Life cycle climate change mitigation through next-generation urban waste recovery systems in high-density Asian cities: A Singapore Case Study

Abstract

The potential of implementing waste recovery strategies on three kinds of waste – food, sewage, and plastic – in reducing waste-related greenhouse gas emissions in Singapore was evaluated using life cycle assessment. It was found that the proposed strategies are capable of reducing 1,087.80 kgCO2-eq per tonne of plastic waste, 53.00 kgCO2-eq per tonne of food waste, and 43.86 kgCO2-eq for the combination of one tonne of sewage waste and one tonne of food waste. When uncertainties of the three waste streams were considered in sensitivity analysis and projections of waste quantities to 2025 were performed up to a 95% confidence level, it was found that the proposed strategies could reduce about 37.13% of the GHG emissions from the business-as-usual disposal waste technology (that is, incineration). This corresponds to an average reduction of 0.53 million tonnes CO2-eq per year, which is equivalent to the annual GHG emissions from electricity consumptions of 256,322 households in Singapore.