major asteroid strike. It’s less feasible in the event of a near-instant wipeout like a nuclear war. An effective existential insurance policy would require the refuges to be populated full-time, which would mean a rotating cast of individuals who would agree to serve a tour of duty as humanity’s backup.
Simply to avoid inbreeding, a refuge would need a minimum of 50 people, and probably closer to 80. (It’s believed that fewer than 70 people managed to colonize Polynesia, which now has a population of around 700,000.)29 Five hundred would be a better figure, to ensure sufficient genetic and skill variety. The number would also depend on how long the refuge population would need to stay underground. A study on very long-term, multigenerational space missions indicates that 160 people would be needed to keep an isolated population going for two hundred years.30 Anders Sandberg at the Future of Humanity Institute has said that you’d really need closer to 5,000 people to be assured that the species would endure for another thousand years at least.31 Either way it would get very crowded down there. Feeling claustrophobic yet?
There’s also the question of who should go. There would presumably be no shortage of volunteers in the event of an actual catastrophe, but it might take something close to a draft to convince a rotating group of people to spend months or even years of their lives underground so they could rebuild humanity in the extraordinarily unlikely event of an existential disaster. You might expect we’d want the best and the brightest—scientists, artists, soldiers. But these ultimate refugees would most likely be reentering a world that was no longer modern. No electricity, no infrastructure, nothing that supports what most of us spend our lives doing. The best option might be subsistence farmers and actual hunter-gatherers, human beings who would already be familiar with the basic lifestyle that would now be necessary, once modernity had been swept away.
Unless the U.S. government is much better at keeping secrets than it appears to be, no such doomsday refuges exist, and there are no plans to build any. But humanity may find itself in a place where—as seems to have been the case after Toba—a small population does manage to survive a great catastrophe. Even with the worst our planet might be able to throw at us, total extinction—the death of every man, woman, and child on Earth—isn’t a given, because of what has been called the “last few people problem.” The same adaptive traits that have enabled Homo sapiens to spread to every spot of land on the planet and reach more than 7 billion in numbers also make us very hard to kill off completely.
Given enough time, we might even get back to where we are today. The Hutterite community in North America holds the distinction of having the highest rates of population growth in history, increasing 18-fold in just 70 years.32 Starting from a single surviving couple, if each woman had a mere 8 children, we could theoretically get back to 7 billion people in less than 600 years—and start this whole thing over again.33
Redevelopment would have to take a different path, however, because it took us tens of thousands of years to develop the technologies needed to move from hunting and gathering to settled farming, and thousands of years more t
o reach the Industrial Revolution. In fact there’s no guarantee that industrialization would happen again—the birth of industry happened only once, in nineteenth-century Britain, before it spread around the world, and if we reran the tape of history it might not happen at all.34 Survivors would presumably have residual expertise that could be handed down to their descendants, but our first go-round with industrialization was powered by fossil fuels that were easy to take out of the ground. Those supplies of coal and oil are long gone, however, and they won’t be replaced anytime soon. The warming created by the earlier burning of those fossil fuels would continue, which means that survivors would also have to contest with gradual climate change for decades, at least until carbon concentrations in the atmosphere began to decline.
In his book The Knowledge: How to Rebuild Civilization in the Aftermath of a Cataclysm, the British academic Lewis Dartnell explores how we might be able to transmit the best of human experience and knowledge to a band of postapocalyptic survivors. Dartnell suggests creating a start-up manual for civilization—not a library of our most glorious cultural and scientific achievements, but an actual how-to book for the practical knowledge needed to help a broken society pick up the pieces. Think engineering, farming, and basic medicine, not liberal arts. Though Dartnell believes that keeping it in book form might not be the best idea. “I think you want an apocalypse-proof, unhackable Kindle,” he told me. “Paper books have a habit of being flammable.”
If we really want to protect ourselves from the end of the world, however, we might want to think about getting off it.
As the richest man in the world, with a fortune worth around $130 billion as of early 2018, Amazon founder Jeff Bezos has a lot of money, and he could choose to spend it on anything on Earth. But he doesn’t want to spend it on Earth. In 2000 Bezos founded Blue Origin, a private spaceflight company, and he has said he now liquidates about $1 billion in Amazon stock each year to fund its work.35 Given that Bezos is Bezos, he likely has a business reason for spending billions on rocket ships—and if there’s not one now, he’ll find it soon enough. But the richest man in the world has a higher purpose. “We have to go to space to save Earth,” Bezos said in 2017. “We have to hurry.”36
Bezos has always been a space nerd. As an undergraduate at Princeton University, where he led the school’s chapter of Students for Exploration and Development of Space, he was inspired by the work of the space colony theorist Gerald O’Neill, who was finishing his academic career at the college. The kicker of Bezos’s high school valedictorian speech was this: “Space, the final frontier. Meet me there.”
But Bezos isn’t the only tech billionaire with a side hustle in space travel. When he isn’t building self-driving cars or warning the world about the dangers of AI, Elon Musk also runs the private rocket company SpaceX, which has already begun flying missions for NASA. And like Bezos, Musk thinks that spreading to space is our destiny—though he has a characteristically dramatic way of putting it.
“If we were a multiplanetary species, that would reduce the possibility of some single event, man-made or natural, taking out civilization as we know it, as it did the dinosaurs,” Musk told Rolling Stone in 2017.37 “It makes the future far more inspiring if we are out there among the stars and you could move to another planet if you wanted to.”
And Musk, it seems, wants to. He has said that SpaceX is working on an interplanetary rocket capable of making the trip to Mars, 34 million miles away, and plans to launch cargo vehicles to the Red Planet by 2022. It’s all part of his master strategy to put one million people on Mars over the next several decades. “I’ve said I want to die on Mars,” Musk told the audience at South by Southwest in 2013. “Just not on impact.”38
Space colonization may be the next big thing in the tech world, but it’s long been considered the ultimate solution to existential risk—and the ultimate destiny of human beings. Stephen Hawking, whose robotic voice was beamed into space even as his earthly ashes were interred between Charles Darwin and Isaac Newton at Westminster Abbey, once said that humanity had a thousand years to make it safely off the Earth. By 2017, shortly before his death, he had revised that deadline to just one hundred years. “I strongly believe we should start seeking alternative planets for possible habitation,” he said at the Royal Society of London. “We are running out of space on earth and we need to break through technological limitations preventing us from living elsewhere in the universe.”39
It’s true that spreading off world would provide protection from a number of existential risks. Asteroids, supervolcanoes, even nuclear war—the Earth could be utterly destroyed and our space colonists would remain safe. Given the distances involved in interplanetary travel, even the most finely engineered disease would be unlikely to remain infectious long enough to kill off-worlders. Climate change, of course, is a problem for Earth and by Earth. “By definition, whatever causes us to go extinct will be something the likes of which we have not experienced so far,” the Princeton astrophysicist J. Richard Gott wrote in 2007. “We simply may not be smart enough to know how best to spend our money on Earth to ensure the greatest chance of survival here. Spending money planting colonies in space simply gives us more chances.”
That attention is again being paid to the possibility of space colonization is chiefly because two very rich men are willing to spend a lot of their money on the idea—even though NASA hasn’t carried out a manned spaceflight since retiring the shuttle in 2011. But Bezos—who has predicted that one day there will be a trillion human beings living throughout the solar system—is on to something. “If you take current baseline energy usage, globally, and compound it at just a few percent a year for just a few hundred years, you have to cover the entire surface of the Earth in solar cells,” Bezos said during a talk at the Yale Club in early 2019. “Everybody on this planet is going to want to be a first-world citizen using first-world amounts of energy, and the people who are first-world citizens today using first-world amounts of energy? We’re going to want to use even more energy.”40
We will need more raw materials, more energy, more space. Just as we once grew by spreading across this planet, we will eventually need to grow by leaving it. It might be a hundred years—it might be far longer—but humankind’s future as a technologically developing species means expansion, possibly endless expansion. To miss out on this future—whether because of extinction or a catastrophic setback—is to suffer what Nick Bostrom has called “astronomical waste.”41 It’s the loss of the cosmic inheritance—all that energy, all that space—that could be ours.
This is the ultimate expression of existential hope: a human civilization that endures for millions, even billions of years, growing powerful and energy-rich enough to support trillions of human beings, all able to live lives of unimaginable material and intellectual plenty. It’s only going to happen, though, if we make it off this rock, and tap the endless energy sources of the universe—and if no alien civilizations, biological or artificial, have laid their claim first.
According to at least one theory, the universe has an expected life span of 80 billion years, give or take a few billion,42 which might make it seem as if we have plenty of time to claim our inheritance. Time lost is time we won’t get back, however. Bostrom estimates that for every century space colonization is delayed, we potentially lose the lives of 1043 humans who could come into being only if we seize the galaxy.44 This is our cosmic opportunity cost.
There’s a difference, though, between fumbling the present so badly that we allow an extinction to occur on our watch, ending the human story prematurely, and delaying the launch of humanity on a cosmic voyage not all of us necessarily want. Space colonization may be our destiny, but it won’t keep us safe—not for the foreseeable future. The energy and money that might be spent on nascent efforts to move off planet would be better used combatting existential threats that could end that future—and readying our survival, should the worst occur. That, as the existential risk expert Seth Baum wrote,
“is doing good on a literally astronomic scale.”45
Space is at best a distraction for now. Mars may be the other planet in the solar system most conducive to life, but it is still far more hostile than any place on Earth, save perhaps the bottom of the ocean. Just the round-trip to Mars and back would expose astronauts to up to two-thirds the radiation limits advised for space workers, putting them at unknown risk of cancer. Mars has been gradually losing its atmosphere for billions of years. It is very cold, and the air is unbreathable. There is a reason that as far as we know nothing currently lives on Mars. It’s a bad neighborhood.
The major problem with Mars as an existential risk refuge—or anywhere else off planet—is that it is very difficult to imagine how it would be possible for the Earth to be screwed up so badly, by natural disaster or war or disease or climate change, that it would somehow become more hostile to humans than Mars. We could have runaway climate change and Earth would still be preferable to Mars. We could have a volcanic winter that lasts for years—and you could still grow more food on Earth than Mars. While proponents of colonization have said we could eventually terraform the Red Planet to make it more hospitable to humans—perhaps by thickening its atmosphere to retain heat—NASA scientists have confirmed that doing so is essentially impossible, at least with current technology.46 Also, if we plan on terraforming a planet with a problematic climate to make it easier for us to live there, we might want to start with Earth. Even Bezos himself is deeply skeptical about what he has called the “Plan B” argument for space colonization. “Do me a favor, go live on top of Mount Everest for a year first, and see if you like it—because it’s a garden paradise compared to Mars,” Bezos said at the Yale Club talk.47