Overview:

We together form a giant complex system, a swarm. It exists because we’re born defenseless but with a big brain. Lacking claws and fangs we need each other to get food and we’ve organized ourselves around that basic fact since our species began. Despite walking upright, making tools, and talking, we did what most other animals did—we roamed to gather our food. Then, millennia ago, some of us started to farm. That then triggered many changes in our swarm’s structure. Our actions cause its changes, but we needn’t have planned that, nor must we have changed in some fundamental way before it could change. Our swarm falls into certain styles of organization because that’s how certain kinds of complex systems link themselves over time. It’s not special to us; it’s something that all networks beyond a certain level of complexity can do.

This chapter sketches why our swarm is important by telling the story of how we turned into farmers millennia ago. Instead of that being a conscious act, it likely happened because as the last ice age ended our swarm fed back on itself in a process called autocatalysis. Its structure also changed a lot in a process called phase change. Those two kinds of complex system behavior have shaped us from then through the middle ages until today. They’ll continue to shape us in the future. For instance, although no one planned it, we’re now well on our way to becoming an urban species. And despite a lot of worrying today, we’re also unlikely to run out of food anytime soon.

Autocatalytic Runaway

It’s 11,600 years ago, the last ice age is ending, and we’re heading into a big change in our food supply, although we don’t know it yet. Our tribes in the wind-swept hills of northern Iraq are out looking for lunch. There are about 25 of in a tribe and we’re tall and slim and fit and healthy. We eat anything we can find, from gazelles to berries to grubs. We’ve plenty of spare time and our dogs help with the hunt. We may not live long, but we’ve few diseases—there aren’t enough of us for them to persist. We’re also hardy from unceasing exercise. All of us are related, and all of us, including children, are armed. Anyone truly sick, or maybe even just lame, simply dies. We can’t stay to nurse them for long because to stop moving is to starve. We’re grimy, our table manners aren’t pleasant, and we don’t smell too good either, but we aren’t stupid. The stupid die. Things have been this way for at least the last 40,000 years and they seem set to continue this way for the next 40,000. Our only real problem is that we aren’t always certain of finding food, and right now we’re starving.

But now observe the fateful moment: One of our little Iraqi tribes nears a golden field of a strange long-stemmed grass. Perhaps we haven’t sighted a gazelle or wild ass herd in many days, or maybe we’d herded a few goats but disease killed them. Whatever the reason, we’re hungry. We’re so hungry we’re ready to eat grass. One of us, perhaps a woman, wonders if the grass seeds clustered on the waving stalks are good to eat. Squatting to pull some up, she finds that they come off in her hand, as if meant to be easily harvested. We then gather several lapfuls of seeds. That night we make unleavened bread, like today’s tortillas or chapatis. We pound the wild wheat seeds to a pulp, mix with water, and lather the paste on a flat rock near the fire. Painted by the warm firelight, our band forms a tableau, a freeze-frame of our species before the fast-forward changes to come. Perhaps months (years? centuries?) later, we discover how to ferment the same grass seeds. Now we have beer. We don’t, however, at once give up hunting and gathering to become bread-eating, beer-swilling hicks. Foraging is what we know. It’s kept us alive for millennia. So we keep roaming, following our food.

All that must have happened many times before, starting about 3,000 years further back in time, when our planet had first started to warm out of its long deep freeze. One of our bands in Iraq though was special. We kept returning to the field of wild wheat. One day, instead of discarding our brushwood huts and moving on as always, we built a more permanent camp of mud-brick. We returned to it seasonally as game dried up elsewhere, but we still didn’t settle. We continued to hunt and gather and harvest. We also didn’t plant anything for centuries. Perhaps the idea hadn’t occurred to us, but it’s just as likely that we simply had no need. Then one day everything changed. Our numbers had risen beyond the level we could support by foraging alone. We were trapped.

That little band of ours now had some place to defend and that one place had to give us everything we needed to survive. We formed settlments—they were too small to even call them villages. One of those settlements, Shanidar Cave in northern Iraq, gelled about a thousand years after our first mud-brick huts. Soon it supported up to 150 of us—perhaps six times more than foraging alone could feed. Grass seeds, which we today call wheat and emmer and rice and so on, then became ever more important to us. They became our only reliable food source. That’s the nexus at which everything started to change for our species. That’s when we began to become something truly new.

Look at those wild wheat seeds on a stalk. As they ripen, their stalk shatters and they fall to the ground to sprout. For a few mutant plants though, the stalk fails to shatter. Normally that genetic strain would occur only rarely since it can’t make new plants. But 11,000 years ago it was lucky because hungry people were roving nearby. We ignored all the wheat stalks that had done the right thing and shattered. Picking up their scattered seeds would take more energy than eating them would give. But the mutant plants still had their ripe seeds on the stalk. That put them in the perfect position for us to harvest them efficiently. Then, after a thousand years or so, we planted some of the mutant seeds we didn’t eat. That gave those mutants an advantage over their normal cousins, so they spread. And that was what led to our big change—and all our big changes since. With that, not just settlement but farming itself began.

Today we still don’t know what triggered our first settlements back then. Likely though it was linked to the melting ice because it was a global change for us. Within the next few thousand years our species also tamed rice, beans, squash, and yams—in southern China, northern India, north-central Africa, and central America. Today we still live with the genetic changes we started back then. For example, we first tamed maize in Mexico’s central highlands about 5,600 years ago. At the time, wild corn cobs were under half an inch long. By 1492, when the Spanish showed up in the Americas, we’d already been selecting bigger ones for four millennia. By then, some cobs were already six inches long. Today, some are 18 inches long. Without our help, such mutant maize plants would quickly die out. Their kernels couldn’t escape the cob to sprout. So today’s corn cobs exist solely because we support them. Wheat, apples, peas, watermelons—all our crops today are the same. None are ‘natural.’ If we were to vanish tomorrow, the corn we know today would grieve, for it would vanish within a season. Over time, its descendants would turn back into something small, hard, and dry. Many other gene distributions would change too. Poodles would transform back to gray wolves. Cows would go back to being wiry aurochs. Watermelons would turn back into small, bitter berries. Today’s sheep and wheat, and all our other tamed animals and plants, would all vanish. We’re as much a part of our mutant plants’ reproductive system as they are of ours.

That taming millennia ago didn’t only change the plants and animals around us; it also changed how we lived. For one thing, slavery became more likely. When we were all hunters and gatherers 11,000 years ago, we weren’t meek. We could maim and rape and kill just as well as anyone else can, but we likely didn’t take slaves. They would have had no point. Back then, we all got about on foot. Each new mouth would’ve meant having to add about 80 acres to our food-gathering range. Capturing someone to do your laundry would’ve made zero sense. But once we started turning into farmers, new hands became worth more than their new mouths. As farmers, we also had more work to do, and it was more continuous work. So slavery would’ve started making sense. We could both feed slaves and get them to make more food than they eat. Also, once we were stuck in place, we could invest in more permanent things—like slave pens. Even herders can’t stop slaves from running away as cheaply as farmers can. Then once we had long-distance trade, slavery would’ve made even more sense. Before the horse, the camel, the ship, as slaves we could just run away. Our ex-captors could only follow on foot.

But, for many reasons, farming’s biggest change was what it did to our numbers. First, as today’s female athletes and dancers know, low body fat lowers female fertility. Ovulation slows or even stops. Thus, hunter-gatherer females have few children. But as our food supply grew more reliable, female body fat grew more uniform throughout the year, so ovulation regularized. Birthrate rose. It rose for another reason too. Hunter-gatherer mothers are forced to carry their infants, so they suckle them more since infants are always close to the breast. Breast feeding releases hormones that reduce fertility. But once we settled, we no longer had to carry our babies all the time. That in turn reduced suckling. That then raised our birthrate. Settlement raised our birthrate for yet another reason. Once we no longer had to carry our kids around all the time, women could have more than one at a time. Plus, farming needs more labor than foraging. It also needs more continuous labor. So an extra pair of hands, enslaved or not, became worth more than an extra mouth. Thus, as we turned into farmers the cost of kids relative to their future labor value fell. Women, instead of reproducing every three or four years as before, turned into yearly baby machines. So once we settled down and also had a reliable food supply, we multiplied like rats in a grain silo. The more tamed plants we had, the more of us there would be to ensure yet more tamed plants.

That kind of self-feeding cycle isn’t unique to us. Chemists might call it an autocatalytic (‘self-stimulating’) reaction. A catalyst is anything that stimulates a chemical reaction while remaining unchanged. An autocatalytic chemical reaction thus helps itself continue. It makes its own catalyst. The more the cycle goes on, the more catalyst it makes, which helps the cycle go on, which then makes more catalyst. It’s a beast whose hunger rises the more it eats. Physicists use the same idea. A nuclear explosion starts when enough radioactive atoms release neutrons in a small enough space. As the number of neutrons rises, so does the chance that they’ll hit new atoms, which will release energy—and yet more neutrons. If the reaction starts with fewer atoms than the critical mass needed to chain-react, it dies quickly. If it has more than that critical mass, it quickly goes autocatalytic. A nuclear explosion results.

Something similar happened to us 11 millennia ago. The mutant plants we ate couldn’t flourish without us to nurture them. We couldn’t flourish without them to eat. The two of us thus grew on each other, like two intertwining vines neither of which could support itself alone. So just as we selected mutant families of crops, so too must they have selected mutant families of humans. Genetically, our species hasn’t changed much since then—there hasn’t been enough time yet—but we’ve changed everything around us, and that’s changed how we must live. We’ve changed our food, but our food has also changed us. But that’s only half the story of how we became farmers. Autocatalysis put us on the treadmill of technological change, but it didn’t nail us in place. That came next as we changed phase.

Changing Phase

Today we like to congratulate ourselves on our cleverness in constructing the comfortable world that many of us live in today. But our lives today aren’t necessarily any better or worse than our lives were 11,000 years ago. Back then, we couldn’t amass much since everything had to go on our sweaty backs, but we weren’t naked apes hefting big stone axes. We each carried about 20 pounds of food, weapons, tools, and babies. Weight was the enemy, so we likely didn’t make most of our tools with stone. Instead, we probably made grass shoes, leather bags, and string baby slings. All that has washed away in the river of time, leaving only our stone, and sometimes horn, tools. We must also have made slingshots and bows, drugs and medicines, tents and waterbottles, plus clothes, ornaments, tattoos. In short, our technology was already well-developed, and after millennia of fine-tuning by clever people with loads of time on their hands, it was well adapted to our needs. Even so, only about four million of us were alive at the time. Our toolbase couldn’t support any more than that.

Today we number in the billions and half of us live in cities, with more moving to cities all the time. But we don’t live as we do now because millennia ago we foresaw our present lives, or even desired them. We made the steps but didn’t plan the journey. We’re half-urban today because we fell into our present, trapped in an autocatalytic food cycle that we unwittingly began 11,000 years ago. But once that cycle got going our growing toolbase then changed us permanently. Our tools change us just as much as we change them. We didn’t plan what happened next.

Skeletons from 10,400 years ago tell us why. Buried in the sands of Abu Hureyra, on the banks of the Euphrates in northern Syria, they speak of females in pain. They had enlarged and often injured toe joints, curved and buttressed femurs, enlarged knees, and damaged, or even crushed, spinal disks. They must have had to kneel to grind nuts and grain. Plus, with only stone grinders and sweat, it must have taken them hours each day to grind enough flour for just one family meal. Adolescent skeletons also speak of regular and excessive strain. They must have carried heavy loads on their heads daily. And everyone—girls and boys, men and women—also had fractured teeth. Likely, that came from eating partially ground grain and bits of stone flaked off during the grinding.

“In the sweat of thy face shalt thou eat bread, till thou return unto the ground.” Wise words. But no one mentioned millennia of pain. Why did we put up with it? Why not give up the farming fad and go back to foraging? Perhaps many of us did, but after farming for a while it was too late for most of us. We were already too many. For instance, in Abu Hureyra we’d sited our village on a gazelle migration path. For a while the pickings must have been good. We grew fat. Our birthrate rose. But as the planet warmed and its climate changed, the herds declined. By then we were too many to go back to roving. Oops. Nurturing mutant grain became more and more important to us. We were stuck.

So we invented new tools. By about 9,000 years ago in Abu Hureyra, weaving had already become a speciality among a few women. Fewer fractured teeth overall suggest that we then figured out how to weave sieves fine enough to sift our flour. Then, as the climate dried further, gazelles vanished. We turned to herding sheep and goats, and more planting. Then we figured out how to hand-throw clay pots—perhaps we’d noticed that pots are good ways to store grain against rats. We may have then made more pots to soak our grain and cook it into porridge because our fractured teeth then disappeared. With our new soft foods though, tooth decay, once rare, grew. Our bodies aren’t built to live well only on starches. However, with no more teeth-breaking, our numbers also grew. Those of us with few or no teeth could survive longer. Before, we simply died. Disease then rose, presumably from more crowding and more tamed animals. Our larger numbers also served as a disease reservoir. Illnesses could then circulate for decades without dying out. They could even move back and forth between us and our newly tamed food animals. So they persisted. Infant deaths climbed too, perhaps for the same reason. Each solution to a problem led to a new problem, which led to a new solution. We were caught in an autocatalytic technology trap. We’re still in it today.

Even though we invented all those new tools, we didn’t intend their effect. What hunter-gatherer 11,000 years ago would’ve interrupted the campfire songs to say: “Let’s farm! Sure, we’ll lose about five or six inches in height. We’ll be sickly too. We’ll get less protein, we’ll eat too much starch, we’ll have less variety in our diet, and we’ll have to work harder. We’ll invent slavery, more women will die in childbirth, and more babies will die. Plus we’ll be in great pain for thousands of years. But we’ll just have to bear it so that our remote descendants can have mobile phones.” Who would give up millennia of one way of life to become a farmer?

That question is hard to answer if we assume that we foresee our future, or that our plans for it mostly succeed. But if we abandon those assumptions its answer becomes obvious since a thousand farmers can live on the land that 25 foragers need. If it ever came to war, those legions of runty, sickly, gap-toothed farmers would wipe out the few tall, healthy, nomads. Even when the rovers won, the hordes of farmers that they would then rule would swallow them, as a pond swallows a flung pebble. A few centuries later, the ripples would’ve died down and it would be much the same as if they’d lost. We’d farm mostly the same foods. We’d make roughly as many babies. We’d be able to feed about as many priests and warriors—although they might serve different gods and have different weapons. Life would go on much as it had before, except that we’d have changed some of our names and customs. So whether the rovers won or lost made no real difference.

That’s what happened to the Amorites in Sumeria over 4,000 years ago. They came with their flocks down from the hills surrounding Sumeria and took over. For a while life must have been good for them. But over time they had to turn into farmers just like the folks they ruled. That also happened to the Hyksos in Egypt 3,700 years ago. Same for the Vikings in Europe 1,200 years ago. The Turks in Persia, the Mughals in India, the Mongols in China, the Bantu in Africa, whether they came on foot or by longship, the farm swallowed them all. In short, become a farmer and you must stay a farmer. And anyone not a farmer who tries to make you stop being a farmer must also become a farmer. The only way to stay nomadic was to kill all farmers, keep away from them, or become a herder and trade with them. And every generation there’d be more farmers crowding your land.

As with autocatalysis, that reaction mechanism isn’t special to us. Physicists might call it a phase change. Water, for example, has several phases. In its liquid phase, it won’t expand to fill a room, it’ll dissolve sugar but not rubber, and so on. But all those properties change as it freezes into ice or boils into steam. The advent of farming shows that we too can phase change. As a species, we’re stable if we’re all in one phase or the other—either nomads or settlers. When we’re a mix though, rovers feel pressure to settle. It doesn’t matter whether we like it. It’s irrelevant whether we planned it. It’s unimportant if we even notice it. In time, most of us will phase change into farming. One way of life needn’t be better or worse. Both are just life. But inheritors of early farmers, descendants of their tools as much as their loins, choose not to see that. Instead, they see a wave of change across the world with foragers turning into farmers nearly everywhere. They thus conclude that farmers are ‘better’ than foragers. So they look at any remaining nomads and see ‘savages.’ Then, some later inheritors call them ‘noble savages.’ Both terms are about as sensible as ice calling steam hotheaded, or steam calling water dense.

In sum, we didn’t start to build our current half-urban world 11,000 years ago ‘because we grew smarter.’ Nor did we do it ‘because it was better.’ Farmers weren’t taller, healthier, better fed, or more relaxed than foragers. Nor does it explain anything to say that farmers were ‘less savage’ or ‘more civilized.’ Nor did we look ahead and see that we’d suffer for millennia but still decide to farm. We’re not stupid. Settlement, followed by farming, likely first happened because it was the only choice for some of us at some time. All our other groups in the same position died. Autocatalysis then took over. Once that happened to enough of us in enough places, network effects then amplified its spread until most of us phase changed. We didn’t have to like that, plan it, foresee it, or even notice it. The things we have today, the ways we organize ourselves, the lives we lead, aren’t here because they’re necessarily ‘good.’ They’re here because they are, or were at one time, good at helping us survive. However, once they trapped us into expanding our technology, we spread everywhere until we cultivated even marginal foods. So whenever the next climate change, or plant blight, or other food catastrophe hit, we were always caught with our populations rising. We’ve been hungry a long time.

A Hungry World

Once many of us had phase changed into farming by about 5,000 years ago we began a way of life that then lasted for millennia, and it’s still the norm for about half of us today. For all that time we’ve been trying to make our food supply more reliable. Some of our biggest changes, however, have happened only since the middle ages. Back then, peasant diet varied with the region and the season but in Europe, to choose one particular case, our staples were, and still are, cereal grasses: wheat, barley, oats, rye. We made them into bread or porridge. We also fermented them to make ale, our universal drink. To those we added peas and beans, turnips and cabbages, leeks and onions, and honey. Most of our protein came from eggs, lard, or bacon drippings. Meat was rare. Oxen and horses were more valuable for manure and plowing. Cows were for milk, butter, and cheese. The forest deer were for our manor lords. Instead, as peasants we raised pigs. They can live on kitchen slops, forest beechnuts, and acorns. We built fishponds in the river, and we raised poultry—though not for the meat, but for the occasional egg. Men with swords or bibles took the rest. Most of our extra animal protein went to our lords temporal as tax and our lords spiritual as tithe.

Whether as peasants or lords, we built all our meals around the staff of life, bread. Mold was always a problem. Soft breads wouldn’t keep, so we often baked them into bricks. We didn’t eat them, we gnawed them. The toothless ate porridge. We salted what we could, but salt was so rare that we sometimes used it as money. We also had fresh fruit and vegetables, but only in summer. It was the same for dairy products, except for a little hard cheese and perhaps some salted butter. At year’s end, lacking enough fodder, we killed most of our livestock for winter food. A cow though was also a source of manure for the fallow fields—and thus future hay, and so future cows. Cow flops were also a good fuel source and building material. So we had to balance our yearly cow-killing against the amount of grass we could gather and store before the autumn rains spoiled the hay. Every decade or so we made poor choices, or the weather forced our hand, as when Europe first plunged into the Little Ice Age.

Starting in 1314, Europe then had a Great Famine. It lasted seven years. Triggered by the Little Ice Age, the cold and rain destroyed crops. It also killed both our food animals and draft animals. The poor among us, which was about nine-tenths of us, ate diseased cattle, pets, rats, insects. We ate the leaves off trees. We ate grass. Then all hope died and we began to eat each other. Millions of us died. That famine then worsened Europe’s Hundred Years’ War. Both then worsened Europe’s first visit from the Black Death. Millions upon millions of us died.

But while that was extreme, it was hardly surprising. Widespread famines had come to Europe before in 1257-9, and would come again in 1346-7. Just in the 50 years before 1314, England alone had suffered famine roughly every 11 years. Nor was our famine cycle special to Europe, or even the fourteenth century. In India and China we suffered just as badly and just as often. Everywhere that we could write, roughly every decade or so we wrote about hard times. One poor harvest was just about bearable. Two in a row and food prices went mad. Famine came. Epidemic followed. War wasn’t far behind. Then came pestilence. It was a familiar cycle.

Even without famine, most of us in medieval Europe went hungry twice a year—in the spring, after winter stocks were gone, then in July, the month before harvest. A failed harvest didn’t always mean famine, but it always at least meant hunger. First we foraged for beechnuts, berries, and nettles. Then we ate any older farm animals. Then we ate our future by eating all the rest. When those were gone, we phase-changed back into foragers. We abandoned our homes and tools and roamed the land. We risked death to poach eels from millponds, and squirrels, rabbits, and birds from the lord’s forest. If caught, we might be killed—if the wolves or bears or wild boars didn’t get us first. Granaries were our banks during such lean times, and mold, weevils, moths, and rodents were our eternal enemies.

Food wasn’t our only problem though. Damp and cold killed us just as casually as hunger did. The poorest of us lived in small, dark, smoky huts, which we built of poles daubed with clay, manure, and brush. We roofed them with thatch and covered their earthen floors with straw. We had no chimneys and no windows. At around five feet tall, we were short and bent. Our skin, like a cured ham, was leathery from our household smoke. By 30 we were nearly toothless. Most of us didn’t live to see 35. Dirty and rank, we lived with our livestock and we knew everything about lice, fleas, and dung—and nothing about microbes. One in four of us died before we were a year old. And all of us were always working. We tended the fires, the livestock, the fields. We made food, thread, cloth. We repaired clothes, bedding, cottages. In any scraps of time left over, we sewed or carved something to trade. Our bones from that time show extensive osteoarthritis, spinal deformations, bony growths, and joint enlargements—the result of decades of toil. When we were foragers, to stop walking was to die. Once we were farmers, to stop working was to die.

Of course, our lives weren’t always that hard. For much of the time we managed to stave off outright hunger. When we could control our numbers and the weather didn’t act up, we even feasted. Also, not all of us in 1314 lived hard. A few of us were ladies in pointy hats or knights in shiny armor. But the risks were always there for everyone. With over nine-tenths of us rural, and with many rustics owned by their manor lords, many of our lives were hard. For millennia, and all over the globe, our species lived on that tightrope. Then, a couple centuries ago, a fifth of us left that hungry world. Soon another fifth will have done so. Instead of constantly asking ‘When next can we eat?,’ we started asking today’s big three imponderables: Why are we here? Where are we headed? Do these clothes make me look fat?

That was a phase change just as big as the one that brought us into farming in the first place. How did it happen? Today we tell many stories about it. One of them has it that today’s rich are rich only because they stole from yesterday’s poor. That story makes some sense. The ancestors of today’s rich did indeed steal a lot, and killed millions to do so. For example, in the late nineteenth century, Belgians caused the deaths of at least eight million Congolese and stole literally tons of ivory and rubber. But is that mainly why their descendants are fat today? That story is certainly popular, especially among our poor. It’s also a good argument in the short run. Our rich can indeed steal. Our poor have indeed been stolen from. All our millennia of looting surely made a huge difference. Our rich can also be efficient thieves. Our poor might love to steal well too, but lack the really good housebreaking tools—inside information, numbered Swiss bank accounts, tanks. But the idea makes no sense in the long run. No amount of theft among ourselves can explain the difference in our lives between 1314 and today. All theft can do is rearrange who has what stuff. It can’t make more stuff. Most of what we have today we stole from the universe itself.

Most other animals can’t do that. They always have a carrying capacity; that is, some limit to how much their numbers can rise before dying back to a normal size. That’s true for us too, but we’re nowhere near our limit. Because we invent things and we trade things, there’s no fixed amount of human food. Even something as seemingly simple as our invention of pots changed our food supply. Suddenly we could store more food than we could before. Whenever we make an important new tool—the pot, the plow, the tin can, the train—we can use it to make or store or move lots more food. That works for our non-material tools too: a bank, a credit system, a pension plan. Each of our new tools pushes down our food-to-tool exchange rate. Gazelles can’t do that.

Further, the periods during which that exchange rate stayed fixed—once millennia, then centuries, then decades, and perhaps soon, years—are shortening. That’s happening because beyond a certain point we fell into a new autocatalytic cycle. Like radioactive atoms spewing neutrons, once we had a critical mass of tools, the more we had, the more new food we could make (or store, or move). The more food we had, the more of us there could be. The more of us there were, the faster our tools grew. In some parts of the globe today, our tool supply is now growing far faster than our numbers can, so some of us now worry about being too fat rather than too thin.

In essence then, it’s our tools and trade that determine the amount and reliability of our food supply, not our thefts or threats. Unlike food, a tool is often easy to copy and transport. It, or the ideas behind it, can also last a long time. So it can both spread among us through trade and add up. It doesn’t matter whether that new tool is a new fertilizer, a new vaccine, or a new banking system. One day, our newest tools may grow so cheap that their marginal food-cost may become negligible. We shan’t then need any more new food to produce more new tech. At that point we’ll have left the food economy. We’d be in the technology economy. We’re not there yet, but we’ve already made a vast machine that turns knowledge and tools into yet more knowledge and tools—and, almost incidentally, into yet more food. That machine is an amalgam of all our tools and ideas. To build it we didn’t merely cheat each other. We cheated the cosmos—and it’s far richer than any of us are. We found ways to make more food, to store more food, to trade more food. That’s what many of our technologies do. They reduce our ignorance and enlarge the possible.

But if that’s so, how come we usually don’t see ourselves and our food supply that way? Well, until a few centuries ago, big increases in our food supply used to be rare. Most of the time our supply really was mostly fixed. The only way for me to get more food was to kill you or steal from you. Thus the Belgian sack of the Congo, among many others. That then led to the belief, popular especially among our rich today, that we have a carrying capacity, as gazelles do. More of us—a codephrase for more of us who’re poor—are just a bigger drain on our resources. Sooner or later we starve back to our carrying capacity. But unlike gazelles we can change our limits. We make new tools, and we trade what we have. We band together into a giant swarm, inventing our way out of hunger, even though we don’t plan it that way. We needn’t make our swarm consciously, nor need we make it because we’re peaceful, selfless, caring, or farseeing. We do it because we can and because it benefits us. Trade is the glue that binds us all, and our wit is the weapon we use to carve a place for ourselves on this planet.

Back in Europe’s fourteenth century, travel was so slow and costly that most of our manors there had to be largely self-sufficient. When hard times came we had nothing to do but starve—or make someone else starve. Today, many of us, especially in our richest nations, have forgotten that past. We preach individual, familial, corporate, and national self-reliance just as our manor lords once did. It’s a wonderfully bracing fiction—the frontier life, rugged individuals, everyone for themselves. But in practice, and with rare Robinson Crusoe exceptions, we’ve never been self-reliant. We’ve always worked together. It’s our awareness of, empathy for, and network linkage to each other that distinguishes us from the beasts that perish. We live by each other’s grace.

Seeds of the Future

We’ve changed our food supply a lot over the millennia, but our changes aren’t over yet. Today, 12 percent of us are still chronically hungry. That percentage has halved just since 1970, when 25 percent of us went hungry, but today’s 12 percent is still 852 million of us. That’s about twice as many as all of us alive in 1314. It’s over 200 times as many of us as were alive 11,000 years ago. We also still have famine today. It’s just rarer. When it comes, its effects are also more localized. Mainly it affects our poorest families within our poorest countries. Even in our richest countries, where there’s more than enough for everyone to eat, our poorest can still sometimes starve without enough money—or a gun.

So even though billions of us have now left the hungry world, millions of us are still starving. Today many of us explain that largely as a political or economic problem. We then use the magic word ‘overpopulation,’ as if it explained something. But while gazelles can be overpopulated, we can’t be. What population we can support depends on our tools and we still have far to go before we can’t improve them anymore. Although we don’t think of it that way, our food tech is still too costly and uncertain. To re-imagine our farms though, we must first re-imagine our food, and that means first recalling a little chemistry.

All living things on earth are mostly made of just a few elements. The big four are: carbon, hydrogen, oxygen, and nitrogen. Then there’s a little phosphorus, sulfur, potassium, and so on, then some trace amounts of a few others. A whale, a petunia, Diana Ross and the Supremes, they’re all made of exactly the same stuff. But to feed ourselves we can’t simply down a bucket of carbon and inhale a cubic foot of hydrogen. We need the stuff in particular structures. Glucose, for instance, is one such structure. It’s made of carbon, hydrogen, and oxygen. When digesting it, our body converts it into other structures of the same three elements. All such structures represent information. Arrange a bunch of the elements one way and you get albumin—it’s the chief protein in egg whites. Arrange it another way and you get urea—it’s the chief component of urine. All our foods are thus just particular structures of nine or so atoms. It’s their structure, their information content, that makes one a food and another a toxin. So when we eat, we’re not just taking in atoms for spare parts and gaining energy by rearranging them. We’re also consuming information. Matter, energy, and information—that’s all a lifeform is.

For example, for you to eat a slice of carrot cake, someone first had to get, handle, and transport a carrot seed. That seed contains all the information the future carrot plant will need to build itself. Someone then had to till some soil and plant the seed. The plant then built itself with energy from the sun. It also soaked up matter from its surroundings—mainly carbon dioxide from the air, plus its water and mineral supply. While it did so, someone watered and fertilized it, and protected it from predators, diseases, and competing plants. Then someone harvested it—discarding everything it took months to grow, except its root. Someone then cleaned and bagged that root, and either sprayed it with antibacterials or canned it. It also had to be handled and transported for display and sale. Then it was cleaned and grated. Then cooked. All that took energy. And that’s not even counting the rest of the cake.

That process seems both efficient and unalterable—until we look at it with a chemical engineer’s eyes. Our plants are good at what they do, but what they mainly do is make more of themselves. They use huge amounts of land, water, and energy to rearrange nine or so elements present in dirt, air, and water into more plants. Because they do that, they supply four-fifths of our nutrition. We’d die without them. Worldwide, the average adult human male today consumes about 2,700 kilocalories of food energy a day (an adult female, about 2,000). That’s about the same amount of energy we’d get by burning a pound of coal, which would cost about one U.S. cent. But it costs our species far more than that to feed ourselves today because our current food tech is vastly inefficient.

Take one of our crop plants at the equator. It uses less than one percent of the sun’s energy reaching it. It often doesn’t even bother to capture that much. Of what little it does capture, it uses about half that just to transpire water from its leaves, which is how it keeps its sap flowing upward. Its problem isn’t too little energy—it’s too much energy, and too little of either water or carbon dioxide. It needs carbon dioxide to make its carbohydrates, but carbon dioxide is scarce in the atmosphere. It also needs water to move minerals from the soil to its cells—plus about one percent more for photosynthesis. Any more energy than it can use is wasted. So a plant isn’t good at capturing the sun’s energy—it’s good at avoiding the capture of the sun’s energy. It throws away over 99 percent of the energy it might have used. We’re no better. We only get to eat about one percent, or less, of that. That’s because we discard around 93 percent of the average plant as inedible. Of the remaining seven percent, we eat only about 13 percent. We use the rest to seed, nourish, protect, harvest, transport, prepare, and sell those edibles. In sum, between our plants’ wastefulness and our wastefulness, when we eat a plant product today we’re failing to capture at least 99.99 percent of the energy that the plant originally got from the sun.

Said that way it’s clear that our food supply is inefficient. But we worsen the inefficiences beause we like to eat animals too. Making animal protein the way we do today means yet more waste because all animals eat food only as soup. That, for example, is what our body turns all our food into before it can use it for anything. Eating an animal or plant is like taking jackhammers and blowtorches to a jet until it’s in bits so fine you could draw them through a straw. Then we use its flecks of metal and plastic for spare parts and its jet fuel for energy. All the jet’s intricate parts, like its engines, which took so much energy to build, get pulverized into tiny pieces. Digestion is inherently wasteful. So when worms eat plants, then chickens eat worms, then we eat chickens, at each step we’re losing energy. We’re eating something whose plant equivalent could’ve fed at least ten of us. Thus, often when we eat an animal today our species loses at least 99.999 percent of all the energy we get from the sun.

To compensate, we add even more energy. For instance, on the Canadian prairies an acre of wheat annually needs about 80 pounds of nitrogen fertilizer. So we inject into the earth about 1.6 million kilocalories of energy per acre per year. That’s not counting the cost of phosphorus, sulfur, and potassium fertilizer. Nor does it count the diesel fuel we burn for tillage and transport. Processing our food burns yet more energy. It costs three times as much energy to put a can of applesauce on a grocery shelf as it does to put the same amount of apples in the produce department. It takes 15 times as much energy to make a bag of potato chips as it does to make an equal amount of potatoes. Plus, managing all that takes the effort of at least half of our entire species. Our current food supply is very wasteful.

If we’re to change how we think about farming we must first change how we think about plants. To an engineer, a plant is a self-building factory. It takes in dirt, water, air, and sunlight and builds parts: a structural shell (its stem); pipes, filters, and hydraulic pumps (its vascular bundles); storage bins (its roots); and solar cells and gas exchangers (its leaves). It also builds a reproductive mechanism (its seeds). Those seeds can build yet more factories. They’re factory-starters, rich in the building materials that future factories will need to start building themselves. They serve to transmit matter, energy, and information into the future.

A few of those factory-starters—grains, legumes, tubers, and such—are so big, so easy to harvest, so easy to store, that it’s worth our while to eat them alone. Sometimes though, we instead eat the factory’s solar cells, as in spinach and lettuce. Sometimes, as in celery and asparagus, we eat its shell and hydraulic system. We might also eat its extractors and storage system, as in carrots and radishes. Or we might eat its outer casing (sassafras and cinnamon), its hydraulic fluid (maple), its capsule casing (dandelion, nasturtium, pansy), or the whole thing (sprouts and mushrooms—although a mushroom is a fungus, not a plant). When we eat a plant, we’re eating a factory.

Seeing plants as factories helps us see our farms anew. Today, we protect our little green factories by aerating and nitrogenating their mineral supply. We also raise their phosphorus and potassium supplies. We raise and control their water supply. And we separate them so that they don’t have to compete for such supplies. In short, when farming today, what we’re really doing is manually injecting our intelligence into a plant’s lifecycle. In the future we might pack all those smarts into the plant’s seed itself.

For example, every plant needs nitrogen to make its proteins and genes. We need it for the same reason. Nitrogen makes up 78 percent of the earth’s atmosphere. You’d think it would be easy to get. Not so. Most plants are such saps that they never figured out a way to capture it. So for them, nitrogen alone is useless. They can only use it in the form of ammonia or nitrates, and those get made only rarely (fire, lightning, rock weathering). Plus, once made, they dissolve easily. So it’s lucky for plants that animals concentrate nitrogen in their bodies. To a plant, an animal is a walking bag of nitrogen (and carbon dioxide). That’s why corpses, urine, and dung make such good fertilizer. So when we fertilize a plant, we’re mainly giving it more nitrogen. But we may not need to do that forever. Legumes, like peas, soybean, and clover, long ago found a clever way out. As symbionts, their roots make a place for nitrogen-fixing microbes, which makes them protein sources. And that’s where we get most of our protein today. We all make meals by pairing proteins with carbohydrates: soy and rice, bean and maize, lentil and potato. (And of course, bangers and mash, burger and fries.) So one day we might remake our cereals to extract nitrogen as legumes do. If so, we’d no longer need fertilizers. There are many more ways we could change our food plants as we learn more about their genetic heritage.

Such smart seeds would change us, just as mutant grass seeds changed us 11,000 years ago. For one thing, we’d need far fewer farmers. Our use of fertilizers, herbicides, insecticides, and fungicides would also drop. Also, more of the cost of farming would fall to the cost of the planting and harvesting machines, and the cost of the seeds. They, in turn, would cost more as they take more effort to debug and become more efficient at feeding us. Seed piracy would also grow since the biggest cost would then become that of designing the seeds in the first place. Real estate prices would also change as smart seeds change the meaning of the word ‘arable.’ We would also, no doubt, make many mistakes. We might even cover the planet in a new superweed, like kudzu. The effects of moving from plant farming to seed programming would be immense. Much of the planet’s biomass would turn itself into our food. But however smart our future seeds get, they’d still need much land, water, and energy. Even a smart plant is still a stupid food factory.

The Food Factory

Genetically engineered seeds are already here, in early form, but we’re still not anywhere close to the end of our millennia-long sequence of food supply changes. In both our rich and poor countries today, our farms are, by far, the biggest modifier of our world. That’s because of the sheer amount of land and sea that today’s farming needs. Across the globe we give 4.4 billion acres to our crops, and 8.1 billion acres to our livestock. That’s about two-fifths of all available land area on the planet. We’re now losing about 15 million acres of primary forest a year. Farming on land and sea, far more than our cities or industry, destroys the habitats of millions of species. They’re now going extinct at the rate of perhaps 100 a day. Nine-tenths of all big predatory fish—including tuna, cod, and halibut—have vanished from the continental shelves just since 1950.

Our farms, no matter how ‘organic,’ are also, by far, our biggest water user. Our food, just as our body, averages about 65 to 75 percent water by weight. Most fruits, for instance, are 90 percent water. A pound of wheat needs 120 gallons of water to grow. A pound of rice, 144. We don’t see our foodstuffs that way, but they, and we, are mostly just bags of water. So when we grow food we’re mainly making tasty water. (Which we then turn into soup....) But we need a lot of water to do so because our plants need the stuff to run their sappy conveyor belts. Each of us drinks about a gallon of water a day, but the food we eat that same day could have needed up to 1,250 times as much water a day to grow. Growing the ingredients for a simple loaf of bread may have needed more than two tons of water. Thus, of all the water our species uses, we use ten percent at home and 20 percent in industry. Our farms gulp 70 percent. Plus, both homes and industry return up to 90 percent of water used. Farms return only 30 percent. Most of the rest is lost to evaporation.

Today’s food tech is thus a slow, destructive, expensive way to turn matter and energy into food. Will that ever change? Predicting the future of food is even harder than that of farming alone. It’s hard to step out of our place in time and distinguish between a thing and its function. Take your refrigerator. At first glance, it looks like it mainly keeps your foodstuffs cold. That’s wrong. Mainly it keeps them fresh. Today we use cold to do that, but a device that slows decay with radiation, drying agents, or electromagnetic fields, would turn our iceboxes into food closets. But such a change would have to wait until we better understand the proteins that make our food. And for that we need to understand a bit of molecular biology.

Until recently, we’ve focused on the genome—the list of genes that specify proteins in a cell. But it’s proteins that act. They build things, break things, move things, notice things, signal things. Over half our body’s dry weight is protein. (That’s why nitrogen, which makes up a big part of all proteins, is so important.) Identifying and classifying genes is called ‘genomics.’ Identifying and classifying protein function and relation is ‘proteomics.’ In a way, genomics is like building phone books: we’ve now figured out a long list of names (genes) and phone numbers (proteins those genes code for). We now have such phone books for hundreds of lifeforms, from viruses to fruit flies to us. Those phone books, however, so far only have a white pages section. To make sense of a lifeform we also need its yellow pages—we need to know what all those proteins do. Before we dial a number we want to know whether we’ll be calling a plumber or a hairdresser. That way we can start replacing one set of numbers with another.

That’s important because, like a plant, a single cell is a self-building factory. It makes whatever its genome tells it to make. If we change its genome we can get it to make new things. So if we knew what we were doing, we could make a microbe that eats plastics, thus making our plastics biodegradeable. We could also make one that cleans up oil spills. Or one that clears arteries. Or one that makes meat.

Figuring out how to do that is hard, but we have one irreplaceable tool to attack it—the computer. The problem is mainly that of teasing apart the effects of thousands of proteins interacting in giant catalytic networks in the cell. It’s a bit like crashing a big party and identifying circles of friends by seeing who talks to whom, then watching each circle to see who gossips most, and what the topics are. (It’s not really that easy. For example, topics can change depending on nearby topics; but you get the idea.) So once we understand how a strawberry plant works, we could start thinking about building one from scratch. Then we might modify it to make something that no strawberry plant has ever made—raspberries. Or potatoes. Or steaks.

Mere science fiction? Well yes, but we’ve already redesigned many microbes. We’ve remade some to use artificial amino acids to build new proteins. We’ve built viruses from scratch. We’ve changed cells to build themselves simple digital circuits. There’s no reason we couldn’t one day change cow cells so that they make a hunk of cow—without a cow. The hard part will be to make a life-support system for such artificial genomes to copy themselves in. Once that’s done, we’ll make such things by the vatful. But we’ll take a long time to figure it out. Before we do, we’ll likely steal a ready-made support system from somewhere: perhaps a strawberry plant. Once we do, we might start building a general food machine.

Today we think we’ve industrialized our farms, but all we’ve really done is mechanized them. We don’t make our food. We watch it being made by a large, automated factory we call the earth. We fiddle with its knobs and dials, but mostly it does the job for us. Only now do we know enough about genes to begin to make our own food, and that can’t happen overnight. Whenever our first food machines arrive, whatever they’ll look like, they’ll be prototypes. They’ll be too costly, awkward, or unsafe for the home. So at first they’ll likely only shift a little food production from farms to factories. Thus, just as we once shifted from wearing cotton and linen to plastics, so might we shift from growing potatoes to extruding potatoes. And just as with our first plastics, those potato factories might first shape their products to look just like natural potatoes. But one day we’ll get used to potatoes that come from a factory. New potato styles—new colors, textures, shapes, sizes—won’t scare us anymore. There’s no reason that meat factories can’t follow. One of the new foods may even fill a hugely desirable niche, as did nylons—whose only natural equivalent is expensive silk stockings.

Most of us needn’t even notice the new food factories at all. We’d continue to buy our food in grocery stores and markets. It’s just that the store would get some of its food from a factory rather than a farm. Sounds crazy? It’s already happened. Quorn, for example, is a cheap fake meat made from vats of fungus. And we’re already planning to make vat-grown pork from pig stem cells. Today, such meat-sheets would cost over $1,000 U.S. a pound, but one day that price might drop to $1 U.S. a pound. Food builders might then hop from factories to stores. Limited use in rich homes would then be just a question of time. The word ‘homemade’ would then gain a whole new meaning. As with the farms before them, our first food factories might then either go bankrupt, or shift to foodstuffs still outside the grasp of most home food machines. There would also have to be a whole new class of factories to build the new home food machines in the first place. Our fridges might then stop being food-storers. They’d become food-makers.

One day a fridge might even become something that some of us might call a ‘food machine.’ Perhaps it’ll be a plant-like device. Maybe it’ll even look like a strawberry plant. It might grow in a bucket that you plug into a wall socket and fill up weekly with water and minerals. As a byproduct, it might make oxygen, as natural plants do. Such food machines might even go into our spaceships. Dirt farmers may become increasingly weird atavists. Perhaps they’ll grow only the bulk plant-products we need for fibers, fabrics, paper, rubber, spices, and livestock feed. But even they could use the new machines to make such things. If that’s our future, our whole farming industry, from dairies to rubber plantations to fisheries, might well one day simply go away. And half our species would then be free to do something other than farming.

When we think about the future we often imagine that just because things have gone a certain way for 11 millennia that they must continue that way for 11 more. It’s a pity that more of us don’t think about just how strange the world is. If we did, we’d start thinking bigger than we’re used to. We might, for instance, imagine a future world where we’ve built cheap, hardy, rust-proof food machines that make meat from grass, or sweets from flowers, or fruits from dirt. If we knew enough, there’s no physical reason we couldn’t one day build such devices. Not only that, we might even build them so that they could repair themselves, or move around to find new inputs for themselves, or keep themselves out of harm’s way. We might even figure out how to let them reproduce. With such devices all we’d have to do is let them loose in a field of grass, garden of flowers, or patch of dirt and come back every now and then to harvest them. Why not? We already have such devices—we just didn’t make them. We call them cows and bees and strawberry plants.

By now, you’re probably rolling your eyes. Or you’re already on the phone telling you friends about this ludicrous idea. It’s loony to think about such a stack of possibilities today, isn’t it? Even if it were to happen, it would take centuries. Right? But what if food machines started showing up a few decades from now? Their existence depends on how much computational power we can muster, and that’s speeding up right now. Of course, even if they do come to exist few of us would rush out and buy such a thing. It’s too alien. It could break in all sorts of new and exciting ways. We won’t be prepared for any of them. It won’t happen tomorrow either; nothing does. Further, food snobs would continue to buy hand-grown food. Elites would continue to pay enormous sums for salted fish eggs. And connoisseurs would continue to drink hand-made fermented grape juice grown only in specially blessed earth. But bit by bit, as our computers continue to gain power, our vast fields of energy-wasteful crops may well wither away.

Once upon a time we invented pots to protect grain from rats. Then we found that we could also use them to make porridge. (Or perhaps it happened the opposite way.) Our teeth-breaking ended and our food stores grew. Just so might our fridge one day morph from ice-making to food-making. If so, its name would change as its uses and appearance change. Kids growing up with it won’t think of it as a ‘food machine,’ despite what their clueless parents might say. Nor would they think of it as a ‘refrigerator,’ regardless of what their even more clueless grandparents might say. As for the ‘icebox’ of their great-grandparents, they may not even understand the reference. Instead, they may think of it as a smart tree. They’ll compare it to things that look and act similarly, which may be apple trees or tomato plants, not washing machines or air conditioners.

A wise technocrat would stop talking now, but let’s press on out of science and engineering and see a little of what such a change might mean because nothing that large happens in a political vacuum—and if it does happen it’s sure to have economic consequences. First off, it still wouldn’t mean food utopia. For one thing, food machines, as partly digital devices, could crash. They could also be hacked. Also, even though they might live in kitchens and not gardens, as food sources they’d still have pests. Mice and roaches and microbes would still be hungry. Such a device might defend itself better though, since it could have digital pest sensors. Or perhaps it’ll just live inside a fridge. It needn’t need sunlight. (It plugs into a wall socket, remember?)

Further, such devices would bring wrenching change in the short run. Our present food producers won’t stand for that. They’ll fight that possible future, just as foragers fought farmers in the long ago. The whole food handling, processing, and distribution business would also be rigid with fear. They’re sure to lobby against any change, taking to the streets to warn us about the new frankenfoods. So politics, not science, would decide if food machines become widespread. Further, in countries with good distribution networks, economies of scale may well work against home food machines. After all, they do just that today for water and power. Few of us have our own wells or generators; it’s often far cheaper to centralize production then distribute its results. So economics, not engineering, would decide whether our future food machines might become more like power stations or more like washing machines. Finally, once food machines exist, someone, somewhere, will hack one. They’ll then use it to make homemade cannabis, cocaine, heroin—or gunpowder, gelignite, nerve gas. A food machine is really a disguised organic matter converter. It needn’t only make food. So legal and military needs would also matter.

So despite today’s climbing birthrate, rising urbanization, and wasteful farms, a food machine may still take us many decades to make—if we ever make one at all, that is. Although we’re most likely to need it in poor countries we’re most likely to create it in rich ones. And what’s the incentive? Today, food is a nearly negligible cost for our rich, but it’s still a huge cost for our poor. For example, average food cost in the United States is now around ten percent of income. In Eritrea, a former province of Ethiopia in Africa, it’s as much as 71 percent. Those of us who most need food machines can’t afford to make them. And those of us who can, don’t care.

But wait, we all care about starving babies, don’t we? Well, we sure say we do. But our rich also care about being too fat and that’s what we’re more likely to work on first. We also live with massive network effects related to food. Our rich nations already have a reliable food supply, and they’ve built a huge toolbase to ensure it. They’ve costly machines, trained farmers, and extensive credit systems. Those support huge equipment purchase and training, and vast storage facilities and transport networks. Add to that many schools and research institutes. Then add fast, long-range communications, and a wealthy and stable—and literate—home market. Our poor countries have little of that installed base. They also have less incentive to increase their food productivity since they couldn’t sell more of it abroad anyway. Rich countries won’t let ’em. Tariffs, quotas, subsidies, and dumping duties shut out foreign competition. We’re thus likely to make vast quantities of expensive, empty food—fat-free, calorie-free, taste-free—long before we make vast quantities of cheap, nutritious food.

Even so, what may happen around the world isn’t clear. For example, many peasants in our poor countries today lack property rights to their land. They’re already at the mercy of rich absentee landowners, who might choose to replace them with food machines. Also, a big and rapidly industrializing country—China, India, Brazil, or perhaps even Russia—may choose to spend the resources needed to invent food machines. They’d be more quickly freeing their people from the soil. A food machine might also fall out of research aimed at something else entirely. Sounds unlikely? Our first artificial fertilizers fell out by mistake when a French chemist tried to make cheap diamonds, a Canadian inventor tried to make cheap aluminum, and two German dyers tried to extract gold more cheaply. None of them planned to make fertilizer.

Finally, as the years pass, the technology behind food machines won’t stay there. It may enter our bodies. Some of the beings living off of a future food machine might be wearing bodies that look human, but they may be much modified from ours today. By then, some of us might have even remade our bodies to carry plant genomes. By carrying the full carbon cycle within ourselves, we’d end forever even the potential for hunger. If so, such beings wouldn’t need to eat. They’d also be wholly independent of nearly all of our planet’s vagaries. Perhaps they may sun themselves every morning and plug themselves in at night—the new couch potatoes. While doing so they might well wonder how we today could ever have been so barbaric as to kill and eat another living thing, animal or plant.

The Later Middle Ages

Today half of us live in cities and over a billion of us live in relative comfort. By 2015, another half-billion of us will likely have drawn ourselves up to that level of comfort. We’re doing well, all things considered. However, after millennia of business as usual our food technology might well change a lot this century. First off, our information tools, particularly computers, are now rising fast. We’re now learning a lot. That’ll give us new options. We’ll need them too because our species is heading for a peak population of roughly nine billion by 2050. For every three of us today there’ll be four of us by then. We’re not only increasing our numbers, we’re also increasing our incomes, and thus our overall energy demands. As our big and poor nations fully industrialize our wasteful food may become too fuel-expensive. Oil prices, at least, are certain to spike. Within a few decades we’re likely to enter a fuel crunch. We’re also now finally leaving the agrarian age that we started entering 11,000 years ago. Half of us are urban today, and more of us are quickly becoming so. We’re beginning our urban age. And the autocatalysis that’s phase-changing us into urbanites today is much the same as that which drove us to become villagers millennia ago.

Roughly speaking, our species today is about where Britain was in 1813, or where the United States was in 1880. That’s when farm labor first fell below half the workforce in those countries. It took another 40 or so years, till 1851, for most of Britain to become urban, and, similarly, till 1920 for the United States. So, by 2040 or so our species may be two-thirds urban. By then many more of us will be relatively rich, but billions more of us will be alive. Food demand, and thus land, water, and fuel demand, will all peak together. Large, long-term network trends are converging on a point somewhere not too far in our future. We’re nearing a crisis point.

Chances are we’ll survive it. We’ve already changed our food supply a lot. In 1998 Eritrea was one of our poorest countries. By today’s standards, three in four of us there were undernourished—the highest figure in the world at the time. Yet Eritrea in 1998 ate better than France did in 1705. Similarly, India in 1998 ate better than Britain did in 1850. Today, we live about ten years longer than we did just 30 years ago. Since then, our proportion of poor has dropped, our average income has doubled, our infant deaths have halved. Over four in five of us in poor countries now have at least adequate diets. In our poor countries from 1961 to 1992, our per-person daily kilocalorie intake jumped by a third even while our population doubled. By 2015, over half a billion more of us will join the world’s middle class. We’re doing better materially than we ever have, but we’re also straining our resources, given our current tools.

So one day we’ll again change our food tech—or we may again face famine and cannibalism, even in the richest fifth of our planet. Perhaps we’ll run out of one of our presently cheap resources. Or maybe we’ll suffer overly abrupt climate change. Or perhaps one of our clever genetic trials will go wrong and blight one of our chief cereals. (Rice alone feeds nearly half of all of us alive today.) Even with our paltry information tech today though, we have a far better chance now than before of seeing our next food calamity coming. Europeans in 1314 had no warning before some of them had to rob graves and eat their dead. Our swarm is now much bigger and stronger. Perhaps that’ll be enough for us to make new food sources before disaster is full upon us.

Or perhaps not. Maybe we won’t let ourselves see that our food supply is too wasteful, or that we can change it, until it’s too late. And even when we finally start to change it, we might simply prepare for disaster rather than try to solve our real problem: wasteful food. Why not? It’s happened many times before. For example, in China from 1958 to 1961, we let political insanity and bad weather kill 30 million of us. Villagers didn’t want to have to kill and eat their own children. So they swapped them with each other. As many of us died in China then as were alive in all of northern Europe in 1314.

Taking the long view though, famine management is part of a vast pattern of change going back at least to the beginnings of human settlement. From the moment that someone thought that certain grass seeds weren’t half bad when pounded and baked, we entered into a covenant with the soil. It hasn’t ended. Everyone whose hands have dug a yam or carrot out of black earth knows that. That covenant goes both ways though. Since at least the first ragged flint sickle tore through a sheaf of wild grass 11,000 years ago we’ve shaped our plants and they’ve shaped us. Pots to hold grain, granaries to hold pots, potters to build pots, masons to build granaries, soldiers to guard granaries, metal weapons for the soldiers, miners to get the metal, smiths to shape it, artists to decorate it, priests to bless it, raiders to steal it, more priests to pray for more pots and bigger granaries and fewer raiders, rulers to gather the surplus grain and feed the soldiers and priests.... Each step set up the next. We didn’t know where we were going, and we didn’t know what we were doing. Every change had a cost—often bloodshed, sometimes genocide—but always pain and dislocation. The strong often fought each change, and the past often fought the future. The weak usually only saw the sword or the whip. Each change also had ongoing costs, even after the pain of the change itself had smoothed away. Nuclear power plants have problems, but then so do hydroelectric dams. Trucking food around creates pollutants, but oxcarts have problems, too.

Unable to see into the future, we’ll always be like that. We change things around us for our own local, selfish, and short-term reasons, not knowing what their long-term network effects will be. The industrial phase change that gave us tractors, for example, had nothing to do with farming. As much as anything else, it started with trying to pump water out of Cornish tin mines. Our first tin can wasn’t made of tin—it was a champagne bottle. We got it when a Parisian cook found a new way to preserve fruits for his candy business. Our first fridge had nothing to do with preserving food. It started with trying to cure malaria in Florida. We’re always stumbling into our future, and mostly we’re looking at our sore feet, not the distant horizon. It’s always been so. It’ll always be so.

However our changes started, though, and for whatever goofy reasons we forced them through at first, many changes that our swarm let persist reduced our uncertainty about our food supply. A drought in northern China in 1877-8 killed between 9 and 13 million of us. Half a century later, famine came again. It was the most severe drought there in two centuries, yet, despite our larger numbers, and our usual bickering and muddle, only three million of us died. The earlier famine showed that far worse was possible. The railroad and the telegraph helped make the difference. Neither originally had anything to do with famine.

Until recently, change for us has nearly always been gradual, unforeseen, fitful. But such unintentionality is too untidy for us. So we ignore it. Instead, we make up stories about our past. We tell ourselves that we did it all deliberately and that everything was always heading to the here and now. That stance has emotional value. For instance, our history books often say that once we settled down 11,000 years ago we were no longer ‘forced to roam,’ as if roaming were a silly thing to do. Since we spent at least 40,000 years doing it, we must have been too stupid to see that farming was ‘better.’ Conclusion: our forebears were as dumb as a bag of rusty hammers—and we today aren’t. Even our science can be tinged with such stories. Four-limbed animals first colonized land about 360 million years ago. Many of our biology texts still couch that event as ‘the conquest of land’ or ‘the liberation from water.’ But what slavery was there in water? And did four-limbed animals really take away the land from the six-limbed and eight-limbed? There still are quite a few insects and spiders about.

We tell such human-centered, today-centered stories not because they’re true but because they give those of us alive today meaning and importance. If they were true, then we today must be the purpose of the universe. Thus, when looking back we often think we see a drama—sometimes a comedy, more often a tragedy, but always a simple story with vast and satisfying movements toward a dramatically pleasing end. Snipping and folding, embossing and rearranging, we made that story out of what to us at the time was merely a train of events. Stapled to one point in time, we look back and judge our parents by our standards, not theirs. And if we look ahead, it’s only to imagine that our children will live just as we do today.

We thus label an era the ‘middle ages,’ a name that says more about us today than it does about us back then. It’s a name as relative as place names like the Middle East, and it’s a name that those of us alive at the time surely didn’t give to our age. Back then, we didn’t think of ourselves as merely a way station on the road to today. Then, just as now, we thought we were the purpose of the universe. So just as we today look back in sardonic wonder on our lives in the middle ages, so too may our equally self-centered descendants write smarmy critiques of today’s way of life. They may pen endless diatribes about our wasteful farming, our pathetic industry, our limited knowledge—today’s equivalent of pointy hats and shiny armor. They may craft smug histories of our immense ignorance, bizarre beliefs, disgusting habits, appalling manners, and our short, ugly, boring, and pointless lives. By then, the technological juggernaut that they dwell within may well have catapulted their power over nature so far ahead of ours today that they’ll think of those of us alive today as savages. Perhaps they’ll rename today’s whole age—from around 1750 to this evening—the ‘later middle ages.’ All that will let them look down on us early-twenty-first-century, mobile-phone-clutching, half-urban savages. Maybe, if we’re lucky, they’ll call us noble savages.