An Analysis of the Climate Change Mitigation Potential of Solid Waste Management Scenarios for the Small Island Developing State of Mauritius from a Life Cycle Sustainability Perspective

The waste sector is the second-largest contributor to greenhouse gas emissions in Mauritius owing to landfilling. Hence, the Mauritian Government has decided to devise strategies to reduce landfilling. However, the solid waste management strategies of the Mauritian Government have been criticized for lacking evidence-based analysis with respect to sustainability. Thus, the present study attempted to bridge this science-policy gap by evaluating the sustainability level of a solid waste action plan proposed by the Mauritian Government (Scenario 1: 27% landfilling, 22% recycling, 31% composting/anaerobic digestion (AD) (out of the 31%, 50% organic waste for composting and 50% for AD), and 20% waste-to-energy (mass incineration)) and by comparing it to the business-as-usual (BAU) practice (95% landfilling, 5% recycling) and two alternative scenarios (Scenario 2: the same as Scenario 1 but substituting mass incineration with refuse-derived fuel and Scenario 3: the same as Scenario 1 but changing the amount of organic waste for AD and composting to 90% and 10% respectively). A Life Cycle Sustainability Assessment approach was undertaken by applying the ISO 14040 guidelines to evaluate environmental impacts in terms of global warming potential (GWP), economic impacts in terms of net present value (NPV), and social impacts in terms of number of employment generated. The impacts were thereafter combined using the Analytical Hierarchy Process. The results demonstrated that Scenario 3 was the most sustainable, followed by Scenario 1, Scenario 2, and the BAU. The study also revealed that Scenario 1 was more sustainable than the BAU, hence providing an evidence-based support for the government’s action plan, which might kick-start its implementation in Mauritius. Nonetheless, Scenario 3 can be considered an improvement for Scenario 1.