4. Assessment of the Forest Carbon Balance Due to Deforestation and Plantation Forestry in Southeast Asia

Assessment of the carbon balance due to changes in forest land uses could serve as an important benchmark for the Reducing Emissions from Deforestation and Forest Degradation (REDD+) scheme of the United Nations Framework Convention on Climate Change. Here, we assessed the carbon gains and loss due to deforestation and plantation forestry in Southeast Asia during the implementation period of the Paris Climate Agreement between 2020 and 2030. Data on forest cover and carbon stocks were obtained from the most recent forest resources assessment report by the Food and Agriculture Organization. We performed a regression analysis to obtain parameters and initial values for predicting the forest cover change, where logging was assumed to take place in both natural and plantation forests. Between 2000 and 2020, Southeast Asia lost about 0.5%, or 1.1 million hectares, every year, whilst plantation forests gained 1.8%. Carbon stocks in natural forests declined to 15.7 petagrams of carbon (PgC) in 2030 from 19.7 PgC in 2000. On average, Southeast Asia emits about 468.6 teragrams of carbon dioxide per year (TgCO₂ year⁻¹) due to the loss of natural forests and logging, or about 23% of emissions, from tropical forests. Plantation forests gain about 25.9 TgCO₂ year⁻¹ between 2000 and 2030. Between 2020 and 2030, Southeast Asia is likely to emit about 442.7 TgCO₂ year⁻¹. If a retrospective approach is used, the forest reference emission level for this region is 424.2 TgCO₂ year⁻¹ during the implementation period of the Paris Agreement. Carbon revenues under the REDD+ scheme were estimated at US$2.4 billion annually under the Paris Agreement. Our study suggests that plantation forests could play a role in increasing role wood supply to the region, but caution is needed because large-scale plantations can cause environmental destruction.