Consideration of alternative approaches to regulating CO2 emissions from light-duty road vehicles for the period after 2020

A very important and challenging goal of the European Union is to reduce greenhouse gas emissions until 2050 by 80% or more relative to 1990. In order to achieve this goal, increasing GHG constraints are required in every sector of the economy. Specifically for transportation, the objective has been set to cut EU-27 greenhouse gas emissions by 60% in 2050 relative to 1990 [EC 2011]. While this ambition is defined at a sectoral level as ‘total GHG emitted’ according to IPCC procedures, the current vehicle emissions regulations are defined on the level of ‘Type approval TTW CO2 emissions’ in g/km. This causes a divergence between the regulatory approach and actual direct GHG emissions from road vehicles. Since manufacturers cannot directly influence driving behaviour and distance driven, the discrepancy between regulating g/km emissions and an overall target set at the level of absolute emissions cannot easily be overcome. Besides these factors, also the drivetrain types, chosen by manufacturers to meet the target, greatly influence the ‘total GHG emitted’ according to IPCC definitions and well-to-wheel (WTW). Even though manufacturers can also not directly influence the well-to-tank (WTT) emissions associated with production of energy carriers used in the vehicles, the regulation could be defined in such a way that manufacturers take account of these WTT emissions in their technology choices