But the oil palm didn't stay in Africa. Europeans brought the oil palm to southeast Asia in the 1800s and tried growing it on plantations. But it didn't start catching on in a big way until the mid-1960s. One big booster was the World Bank, which spent nearly $1 billion to fund oil palm cultivation as a way to promote economic development and lift people in rural areas out of poverty, according to this World Bank report. About half of that money went to fund a series of projects in Indonesia, which became the world's biggest producer. Between the 1960s and the 2000s, the amount of land devoted to growing oil palm cultivation increased eight-fold and spread to tropical areas across the globe.
"The plant was improved and hybridized, and varieties were developed that grew very well in large monoculture plantations," Conant explains.
Palm oil became a lucrative crop to grow. "It actually is a very efficient crop, in terms of the amount of oil it produces per acre of land," Conant says.
Additionally, new uses were developed. "It's good for replacing margarine, in that it's got a high melting point, and when it's refined, it has no flavor. That makes it good for baking," Conant says. In the mid-2000s, after the U.S. Food and Drug Administration started requiring the listing of trans fat on nutrition labels because it was linked to heart disease, processed food manufacturers began looking to palm oil as a trans-fat-free alternative, according to Harvard Women's Health Watch.
According to a recent joint project by journalism organization ProPublica and The New York Times Magazine, the U.S. and other western nations in the mid-2000s drafted environmental laws encouraging the use of vegetable oils such as palm oil as fuel, as a way to reduce carbon dioxide output and slow global warming. But that well-intentioned move backfired, according to the article, because the clearing and burning of forests for oil palm cultivation actually led to the release of massive amounts of carbon that had been stored in the peat on forest floors.
"Oil palm trees often grow best in places where rainforests were," Conant says. "It's definitely a factor in deforestation."
Oil palm cultivation brought other problems as well, Conant says. Monoculture cultivation is needed to produce a profit, and that wears out the soil after 25 or 30 years, he says. "It can be very difficult to restore the land afterward."
And while the palm oil industry provides employment for millions of people, it also has been plagued by accusations of human rights abuses, including the use of child workers, according to this 2018 U.S. Department of Labor report. This December 2018 article in Sierra magazine, for example, describes indigenous Guatemalans working 16 hour days on oil palm plantations, and suggests that use of oil palm cultivation contributes to food scarcity, because it's taking up land where local farmers otherwise could be growing corn, beans, rice and other subsistence crops.
In response to the growing criticism of palm oil, various stakeholders — agricultural producers, manufacturers who use palm oil in products, banks and investors, and some environmental organizations, among others — have started a movement to promote "sustainable" palm oil. The Roundtable on Sustainable Palm Oil, founded in 2004, has established a set of principles, which includes avoiding use of forests that provide habitat to endangered species, reduction in the use of pesticides and burning to clear land, fairer treatment of workers according to local and international labor standards, and consulting with local communities before new plantations are developed. According to RSPO's website, 19 percent of global palm oil production is now certified as sustainable. WWF encourages companies to use certified sustainable palm oil.
But in addition to promoting sustainability, Conant says, it's crucial to stop the growth of oil palm cultivation, and reduce the amount of land devoted to it. Consumers can help drive such change. "Because most palm oil in the U.S. is found in junk food and cosmetics, the best way to avoid it is to not eat junk food," he says.