Global climate change mitigation scenarios for solid waste management

Abstract

The waste sector is an important contributor to climate change. CH4 produced at solid waste disposal sites contributes approximately 3–4 percent to the annual global anthropogenic greenhouse gas emissions. Emissions from solid waste disposal are expected to increase with increasing global population and GDP. On the other hand, many cost-efficient emission reduction options are available. The rate of waste degradation in landfills depends on waste composition, climate and conditions in the landfill. Because the duration of CH4 generation is several decades, estimation of emissions from landfills requires modelling of waste disposal prior to the year whose emissions are of interest. In this study, countryor region-specific first-order decay (FOD) models based on the 2006 IPCC Guidelines are used to estimate emissions from municipal solid waste disposal in landfills. In addition, IPCC methodology is used to estimate emissions from waste incineration. Five global scenarios are compiled from 1990 to 2050. These scenarios take into account political decision making and changes in the waste management system. In the Baseline scenario, waste generation is assumed to follow past and current trends using population and GDP as drivers. In the other scenarios, effects of increased incineration, increased recycling and increased landfill gas recovery on greenhouse gas (GHG) emissions are assessed. Economic maximum emission reduction potentials for these waste management options are estimated at different marginal cost levels for the year 2030 by using the Global TIMES model. Global emissions from landfills are projected to increase from 340 Tg CO2 eq in 1990 to 1500 Tg CO2 eq by 2030 and 2900 Tg CO2 eq by 2050 in the Baseline scenario. The emission reduction scenarios give emissions reductions from 5% (9%) to 21% (27%) compared to the Baseline in 2030 (2050). As each scenario