Emission Factor

An emission factor is the mass of a pollutant or greenhouse gas released per unit of fuel burned or activity performed, for example grams of CO2 per gram of fuel. For marine fuels the carbon factor Cf converts fuel consumption into CO2 for EEDI, EEXI, and CII: heavy fuel oil uses Cf of 3.114, marine diesel and gas oil 3.206, and LNG around 2.750. The IMO Life Cycle GHG Intensity Guidelines extend this to well-to-wake factors covering CO2, methane, and N2O. Multiplying fuel mass by the factor gives the emission inventory; the factor’s accuracy sets the inventory’s accuracy.