The emissions presented for the transport sector are calculated by multiplying the activity data figures with the emission factors. The numbers are part of the Norwegian emission inventory.
Activity data relevant for the transport sector can be annual fuel consumption for private cars.
Emission factors are established by researching the kinds and amounts of pollutants from combustion of fuels in a car engine. This is combined with information about the composition of the vehicle fleet in Norway. Then a representative amount of emissions from the vehicle fleet can be calculated for a specific year by combining emission factors and activity data.
The Emission Inventory is compiled and maintained by the Norwegian Environment Agency together with Statistics Norway. The Norwegian Environment Agency is responsible for developing emission factors and for collecting information from point sources. Statistics Norway is responsible for drawing up data models to model the emissions and to collect activity data. Statistics Norway also does the final calculations by applying the data model.
The data for the transport sector is published about one year after the collection of the data. Emissions that occurred in 2009 will be published at the beginning of 2011.