Climate Change Effects of Gases from Municipal Solid Waste Landfills

Direct and indirect effects of landfill gases and interrelationships between direct and indirect climate-forcing emissions and cover soil characteristics were analyzed at 5 municipal solid landfills in California. Fluxes of 80 chemicals were quantified across daily, intermediate, and final covers using static flux chambers. Whole-site emissions were scaled up using the flux data. Direct and indirect climate-forcing emissions were estimated through application of global warming (direct), atmospheric degradation (direct), tropospheric ozone forming (indirect), stratospheric ozone depleting (indirect), and secondary aerosol forming (indirect) potentials reported for each chemical. Methane emissions accounted for 46 to 99% of the total direct climate-forcing emissions. Nitrous oxide and F-gases collectively accounted for 1 to 99% of the total direct climate-forcing emissions. Overall direct emissions accounted for 93 to nearly 100% of the total combined (direct and indirect) climate-forcing emissions. Correlations were observed: a) between direct and indirect climate-forcing emissions of greenhouse gases and water content parameters as well as void ratio and b) between direct and indirect climate-forcing emissions of NMVOCs and mass of water in a cover profile, volumetric air content, temperature, and volumetric solids content.