These gains were achieved despite the fact that West Germany had already made significant progress in improving its SWM practices and reducing landfill gas (methane) emissions prbr to 1990. The results show a potential 10 to 15% contributbn to reducing total national GHG emissions from improved SWM, including landfill mitigatbn and diversion, recycling and energy from waste. To help focus policy efforts, the total reductbn required by 2050 to achieve such stabilization was divided into seven equal parts, each of 1 billbn tonnes of carbon per year, known as 'stabilization wedges'. It has since been argued that reductions achieved through improvements in integrated solid waste management could roughly equal the reduction goal of one of these wedges.13 This suggests the potential to reduce current total GHG emissbns by around 14%, roughly in agreement with the independent German estimate.