The Knowledge: How to Rebuild Our World From Scratch (5 page)

In the situation we’ve imagined (loss of people, but no massive destruction of the stuff that surrounds us), you’re not likely to want for shelter: there will be no shortage of abandoned buildings in the immediate aftermath. It would be well worth it, though, to embark immediately on a scavenging foray to a camping store to get yourself some new attire. The dress code for the end of the world will be pragmatic: loose, durable trousers, layers of warm tops, and a decent waterproof jacket will keep you comfortable while you spend a lot more time in the open or in unheated buildings. Sturdy hiking boots may not look very glamorous, but in a post-apocalyptic world you really don’t want to lose your footing and break your ankle. Over the first few years, the best place to forage for clothing that has not yet been destroyed by insects or the penetrating damp would be large shopping centers. It’s a long way into the deep interior of a mall, and goods would be safe from the elements.

Warm clothes aside, it is fire that will best ensure your survival. Fire has played a fundamental role in human history, protecting against the cold, providing light, enabling us to smelt metals and cook food to render it more digestible and pathogen-free. In the immediate aftermath of the collapse, you won’t need wilderness survival skills such as rubbing sticks together to ignite tinder. There will be plentiful boxes of matches left in convenience stores and homes, and disposable lighters will continue working for years.

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IF YOU CAN’T FIND MATCHES OR A LIGHTER,
there are less conventional methods for starting a fire using scavenged materials. If it’s a bright day, sunlight can be concentrated into a hot focus using a magnifying
glass, a pair of eyeglasses,
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or even the curved base of a soda can that has been polished with a square of chocolate or a dab of toothpaste. Sparks can be generated by touching together jumper cables attached to an abandoned car battery and steel wool scavenged from a kitchen cupboard will ignite spontaneously when it is rubbed against the terminals of a 9-volt battery liberated from a smoke detector. There will be an abundance of excellent tinder lying around deserted human habitations, such as cotton, wool, rags, or paper, especially if you douse it in a makeshift fire accelerant like Vaseline, hair spray, paint thinner, or simply a drop of gasoline. And you won’t struggle to find fuel to burn, even in an urban environment. Populated areas are packed with combustible materials, from furniture and wooden fittings to garden shrubs, that can be thrown on a fire for heat and cooking.

The issue is not starting a fire or keeping it going, but where to make it. The vast majority of recently built houses and apartments have no working fireplace. If need be, you can safely contain a fire within a metal trash can or bring a barbecue indoors, or if the apartment has a concrete floor, you could rip away a patch of carpet and light a fire directly on the concrete. You’ll need to allow the smoke and fumes to escape through a slightly opened window (especially if you’re forced to resort to combusting synthetic fabrics or furniture foam). But your best bet would be to try to find an older cottage or farmhouse that is appropriately equipped to be heated by fires rather than radiators—this is one of the major incentives to abandon the cities as quickly as possible after the Fall, as we’ll see in a bit.

After shelter and protection from the elements, the second priority on your list is to secure clean drinking water. Before the municipal water supply runs dry you should fill your bathtub and sinks to the brim with water, as well as any clean buckets or even strong polyethylene trash bags. These emergency water stores should be covered to keep them free from detritus and to block the light that allows algal growth. Bottled water can be scavenged from supermarkets and from water coolers in office buildings. Other reservoirs of water you’ll be able to drain include hotel and gym swimming pools, as well as the hot water tanks in any large building. In time, you’ll come to rely on water sources you’d normally have wrinkled your nose at. Every survivor will need at least three liters of clean water every day, and more in hot climates or with exertion. And keep in mind that this is for rehydration alone, and does not include water necessary for cooking and washing.

Water that doesn’t come from a sealed bottle must be purified. A surefire method for sterilizing water of pathogens is to bring it to a hearty boil for a few minutes (although this offers no protection against chemical contamination). This is very time-consuming, however, and will rapidly eat through stocks of fuel. A more practical, longer-term solution for purifying larger volumes of water, once you have settled down after the Event, relies on a combination of filtration and disinfection. A rudimentary but perfectly adequate system for filtering out particles in murky lake or river water uses a tall receptacle such as a plastic bucket, a steel drum, or even a well-cleaned trash can. Punch some small holes in the bottom, and cover with a layer of charcoal, either taken from a hardware store or created yourself using the instructions
here
. Alternate layers of fine sand and gravel on top of the charcoal. Pour the water into your receptacle, and as it drains through, it will be effectively filtered of most particulate matter.

The first option for disinfecting this filtered water to eliminate waterborne pathogens is to use dedicated water-purification treatments, such as iodine tablets or crystals available from camping stores. If you can’t find any, there are some surprising alternatives that will also work perfectly well, such as chlorine-based bleaches formulated for household cleaning. Just a few drops of a 5 percent liquid bleach solution that has sodium hypochlorite listed as the main active ingredient will disinfect a whole liter of water in an hour. But carefully check the label to ensure that the product doesn’t also contain additives such as perfumes or colorants that may be poisonous. Several fluid ounces of bleach found under a kitchen sink can purify around 500 gallons of water—almost two years’ supply for one person.

Products used for chlorinating swimming pools, scavenged from the storeroom of a gym or wholesaler, can also be used at a weaker dilution to disinfect drinking water. A single teaspoon of this calcium hypochlorite powder is enough to disinfect 200 gallons of water (but again, be careful it doesn’t contain any antifungal agents or clarifier additives). Later on in the rebooting process, once all the readily available chlorinating agents are gone, you’ll need to create your own from scratch using seawater and chalk as raw materials, as we’ll see in Chapter 11.

Plastic bottles can be used not just for storing water, but for sterilizing it as well. Solar water disinfection, or SODIS, employs only sunlight and transparent bottles, and is recommended by the World Health Organization for decentralized water treatment in developing nations—a perfect low-tech option for the post-apocalyptic world. Tear the labels off clear plastic bottles—but don’t use bottles bigger than two liters, as the crucial part of the Sun’s rays won’t be able to penetrate all the way through—fill them with the water to be disinfected, and lay them down outside in full sunlight. The ultraviolet component of the Sun’s rays is very damaging to microorganisms, and if the water warms up to above 50 degrees Centigrade (122°F), this
deactivating effect is greatly enhanced. A good system is leaning a sheet of corrugated iron angled to the Sun and stacking the water bottles in the grooves. Painting the sheet black helps the heat sterilization effect.

However, glass and some plastics, such as PVC, block out the UV rays. Check the bottom of the plastic bottle: most are now manufactured with a recycling symbol, and you want to pick out those marked with a (1), indicating they are made of PET. If the water is too murky for the sunlight to penetrate, you’ll need to filter it first. In bright, direct sun, this method can disinfect water in around six hours, but if the sky is cloudy it’s best to leave it for a couple of days.

How long will you be able to continue dining out on the leftovers of our civilization? The expiration date on modern packaging is only a guideline and often underestimates deterioration by a considerable margin. So how long would different food types actually remain edible? Some products will last more or less indefinitely, including salt, soy sauce, vinegar, and sugar (as long as it stays dry), and we’ll see in Chapter 4 how these substances can be used to preserve food.

Other staples of our diet won’t fare as well on the shelves of deserted supermarkets. Most of the fresh fruit and vegetables will have wilted and rotted within weeks, but tubers will persist much longer, since they evolved to store energy over winter for the plant. Potatoes, cassava, and yams will all have a good chance of lasting more than six months if they’re in a cool, dry, and dark place.

Cheese and other treats on the delicatessen counter will be moldy within weeks, and after a matter of months the butcher’s unpackaged meat cuts will have decomposed to leave only the odd T-bone or rack
of ribs. Eggs are actually surprisingly resilient and can remain edible for more than a month without refrigeration.

Fresh milk will be spoiled within a week or so, but “shelf safe” milk in UHT packs (pasteurized at ultra-high temperatures) will last years, and powdered milk even longer. Since it’s the fat content of dried foodstuffs that often spoils first as it undergoes rancidification, fat-free powdered milk will remain potable the longest. Lard and butter will spoil quickly within defunct refrigerators, and cooking oils will also turn rancid over time. (But once unfit for human consumption, their lipid content can still be used to make soap or biodiesel, as we’ll see later on.)

White wheat flour will keep for only a few years, but longer than whole wheat flour, which, due to the much higher oil content, goes rancid quickly. Flour products such as dried pasta will also last for a few years. The nutritional content survives far better if the grains have not been cracked or ground (which exposes the inner germ to moisture and oxygen), so unmilled whole wheat grains remain good for decades. Likewise, whole corn kernels will remain nutritious for around ten years, but this persistence time drops to only two or three years for cornmeal. Dried rice will keep well for between five and ten years.

This all assumes that the remnant food will be in conditions favoring preservation: cool and dry. This isn’t an unreasonable expectation for the interior of a large supermarket in temperate regions, but if you’re living in a hot, humid climate, food will begin to decay rapidly as soon as the grid goes down and air conditioners rumble to silence. After the refrigerators and freezers fail, the pungent aroma of putrefying food will attract many nonhuman foragers: rats and insects, as well as packs of dogs and other former pets now growing increasingly hungry. Even well-packaged food is likely to succumb to the onslaught of teeth and claws, so the food resources available to the survivors may be limited less by expiration dates than by pests—no different from the granaries of the earliest civilizations.

By far the largest reserve of preserved sustenance, however, will be the rows upon rows of canned food that fill the supermarket shelves. The armored packaging will not only resist the post-apocalyptic plagues of vermin and insects, but the heat treatment during the canning process is exceptionally good at protecting their contents against microbial spoilage from within. Although the printed “best before” date is often only two years in the future, many canned products will keep for several decades, if not more than a century after the fall of the civilization that produced them. Rust or dents on the can itself do not necessarily mean that the contents are compromised, as long as it shows no signs of leakage or bulging.

So if you were a survivor with an entire supermarket all to yourself, for how long could you subsist on its contents? Your best strategy would be to consume perishable goods for the first few weeks, and then turn to the dried pasta and rice, as well as the more resilient tuber vegetables, before finally resorting to the most reliable reserve of canned produce. Assuming also that you are careful to keep a balanced diet with the necessary intake of vitamins and fiber (the health supplements aisle will help you here), your body will need 2,000 to 3,000 calories a day, depending on your size, gender, and how active you are. A single average-size supermarket should be able to sustain you for around 55 years—63 if you eat the canned cat and dog food as well.

This calculation naturally scales up, from a single individual with a supermarket at his or her disposal to the surviving population of a cataclysm surrounded by the preserved sustenance of a whole nation, from small corner stores to enormous distribution warehouses. For example,
the UK Department for Environment, Food and Rural Affairs (DEFRA) estimated in 2010 that Great Britain has a national stock reserve of 11.8 days of “ambient slow-moving groceries” (nonperishable, unfrozen produce such as rice, dried pasta, and canned goods). With an apocalyptic population crash, this would equate to up to fifty years supply for a surviving community of a few tens of thousands of people.
Thus a post-apocalyptic community large enough to rapidly reboot technological civilization should have sufficient breathing room to reinstate agriculture and grow its own food.