The role of global waste management and circular economy towards carbon neutrality

Solid waste management is a cross-cutting issue that significantly influences multiple aspects of sustainable development globally. The waste sector is a major anthropogenic source of global greenhouse gas (GHG) emissions. Most global GHG assessments of waste management rely on generic data due to limitations in available data. This research used reflective inventory data for municipal solid waste (MSW) treatment systems related to the income levels of countries, resulting in more context-specific and comprehensive assessments of GHG emissions. This study aims to assess life cycle GHG emissions from the global MSW management sector for the years 2023, 2030, and 2050 and then analyses the global and regional waste management goals set by the United Nations Environment Programme (UNEP) and the European Union (EU) to identify hotspots in the MSW management systems and critical factors that influence GHG emissions from the waste sector. The study was conducted in accordance with the standards outlined in ISO 14067:2018. The results show that the average global GHG emissions from 1 tonne of MSW in 2023 based on the existing MSW management practices was approximately 89.7 kg CO_2e. The major contributor was the open dumping of MSW, contributing almost 70 % of GHG emissions. The global MSW management sector emitted a total of 173.2 Mt CO_2e GHG emissions in 2023. If no improvements are made to existing systems, GHG emissions from the waste sector are projected to increase to 203.4 Mt CO_2e by 2030, and to 289.5 Mt CO_2e by 2050. Achieving waste management goals can reduce GHG emissions by approximately 1 % to more than 160 %. The implementation of the circular economy in the waste sector has the potential to achieve net zero emissions from the global MSW management sector by 2030 and 2050. This study provides achievable MSW management targets for the world and highlights key factors to achieve carbon neutrality from the waste sector. Prioritising policies such as upgrading open dumps, standardising household-level waste separation procedures, minimising food waste, establishing national recycling targets, and promoting circular economy through a zero-waste approach could substantially reduce GHG emissions from the waste sector. These findings are important for the adoption of circular economy principles in MSW management systems to effectively support the pursuit of carbon neutrality goals.