Emission factor
From Biocrawler, the free encyclopedia.
An emission factor can be defined as the average emission rate of a given pollutant for a given source, relative to units of activity. They can be used to derive estimates of gas emissions (for instance greenhouse gas emissions) based on the amount of fuel combusted or on industrial production levels. The level of precision of the resulting estimates depends significantly on the activity in question. Carbon dioxide emissions from the combustion of fuel can be estimated with a high degree of certainty whatever the fuel is being used for as these emissions depend almost exclusively on the carbon content of the fuel, which is generally known with a high degree of certainty. By contrast, the levels of non-CO2 emissions from combustion depend on the precise nature of the activity in which the fuel is being combusted. For instance methane emissions from transport depend on the vehicle type, whether the vehicle has been fitted with emissions controls and so on. Therefore, because of the uncertainties involved, the estimates of non-CO2 emissions from transport using emission factors will be much less precise than estimates of CO2 emissions.
