“CO2equivalent”?

♤ GHG emissions/removals can be expressed either in physical units (such as grams, tonnes, etc.) or in terms of CO2 equivalent (grams CO2 equivalent, tonnes CO2 equivalent, etc.).

♤ The conversion factor from physical units to CO2 equivalent is the Global Warming Potential (GWP) of the corresponding GHG.

♤ If X Gg of CH4 is to be expressed in terms of CO2 equivalent, then it is multiplied by 21, which is GWP of CH4 over 100 years timescale.