Twentieth International Conference on Environmental, Cultural, Economic & Social Sustainability

Abstract

Regulations requiring the diversion of rapidly degrading organic waste from landfills (i.e., organics diversion) are becoming abundant globally to achieve global warming potential (GWP) reduction. Policies must be financially attainable and consider other environmental and social impacts to avoid burden shifting. The environmental impacts (ISO 14040 life cycle assessment standards), life cycle costs (present worth analysis), and environmental damage costs (CE Delft’s method) associated with managing 1 kg municipal solid waste over 20 years were quantified. Scenario analysis included multiple technologies (landfilling, composting, anaerobic digestion, pyrolysis) and sorting strategies (separating all organics, only food, only yard waste). Breakeven analysis evaluated the impact of different policy interventions (i.e., carbon tax, renewable energy credits, biochar subsidies). Overall, organics diversion policies focused on climate change will only be effective if they divert food waste; relative to landfilling, diverting food waste to composting, pyrolysis, or anaerobic digestion decreases GWP by 63%, 70%, and 74%, respectively, whereas diverting yard waste only decreases GWP by 12%, 24%, and 14%, respectively. There is a large economic cost associated with these GWP decreases; diverting organics to composting, pyrolysis, or anaerobic digestion increases costs by 13%, 95%, and 147%, respectively. Policy interventions could be implemented to make organics diversion economically competitive with landfilling; for example, pyrolysis could be competitive with an 18 USD/tCO2e carbon tax, a 34 USD/MWh renewable energy credit, and a 0.78 USD/kg biochar selling price. Ultimately, this work’s policy analysis identifies realistic avenues for navigating the economic and environmental tradeoffs associated with waste management.