What are the definitions of activity data, an emission factor and an implied emission factor?
Activity data, according to the Revised 1996 IPCC Guidelines for National Greenhouse Gas Inventories, are defined as data on the magnitude of human activity resulting in emissions or removals taking place during a given period of time. An emission factor is defined as the average emission rate of a given GHG for a given source, relative to units of activity. An implied emission factor is defined as emissions divided by the relevant measure of activity: IEF = Emissions / Activity data For source/sink categories that are composed of several subcategories, the emissions and activity data in the formula above are summed up across all subcategories. Hence, the implied emission factors are generally not equivalent to the emission factors used to calculate emission estimates, but are average values that could be used, with caution, in data comparisons. For information on actual emission factors, the latest national inventory report for the relevant Party should be consulted.
