by Charles C. Mann

The historian Alfred Crosby coined the term Columbian Exchange to describe the dramatic changes resulting from the global dissemination of species triggered by the discovery of the New World. Civilizations all over the planet were profoundly changed as a result of Columbus’ discovery.

The impact on China was huge. When the potato, indigenous to Peru, was brought to China, it rapidly increased the amount of arable land available to Chinese farmers. Chinese agriculture was divided into two zones: a wheat-growing zone in the north and a rice-growing zone in the south, but both crops required flat terrain. The potato grew well on sloping ground, so millions of Chinese peasants cleared hillsides and planted potatoes. This triggered a small population explosion in China. It also led to floods that killed millions, because the now-denuded hillsides no longer retained rainwater. 

China was also profoundly affected by the sudden appearance of silver from Potosi, the mountain of silver that the Spanish discovered in Peru. For a century, Spanish galleons carried tons of silver every year from Peru to Manila, where they traded it for Chinese goods. This boosted China’s economy by providing specie for expansion.

I wonder, however, why China did not respond more aggressively to the new trade system. China had explored maritime expansion with a series of expeditions on the early 1400s reaching as far as eastern Africa. But then China abandoned the expeditions, apparently concluding that there was little of value or interest in the world outside China. The Spanish silver changed everything; now the outside world had something China desperately needed. Why did the Chinese government react so passively? Its merchants were all over the Spanish, demonstrating impressive mercantile energy, yet the government kept the Europeans at arms’ length, preferring most of the trading activity to take place in Manila. The Chinese government’s passivity cost it dearly in the ensuing centuries.

Maize — Americans call it corn — was another big contribution of the New World to China and the rest of the world. 

In the late 19th century, the discovery of the utility of rubber for many industrial products created an economic boom. The trees that produced the latex sap were native to Brazil, but they were quickly transplanted to Southeast Asia, where fortunes were made by setting up huge plantations. Again, this brought great wealth to China, Vietnam, and Laos, but the Chinese government seemed unwilling to demonstrate any initiative. 

Europe also enjoyed huge benefits from the Columbian exchange. The potato had similar beneficial effects on European population. It grows easily and, unlike so many other crops, it satisfies almost all human nutrional needs. Ireland enjoyed a population boom until the mid-nineteenth century, when a potato disease led to famine. Tomatoes are loaded with vitamins, grow easily, and were quickly integrated into European cuisine. 

Tobacco had a huge impact all over the world. The Europeans went wild over it; tobacco plantations were set up all over the New World to grow this addictive source of nicotine. The Chinese also took to tobacco.

Chocolate was another important important import from the Americas; Europeans loved the taste and used it in a huge array of culinary delights. Their appreciation of chocolate required two other components: milk and sugar.

Sugar cane originated in India, but it came to Europe through the Islamic world. The climate in the Islamic countries was not ideal for growing sugar cane, so it remained expensive and never became a large part of the European diet — not until the Europeans put together a complex trading system.

It started small, with the planting of sugar on the island of Madeira, far off the coast of Morocco in the Atlantic. The sugar crop there was reasonably successful. Then two islands, Sao Tome and Principe, were discovered much further south in the Gulf of Guinea, and their climate was ideal for growing sugar cane. There was only one problem: malaria killed most of the Europeans. Oh, well.

But the African kingdoms on the nearby coast engaged in quite a bit of slave-taking. The primary military strategy used for warmaking was the slave-raid; this kept border regions depopulated and stabilized international relations. The Europeans had learned to bypass Africa in their trading expeditions because the Africans had nothing of value to offer other than a small amount of gold. But then somebody realized that Africans had greater resistance to malaria than Europeans. They traded European manufactures (primarily beads) for slaves, transported the slaves to Sao Tome and Principe, and put them to work growing sugar cane. This turned out to be a hugely profitable system. 

But Sao Tome and Principe are small islands, and that limited production. The next step was to extend the system across the Atlantic Ocean to Brazil, and later, the Caribbean. Thus developed the triangular trade system: you sailed from Europe with a load of beads, which you traded in Africa for slaves, which you transported to the New World and traded for sugar, which you transported to Europe. The triangle was hugely profitable. It was later extended to produce tobacco. 

The vulnerability of Europeans to malaria remained a huge problem, so there were few Europeans overseeing the sugar-cane plantations; in many cases the slaves outnumbered their overseers by tens to hundreds to one. So why didn’t the slaves revolt or at least run away? The Europeans learned to keep the slaves weak through overwork and starvation; weak enough to work, but not strong enough to fight. Of course, this kept mortality rates among slaves high, but there was always a steady supply of new slaves. 

Many slaves did run away and form refugee villages far from European control; and slave revolts were common enough that Europeans developed brutal tactics to keep the slaves in terror. 

Sugar was immensely popular in Europe; it is the only civilization, as far as I know, to have developed candy. In the late nineteenth century, sugar provided almost half the caloric intake of lower-class English.

All in all, a fascinating book that I highly recommend.