Carbon Emissions Associated with Organic Solid Waste Management in Developing Countries: A Brazilian Case Study

Municipal solid waste (MSW) management in Brazil faces significant challenges related to waste segregation, collection efficiency, and environmentally adequate disposal. This study quantifies the carbon emissions associated with organic solid waste management, from 2022 to 2034, in the city of João Pessoa (Northeast Brazil). To this end, the Life Cycle Assessment methodology is applied to two scenarios: Scenario 1 (where all organic fraction is landfilled) and Scenario 2 (progressive implementation of composting for the domestic organic waste, starting in 2023, with increases each year until reaching 50% in 2034, and the remainder being landfilled). The latter is proposed based on the targets established in the Municipal Solid Waste Plan of João Pessoa. Projection for MSW considered a per capita rate of 0.86 kg/inhab.day, combined with a population growth rate of 1.92%/year. The results indicate that Scenario 1 emits 825 Mt CO2-eq while Scenario 2 emits 704 Mt CO2-eq for the study period (a reduction of 15%). A sensitivity analysis examined the effects of increasing transport distance (25–45 km) and the organic fraction of MSW (35–45%) on GHG emissions. Although total emissions rose under both conditions, the comparative environmental advantage of composting over landfilling remained stable. These results confirm the robustness of the analysis and reinforce composting as a low-carbon, effective strategy for managing urban waste.