The production of waste and wastewater, whether household refuse, agricultural or industrial is also a source of greenhouse gas emissions. These occur mainly in the form of methane emissions during anaerobic digestion of organic matter present in waste and wastewater. Irrespective of the final destination and type of treatment used, waste management and wastewater treatment operations are always responsible, in one way or another, for greenhouse gas emissions. Landfills, in particular generate significant emissions. Although emissions are lower for incineration, in terms of global warming, the combustion creates atmospheric emissions raising other environmental issues.
Beyond the consideration of direct emissions from the end-of-life of products like, landfills, incinerators and others, it is fundamental to take into account emissions derived from the products’ own life cycle: from the design phase, to use and to its end-of-life and final destination. It follows then that reducing the production of waste and wastewater is the most efficient strategy to resolve this issue. To maximize the re-utilization of goods and to recycle materials point to one approach: to "close" the life cycle of materials and to properly manage resources.