How does the ?Zero-waste City? strategy contribute to carbon footprint reduction in China?

The Zero-waste City program and carbon peak plan are currently vital environmental strategies in China. Solid waste management systems are closely related to greenhouse gas emissions, and Zero-waste City programs are highlighted because of their great potential for carbon footprint reduction and pollution mitigation. However, a knowledge gap remains in terms of quantifying the carbon footprint when implementing Zero-waste City programs. Here, we developed a methodology for accounting for the carbon footprint of a solid waste management system, and Ningbo city, which is one of the first demonstration Zero-waste Cities in China, was chosen as the study case. The material flow and carbon footprint of construction and demolition waste, industrial waste, hazardous waste, sludge, and municipal solid waste were analyzed. The results show that the carbon footprint of the solid waste management system in Ningbo city was -1679.9 Gg CO2_eq in 2018, which can be divided into 3472.5, 1131.3, and -6283.8 Gg CO2_eq by Scopes 1, 2, and 3, respectively. According to the scenario analysis, the SWMS in Ningbo city can achieve a carbon footprint reduction potential of at least 5771.5 Gg CO2_eq by 2025, by implementing the Zero-waste City strategy. This suggests that waste minimization, construction and demolition waste recycling, and municipal solid waste recycling are the most effective measures for carbon footprint reduction.

Automated summary

The Zero-waste City program and carbon peak plan are important environmental strategies in China. A study was conducted in Ningbo city, one of the demonstration Zero-waste Cities, to analyze the carbon footprint of the solid waste management system. The results showed that waste minimization and recycling are effective measures for carbon footprint reduction, with a potential reduction of at least 5771.5 Gg CO2_eq by implementing the Zero-waste City strategy by 2025.