Strong forest and peatland protection must be enacted and enforced to deal with the industrial-scale expansion of the plantations, the study by the National Academy of Sciences said.
Researchers from Yale and Stanford universities participated in the study and found that about two-thirds of lands outside of protected areas in the West Kalimantan Province in Indonesian Borneo are leased to oil palm agribusiness companies.
Fifty percent of oil palm plantations established last year where on peatlands, and when peat soils are drained for oil palm cultivation they begin to release the greenhouse gas carbon dioxide, researchers said.
"Preventing oil palm establishment on peatlands will be critical for any greenhouse gas emissions-reduction strategy," Yale researcher Kimberly Carlson said.
Even if future oil palm expansion is halted in forests and peatlands, greenhouse gas emissions will decline by only 3 percent to 4 percent, she said, even with a moratorium on oil palm expansion.
Instead of a moratorium, she said, "protecting secondary and logged forests, as well as peatlands, is the strategy that most effectively reduces carbon emissions and maintains forest cover."
Indonesia is the global leader in the production of palm oil, a form of edible vegetable oil used in many products including cookies, crackers, popcorn, frozen dinners, low-fat dairy, candy, soap and cosmetics.