Have you seen this reference around in any reading? Global warming potential (GWP) is a measure of the relative global warming effects of different gases. GWP assigns a value to the amount of heat trapped by a certain mass of a gas relative to the amount of heat trapped by a similar mass of carbon dioxide (CO2) over a specific period of time. Carbon dioxide was chosen by the Intergovernmental Panel on Climate Change (IPCC) as the reference gas and its GWP is taken as 1.
Therefore, in terms of a GWP value, CO2 = 1 and HFCS (Hydrofluorocarbons) have a GWP value of 2 to 14,000 for example.
Source: UNEP