Verra has released clarifications to two Clean Development Mechanism (CDM) methodologies for composting: ACM0022: Alternative waste treatment processes, v3.0 (external) and AMS-III.F.: Avoidance of methane emissions through composting, v12.0 (external). The two CDM methodologies apply to activities that reduce methane emissions from organic waste, with ACM0022 covering alternative waste treatment processes (e.g., composting under aerobic conditions, gasification, anaerobic digestion with biogas recovery) and AMS-III.F. covering controlled biological treatment through composting or anaerobic digestion in closed reactors.

The clarifications confirm that the methodologies, which refer broadly to composting projects, are also applicable to insect composting projects in the Verified Carbon Standard (VCS) Program. The clarifications are effective as of February 14, 2025.

The primary clarification to each CDM methodology stipulates that composting under these methodologies covers any type of controlled aerobic biological treatment, including microorganisms, insects, earthworms, and others. Therefore, composting activities involving insects are also included in each methodology.

Insect composting is an alternative waste management practice with aerobic conditions; it reduces methane emissions when replacing anaerobic waste treatment practices that do not include methane destruction. This method transforms organic waste into compost and, depending on the process, may have additional benefits, such as offering substitutes (for example, in animal feed) for animal or crop-based protein sources that are associated with higher greenhouse gas emissions and use of land and other resources.

The clarifications to ACM0022 (PDF) and clarifications to AMS-III.F. (PDF) documents contain additional guidance, including on the following topics:

  • Determination of the methane and nitrous oxide project emission factors
  • Procedures for demonstrating additionality
  • Use of the latest version of Intergovernmental Panel on Climate Change (IPCC) documents