Quantifying carbon reduction potential of "Zero-Waste City" pilot: A case study of Shenzhen based on Source...

The "Zero-Waste City" (ZWC) pilot and the carbon peak plan are essential environmental strategies in China. Solid waste management is a critical but often overlooked driver of greenhouse gas emissions, making ZWC pilot increasingly significant. However, quantifying their carbon reduction impact remains understudied. This study proposes a carbon emission accounting method for solid waste management based on the Source reduction-Recycling-Disposal (SRD) framework, comprehensively considering source reduction, resource utilization, and disposal. Shenzhen, one of the first pilot ZWC in China, was selected as the case study. The results show that Through its active participation in the ZWC pilot, Shenzhen has accomplished substantial carbon reductions, with total emissions declining from -96.51 Mt of CO₂eq in 2018 to -195.13 Mt of CO₂eq by 2020, with per-ton-waste emissions decreasing from -0.06 to -0.12 t CO₂eq, reflecting an impressive 102 % reduction. Scenario analysis projects this number will further decrease to -554.7 Mt CO₂eq (-5.0 t CO₂eq/twaste) by 2035, resulting in a total reduction of 183 %. Waste nonferrous metals show the highest carbon reduction potential (46.08 %, -25.5 Mt CO₂eq), followed by waste paper (14.13 %, -6.5 Mt CO₂eq), with recyclable resources and municipal solid waste contributing 52.84 % and 26.70 % respectively. The study also finds that source reduction (contributing 62.31 %) and recycling (contributing 40.90 %) are the most effective carbon reduction strategies. These findings provide valuable management decision-making support and a methodological framework for further advancing China's "Zero-Waste City" pilot.