Palm oil is found in everything from food to cosmetics. Its rise to the status of the most widely consumed vegetable oil has had devastating effects on forests, wildlife - and most recently some of Hong Kong's beaches.
The rise of palm oil to become the most widely consumed vegetable oil on the planet is astounding. In 1970, yearly palm oil production stood at about one million tons. By 2016, that figure had jumped to around 63 million tons.
Made from the reddish fruit of the oil palm tree (Elaeis guineensis), it's extremely versatile, which is why it has replaced animal and other vegetable oils in many products, according to environmental group WWF. The oil is found in all kinds of products, including lipsticks, ice cream and soaps, and is widely used as a biofuel.
Indonesia, China, the European Union and India are the world's biggest palm oil consumers. Nearly half of all palm oil produced goes to the latter three, none of which produce the oil and are entirely dependent on imports to meet demand.
Palm oil with a price for the environment
Most of that palm oil comes from Indonesia and Malaysia. Rising demand for the cheap product has led to widespread destruction of rainforests, cleared to make way for monoculture plantations. This is threatening ecosystems and the habitats of many animal species, says the Union of Concerned Scientists.
Numbers of Bornean orangutans, for instance, have fallen so sharply that environmental groups fear they will be extinct within a decade. The primates are particularly susceptible to deforestation because they spend 90 percent of their time in trees. And Borneo has lost significant numbers of trees due to logging, one of the biggest drivers of which is palm oil, says WWF.
Between 1973 and 2010, forest cover on the island fell from 76 to 28 percent, writes Scientific American.
A palm oil spill near Hong Kong has also made headlines this week after two vessels collided, spilling about 1000 tons of the stuff into the Pearl River estuary. Dead fish, shells, rocks and rubbish coated in palm oil washed up on beaches that were also covered in stinking clumps of the oil.
Environmentalists fear decaying palm oil could cause an algae bloom, which would compete with fish for oxygen, and could have negative consequences for wildlife in the region.
Sustainable palm oil?
Sustainable palm oil certifiers say they are seeking to lessen the environmental impact of cultivating the trees on habitats and species like the orangutan
There are attempts to make greener palm oil. The Roundtable on Sustainable Palm Oil (RSPO), for instance, is made up of industry players who have joined forces to set criteria for certified palm oil that minimizes the negative impact of the plant's cultivation.
Some experts say the criteria are too lax but represent a start. The main problem, they say, is that most palm oil is not certified - around 80 percent worldwide.