No abstract

conceived the idea for the paper; J.M.M. and K.A.S. contributed to the design of the research; M.K.H. and Firooz Firoozmand. identified the case studies, while F.F. and Pauline Rutter prepared the materials and resources and compiled the process documentation of the case-study workshops; F.F. and P.R. carried out the data collection; J.M.M. and K.A.S. led on the conceptual framework, and J.M.M. carried out the data analysis, the situating and linking of the work to other literatures, and the writing of the paper; J.M.M., K.A.S., and M.K.H. contributed to clarifying the focus and general structure of the paper as well as its relevance and methodological approach; all authors worked together on improvements to the paper.

Cities all over the world are trying to divert municipal waste away from landfill and fossil fuel-assisted incineration and toward circular economies where waste is converted into new resources. Residential food waste is the most challenging sub-stream, as it is the worst culprit in producing greenhouse gases in landfill and incineration, and it is almost impossible to have residents separate it cleanly at source. Here we investigate the outstanding diversion results of Shanghai Municipality since the introduction of the July 2019 Municipal Regulations, of over 9600 tons per day of clean food waste, still maintained two years later. In particular, we question why they might have increased so sharply after July 2019 and examine historic policies to determine broad policy intentions, their implementations, and officially reported tonnages of different resulting waste streams. It was found that many prior steps included infrastructure building and piloting different behavioral approaches. However, the July 2019 policy brought in legal responsibilities to very clearly defined roles for each stakeholder—including for the residents to sort and for local governances to support them—and this pulled all the operational elements together. The immediate and sustained jumps in clean food waste collection fed biogas production (0.1–1.0 GWh/day) and energy-from-waste (less wet) (5.4–8.6 GWh/day).