Impacts of Oil Palm Plantations on Climate Change: A Review of Peat Swamp Forests’ Conversion in Indonesia

Indonesia possesses a rich biodiversity with abundant natural resources such as tropical rain and peat swamp forests, oil and gas deposits, and fertile soils just to name a few. The state policies on natural resource management were decentralized and the power and local autonomy rights were given to provincial and district governments. This resulted in an enormous expansion of oil palm plantations across the country especially over the last three decades. On the one hand it boosted the country’s economy by bringing foreign money reserves, but on the other hand has led to severe deforestation, shifting cultivation, peat swamp forests conversion and land degradation. Thus, due to the severity of these environmental consequences and associated climate change implications, oil palm development has received significant attention from all stakeholders and is the subject of global debate. This paper aims to discuss the results of various studies regarding emissions of GHGs from oil palm plantations in Indonesia and highlights the fundamental methodologies followed in assessing GHGs emissions. We found throughout contradictions in the reported rates of oil palm encroachment over peatland and GHG emissions. The former because of diverse methodologies followed in each study i.e. different amounts of time spent in the field, scales of study area, analytical techniques in GIS (data sets and supplementary remote sensing); and the later because of both differences in instrumentation and underlying principles; such as indirect GHG assessments from subsurface drainage(level of water table), subsidence, soil and biomass carbon stock differences, autotrophic and heterotrophic respiration, close chamber methods, eddy covariance techniques and utilization of micrometeorological stations. Finally, the review concludes that almost all studies demonstrate a linear increase in oil palm plantations and proclaim a net negative climate change impact due to conversion from peat swamp forests to oil palm plantations. Therefore, it is being suggested that the pre-existing GHG inventories data should be further worked out to developa ‘standard carbon sequestration model for peatlands’, supported by updated countrywide peatlands mapping and policy reforms which should address both economic development from the oil palm sector and consider mitigation of GHG emissions from peatlands conversion.