Sometime in the 1980s, an unprecedented change in the human condition occurred. For the first time in known history, the average person on Earth had enough to eat all the time.
Depending on their size, adult humans need to take in about 2,000 to 2,500 calories per day to thrive. For as far back as historians can see, a substantial number of Earth’s inhabitants spent much of their lives below this level. Famine and want were the lot of many — sometimes most — of our species.
Even wealthy places like Europe were not protected from hunger. France today is famed for its great cuisine and splendid restaurants. But its people did not reach the level of 2,000 to 2,500 calories per day until the mid-1800s. And even as the French left famine in the rear-view mirror, starvation was still claiming hundreds of thousands of Irish, Scots, and Belgians. As late as the winter of 1944–45, the Netherlands suffered a crippling famine — the Hongerwinter. More than 20,000 people perished in just a few months. Food shortages plagued rural Spain and Italy until at least the 1950s.
In poorer regions the situation was bleaker still. The United Nations created the Food and Agriculture Organization in 1945. One year later, the FAO issued the World Food Survey, a forty-page report that was the first-ever comprehensive attempt to measure what the world ate. Half the Earth’s inhabitants, it reported, subsisted on fewer than 2,250 calories per day. Globally, just one out of three people had clearly adequate diets.
Worse, many believed, humanity’s rising population meant that the task of feeding everyone would get harder. Between 1950 and 1990, human numbers doubled, from 2.5 billion to 5 billion. (The figure is now more than 8 billion.) So overwhelming seemed the task of providing for all these people that a stream of bestselling books argued it was impossible. The most famous warning — The Population Bomb, published in 1968 by Stanford ecologist Paul Ehrlich — began with a stark statement: “The battle to feed all of humanity is over.” The book promised that “hundreds of millions of people are going to starve to death” in the 1970s because farmers would not be able to grow enough food. No matter what we do, Ehrlich wrote, “nothing can prevent a substantial increase in the world death rate.”
But hundreds of millions did not starve to death. The world death rate did not substantially increase. Instead, harvests rose — and have kept rising. By the 1980s, farmers were producing so much food that the global average food consumption had reached 2,000 to 2,500 calories per day, a landmark in history. Today the average is closer to 3,000 calories per day, and the emerging problem is obesity — too much food, rather than too little.
The picture is not wholly rosy — still do not get enough to eat. But hunger today is generally due to low incomes and poor food distribution, rather than failing to grow enough food. Farmers produce enough for everyone, but not all get what they need. Still, our daily lives are nothing like those of previous generations.
What happened? Modern agriculture.
Farming is one of our species’ oldest activities, dating back roughly 13,000 years. About six thousand years ago, farmers began using draft animals — horses, oxen, and so on. For millennia after that, what farmers did in their fields changed little. But in the 1960s and 1970s, in what is called the “Green Revolution,” research scientists, government agencies, agricultural businesses, and farmers themselves put together a new, strikingly more productive version of agriculture — Farming 2.0, if you will.
Today, Farming-2.0-style agriculture — which began with innovations in field crops like wheat but spread to other parts of farming, such as cattle ranching and chicken-raising — is by almost any measure the world’s most critical industry. It is directly responsible for our daily bread. But despite its overwhelming importance, Farming 2.0 is in many ways unknown to most of us, because it has been so smoothly successful that we have almost no picture of the underpinnings of the vast system that provides us with breakfast, lunch, and dinner. Too few have any sense of its scope, what brought it into existence, and in what ways it will need to change.
Its scale is staggering. Some 40 percent of our planet’s land is covered by cropland and pasture, the overwhelming majority of which is devoted to this type of agriculture. Increasingly, the farms themselves are huge — one in China covers 22 million acres. And they are supplied and their products processed and shuttled about the world by a web of gigantic multinational companies — Cargill, BASF, Wilmar, Archer Daniels Midland, and others. Supervising this enormous network of production and exchange are agricultural agencies in every world government that set rules for and inspect what farmers produce and sell. The result of this huge, global system is on display in every supermarket. The gleaming arrays of highly networked international goods — fruit from Peru, pasta from Italy, sugar from Brazil, vegetables from the Netherlands, condiments from China, coffee from Ethiopia — that line the aisles would have astonished our grandmothers and great-grandmothers.
All of this was brought into being by the Green Revolution. In its simplest form, the Green Revolution was a mix of two ancient technologies — or, rather, modernized versions of them — and one brand-new science. The old-but-updated technologies were fertilization and irrigation; the new science was genetics. Combining these three into Farming 2.0 was, arguably, the most important event in the twentieth century — it literally reshaped the face of the Earth.
Fertilization is the older of the two old technologies. People have known for at least 8,000 years that adding organic substances — notably, animal feces and urine — to the soil helps crops grow and flourish. But for almost all that time nobody knew why manure is good for crops. Only in the first decades of the nineteenth century, in a scientific breakthrough, did several German researchers discover that plant growth was controlled by the amount of nitrogen they take in through their roots — and that manure and every other type of fertilizer work principally because they add nitrogen to the soil.
Without nitrogen, plants cannot perform photosynthesis, the process by which they capture power from sunlight and carbon dioxide from the air to drive their growth. More technically, plants primarily need nitrogen because it is an essential constituent of rubisco, the molecule at the heart of photosynthesis. Like military recruiters who induct volunteers into the army and then return to their desks, rubisco molecules take carbon dioxide from the air, insert it into the tangle of chemical reactions that makes up photosynthesis, then go back for more. Rubisco’s facilitating actions are the limiting step in photosynthesis, which means that the rate at which rubisco functions determines the rate of the entire process. The more rubisco, the more photosynthesis; the more photosynthesis, the more crop growth; the more crop growth, the greater the harvest. For a plant, putting nitrogen in the soil is a bit like recharging the batteries that its cellular engines draw upon.
At first glance, the notion that soil could somehow be short of nitrogen seems odd. Nitrogen makes up more than three-quarters of the atmosphere. How could it be in scant supply? The reason is that more than 99 percent of the Earth’s nitrogen is in the form of nitrogen gas. Nitrogen gas — N2, in chemical notation — consists of two nitrogen atoms bound together so tightly that plants’ cellular machinery cannot split them apart for use. Instead, plants can absorb nitrogen only when it is combined with other elements, such as hydrogen, carbon, and oxygen, into compounds that plants can break up.
Scientists refer to the process of creating usable nitrogen mixtures as “fixing” nitrogen. In the soil, nitrogen is mainly fixed by microorganisms. Some break down organic matter, making its nitrogen available to plant roots in easily digestible forms. Others, such as the symbiotic bacteria that live around the roots of clover, beans, lentils, and other legumes, use clever biochemical tricks to break apart nitrogen gas and change it into compounds that plants can take in. A small amount is fixed by lightning, which zaps apart airborne N2 molecules, after which they combine with oxygen into compounds that dissolve in rainwater.
In the mid–nineteenth century, some of the same scientists who had discovered nitrogen’s essential role in photosynthesis realized that factory-made nitrogen compounds — chemical fertilizers — could substitute for manure. The trick was to make those artificial compounds. And the key to making them, chemists believed, was to learn how to manufacture ammonia — the same substance that is in ordinary household ammonia today — as a precursor, because they knew that ammonia could be easily transformed into the kind of nitrogen-containing substances that plants can absorb.
Chemically speaking, ammonia (NH3, to scientists) is simple: one nitrogen atom and three hydrogen atoms, arranged in a rough pyramid. Researchers had long known how to get pure hydrogen — the H in NH3 — from hydrogen gas. But, like plants, they were unable to pry apart N2, nitrogen gas, to make NH3. Decades of attempts to make synthetic ammonia failed.
Early in the twentieth century, a German scientist named Fritz Haber found that he could break up nitrogen gas by heating and compressing it in the presence of special alloys that catalyze — facilitate — the process. The catalyzing alloys were Haber’s special contribution. Building on Haber’s work, a German chemical engineer named Carl Bosch then figured out how to produce ammonia on the industrial scale needed for farmers’ fields. Both men received Nobel Prizes.
The prizes were richly deserved; the Haber–Bosch process, as it is called, was arguably the most important technological development of the twentieth century, and one of the most consequential human inventions of any time. It made it possible to win “bread from air,” as the German physicist Max von Laue wrote in an obituary of Haber.
Because Haber and Bosch completed their work in the run-up to the Second World War, the Haber–Bosch process was not widely deployed until after the fight was over. The first leg of the Green Revolution — the first part of the rise of Farming 2.0 — was for countries across the world to build fertilizer factories.
Today more than 1 percent of the world’s industrial energy is devoted to making ammonia fertilizer. “That 1 percent,” the futurist Ramez Naam says, “roughly doubles the amount of food the world can grow.”
Increasing the food supply fostered an increase in human numbers. The energy scientist Vaclav Smil has calculated that fertilizer from the Haber–Bosch process is responsible for about 40 percent of the world’s dietary protein. Roughly speaking, this is equivalent to feeding 40 percent of the world: about 3.2 billion people. More than three billion men, women, and children — an incomprehensibly vast cloud of dreams, hopes, and fears — owe their existence to two obscure early-twentieth-century German chemists and the fertilizer industry they spawned.
Equally important to Farming 2.0 was the second leg of the Green Revolution, irrigation. Irrigation dates back nearly as far as fertilizer — the oldest known example is from about 6000 b.c., in the Jordan Valley, which lies between Israel and Jordan. But it sprang up independently in many places, from ancient China to ancient Mexico to ancient Zimbabwe.
In every one of these places, the basic concept was simple: divert water from a river or lake above the farm into its fields, watering the crop. But irrigation was difficult to establish in most areas, because those rivers and lakes are typically lower than the farmland around them, and water doesn’t flow uphill. Mechanical pumps to extract water from wells, over riverbanks, and up slopes did not exist until classical Greece — the famous mathematician Archimedes is known for one especially useful type, a screw — and high-capacity pumps were unknown until the Renaissance. But even when better pumps became available, so much energy was required to pump the volume of water necessary to flood fields that more often than not irrigation was impractical.
In most cases, the arrival of fossil fuels — compact, easily transportable energy — answered the question of how to make large-scale irrigation practicable. In the late nineteenth century, farmers on the Great Plains of North America erected thousands of windmills to pump groundwater from wells into their fields. But those windmills could typically draw water from no deeper than 30 to 60 feet, and digging wells was expensive. In the mid–twentieth century, pumps powered by fossil fuels let farmers reach 300 feet below the surface to the great Ogallala Aquifer, an underground region of water the size of Lake Huron that stretches from South Dakota to Texas. Plains agriculture exploded. By the late 1970s, water from the Ogallala was responsible for much of the wheat, corn, alfalfa, and cotton grown in the United States. Forty percent of the nation’s cattle drank it.
When water couldn’t be pulled out of the ground, nations used new engineering techniques to build huge dams and canals to store irrigation water. Construction began in the mid-1800s on the first great modern water storage complex, in the Indus Basin between Pakistan and India. Slowly increasing in scale, and including one of the biggest dams in the world, this massive project grew to transform the Indus into a global agricultural power. Other big projects were built in the Ganges Valley in India, the Soviet Union’s Aral Sea, Egypt’s Nile Valley, and the Colorado, Columbia, and Central Valleys in the United States. Today, a quarter of the world’s cropland is irrigated — but it provides roughly 40 percent of all the food humans consume.
The third part of the Green Revolution was the introduction of genetics — or, more precisely, the use of genetic tools to create new varieties of crops that could take better advantage of the sudden rise in fertilizer and irrigation.
This effort largely traces back to a little-known project in Mexico during and after the Second World War. So many Mexicans then were suffering from hunger and malnutrition that the resultant unrest had led the United States to fear its neighbor would fall to a fascist coup. The U.S. government asked the Rockefeller Foundation, one of the biggest and most influential U.S. research-funding charities, to help Mexico increase its production of corn, the country’s primary staple food.
The corn project met with little success. But the foundation ended up changing the world anyway. As a side project, it brought down a young plant-science researcher, Norman Borlaug, to look at stem rust, an ancient disease that afflicted Mexico’s wheat crop. In conventional terms, hiring Borlaug for this task was an odd, even foolish choice. Borlaug knew little about wheat, had never been to Mexico, and didn’t speak Spanish. But, as it turned out, his intense ambition and endless willingness to work made up for these deficits. In an unprecedented move, he collected hundreds of varieties of wheat and bred them together in every imaginable combination, hoping to create a novel hybrid that could naturally fight off stem rust. The task was breathtakingly arduous — one reason it had never been tried.
Wheat flowers, known as florets, grow in little bunches atop the stalks. Like many other varieties of flower, each wheat floret has both male and female reproductive organs. Rising on thin stalks from the center of the floret are the stamens, the male parts of the plant, which contain the pollen in little pods at the tips. Below these are the delicate filaments of the female parts of the flower, the stigmas, with the ovary below. When the stigmas develop enough to be capable of reproduction, biochemical signals cause the stamen tips to burst, releasing thousands of dust-like grains of pollen. The grains settle on the ends of the stigmas. Sensing their arrival, the stigmas create a small tube that permits the pollen to link to the ovary beneath. Male and female mechanisms join and begin creating a seed, the grain that the farmer will harvest.
Because both pollen and ovary come from the same plant, the new seed has the same genes as its parent — it’s an identical copy. To create new varieties, plant breeders must stop wheat from fertilizing itself. In Borlaug’s case, this boiled down to him and a couple of assistants sitting on little home-made stools in the sun, opening up every floret on every plant of a particular variety, carefully plucking out the stamens (the male parts) with tweezers, hundreds of plants at a time. When they were done, the wheat was entirely female — the plants had been, so to speak, feminized. Borlaug and his assistants then covered all the altered florets with folded paper so that no pollen could get in.
In the next step, they snipped off the stigmas (the female parts) from a second wheat variety, making those plants entirely male. Opening the paper covers on the previously “feminized” florets, Borlaug inserted the stigma-less, male florets, twirled them around to release their pollen, then sealed the paper back up. And then he did this all over again for the next two wheat varieties, and the next two — hundreds of thousands of breedings in all, each and every one performed under the harsh Mexican sun. After a few days he removed the paper from all the hybrids, hand-planted them in fields, let them grow, and exposed them to stem rust. Most would die, but a few would survive, and he would breed the survivors to make new varieties, hoping to create resistant hybrids.
After years of labor, Borlaug bred rust-resistant varieties of wheat. But he did more than that. He bred wheat varieties that were more productive than others, and, realizing that those high-yield ones would bear so much grain that they would become top-heavy and fall over, he bred varieties that had much shorter, stronger stalks — dwarf wheat, as it is called. Even more than that, his varieties were unusually tolerant of local conditions — they could be planted almost anywhere.
Borlaug’s varieties doubled, tripled, even quadrupled yields — but only if the plants were massively fertilized and given plenty of water, which usually required irrigation systems. Within a decade, Mexico changed from a country that had to import much of its wheat to a wheat exporter. Borlaug’s wheat then went to India, Pakistan, Egypt, and other nations, raising their yields, too.
The results convinced the Rockefeller and Ford Foundations to try the same thing with rice. The staple crop of much of Asia, the world’s most populous region, rice is humankind’s single most important food. The foundations established a new laboratory in the Philippines for the rice project — the International Rice Research Institute. In the 1960s and 1970s, IRRI researchers used Borlaug’s mass-breeding methods to develop new, highly productive strains of rice. Like Borlaug’s wheat, the IRRI rice was part of a package that included increased irrigation and fertilizer use. Between 1961 and 2003, Asian irrigation more than doubled, from 182 million acres to 417 million acres, and fertilizer use went up by a factor of more than twenty, from 4 to 87 million tons. Combined with the new rice strains, the consequence was a near-tripling of Asian rice production.
The effects were staggering. In the 1970s, much of South and East Asia were plagued by hunger. By the twenty-first century, Asians had an average of 30 percent more calories in their diet. Millions upon millions of families had more food, and with that came so much else. Seoul and Shanghai, Jaipur and Jakarta; shining skyscrapers, pricey hotels, traffic-choked streets blazing with neon: all are built atop a foundation of laboratory-bred rice.
All this progress came at a cost. Farming 2.0 has transformed human life, but it has also wreaked environmental havoc. Agriculture has always caused erosion, water pollution, biodiversity loss, and other ecological problems. Green Revolution farming, which places more demands on the Earth, has worsened these issues, with irrigation mismanagement and fertilizer overuse being particularly alarming. Poor irrigation practice can poison the soil by filling it with the salts dissolved in water; fertilizer overuse can pollute rivers, lakes, and oceans with the runoff from fields. All these problems must be resolved.
And they are complicated by another. The sheer scale of Farming 2.0, with its giant farms and giant firms, has led food consumers increasingly to mistrust the industry. They don’t believe these enormous, profit-making enterprises have their best interests at heart. The mistrust is aggravated by the very success of modern agriculture, which has made it possible for much of the world’s population to live without having any connection to the farms and farmers who provide their food.
Meanwhile, the world’s population will keep increasing, probably to 10 billion this century. People will likely be more affluent, too, which means they will demand better food. The next task for the next generation of farmers, researchers, and agricultural companies will be to maintain the gains of the past for all these new people while preserving the environment for the future. The task for everyone else will be to learn enough about the food system to help them do it.
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