Volvo looks to change our understanding of greener cars

As reports yesterday highlighted, proposals to curb car CO2 emissions in London may have the unintended consequence of lowering air quality. In other words, by keeping a watchful eye on the greenhouse gases that have a long-term global impact, we risk turning a blind eye to local pollutants like particulates and oxides of nitrogen that lead to more immediate health problems and premature deaths.

Car makers and car buyers have been strongly incentivised to take note of CO2 emissions, through taxation, European directives and the prospect of fines. We should not be surprised, therefore, to find that other pollutants have not been given equal attention.

As Jay Nagley of automotive advisory site Clean Green Cars notes, average CO2 output among car makers now varies relatively little, but there is a much wider range in other outputs. "While CO2 varies by a factor of less than three from best to worst, NOx varies by a factor of seven and particulates by a factor of more than 50," he observes, citing fleet averages for UK cars in the first quarter of 2010.

The difference is down to the use of diesel engines to achieve low CO2 scores. "At present, diesel engines produce, on average, approximately seven times more NOx than petrol engines and only diesel engines produce particulates, " Nagley writes. "Hence a manufacturer like Land Rover (97.5 per cent diesel proportion of sales) is bound to produce far higher levels of atmospheric pollution than Fiat (7.3 per cent diesel proportion of sales).”

Yesterday, car maker Volvo attempted to draw attention to pollutants beyond CO2, launching a campaign called Emissions Equality. It hopes to work with other car makers and ultimately legislators to change the perception that a lower CO2 score equals a cleaner car.

"The focus on CO2 alone gives a false picture," said Peter Rask, head of Volvo in the UK. "We are not saying we should take our eyes of CO2, but that we need an equal focus on other pollutants."

Surprisingly, the effort is not simply a halo-polishing move for Volvo. According to Nagley's figures, Volvo has plenty of work to do to improve its own position in the overall pollution league. He places Volvo 26th out of 32 car brands sold in the UK in overall emissions, 22nd in CO2 output, 30th in NOx and 14th for particulates.

Of course Volvo mostly makes cars that are larger than the European average, so it is bound to lurk in the lower part of the table. And around 90 per cent of its UK sales are powered by diesel engines.

If Volvo's campaign succeeds in gaining traction, particularly if pollutants besides CO2 were to be reflected in road tax and company car tax, then there would likely be a shift in the economics of car production and purchase away from diesel engines and towards other low-carbon automotive technologies, such as petrol-electric hybrids.

It will be interesting to see what reception Volvo receives: if other makers are prepared to take the initiative seriously, or are content to see harmful emissions swept under a low-CO2 carpet.