The Big Ratchet: How Humanity Thrives in the Face of Natural Crisis (18 page)

Today, humanity’s food supply is tethered to the small number of countries that sit on top of these geographically dispersed geologic oddities with large stores of phosphate rock. The small North African kingdom of Morocco, along with politically contested Western Sahara, tops the
list with the largest reserves. Some scientists are claiming that the era of phosphate rock as a ready source of the precious nutrient might be coming to an end, just as the eras of guano, saltpeter, and
bones ended before it. They warn that farmers who depend on packaged fertilizers, such as DAP, MAP, and TSP—shorthand abbreviations for the most commonly used phosphate fertilizers—might be in for
tough times as prices rise. Others claim that supplies are plentiful and that
new technologies to dig more efficiently will circumvent a shortage at least in the near future. But no substitutes—nothing like the phosphate rocks that replaced bones or the Haber-Bosch process for nitrogen—are on the horizon.

Even if the days of cheap phosphate fertilizers last for centuries more, there’s already no escaping the hatchets that our industrial replacement of the nitrogen and phosphorus cycles has created. Indeed, the real hatchets from Haber’s nitrogen-fixing process and the circumvented phosphorus cycle don’t come so much from the prospects of impending shortages. The hatchets that loom at this point in history are different in character. Until this point, the hatchets threatening civilization were about absence: not enough nitrogen, phosphorus, or energy. After this point, the problems come not from too little, but from the abundance made possible by humanity’s cumulative knowledge. The solutions to shortage have created new problems. There can be too much of a good thing.

Hatchets Downstream

Lake 227 is one of fifty-eight small, pristine lakes nestled amid pine and birch trees in the Experimental Lakes Area of southern Canada, four hours’
drive from Winnipeg. The government set up the experiment in the late 1960s to see what happens to algae, fish, and other organisms when nutrients from
surrounding landscapes drain into lakes. Decades of careful experiments, with investigators adding different amounts and combinations of nitrogen and phosphorus to Lake 227 and others,
have yielded some answers.

One of the biggest problems is
eutrophication
, the process that follows when water is enriched with nutrients. Eutrophication is a natural process, but too many nutrients can turn a clear lake into a
noxious algal bloom. Over time, as plant remains and animal wastes continue to run through streams and through the soil to flow into lakes, more algae grow
in the lake. The more these nutrients accumulate in the water, the more the algae grow. With too much algae, light can’t penetrate below the surface, which in turn damages the rest of the life in the lake. When the algal remains sink and decay, oxygen in the water gets used up, depriving other species. The result is slimy, green scum on the surface, fish kills, and a lake inhospitable to species other than the algae. Phosphorus is the key culprit in freshwater lakes. Lifting the lid on the phosphorus constraint propels the whole system to choke itself with too much growth as decomposing algae gobbles up all the oxygen. Eutrophication accelerated by fertilizer and sewage has fouled lakes from North America’s Lake Erie to Switzerland’s Lake of Zurich to East Africa’s Lake Victoria.

Eutrophication is high stakes where people’s food and livelihoods depend on clean lake water. Take, for example, the people living along the shores of Lake Victoria—the tropic’s largest lake, bordered by Uganda to the north and west, Tanzania to the south, and Kenya to the east—who depend on the lake’s fish for affordable protein. When towns along the shore dump raw sewage directly into the lake, the excess nutrients erode prospects for a clean drink of water and a chance at
catching a native fish.

Many countries in the industrialized world have taken measures to deal with the problem. Sewage treatment and regulation of effluents from factories have stemmed the flow of phosphorus directly into water bodies since the 1970s. Bans on phosphate detergents, which burdened the waste stream with the pesky nutrient, have gone a long way in the effort to clean up streams and lakes. A harder problem is the millions upon millions of distributed sources from fields, lawns, rooftops, and streets, which carry phosphorus into streams and lakes, little by little, until the amount adds up to a big problem.

Lake Mendota, bordering Madison, Wisconsin, is a case in point. With the University of Wisconsin campus on its shore, Lake Mendota is one of the world’s most studied lakes. Algal blooms broke out and noxious fumes emanated from the lake as early as the mid-nineteenth
century as settlers moved into the surrounding land, dumping sewage and other
nutrient-rich waste into the water. The lake’s watershed now contains plenty of sources for phosphorus, including the heavily fertilized cornfields, the manure from dairy cows bred to make Wisconsin’s famous cheese, and fertilizers spread by homeowners hoping to grow green lawns. Nuisance algal blooms in Lake Mendota became severe by the mid-twentieth century, but it wasn’t until several decades later that local ordinances and management plans were put in place to control the input of nutrients. Although sewage is now diverted from flowing directly into the lake, and best-management practices for farmers and homeowners are in place, the battle to contain the phosphorus runoff from fields and suburban lawns
has never truly ended.

The unraveling of the phosphorous cycle with the switch to phosphate rock reverberates not just in the environmental realm. The political peril of relying on a few places for a nationally important resource was apparent from the beginning. US President Franklin D. Roosevelt told Congress in his 1938 address to the body that “the disposition of our phosphate deposits should be regarded as a national concern. . . . I invite especial attention of the Congress . . . to the fact that the Eastern supply, while in private ownership, is today being exported in such quantities that when and if it is wholly depleted, Eastern farmers will have to depend for their phosphate supply on the Far Western lands. . . . It is, therefore, high time for the Nation to adopt a national policy for the production and conservation of phosphates for the benefit of
this and coming generations.” Despite Roosevelt’s plea, no national plan was forthcoming. Roosevelt would likely have been even more concerned had he known that in the coming decades the concentration of the critical resource in a few places would become global, with only a handful of countries sitting on top of the world’s supply.

Excess phosphorus running into lakes is not the only hatchet from humanity’s manipulation of the planet’s nutrient recycling machinery. A cascade of consequences falls from a planet
soaked in fixed nitrogen. All
of humanity’s twists of the natural cycle bring more fixed nitrogen from the atmosphere into the soil.
Pseudomonas
bacteria have the impossible task of converting the excess back to nitrogen gas. They just can’t keep up. Once nitrogen gas is fixed from its inert state, it leaks everywhere, as if it were trying to make up for lost time spent pent up in the strong chemical bond. Whatever fixed nitrogen isn’t used by crops moves readily into water, streams, and oceans.

Too much phosphorus causes the eutrophication problem for freshwater lakes. Too much fixed nitrogen causes the problem in coastal waters. One such “dead zone” is in the Gulf of Mexico, where the outflow of the vast Mississippi River dumps the excess industrially fixed nitrogen that farmers have heaped on millions of acres of corn and soy. When extra fixed nitrogen gets into soils, streams, rivers, and eventually coastal waters, algae and plants long-starved for nitrogen grow rampant. Once they die and decay, there’s no oxygen left for fish, crabs, and all the other living creatures. The Black Sea is another case in point, as is the East China Sea and hundreds of other coastlines that drain fields fertilized with more industrially fixed nitrogen than the crops can use. Belly-up fish and green muck are as much a result of Haber-Bosch as endless fields of grain.

Another kickback is felt in the Earth’s atmosphere. The flood of fixed nitrogen means that
Pseudomonas
bacteria convert more nitrate in the soil back to nitrogen gas. Most cycles back to the atmosphere as nitrogen gas, but some as nitrous oxide. Nitrous oxide at room temperature is just laughing gas, but in the atmosphere it acts as a greenhouse gas—and it’s a mighty powerful greenhouse gas. One molecule of nitrous oxide warms the planet nearly three hundred times as much as a molecule of carbon dioxide averaged over a hundred years. The more fixed nitrogen in the soil, the more nitrous oxide there will be in the atmosphere. Carbon dioxide is the main culprit for human-induced climate change and all it entails for rising seas and heat waves, but increasing levels of nitrous oxide have
made a mark as well.

So Haber’s invention and the pivot to phosphate rocks unleashed both good and bad outcomes: more food for more people and more protein, but unequal access to the miraculous fixed nitrogen, fouled lakes, dead zones around the world’s coasts, greenhouse gases in the atmosphere, and perhaps other unknown big kickbacks yet to come to the fore. The trials, errors, and hard work to tap into solutions
set loose even more problems.

For the first time in human history, in the early twentieth century the lid was off on the constraints that the long-ago pivot to settled life imposed. Seemingly endless expanses of phosphate rocks could replace phosphorus in night-soil, guano, and manure. Haber’s process could suck lifeless nitrogen from the air to nourish life. Chemical fertilizers loosened the tight leash on civilization held by the planet’s recycling machinery. They resolved settled life’s conundrum with infertile soils by gobbling up energy and creating an excess that wreaks havoc on streams, lakes, and coastlines.

Another Spigot Opens

Another bottleneck broke open in the nineteenth century, paving the way for the twentieth century’s Big Ratchet. Remember the other conundrum of settled life: the amount of calories humans burn to produce food has to be less than the amount of calories produced for them to eat. Civilization’s challenge is to usurp energy from other sources to produce more food on less land with less human effort. For most of human history, the energy to produce food was tied to the human and animal labor at hand.

Human brawn has supplied energy to grow food since ancient times. Even in our relatively recent history, slaves provided human energy, as with the New World sugar trade that sweetened the teas of Europe. Today, many cultures still rely on human energy to farm. They
don’t have many options for subsidizing their labor with other energy sources. Throughout sub-Saharan Africa, for example, farmers use hand hoes to help them turn the soil—and plant, weed, and harvest by hand—without even the
aid of animal power. The yields are low: a plot of cassava yields about half the amount as the same area in the
crop’s native New World tropics. A farmer who toils without the help of animals, much less fossil fuels to power tractors and plows, needs a lot of human energy to supply a family with even the most basic diet.

Many millennia ago, civilizations added animal power to supplement human energy in their fields. The same strategy is still a common sight throughout India, Bangladesh, and other countries of South Asia. Farmers in rice paddies guide wooden plows. Bullocks, ponderously trudging back and forth across the field, supply the strength to pull the plow. The age-old, time-tested system has fed many millions of people for millennia. More people can live off the same amount of land as the sub-Saharan farmer’s, with less human energy
expended in the process.

The last few centuries pried open the energy bottleneck with solid coal that, when burned, unleashes the ancient sun’s energy buried in plants. But beyond powering factories—such as those that synthesize fixed nitrogen from the air—and supplying electricity from coal-burning plants, the black diamonds don’t help a farmer much: they cannot push a plow or reap a harvest. Oliver Dalrymple, a Minnesotan wheat farmer and land speculator, learned that lesson in the late nineteenth century. He was among the first to hitch a tractor to a locomotive powered by a coal-burning steam engine rather than horses. The engines proved too cumbersome and heavy for farm work. But they were one small step on the path toward
fossil-fuel-powered farming.

The Belgian engineer Jean J. Lenoir took not a small step, but a big leap. His mid-nineteenth-century internal combustion engine ushered in gasoline-powered tractors in the early part of the twentieth century.
These proved vastly more practical than the
steam-engine tractor. The engine, which produces energy from spark-ignited burning inside the engine rather than from the external boiler of a steam engine, takes liquid fuel. Solid coal could not do the job.

The spigot opened on August 28, 1859, in a quiet farming region of northwestern Pennsylvania. The famous Drake Well, named for the entrepreneurial oil-seeker who drilled the hole, struck liquid gold. Oilmen flocked to the region and the industry took off. The oil frontier then moved westward to other parts of the world fortunate enough to sit
atop the rich resource.

Unlike coal, formed from ancient plants on land, oil to produce gasoline formed in ancient seas. Decayed remains of ocean-dwelling bacteria and algae sunk to the sea’s bottom, got buried in sediment, and were squeezed from the weight above. The result is deposits of oil trapped between rock layers. The ancient sun’s energy captured in this liquefied form fueled farm machines and trucks, while the solid form powered electricity from coal-burning plants for milking machines, pumps for wells to extract groundwater, and all kinds of useful devices.

Fuel to propel heavy machinery didn’t just add massively to the energy available from human and animal power on the farm. It also powered machines to build dams that could store water and quench a crop’s thirst where rainfall was too scarce. Trucks poured concrete into massive structures during the twentieth century’s boom time for large dams. Several of these dams—including the Roosevelt dam in Arizona, the Kensico in New York, and the Hoover along the Colorado River—are colossal monuments to these enormous investments in the early part of the century. Within a few decades, the prevailing sentiment was that the huge concrete structures were a path to development. Jawaharlal Nehru, the freedom fighter elected as India’s first prime minister in 1947, described dams as “
temples of modernity.” Newly independent countries sought to build these temples to secure their supplies of water.