Palm oil cultivation has been criticized for impacts on the natural environment,[85][86] including deforestation, loss of natural habitats,[87] which has threatened critically endangered species such as the orangutan[88][89] and Sumatran tiger,[90] and increased greenhouse gas emissions.[86][91] Many palm oil plantations are built on top of existing peat bogs, and clearing the land for palm oil cultivation contributes to rising greenhouse gas emissions.[91][92]
Efforts to portray palm oil cultivation as sustainable have been made by organizations including the Roundtable on Sustainable Palm Oil,[93] an industry group, and the Malaysian government, which has committed to preserve 50 percent of its total land area as forest.[10] According to research conducted by the Tropical Peat Research Laboratory, a group studying palm oil cultivation in support of the industry,[94] oil palm plantations act as carbon sinks, converting carbon dioxide into oxygen[95] and, according to Malaysia's Second National Communication to the United Nations Framework Convention on Climate Change, the plantations contribute to Malaysia's status as a net carbon sink.[96]
Environmental groups such as Greenpeace and Friends of the Earth oppose the use of palm oil biofuels, claiming that the deforestation caused by oil palm plantations is more damaging for the climate than the benefits gained by switching to biofuel and utilizing the palms as carbon sinks.[92][97][98]
While only 5 percent of the world's vegetable oil farmland is used for palm plantations, palm cultivation produces 38 percent of the world's total vegetable oil supply.[99] In terms of oil yield, a palm plantation is 10 times more productive than soya bean and rapeseed cultivation because the palm fruit and kernel both provide usable oil.[99]