Greenhouse gas emission from Thailand's AFOLU sector in upper southern: current trends and future projections

This study aims to investigate greenhouse gas (GHG) emissions from the Agriculture, Forestry, and Other Land Use (AFOLU) sector in Thailand's upper southern region, and to project future emissions through 2030 under two scenarios: Business-as-Usual (BAU) and the National Target (NT) scenario. The study area includes five provinces—Ranong, Chumphon, Nakhon Si Thammarat, Phatthalung, and Trang—characterized by abundant natural resources, including carbon-sequestering ecosystems such as mangrove forests. However, ongoing deforestation and agricultural expansion in these provinces have become major sources of GHG emissions, particularly methane (CH 4 ) from rice cultivation and livestock, and carbon dioxide (CO 2 ) from forest conversion. The study employs IPCC guidelines to assess current emissions and project future emissions up to 2030. Results indicate that the current GHG emissions from AFOLU are primarily from livestock (938,149 tons CO 2 -eq) and rice cultivation (261,745 tons CO 2 -eq). Under the BAU scenario, these emissions are projected to increase to 1.59 million tons CO 2 -eq and 292,793 tons CO 2 -eq, respectively. Net methane emissions are expected to rise, as reductions in rice emissions are outweighed by increases from livestock. Meanwhile, CO 2 emissions from deforestation are also projected to grow significantly. Implementation of mitigation measures under the NT scenario is projected to reduce emissions from livestock and rice cultivation by approximately 5 % and 17 %, respectively. Furthermore, to achieve the national GHG emission reduction targets, the application of regional and provincial-specific mitigation strategies—such as alternate wetting and drying techniques in rice paddies, improved manure management, and sustainable land-use practices—must align with both the local context and consistent national policies. • First sub-national assessment of GHG emissions from Thailand's AFOLU sector in the upper southern region using IPCC Tier 1 and localized activity data. • Integrated spatial analysis across five provinces reveals livestock as the dominant emission source, with methane emissions projected to increase by 70 % under BAU. • Forest land under BAU still functions as a net carbon sink, but sequestration potential improves significantly under NT with a projected 27 % increase in carbon removal. • Application of NT scenario results in measurable mitigation outcomes: 5 % reduction in livestock emissions, 17 % in rice cultivation, and 865,958 tCO 2 eq/year additional carbon sequestration from forests. • AWD rice techniques, biogas adoption, and forest expansion can aid Thailand's 40 % forest area target.