Scatter, Adapt, and Remember: How Humans Will Survive a Mass Extinction

by Newitz, Annalee

  The University of Hong Kong’s Joseph Wu says his models show that countries should always “hedge” by stockpiling two different antiviral medications. That’s because viruses often mutate during flu season, becoming resistant to the drugs used in treatment. But if we dispense two different drugs, the virus can’t mutate fast enough to keep up. Wu’s “hedging” strategy seems to work, at least in computer simulations of outbreaks in urban areas that assume people are traveling between cities fairly rapidly. If the city where the outbreak occurs uses two drugs to combat the pandemic instead of one, 10 percent fewer people overall will be infected than if only one drug is used. And the number of people infected with mutant strains of the virus will go down from 38 percent to 2 percent of the population. Those numbers are quite significant, especially because one of our goals as we stop a pandemic in its tracks is to prevent the microbes from mutating into something we can’t treat at all.

  So what would be an ideal response in the event of a pandemic? As soon as the WHO declares an outbreak, vaccines and at least two different kinds of medicines would be rushed to the most affected regions in order to stop the outbreak from becoming a pandemic. Children would be vaccinated first. If there were no vaccine available, scientists would immediately begin working on synthesizing one. Informal treatment stations would be set up in any region where there had been cases of the disease, so that people could be treated quickly, without bottlenecks. As individuals, we’d take great care to avoid big public gatherings and try to stay home as much as possible. Above all, we’d want coordination between health-care workers and pandemic modelers to figure out the best treatment strategy for each area, given the often limited resources we’ll have at hand.

  The main thing to remember is that stopping a pandemic isn’t about treating individuals—it’s about treating groups who are the most likely to spread the pandemic to others. If your neighbor’s child gets a vaccine, this measure alone could protect your whole neighborhood more than if you and your adult friends all got vaccines.

  Likewise, if we can kill a pandemic brewing in a developing country by sharing our vaccines and antivirals, we will save the developed world, too.

  A global-health surveillance state would look very similar to the world we live in now, except there would be considerably more rapid sharing of information between groups you wouldn’t expect, such as Google and the CDC, or regional Chinese hospitals, mathematicians who model pandemics, and researchers at GlaxoSmithKline. Once a region began to exhibit signs of a flu outbreak, whether reported by doctors or revealed by searches on Google, the WHO would be alerted instantly. Pandemic modelers and vaccine manufacturers could respond with strategies for containment before a pandemic virus even had a chance to jump to a new city.

  Anonymous health surveillance will be an integral part of pandemic-proof cities in the future. Combine surveillance with a good system for modeling pandemics and a supply of at least two antivirals, and you’ve got the blueprint for one of the healthiest cities the world has ever seen. And that’s the kind of city we could survive in for centuries. Unless, of course, we are dealing with a disaster that is so unusual, and so powerful, that we have no models for how it might work. All we can do in that case, as we’ll see in the next chapter, is go underground.

  17. CITIES THAT HIDE

  THERE ARE SOME disasters so catastrophic, and so rare, that we have very little data on them. Call them extreme radiation events. As we learned in chapter two, such an event may have caused the second-worst mass extinction on Earth 450 million years ago. Some scientists speculate that a gamma-ray burst coming from a nearby hypernova may have abruptly ended the Ordovician period, frying the ozone layer off our atmosphere and exposing the Earth’s newly diversified multicellular creatures to high doses of radiation. Creatures deep in the sea would have been protected by the radiation-absorbing water, but all the plants and light-loving swimmers near the surface would have been cooked instantly. Those not boiled to death would have been eaten away by radiation fairly quickly as the sun’s ultraviolet rays beamed down on the unshielded planet. A gamma-ray burst like that could hit the planet at pretty much any time, with very little warning. We would likely be able to see the hypernova with our naked eyes, and would have a few short hours before its stream of radioactive particles showered down on the Earth.

  Such gamma-ray bursts are a very real threat, but they’re extremely unusual. Even less likely than a hypernova is the probability that its gamma-ray burst would be aimed directly at us. A far more likely cause of sudden radiation bombardment on Earth is human warfare. Even a limited nuclear war could pour ionizing radiation down on the planet in the form of nuclear fallout, causing radiation sickness in the short term and triggering cancers that could kill in the long term.

  For people living in cities, it won’t matter if the radiation comes from space or nuclear bombs. To survive, we’ll need to go underground, into subterranean cities whose walls are made of thick layers of rock that can block radiation. We’ve known this for a long time. One of the greatest underground cities of the modern world, the NORAD (North American Aerospace Defense Command) complex beneath Colorado’s Cheyenne Mountain, was designed during the Cold War to protect up to 5,000 residents from atomic blasts and the subsequent fallout. But this isn’t the only underground city humans have built to protect themselves during war. Nearly two millennia ago in what is today central Turkey, Jews and Christians fleeing Rome built villages on top of vast underground cities that could protect thousands of people from Roman raiders—and later, from Muslims during the Crusades.

  We’ve been surviving underground for a long time. And city planners today are building more and more underground structures. You may not think you have a chance of surviving during a radiation emergency, but you’re closer to an underground city than you think.

  Underground Life

  The mounded hills and deep, curving valleys of Göreme, Turkey, are famous for their beauty, and for thousands of undeniably phallic rock columns known as “fairy chimneys.” Though these structures elicit everything from giggles to New Agey declarations about “lingam power” from tourists, what’s most interesting about them isn’t their peculiarly erect shapes. Wind and water have worn them down in this way because the fairy chimneys, like the valleys and cliffs they emerged from, are made of tuff, a pale, crumbly rock composed of highly compressed volcanic ash. Early settlers in Göreme and many neighboring towns in Turkey’s Cappadocia region discovered that tuff was incredibly frangible, and easy to dig out and remold. Small groups of Judeo-Christian mystics driven out of Rome in the second century CE came to central Turkey to hide, and dug spartan monk’s cells into the tuff.

  Over the next several hundred years, these tiny settlements of hermits and outcasts grew. Villagers carved out homes, churches, and vast food-storage pantries, eventually creating a breathtaking architectural style in which gorgeous classical columns and arched church doors appear to emerge from solid rock. Local aristocrats funded incredible subterranean art projects, deep cave churches whose high ceilings are painted with gorgeous biblical scenes that could only be seen in torchlight. Many of the most awe-inspiring examples are still preserved in Göreme’s Open Air Museum, a cluster of churches and monasteries carved into the creamy tuff above a valley full of patchwork farms. From a distance, the ornate, sculpted complex looks like an otherworldly city from a Lord of the Rings movie. During the Byzantine era, however, the need for these cave and tunnel cities was all too real.

  Cappadocians built dozens of underground cities in the era between the fifth and tenth centuries. Historians have conflicting theories about why, but one major reason would no doubt have been raids from neighboring groups and from Muslims during the Crusades. These underground cities don’t just shield inhabitants from the elements—their entrances are hard to reach, or hidden. They are designed to be invisible.

  To imagine how future humans might survive a radiation disaster underground, we need only pay a visit to subt
erranean Cappadocia. On a drizzly day spent near Göreme, I ducked out of the summer rain to visit Derinkuyu, the most extensive of the excavated underground cities in the region. Now open for tourists, the city’s maze of tunnels, living quarters, and community areas extends five levels and 55 meters underground. Cool and sandy, its often cramped corridors are well ventilated by several air shafts. My tour group and I squeezed down a long stairway, then entered a large room that was once a stable. It could easily have housed a dozen goats, sheep, or cows, chomping contentedly from mangers carved right into the walls. Our guide pointed out that villagers typically entered Derinkuyu via secret tunnels from their aboveground homes. These entrance tunnels were small enough in many places that I was forced to bend quite far down as I walked, and I’m a fairly short person. The city’s builders engineered these areas to discourage anyone trying to enter with bulky weapons or armor. Punctuating many of the stairways were deep crevices that held enormous rock discs designed to roll out and block the corridor from invaders.

  Inside the underground city of Derinkuyu, you can see two hallways leading to rooms. The city is five floors deep and housed thousands of people. (illustration credit ill.14)

  Living quarters were honeycombs of interconnected rooms and bed nooks hollowed out of the tuff walls. Though the place looked barren when I saw it, a thousand years ago it would have been very different. People built wooden doors into the round doorways, covering the floors in thick carpets and the walls in draperies. Families from the city above had their own quarters below, full of furniture, favorite pottery, food, and wine. In the living areas of the city, ceilings were high and rooms were cozy rather than cramped. The underground dwellers even had a sanitation solution for long-term sojourns. Waste was packed into clay containers, sealed up, and buried in deep pits below the city’s lowest level. Large public rooms for cooking and eating, as well as wine-making and worship, would have been places where villagers could gather to make decisions about how long to remain underground and hide from danger.

  This ancient city, carved out over centuries, was constantly changing and growing. A deep passage connected Derinkuyu with another underground city several kilometers away. The peoples who made these passages their refuges were employing the same survival mechanisms used by Jews over the past 2,000 years—they had scattered from distant communities in both the west and the east, and adapted themselves to the remote landscapes of central Turkey to protect themselves from persecution and ethnic cleansing. Not only did these communities survive for centuries, but they also created an entirely new way of life—one that many people in the area still enjoy today. Traditional villages in Cappadocia are full of homes built into the tuff of fairy chimneys, with narrow stairways spiraling around the rocks’ girth, leading to sturdy wooden doorways in their cone-shaped tops. Some homes are hewn from the cliffs, where they share space with countless pigeon roosts that locals tend for the fertilizer. Tourists are invited to spend the night in refurbished cave homes, as bed-and-breakfasts take over abandoned dwellings. I spent several days in one such hotel, my bed stashed deep inside a cave that had been modified to have large picture windows overlooking the city of Göreme. With the exception of the windows, my bedroom could have been torn from a future world where humans had to relocate underground for protection.

  But without those windows, the place would have been much more dismal. And that’s why urban planners creating modern underground cities worry as much about the psychological effects of living underground as they do about the structural integrity of underground spaces.

  The Trouble with Tunnels

  If we’re going to survive a nuclear war, a meteor strike, or a radiation event, there is no doubt that we’ll have to live underground for months, or even years, as the planet recovers. In the unlikely event that a gamma-ray burst burns off the ozone layer, it could be centuries before life could thrive on the surface again—whenever we stepped outside our underground homes, we’d need to wear protective covering to shield us from the sun’s ultraviolet radiation. The good news is that three feet of packed dirt over your head can significantly reduce the intensity of radiation, and a layer of concrete can provide more safety still. We have the engineering ability to create radiation-shielded cities by going underground. The question is how we would live there.

  In the event of a radiation emergency, people might find themselves having to create cities in already-existing underground spaces like subway tunnels, mines, sewer systems, and service tunnels. Already-existing underground cities like Montréal’s “RÉSO,” a 20-mile system of tunnels that connect shopping centers, metro stations, schools, apartments, and more, are basically larger and more complicated versions of mining shafts. To make the long, dark corridors more livable, developers build structures inside the bare rock walls, covering up the stone surfaces.

  Making these spaces inviting is crucial to our survival. John Zacharias, a city-planning professor at Montréal’s Concordia University, has studied several underground cities, especially in Japan and China, and told me that the biggest challenge is psychological. Studies on people who work all day in underground space without any access to the outside show rising stress levels. “It’s not dramatic, but is measurable,” he said. “Going down very deep is also something people don’t like.” The new Oedo subway line in Tokyo is 55 meters below the surface, and Zacharias said people tend to avoid it in favor of an overcrowded line it was supposed to relieve. In Finland and Sweden, where underground buildings are common, studies have shown that people are disturbed by the process of descending into the Earth, and that they complain of the monotony in subterranean buildings. The solution, argue civil engineers John Carmody and Raymond Sterling in Underground Space Design, their underground-engineer omnibus, is to make sure underground spaces are “stimulating, varied environments” that give the impression of spaciousness and daylight.

  Many underground cities, like RÉSO, use skylights to bring in daylight, but our future troglodytes won’t have that option because they will need radiation shielding. So they’ll have to arrange underground areas to be different sizes and shapes, with architectural features that make the space interesting to inhabit. Even the residents at Derinkuyu knew this, and their interior spaces were all uniquely arranged, with a wide variety of floor plans. Carmody and Sterling also caution that one of the main complaints people have underground is that they become disoriented without windows, so a good underground city would need a simple layout or clear signs that help inhabitants find their way. Because people get anxious about going deep underground, transitions between levels should be gradual. Ideally, different areas of the city would have dramatically different designs to give the feeling of neighborhoods and landmarks that we use aboveground to figure out where we are. Privacy will also be a premium in spaces like these, where people have a tendency to feel trapped. As we turn our tunnels into our homes, we’ll want to remember to create places to be alone, as well as vast, high-ceilinged rooms that will make us feel as if we’re outdoors even if we aren’t.

  If we are turning mines into cities, or excavating a brand-new subterranean metropolis, there are also a few basic engineering issues we should keep in mind. Agust Gudmundsson, a geology professor at Royal Holloway, University of London, studies underground structures, and he explained that earthquakes will be a threat to life belowground. “Fractures that form or are reactivated during an earthquake may lead to water flowing into parts of the underground city,” he said. Water leakage is one of the main causes of destruction in these developments, and leaks recently led to partial collapse of some tunnels in RÉSO. When we build underground, Gudmundsson cautioned, we have to be vigilant about whether we’re building in regions with faults or cracks—especially if the city will be near a body of water. Just building the city could cause tremors that allow water to come seeping through cracks, causing damage or collapse over time. At the NORAD facility in Colorado, the water-leakage problem was so severe that people walked under umbrellas
through the long rock tunnel that winds deep into the mountain and to the massively reinforced city gates.

  Nowhere to Go but Down

  “The construction of major transit projects such as metros and road tunnels is just a prelude for the true nature of underground development,” argue Dmitris Kaliampakos and Andreas Barnardos, two engineers who specialize in underground development at the National Technical University of Athens. In 2008, the two helped organize an international conference to deal with questions about building underground. Over the past few decades, many cities have witnessed the proliferation of underground building projects, ranging from individual homes expanding underground to RÉSO-like structures such as the one Amsterdam considered building beneath its canals in the late 2000s. “The main driving force behind the process is the continuously growing urban areas,” write Kaliampakos and Barnardos. Building underground saves energy, they point out, because subsurface temperatures stay comfortable year-round; in addition, it allows cities to expand without destroying historic places or producing suburban sprawl. The problem is that most cities don’t have a lot of regulations and codes in place to help developers make these underground spaces. It’s hard for real-estate agents to value underground spaces that don’t exist, and most laws don’t make it clear who owns the land below our feet. These factors, along with the cost of building down, make developers shy about breaking ground.

  Still, the laws are catching up with urban needs. And geologists like Gudmundsson are working with engineers to provide accurate maps of the kinds of rocks and fissures that lurk beneath us, so that we can plan the right spots to tunnel below. As John Zacharias said, “We are going to have a lot more space underground in future, especially as cities build new transportation systems underground.” He predicted that the movements below will also be related to concerns about energy. “We will need places to store water, especially as cities get round to recycling water,” he asserted. “Power plants will go underground. Theaters and libraries are already there. The future city is three-dimensional, and all big cities will be looking to see how they can better use the underground resource.”