Carbon abatement cost optimization in China's municipal solid waste management: a shared socioeconomic pathway analysis

Municipal solid waste (MSW) management in China plays a crucial role in national carbon emissions, contributing significantly to greenhouse gas (GHG) emissions through collection, transportation, processing, and disposal. Effective carbon emission reduction in this sector significantly hinges on the chosen treatment technology paths. However, existing studies often overlook the trade-offs between economic and carbon abatement costs. This study integrates carbon pricing into an MSW treatment optimization model to assess the climate impact of different waste processing pathways. We explore the interaction between waste treatment technologies, economic costs, and carbon emissions under multiple Shared Socioeconomic Pathways (SSPs). Projections indicate MSW may surpass 500 million tons by 2060, with over 67% incinerated and 30% landfilled under current practices. By 2060, under SSP1, SSP2, and SSP5 pathway, incorporating carbon pricing can reduce carbon emissions by 5%-7% and lower total system costs by 12%-35%, compared to the baseline without carbon cost considerations. These reductions are driven by shifts in waste treatment technologies toward more cost-effective and low-carbon pathways. Utilization of chemical pyrolysis and biological fermentation is expected to rise by 2%-9%. While the methods may offer insights for other rapidly urbanizing countries, the findings are context-specific to China's waste management system, institutional settings, and socioeconomic development path. This study provides a foundation for developing climate-resilient waste policies and optimizing sustainable waste infrastructure within the Chinese context.