Carbon dioxide emissions produced by cars have reached an all-time low in Britain, but industry experts think the damaged image of diesel could halt the progress of this 19-year trend.
At the end of 2016 the average new car in Britain produced 120.1g of CO2 per km, which is 1.1% lower than the year before and a third of the value from 2000. The Society of Motor Manufacturers and Traders (SMMT) cites the increase in popularity of diesel cars as the most significant contributor to this reduction, with the average diesel emitting 20% less CO2 than the average petrol car.
However, due to diesel’s higher output of nitrogen oxide (NOx), which is linked to respiratory problems in humans, many politicians, including London Mayor Sadiq Khan, are considering penalising drivers of the highest NOx polluters.
The resulting damage to diesel's image could reduce sales, something the SMMT argues would hinder the UK’s progress in CO2 reduction. It added that the latest diesels are significantly more efficient than older models.
“For [the UK’s reduction in CO2] to continue, modern low-emission diesels and alternatively fuelled vehicles such as plug-ins, hydrogen cars and hybrids must be encouraged with long term incentives," said SMMT chief executive Mike Hawes.
“Turning our back on any of these will undermine progress on CO2 targets as well as air quality objectives," he added. "The UK has a successful track record in encouraging these new technologies, but this must be maintained through a consistent approach to fiscal and other incentives.”
Plug-in hybrid models are often labelled as a cleaner alternative to diesels, and the UK’s demand for this segment is the highest in Europe, representing 23.8% of total sales and ranking ahead of France and Germany.
But growth in the segment slowed by 18.1% in 2016, and industry experts predict the trend to continue with the introduction of new tax brackets in Britain next month. The updated Vehicle Excise Duty rates will move 66% of alternatively fuelled vehicles from tax exemption to being subject to a £130 flat-rate annual fee, meaning one of the strongest pull factors for plug-in cars will be removed.