For the first time, researchers using satellite techniques have measured and mapped the full extent of South-east Asia’s oil palm cultivation - and linked it directly to carbon dioxide emissions.
They reckon there are about 8.3 million ha of oil palm plantations in peninsular Malaysia, Borneo and Sumatra - that is roughly the size of two Switzerlands.
The growing industry provides a valuable resource - palm oil is widely used in food, as biofuel and to make other products such as cosmetics.
Some 880,000ha of the plantations were converted from peat-swamp forests.
High in biodiversity, peat swamps have vast carbon dioxide stores, so clearing the forests resulted in 140 million tonnes of carbon being added to the atmosphere, the researchers concluded from their findings.
The research paper by Dr Koh Lian Pin and his colleagues at the National University of Singapore and Swiss technical university ETH Zurich was published earlier this month in the Proceedings of the National Academy of Sciences.
The paper’s authors also noted that the satellite monitoring techniques could be used to track how far oil palm cultivation had encroached on peat forests.
In addition, their research looked at what implications arise from how the cleared land is being or will be utilised.
Since the early 2000s, 2.3 million ha of peatlands have been cleared, but they have yet to be cultivated. These cleared areas might contain young oil palm, remnants of the original vegetation or grass.
Reforestation of these areas could increase bird, animal and plant life by up to 20 per cent in some parts, whereas planting oil palm would decrease species by up to 12 per cent, the scientists estimated.
‘The fate of these cleared lands has immense environmental implications,’ Dr Koh told The Straits Times by e-mail.
Developing the land would exacerbate carbon and biodiversity losses. In contrast, conservation and regeneration would protect wildlife and help store more carbon.
Dr Koh recommended that areas with lots of peat-swamp forests be protected, such as West and Central Kalimantan and Riau.
Oil palm is not the only industry being studied. Other scientists are measuring the environmental impact of the pulp and paper industry, another sector often involved in clearing of peatlands.
