This paper is part of a series detailing novel methodologies for estimating key components of food systems emissions, with a view to disseminate the information in FAOSTAT. It provides a methodology for estimating the GHG emissions associated with emissions from waste in the food system (e.g., food-related processes in landfills, incineration, wastewater management processes), in an effort to inform countries of the environmental impacts and possible options to reduce them.