Can car labelling lead to better air quality and lower carbon emissions?

Car labelling was introduced in 1992 to inform European consumers about the fuel consumption and carbon dioxide (CO₂) emissions of new passenger cars, to enable them to contribute to achieving a 40% reduction in economy-wide greenhouse gas emissions by 2030 compared with 1990 levels.

Reducing transport emissions has health and climate protection benefits. The 250 million passenger cars in use in the European Union (EU) account for 14% of final energy use and 12% of fuel-related CO₂ emissions. Increasing the fuel efficiency of cars can therefore reduce urban air pollutants, CO₂ emissions and fuel costs.

Energy labelling has been successful in encouraging consumers to purchase energy-efficient domestic appliances (e.g. refrigerators, freezers, dishwashers and washing machines) with 90% of appliances sold in the EU now labelled as class A.

Although causality is difficult to establish, estimates suggest that the EU energy label has contributed to reducing CO₂ emission by about 14 million tonnes per year over the period 1996–2004. However, an estimated 10% of energy savings are lost due to poor enforcement and a lack of cooperation and application across EU Member States.

When it comes to buying a new car, consumers consider factors such as price, fuel consumption, comfort, size, reliability, safety and engine power, as well as brand and image. Although environmental attributes are listed in a car label, information about fuel consumption and environmental impacts appear to be less important than other factors (e.g. price or hauling capacity) in the choice of a car model. Moreover, information on fuel consumption can be perceived by consumers in an ambiguous manner.

In a new review of the status of car labelling in the EU, my colleague Martin Weiss and I find that EU Member States rely either directly or indirectly on the distance-specific CO₂ emissions [g/km] determined in the laboratory test procedures. However, laboratory testing has come under criticism for being unrepresentative of real-world driving and thus underestimating the actual on-road CO₂ emissions of cars.

The gap between the distance-specific CO₂ emissions measured in the laboratory and on the road has been widening in the past decade. It reached 31–49% in 2014. This suggests that the data underlying car labelling in the EU systematically underestimate both fuel costs and environmental impacts.

For example, an average European gasoline car is labelled with 129 g CO₂/km and a fuel consumption of 5.6 l/100 km. However, on the road this vehicle may actually emit 169–193 g CO₂/km and consume 7.3-8.3 l/100 km of fuel (assuming a gap of 31–49% between the certified and actual on-road fuel consumption) resulting in increased yearly fuel cost and CO₂ emissions.

Such discrepancies risk losing consumer trust in the claims of the car label, which, in turn, could undermine the current and future efforts to reduce CO₂ emissions from passenger cars.

In addition, the different methodologies used by EU member states to translate CO₂ emission values into label classes has resulted in differences in the labelling for efficient medium-size to luxury cars.

Not only that, the current European car labelling schemes are unable to differentiate vehicles that emit between zero and 95–100 g CO₂/km. This shortcoming will become of increasing importance as hybrid, plug-in hybrid and electric cars are being promoted as a solution to poor urban air quality.

Finally, although consumer awareness of the European car label is steadily growing, it still remains low with comprehension affecting both familiarity and trust in the label.

More than 80% of people living in urban areas that monitor air pollution are exposed to air quality levels that exceed World Health Organization (WHO) limits with vehicle emissions being a key contributor to poor air quality. To move towards a more sustainable transport system we need to promote walking, cycling and public transport as well as clean and efficient fuels and vehicles.

The car will always have a role in society and therefore if consumers want to buy a car then they should go for the greener and cleaner vehicle. Car labelling could be influential in purchasing decisions but it has to be accurate and reflect emissions and fuel consumption under real-world conditions.

Despite these limitations, car labelling should be part of an overall strategy to reduce transport-related CO₂ emissions and increase societal well-being.

Note: This article first appeared on Gary Haq’s blog, A Human Ecologist’s View.