Tuesday 8 February 2011. The Green Piece Column.
It’s been nearly a year since the scrappage scheme (known as ‘cash for clunkers’ in the USA) ended its run in the UK. At the time we were told that it had been a resounding success (see article) by not only boosting the automotive industry but also helping to lower emissions.
The figures quoted suggested the cars registered under the scheme had average CO2 emissions of 132.9g/km – that’s 27.1 per cent less than the average car scrapped and 9.5 per cent below the average new car registered between May 2009 and April 2010.
However, despite these figures, some scepticism remained with environmentalists arguing that it takes longer than four-six years to offset the CO2 emitted while producing a new car. Now a new study published in the ACS journal Environmental Science & Technology has further called into question the idea of shortening the lifetime of a vehicle (see article).
Misguided concept
Though the scrappage schemes introduced in at least 13 countries around the world were aimed at boosting the automotive industry, there were claims that they would help the environment too by reducing CO2 emissions and bringing more fuel efficient vehicles to the roads. However, a case study of Japanese vehicles used during the 1990-2000 period suggests extending the lifetime of a vehicle reduces CO2 emissions throughout the supply chain.
The authors believe there is little evidence to support the idea that vehicle replacement schemes reduce emissions as the research carried out in the past failed to systematically consider the trade-offs between fuel efficiency improvements and additional vehicle production.
In fact, there are a number of rebound effects to extending vehicle lifetime – for example, if vehicle owners buy more fuel efficient vehicles and the energy cost per unit decreases, they may be encouraged to travel further.
In their study, the authors attempted to empirically investigate the impacts of the lifetime shift of a vehicle on lifecycle CO2 emissions. They found that CO2 emissions associated with motor vehicle manufacturing substantially decrease as car lifetime is extended even though petrol derived CO2 emissions increase. So, total induced emissions actually decrease in response to motor vehicle lifetime being extended – this takes into account production, petrol refining, combustion and other services.
Furthermore, it is believed that while a shorter motor vehicle lifetime results in an accelerated car replacement cycle and reduced combustion-derived CO2 emissions; the reductions are actually less significant than the additional CO2 emissions associated with increased production – meaning the net result is an increase in emissions. In order to offset the emissions attributable to a one year reduction in motor vehicle lifetime, a fuel economy improvement of 12.7 per cent would need to be achieved.
Greener cars are vital
Another of the study’s findings is that the market share of hybrid cars would have to increase significantly to offset the high levels of emissions discharged due to a one year decrease in the average lifetime of fuel-inefficient passenger cars.
The assessment suggests that if the 2000 market share of hybrid cars was 14.1 per cent then a one-year decrease in lifetime would reduce lifecycle CO2 emissions by 0.6 per cent.
Our verdict – Replacement vehicle schemes miss the point
It seems like a long time ago – June 2009 in fact – but the very first edition of The Green Piece Column (see article) offered scepticism about the scrappage scheme.
At the time we suggested that the scrappage scheme, if necessary at all, should be tied to greener cars – i.e. the incentive should have only applied to vehicles fitting below a certain CO2 emission threshold. In fact we suggested that car owners should hang on to their vehicles until they are no longer reliable if they are focused on doing the right thing environmentally – and also look to introduce greener driving techniques to help lower emissions further.
Now this study seems to back our theory with statistical evidence. It states that the belief that a car dependent society can achieve marked reductions in CO2 emissions through improved fuel efficiency may be illusory – and that reducing vehicle lifetime only increases emissions.
Of course the latest Government schemes appear to be on the right lines – the UK Government for example, is offering a £5,000 incentive to electric car buyers. It is the backing of truly green technology that will allow for significant progress to be made in reducing emissions and their associated negative health effects.
Unfortunately for the scrappage scheme, for all of its financial success, it is hard to argue that, from an environmental perspective at least, it was a massive missed opportunity.
Faye Sunderland
