Organic waste composting projects are an emissions-reduction project type within the waste & methane segment of the carbon market. They are designed to divert organic waste from anaerobic disposal into controlled aerobic composting. The carbon benefit comes from avoided methane emissions from diverting organics away from anaerobic disposal. Common project configurations include Municipal or commercial organics composting.

Composting projects usually work best where they demonstrably divert organic waste from anaerobic disposal pathways that would have generated methane. Many of these pathways focus on methane or other potent non-CO2 gases, so they can have strong near-term climate significance; at the same time, the integrity of baseline assumptions, destruction efficiency, and ongoing monitoring is especially important. For buyers and program designers, the most important diligence questions are: Was the waste truly landfill-bound or anaerobically treated in the baseline? Are leakage and process emissions counted?