Remember when the scrappage scheme and the cash for clunkers campaign were introduced and many argued that replacing older cars with new vehicles would be beneficial for the environment? Well now a study published in the ACS journal Environmental Science & Technology is suggesting the opposite.
The study was based on Japanese vehicle use during the 1990-2000 period and found that extending the lifetime of a vehicle helps to reduce lifecycle CO2 emissions throughout the supply chain.
In addition, it revealed that even if the fuel economy of less fuel efficient passenger vehicles were improved to levels comparable to the best available technology, total CO2 emissions would only decrease by around 0.2 per cent.
The study suggests there is little evidence that vehicle scrappage schemes really help to lower emissions because existing studies fail to consider the trade-offs between fuel efficiency improvement and additional vehicle fleet production.
It finds that extending vehicle life reduces the number of new vehicles sold and there is an associated reduction in energy consumed for vehicle production. Also, policies aimed at vehicle lifetime have additional effects including that with reduced spending on vehicles, consumers spend more on other goods and services and generate additional carbon emissions; and if consumers buy more fuel efficient vehicles and the energy cost per unit distance decreases they may be inclined to driver further.
We’ll have more on this issue in next week’s Green Piece Column.
