[2] The fact that CH4, CO, and NMVOCs oxidize in the atmosphere to CO2 is not clearly addressed in the IPCC guidelines for other fossil carbon emission sources such as fugitives from coal mines, oil and gas systems, and industrial processes. A fully consistent inventory should account for this oxidized CO2 from non-combustion sources of fossil-based CH4, CO, and NMVOCs as well as from combustion sources.