Household landfill diversion and the impact on methane emissions

Food waste accounts for approximately 8% of total global greenhouse emissions. Expanding organics diversion (composting) programs is a common solution for reducing methane emissions from landfills, which are primarily caused by organics. This study explores the staggered implementation of a curbside organics program expansion and finds that households increase their diversion behavior by 45%; however, the program costs per household are nine times greater than the social benefit of avoided methane. The cost/ton of carbon dioxide equivalent emissions (CO2e) avoided is then estimated across the United States for these programs. The median organics program expansion would cost $478/ton of CO2e avoided. However, this estimate has substantial heterogeneity because some municipalities, particularly large cities, are served by landfills with methane capture, resulting in the largest potential methane producers having among the lowest methane emissions per household. The findings suggest that current organics program designs may be difficult to justify solely on climate grounds.