Transport
Emissions

Emission factors are a measure of the amount of CO₂ emissions emitted by travelling using a certain mode of transport. Typically, emission factors are calculated based on passenger-kilometres (for passenger transport) or tonne-kilometres (for transport of goods). For example, the emission factor for driving an average gasoline car in Austria is typically around 219 grams of CO₂ per passenger-kilometre. For an average electric car it is 95 grams per passenger-kilometre.

There are direct and indirect transport emissions that are considered. Direct emissions refer to the emissions caused by the vehicle itself during its operation, such as tailpipe emissions from cars. Indirect emissions emerge in production and decommissioning of vehicles, the transport and production of fuel, and the construction of infrastructure. To assess the environmental impacts of different modes of transportation, both direct and indirect emissions are included in emission factors.

Several socio-regional factors additionally influence the calculation of emission factors. National differences play a role, influenced by varying electricity mixes in different countries. Additionally, vehicle occupancy rates have a large impact; the more people travel in a single vehicle, the lower the emissions per person will be. Moreover, the type of energy used to power vehicles is a key factor. Electric cars using renewable energy, for example, are responsible for less carbon emissions compared to electric cars using mixed energy sources.

• 2023. “Emissionsfaktoren für Verkehrsmittel.” 2023. https://www.umweltbundesamt.at/umweltthemen/mobilitaet/mobilitaetsdaten/emissionsfaktoren-verkehrsmittel.