The IPCC's Fourth Assessment Report puts the contribution of the solid waste and wastewater management sector to global greenhouse gas emissions at 2.7%, which might at first sight appear to be comparatively low. According to the IPCC accounting rules this figure does not take into account the impacts of reducing, re-using or recycling of waste as well as waste-to-energy strategies on climate protection. These effects are either attributed to other GHG source categories in order to avoid double counting or they are not accounted for at all. The contribution of these elements of solid waste management to GHG reduction can only be calculated indirectly. SWM experts estimate that globally GHG emissions could be reduced by up to 10% at comparably low costs if sustainable waste management systems where put in place in particular in developing and emerging countries. Additionally they would significantly contribute to improve public health conditions and environmental protection in their countries.The objective of the "Tool for Calculating GHG Emissions in Solid Waste Management" (SWM-GHG Calculator), which was developed by IFEU-Institute, sponsored by KfW Development Bank in cooperation with GTZ and financed by funds of the German Federal Ministry for Economic Cooperation and Development (BMZ) is to aid in understanding the effects of proper waste management on GHG emissions.Additionally, the SWM-GHG Calculator provides guidance information on the costs associated with different waste management strategies.