System dynamics analysis on greenhouse gas emissions from municipal solid waste disposal under waste management policy: Case study Bangkok, Thailand

Rapid urbanization and limited disposal capacity have intensified greenhouse gas (GHG) emissions from municipal solid waste (MSW) management in Bangkok, Thailand. Despite growing policy attention, integrated assessments linking waste composition, treatment pathways, and emission outcomes remain limited. To address this, a system dynamics (SD) model was developed to quantify and compare GHG emissions under five management scenarios toward the city’s 2032 mitigation goals. The model incorporated localized waste composition data and three disposal routes including landfill, incineration, and composting, validated with field data from three transfer stations and IPCC emission factors. The simulation was divided into five scenarios to explore mitigation options. Results indicate that expanding incineration (S1) would increase emissions by 43.5% due to high fossil-based waste. In contrast, reducing food waste by 50% (S2) yields the largest reduction (16.3%), while a 5% plastic waste reduction (S3) and combined food–plastic reduction (S4) offer marginal benefits. Notably, S4 does not outperform food waste reduction alone. The baseline scenario (S0) reflects current practices. These findings highlight that source-level waste reduction, particularly of organic waste, is more effective than capacity expansion. The SD framework provides a decision-support tool for designing low-carbon and resilient urban waste management policies adaptable to similar contexts. • System dynamics model links waste composition to GHG emissions in urban MSW. • Expanding incineration raises GHG due to high plastic-based fossil content. • Reducing food waste by 50% yields the highest GHG mitigation. • Reducing plastic waste has a relatively limited effect on GHG emissions compared to other waste reduction strategies. • The model supports localized strategies for urban low-carbon waste systems.