The Big Ratchet: How Humanity Thrives in the Face of Natural Crisis (25 page)

The largest pivot away from poisonous pesticides might hark back to discoveries revealed before the postwar DDT era. Decades before Müller discovered the magical powers of DDT, Japanese scientists had found that a bacterium in the soil,
Bacillus thuringiensis
, or
Bt
for short, produces toxins that cause sudden death when eaten by insects. They sprayed the plants with insecticides laced with cultivated spores from the deadly bacteria. Here was a safe way to kill the insects but leave mammals and birds unharmed. For many years,
Bt
remained a minor component of pest management as DDT and other synthetic chemicals took the limelight as the pesticides of choice.

In the 1990s, with advances in biotechnology,
Bt
became a prime candidate for genetically engineered crops. Scientists could splice
Bt
-enabling genes into potato, corn, and cotton plants so the crops could produce the toxin at the right time and place to protect themselves from insect pests. Insects would die after munching on leaves. The potential benefits were obvious. Instead of farmers indiscriminately spraying toxic pesticides on crops, the plants themselves could produce the toxins they needed to target their pests.

Within a span of a few short years, farmers were planting genetically engineered
Bt
corn and
Bt
cotton on millions of acres, particularly in North America. It is too soon to say whether the adverse effects of
Bt
for the environment will prove to be costs too high to bear as toxins escape into the wild. Some report that monarch butterfly larvae may be harmed by ingesting the toxic bacteria from the leaves of milkweed plants dusted with the pollen from nearby
Bt
corn. The escaped pollen of
Bt
corn raised the specter of inadvertent effects on other
non-target species as well. Also open to question is how effective the pest-resisting abilities of the genetically engineered crops might be in the long-term. Already, pests resistant to the toxic effects of the bacteria are rearing
their heads. Humanity has twisted nature to produce food in many ways throughout history, but the outcome of this most recent
experiment remains to be seen.

The past suggests that even this new form of genetic engineering will not be the end of the story. Indeed, the story of humanity’s long struggle with insects, fungi, rodents, and other pests can never end. Despite the impressive array of weapons that humans have devised over the millennia—from extracts of plants, such as nicotine from tobacco, or poison from a chrysanthemum, to toxic chemicals like arsenic, synthetic compounds like DDT, and microbes like
Bt
—the millions of other animals, bacteria, and fungi with which we share the planet will always try to partake of the bounty that humanity provides.

Synthetic pesticides as a way to manipulate nature made industrial-scale monocultures viable. Without an effective way to control pests, the losses from weeds, weevils, and worms would have been so large that high-yielding monocultures would not have been worth the effort. And in the effort to keep monocultures viable, worldwide use of pesticides increased fifteen to twenty times
between 1960 and 2000. The postwar marvel of DDT was short-lived. Natural selection and environmental backlashes threw down the hatchet soon enough. But the brief interlude of the effective poison was enough to hook the world’s food supply on pesticides. The quick pivot to less harmful pesticides was surely an outcome of the public outcry from visible, close-to-home scenes of dead birds and wildlife.

Rachel Carson’s view of pesticides points toward thinning eggshells, dead wildlife, and toxic chemicals accumulating in fat tissue. Even the less damaging substitutes are far from proven, risk-free solutions. Borlaug’s view highlights the extraordinary advantage of keeping pests from eating so much of the harvest, not to mention the life-saving value of controlling malaria-carrying mosquitoes. One side paints pesticides as evil, the other as a saving grace. Each view is right from its own perspective.
But the reality, like the larger reality of humanity’s intertwined connections with nature, is far more complex than a simple black-and-white perspective might imply. The answer is not an easy either-or solution, but somewhere between the two extremes.

With pesticides as part of the toolkit, along with postwar factories to produce chemical fertilizers, abundant petroleum to power machinery, vigorous offspring from hybrid seeds, and short, stout stems that withstood the weight of fertilized, amply watered plants, more genetic ratchets were in store for the century’s second half. This time, the repercussions ricocheted around the world.

9: THE REVOLUTION GOES GLOBAL

O
F ALL THE PEOPLE WHOSE IDEAS
and innovations sent the world hurtling toward the post–World War II explosion in what and how much people eat, one name stands out: Norman Borlaug, the plant breeder from the American Midwest who countered Rachel Carson’s criticisms of chemical pesticides. Some revere Borlaug as a humanitarian saint. Others revile him for the enormous changes he ushered in throughout the developing world.

Borlaug came of age in his profession at a time when all the pieces of the Big Ratchet were in place. Repurposed wartime factories could break apart nitrogen’s bond and supply farmers with as much fertilizer as they could afford. The same was true for DDT. Phosphate rocks seemed to be in endless supply. Coal and petroleum were abundant and cheap. Dams stored water to irrigate crops. New, short breeds of wheat were able to withstand the extra weight of abundant growth. Hybrid seeds could make yields soar. Humanity’s accumulated ability to manipulate nature had grown so massive that few constraints were left to prevent a ratchet on a scale never seen before.

Borlaug was born in 1914, around the time that Edward Murray East and Rollins Adam Emerson were doing their experiments with hybrid corn, on an Iowa farm in a small Norwegian American community. For his first eight grades he was schooled in a one-room schoolhouse. Later, to support his university education during the Great Depression, he worked with unemployed men on federal projects. People who knew him claim that this experience, where he encountered firsthand the ravages of malnourishment, sparked his life purpose: to bring food to the
tables of the hungry. Under the tutelage of Elvin Stakman, a plant pathologist at the University of Minnesota, Borlaug found his calling to fight plant diseases that brought disaster to farmers.

In 1944, after a brief stint working at E. I. du Pont de Nemours Company in Delaware to test DDT and other pesticides, Borlaug shifted his focus to Mexico. At the time, crop yields in Mexico were abysmally low. The soils were depleted of nutrients, and a series of wheat rust epidemics had demoralized farmers. Wheat rust, a disastrous fungal disease spread by wind-borne spores, had caused brick-red lesions to appear on the stems and leaves of affected plants, weakening the plant’s stem and usurping nutrients that should have supported the plant’s growth. The rust had caused wheat grains to shrivel up and the plants to fall over onto the ground. Mexico had resorted to importing more than half its wheat. The vice president of the United States, Henry Wallace, had visited Mexico to discuss possible remedies with Mexican officials, and he encouraged the Rockefeller Foundation to set up a research and training program jointly with the Mexican government. At the behest of Stakman, who advised the program, Borlaug was chosen to head the
program’s wheat-research effort.

Borlaug selected the flat, newly irrigated Yaqui Valley in northwestern Mexico as a place to base his work. The first order of business was to breed varieties that could resist stem rust, which Stakman had
deemed “a shifty, changing,
constantly evolving enemy.” Stem rust had destroyed the wheat throughout the valley in previous years. Borlaug set up his experiments while living in an abandoned agricultural experiment station, sleeping on a cot, and cooking over a fire. He had no electricity or vehicle and used equipment donated by local farmers.

Borlaug reckoned it would take at least eight years and many plant generations to develop a rust-resistant variety. But he was not a patient man, and he didn’t want to wait that long. To speed up the process, Borlaug decided to go against the norms of plant breeding. He bred the seeds in the Yaqui Valley during its growing season, and then he took the seeds more than seven hundred miles southeast to a higher elevation, in the cooler valley near Mexico City, to breed the rest of the year. By shuttling the seeds back and forth he could breed wheat year round, cutting the time needed to produce a variety resistant to stem rust in half. The “shuttle breeding,” as it came to be known, was a serendipitous success for another reason as well. Because the shuttle breeding yielded seeds from populations that had been exposed to a different climate, and diseases in each place, the wheat grown from the seeds could withstand many diseases and adjust to different day lengths. Borlaug claimed that his former professors and plant-breeder colleagues had “thought my shuttle breeding scheme was madness. . . . But we forged ahead, and
look what happened.” With rust-resistant varieties, along with fertilizers and weed control, Borlaug’s plots in the Yaqui Valley were yielding good returns, and farmers started to pay attention.

Once the problem of rust lessened, another problem cropped up. With fertilizer, the plants grew so well and so tall that they started to fall over. Earlier success in the United States had shown the advantages of short wheat, so Borlaug sought out varieties with shorter and stiffer straw to breed with the rust-resistant variety. Borlaug got in touch with his colleague Orville Vogel, a plant breeder at Washington
State University, who had a prized stash of short wheat from Japan. Vogel had gotten it from Samuel Salmon, a research scientist with the occupation forces in Japan during World War II, who had noticed the Japanese experimenting with short-stemmed wheat in an agricultural research station. Salmon had brought back sixteen varieties and given them to Vogel. One variety was called Norin 10. Norin 10 was not just short like Pawnee and Wichita. It had dwarf genes, making it even shorter and boosting yields even further. Vogel sent some Norin 10 to Borlaug in the early 1950s.

With dwarf genes from Norin 10 added to the toolbox and the passage of eight more years, Borlaug and his colleagues were able to coax out a variety of shuttle-bred wheat that didn’t fall over. Yields
doubled over the taller varieties. Back in the Pacific Northwest, Vogel had also bred a semi-dwarf variety crossing Norin 10 with his local varieties, and yields for irrigated wheat climbed there, too. The new ankle-high Gaines variety that Vogel had bred spread across the
Pacific Northwest in the early 1960s.

Semi-dwarf varieties of wheat, and later rice, were another turn of the ratchet for the revolution that was underway. The new dwarf varieties were shorter even than the short varieties that breeders had bred in the first half of the century. But the revolution wasn’t just about genetics and breeding. It was all the twists of nature together. “It was the combination of factors—variety, fertilizer, timely weed control, and optimum irrigation schedules—that makes the difference,” Borlaug later wrote in a recollection of his six-decade hunger-fighting crusade. “There is no magic in varieties alone. It has to be the whole package to
achieve significant impact.”

Within twenty years after the program between the Rockefeller Foundation and the Mexican government began, wheat yields soared. More land was producing wheat, and Mexico no longer relied on imports. The Yaqui Valley had become a breadbasket for the country.

From Mexico to India

Despite Borlaug’s great success in Mexico, the specter of Rev. Thomas Robert Malthus still hung over the world of the 1960s. Thanks to the spread of vaccines, sanitation, and other life-saving public-health measures in the developing world, the world’s population was soaring. Unfortunately, the growth spurt was putting the world on a trajectory to outrun food supplies. More children survived to adulthood, and people lived longer. Everyone needed to eat. There was little room to expand agriculture in densely populated Asia. Among the pessimistic was the biologist Paul Ehrlich, whose 1968 best-selling book
The
Population Bomb
described his apocalyptic view of the future: “The battle to feed humanity is already lost,” he wrote. “We will not be able to prevent large-scale famines in the
next decade or so.” Ehrlich reserved his most calamitous predictions for India: “I have yet to meet anyone familiar with the situation who thinks India will be self-sufficient in food
by 1971, if ever.”

Indeed, India’s future looked dismal at the time. Jawaharlal Nehru, the country’s first prime minister and a vociferous advocate of large dams, had died in 1964. Memories of the famine two decades earlier were still fresh. It had killed some 3 million men, women, and children. Lower than normal rainfall in the mid-1960s had led to poor harvests. The population was outstripping production of wheat and rice. Hunger was widespread, and the country was
importing large quantities of grain.