In order to reduce CO2 emissions from international aviation, the Dutch Government is considering the introduction of a CO2 emission ceiling for all flights departing from Dutch airports. This report discusses possible risks with respect to the effectiveness of a CO2 emission ceiling in relation to tankering.
Consequence of refueling for CO2 emission ceiling
A basic design choice for this CO2 emission ceiling is whether to use CO2 emission data derived from aviation fuel sales data (bunker-fuels) or from a modelling approach. A potential problem related to bunker-fuels data could be that not all fuel taken onboard on departing flights is actually required for safe operation of the flight. Tankering is the process where more fuel is taken on board than necessary for safe operation of a flight. Tankering could undermine the effectiveness of a bunker-fuel-based CO2 emission ceiling. Airlines might be able to partially avoid the impact of a CO2 emission ceiling by taking on more fuel on incoming flights to the Netherlands (inbound tankering), as such lowering the need to refuel in the Netherlands.
A modelling approach is insensitive to tankering and can include other behavioural responses to a CO2 emission ceiling as well. More research is needed to investigate whether advanced modelling would improve setting the ceiling and monitoring emissions.
Monitoring CO2 emissions from flights departing from the Netherlands
A recent legislative proposal by the European Commission would reduce the risk of tankering, as the EU proposes that at least 90% of the fuel required for a particular flight has to be taken onboard at the airport of departure. Although no data for the benchmark year 2005 will be available, the government could investigate the potential of this independently verified data as a basis for monitoring CO2 emissions from flights departing from the Netherlands.