The fate of waste organic matter is very important, particularly at a time of concern about food supplies and soil fertility. When composted and returned to cultivation, organic matter provides multiple benefits. It locks carbon in soil; improves the structure and workability of soils (reducing the need for fossil fuels for plowing and tilling); improves water retention (irrigation is a heavy consumer of energy); displaces energy-intensive synthetic fertilizers; and results in more rapid plant growth (which takes CO2 out of the atmosphere). No industrial process can reproduce the complex composition of soil, which needs to be replenished with organic matter; yet incinerators and landfills interrupt this cycle, leading to long-term soil degradation.
When organic waste ends up in landfills, the organic content (such as paper and food scraps) putrefies, producing methane, a greenhouse gas many times more potent than carbon dioxide, especially in the short term.
The Solution: Zero Waste
A far better approach is known as Zero Waste, which aims to close the loop on all material used in the economy. Under Zero Waste, each element of a source-separated waste stream is subjected to minimal treatment so that it can be reused. Clean, source-separated organics (including kitchen discards) are composted or subject to anaerobic digestion; usable goods are repaired and re-used; other materials are recycled.
Besides saving resources and money, and generating more jobs for local communities, Zero Waste produces far less pollution than waste disposal techniques. It eliminates methane emissions from landfills by diverting organics; it eliminates greenhouse gas emissions from incinerators by closing them; it reduces greenhouse gas emissions from industry by replacing virgin materials with recycled materials; and it reduces greenhouse gas emissions from transport by generally keeping such materials close to the end-user.