Towards improving emissions accounting methods in waste management: A proposed framework

This study examines the variability in estimating aggregated and disaggregated emissions from the solid waste sector using worldwide adopted methods for country accounting, life cycle assessment modelling, and corporate reporting. Disaggregation of emissions was conducted by source (waste management process from collection to disposal), gas (CO2, CH4, N2O) or type (direct and indirect) to identify processes contributing most to potential variability in estimated emissions. While similar operational data were introduced in all methods, significant variability in estimated emissions were evident across methods. The variability in aggregated emissions ranged from 3 to 65% that dropped to 2 and 17% when default parameters were standardized across methods. At the disaggregated level, a wider variability was discerned reaching several folds depending on the source, gas or type of emissions. The observed variability can be attributed to differences between methods in approaches and default parameters. These differences can affect emissions mitigation measures/reduction targets or influence investments in carbon credit to meet countries' Nationally Determined Contributions under the Paris Agreement. The study concludes with a framework to address limitations in existing methods with emphasis on increased flexibility in allowing the user to modify default approaches and parameters. (C) 2018 Elsevier Ltd. All rights reserved.