What is the limit to oil palm expansion?
In recent years, the palm oil industry has enjoyed meteoric growth as palm oil has become the most widely used vegetable oil on the planet. It’s found in everything from nail polish to Kit Kats. This boom, however, has come at the expense of the vast tracts of forests that have been cleared to plant oil palm.
Taken together, two recently published studies paint a broad picture of the recent and potential impact of the industry at a global scale: from how much forest has been cleared in the past quarter of a century, to how much land is available for and threatened by oil palm plantations in the near and long term. Both studies conclude that while there’s lots of land suitable for the crop, the majority of it should be off limits because of its value for biodiversity and carbon sequestration.
In a study published in PLOS One, researchers used a combination of Landsat and Google Earth imagery to identify sample palm plantation sites that existed in 2013 in 20 countries. They then looked back in time, as far as 1989, to see if the identified plantations had been previously forested. They found that in Southeast Asia, which produces the vast majority of palm oil today, 45 percent of the plantations had been forests in 1989. In South America, 31 percent of the plantations had been forested land in 1989. Meanwhile, in MesoAmerica and Africa, those figures were 2 and 7 percent respectively, indicating the industry has had far less impact on forest cover in these regions.
The researchers used models to calculate how much land in these 20 countries was currently suitable for palm plantations and how much would be in 2080, accounting for climate change. Then they calculated how much of this suitable land had no protective status that would prevent clearing it for palm.
Overall, they found that in countries where there had recently been high rates of forest cleared for palm, more than 30 percent of the land suitable for palm was unprotected forests. Africa and South America had the largest forest areas under threat from future palm expansion. “History is the best predictor of the future,” said co-author Stuart Pimm. He added that by identifying which plantations arose from cleared forest, they can identify which areas—and ultimately which actors—to keep an eye on in the future.
In another paper, published in Global Environmental Change, researchers tallied how much land was left on Earth where palm oil could be produced sustainably—which is to say without clearing forests of high environmental value. Using databases on soil quality, climate, and topography, researchers determined that there were 1.37 billion hectares of land where oil palm could be grown. To figure out where it should be grown, however, they identified and removed from the total any land that was already in use, protected, or that has a high environmental value. In the end, only 17 percent of the suitable land was left for sustainable palm production.
A number of producing countries were either close to their limit, at the limit, or had overstepped it. When the researchers considered only “very suitable land” that could be used to sustainably grow oil palm, they found 19.3 million hectares available, although much of it is highly inaccessible.
Of course, now that the maps are drawn and the numbers are in, the challenge for conservationists will be to ensure that new plantations go in the places where they ought to. —Catherine Elton | 5 August 2016
Vijay, V et al (2016). The Impacts of Oil Palm on Recent Deforestation and Biodiversity Loss, PLOS One. doi: 10.1371/journal.pone.0159668
Pirker J. et al (2016). What are the limits to oil palm expansion? Global Environmental Change DOI: doi:10.1016/j.gloenvcha.2016.06.007
Header image: products that contain palm oil
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