The Big Ratchet: How Humanity Thrives in the Face of Natural Crisis (14 page)

As it turned out, the leaders of the day did not have to heed the words of Shaw, Hugo, or Liebig. It wasn’t necessary to find ways to reconnect the severed cycle. There was another solution, although it proved to be fleeting. The wind power that had carried seeds, plants, and animals around the world in the Age of Discovery provided the solution, this time by carrying excrement much further afield than the night-men of the past had ever done.

Boobies and Cormorants

The solution came via seabirds who feasted on the anchovies and sardines that were abundant in the nutrient-rich waters off the western coast of South America. The birds’ droppings, known as guano, are rich with the two key components of fertilizer, fixed nitrogen and phosphorus—just what the crops in England and the rest of Europe needed to compensate for the one-way flow of nutrients from countryside to city.

The Incan farmers of South America knew the value of guano for fertilizing their crops long ago. Although they used human manure to fertilize crops on the terraces that they built inland on steep mountain slopes, near the coast they used the treasure trove of nutrients from small islands off the shoreline. Nutrient-rich, upwelling ocean currents sustained large populations of fish, which in turn fed massive populations of boobies and cormorants. It doesn’t take much imagination to envision the amount of excrement coming from the guts of these birds as they flew overhead or landed on the rocks. With the dry air and rocks
jutting from the sea, droppings deposited by birds built up over millennia. Without rain to carry away the excrement from the rock islands, the nitrogen- and phosphorus-rich guano accumulated like snow in white piles hundreds of feet deep.

As early as 1560, the son of an Inca princess and Spanish conquistador, Garcilaso de la Vega, had published an account of how the Incas regulated the use of guano. Extracting guano during bird breeding time was punishable by death, and killing a seabird was a serious crime. Rulers strictly prescribed who could take guano, how much they could take, and from which locations they could take it. Garcilaso de la Vega’s account of the rich fertilizer didn’t have much impact on the Spaniards at the time. Gold was what they were after in South America, not bird excrement. But the guano proved to be truly valuable. This was the gift of the seabirds to Incan farmers, and to agriculture in Europe and North America, once ships could haul it across the Atlantic.

In the early 1800s, shortly after Malthus warned of food shortages to feed the growing numbers of people, the German explorer Alexander von Humboldt encountered the Incan farmer’s secret fertilizer. Humboldt wrote in his diary about his expeditions to South America and his caravans of mules that carried vast “collections of new mineral substances,” including guano from the islands off the Peruvian coast (they also carried limestone and other rocks, as well as bamboo and the barks of trees that
were said to cure malaria). He carried these samples back to Europe, where the scientists of the day proclaimed guano’s richness in nitrogen and phosphorus.

By 1840, Humboldt’s discovery had sparked a booming trade in guano. Workers in Peru mined beds of the bird excrement, loading it onto ships for transport to Europe and North America. Peru prospered from the trade, as did the middlemen. The British firm Antony Gibbs & Sons amassed a fortune from a virtual monopoly, paying $15 a ton and selling it in Britain and the
United States for $50. The problem with
soil fertility was resolved for the time being, at least for those who could afford to buy the imported guano. Less wealthy farmers continued to fertilize their fields with farmyard manure, woolen rags, soot, butcher scraps, hair, and
all sorts of nitrogen-containing waste.

Competition for guano deposits became fierce. The US government passed the Guano Island Act in 1856 to bolster American’s claim on the lucrative resource, stating that “whenever any citizen of the United States discovers a deposit of guano on any island, rock, or key, not within the lawful jurisdiction of any other government . . . such island, rock, or key may, at the discretion of the President, be considered as
appertaining to the United States.” Under these auspices, American entrepreneurs scurried to claim islands and atolls scattered the world over. Among the scores of islands claimed under the act were Jarvis and Baker islands, two remote, uninhabited coral outcrops in the South Pacific; Navassa Island, a tiny protrusion of barren limestone in the Caribbean; and
Christmas Island off the coast of Australia.

Competition for guano led to war. Thick guano deposits on the Chincha Islands off the Peruvian coast were a prime site for ships loading the valuable fertilizer destined abroad. In August 1863, a fight broke out on the docks between some Spaniards and some local people. The incident escalated into a war when Spain used the fight as a pretext to seize the island, pitting itself against a quadruple alliance of Peru, Chile, Ecuador, and Bolivia. The war lasted from 1864 to 1866, and with the Spaniards defeated, Peru returned to its guano-induced prosperity.

At the peak of the trade in the late 1850s, Britain was importing about 300,000 tons of guano a year and distributing what British farmers did not use to the rest of Europe. The United States peaked at
a little over half that amount. Farmers were using the fertilizer, but paying a hefty price. Some farmers in the United States complained that Peru’s monopoly, combined with a lobby in Washington to keep guano prices high, meant that “you are buying your guano now, and each day regretting
that its unreasonably high price renders you unable to strew it with a liberal hand over your hard-worked
and poorly fed fields.”

As the decades went on, the guano piles wore down, as did the quality of the fertilizer. After fifty years, the guano supply was exhausted, even with seabirds replenishing the stock. Instead of thick piles of white excrement, the islands were left with bare, exposed rock. British imports tapered off to 20,000 tons a year by the end of the 1880s.

The dwindling guano did not mean the end of the South American fertilizer trade. The dry climate of South America’s western coast was not only good for preserving guano. The inland desert held a second trove of nitrogen: saltpeter. Found in the hardened deposits of evaporated Andean meltwater, the nitrogen-containing compound replaced guano as a source of fertilizer for Europe and North America as the craze for bird droppings ended. No less important was the prized value of saltpeter for making gunpowder and explosives.

Once again, the rush for fixed nitrogen led to war. Chile declared war on Peru and Bolivia in an attempt to gain control of saltpeter-rich desert provinces. The War of the Pacific, also known as the Nitrate Wars, left Chile the victor in 1883. Bolivia lost its access to the coast, leaving the country desperately landlocked. Peru’s economy, without access to saltpeter and with little guano left to mine, collapsed. The country was bankrupt.

The guano and saltpeter trade of the nineteenth century transferred vast quantities of nutrients from dry, warm South America to damp, cold Europe, where it ultimately fueled industrial laborers in the continent’s cities. What a circuitous route for atoms of the two key nutrients that feed civilization, nitrogen and phosphorus. Instead of recycling back to the fields directly through human waste, the nutrients taken from the soil to feed the cities were replenished from far-away South America. The absurdity of the situation was clear to some at the time. Karl Marx observed that the division between town and country
“disturbs the metabolic interaction between man and earth, i.e. it prevents the return to the soil of its constituent elements consumed by man in the form of food and clothing; hence it hinders the operation of the eternal natural condition for the
lasting fertility of the soil.”

Whether the cross-Atlantic transfer was absurd or not, it was certainly not permanent. The guano and saltpeter bonanza from South America was only a temporary solution to the conundrums of settled life. Abandoned guano mines stand as a testament to the brief era. Today’s market for Peruvian guano is a pittance of what it was in the heyday, targeting a niche market of organic farmers willing to pay high prices for bird excrement. As the saltpeter trade continued after guano was depleted, prices skyrocketed, partly because the easily reached deposits were being exhausted, and partly because the sellers manipulated the supply to maintain high profits. High prices spurred the search underway in Europe for the next pivot to
new sources for fertilizer.

Sun-Powered Cargo

The brief respite that guano and saltpeter provided for European and North American soils firmly entrenched overseas’ trade as another tool in humanity’s toolkit to keep soils fertile. The idea to hitch a ride across the ocean on sun-powered winds was nothing new. For centuries before the first shipment of guano set sail from Peru’s shore, a great exchange of plants and animals had already been altering diets and landscapes around the world, in essence moving the sun’s energy from place to place across oceans in the form of calories in food and labor from animals.

The plants and animals of the New and Old Worlds had evolved separately since the slow grind of plate tectonics had broken apart the Pangaean supercontinent a few hundred million years ago. By medieval times, sophisticated human cultures and accumulated knowledge
had evolved in each of these worlds to exploit these species for food and energy. Before the globalizing jolt following Columbus’s famed journey, Aztec and Mayan societies in the New World ate corn, beans, and squash. Incan societies ate potatoes and quinoa. In the Old World, medieval Europeans subsisted on wheat, barley, and rye; Africans on
yams, banana, pearl millet, and sorghum; and East Asians on foxtail millet and rice. Horses and oxen supplied labor in some parts of the Old World. In the New World, with horses extinct since the onset of the Holocene, human labor largely powered societies. Buffalo were not easily tamed, and llama, alpaca, and dogs were poor substitutes for stronger beasts of burden.

The long-severed New and Old Worlds reestablished their connection when Christopher Columbus set sail with his crew from the coast of Spain in August 1492 on the
Niña
, the
Pinta
, and the
Santa Maria
. He didn’t achieve his original goal—to find the East Indies—but he set in motion a massive pivot that changed the fate of civilizations and rearranged the natural world—nearly rivaling the planet-transforming transition of our species from forager to farmer.

Powering this Earth-changing exchange once again was the sun, which drives the trade winds that carried Columbus and his crew across
the Atlantic. The sun’s energy beats down on the equatorial surface to heat the air. As the hotter, and so less dense, air rises, the cold air sinks from above to replace it. The sinking and rising air would cause one big, continuous conveyor belt from the Equator to the poles were it not for the daily spin of the Earth on its axis as it moves beneath. Because the planet spins faster than the air, this big single conveyor belt breaks up into three smaller cells, each one continually turning like a wheel. The cells form the trade winds—so named for the routes they opened for exchange between the Old and New Worlds—on either side of the Equator. These engines of the trade winds are sometimes called the Hadley cells, a name honoring the English amateur meteorologist George Hadley, who noted the link between the rotating Earth and the
trade routes of his era in 1735. The trade winds carried Columbus westward, where he landed in the Bahamas in October 1492. He returned via the northward loop of a Hadley cell that blows winds eastward toward Europe.

The New World that Columbus opened to other conquistadors and explorers—Hernando Cortés, Francisco Pizarro, and Vasco Nuñez de Balboa—during the wind-powered Age of Discovery had little resemblance to the Old World. Reconstruction of Columbus’s diaries note his observation that “all the trees are as different from ours as day from night; and also the fruits and grasses and
stones and everything.” This difference was not to last. Alfred Crosby, the historian who coined the term for the “Columbian Exchange,” the transcontinental transfer of species following Columbus’s voyages, wrote of the day that Columbus landed ashore on the Bahamas: “The two worlds, which were so very different, began on that day to become alike. That trend toward biological homogeneity is one of the most important aspects of the history of life on this planet since the
retreat of the continental glaciers.”

The sun-powered homogenization was partially intentional and partially accidental. Royal officials encouraged ships departing Spain for the New World to transport cattle, sheep, and other domestic animals
as well as seeds for wheat, barley, and grapes, among other crops. Rice, soybeans, oranges, millet, sugar, and coffee were also among the crops that went from the Old World to the New. In the other direction, a 1525 royal order decreed that shipmasters sailing from the New World bring animals and
plants back to Spain. By the time the height of the exchange passed, tomatoes, chili peppers, peanuts, cacao, vanilla, eggplant, tobacco, potatoes, manioc, corn, and sweet potatoes had traveled eastward from the New World to the Old World via the sails powered by the Hadley cells.