City-Level Nexus of Embodied Waste Carbon in China

Waste management and carbon emission reduction, both central to the Sustainable Development Goals, are increasingly encouraged to be integrated due to the strong and inherent linkages between waste generation and greenhouse gas emissions. A system-wide understanding of this relationship across the entire supply chain, from production to final consumption, is fundamental for identifying leverage points for source reduction. This study provides a novel city-level assessment of the coupling coordination between waste and carbon emissions in China. The results reveal that, although megalopolises act as consumption hubs, benefiting from reduced local generation of hazardous waste, industrial solid waste, and carbon emissions through outsourced production, they still exhibit consistently high coupling coordination between carbon and waste emissions. Furthermore, demand-side strategies are equally critical because coupling coordination is 20.4-68.8% higher from the consumption perspective than from the production perspective, underscoring the decisive role of final demand in driving upstream environmental pressures. Between 2015 and 2019, the average coordination between hazardous waste and carbon emissions from a production perspective increased by 18.4%, whereas other coordination indicators remained relatively stable. The strengthening was particularly pronounced in medium and small cities, where increases in hazardous waste and carbon intensities were the primary drivers, outweighing the influence of sectoral output changes. These findings provide a foundation for integrated environmental governance to support both carbon neutrality and zero-waste development goals.