One of the most striking statistics thrown up by the RAC's recent Air Quality and Road Transport report is the assertion that 50% of the total health impact of air pollution is caused by urban traffic, and the cost of the pollution caused by urban transport alone is estimated at between £4.5bn and £10.6bn a year.

Startling as these figures are, perhaps the real surprise for many casual observers may be that carbon is not necessarily the prime suspect. For decades, we've been used to hearing about the need to reduce carbon and the advantages of low carbon vehicles have been much trumpeted but, as the RAC report is at pains to point out, carbon is only part as the problem.

In fact, vehicle emission standards have been lowered by 80-90% over the last 25 years, which has been largely successful in driving down vehicle emissions with the notable exception of nitrogen oxide. Similarly, while the UK is broadly compliant with many EU objectives around air quality, the exception is nitrogen dioxide where widespread challenges remain.

The problem with this, as well as the threat of £300m of fines from the EU, is nitrogen oxide causes a substantial amount of avoidable suffering: 400,000 premature deaths across the EU, plus respiratory and cardiovascular problems and damage to the environment.

The report identifies one of the major culprits behind the stubbornly high levels of nitrogen oxide as the growth in popularity of diesel cars, which itself has been driven by higher fuel efficiency and tax regimes designed to reward vehicles with low carbon emissions.

The problem is compounded by the fact that the new generation of diesel vehicles have failed to replicate the emissions standards achieved in laboratory testing in the 'real world', meaning that expected improvements in the levels of nitrogen oxide have failed to materialise.

The challenge this presents local councils is two-fold, firstly to grasp this relatively new political hot potato and then be seen to take visible, practical steps to reduce nitrogen oxide levels. Over laying all of this is the need to communicate the importance of reducing nitrogen oxide levels to the public, although this will also need a shift in government rhetoric and media commentary.

Many UK cities now have a car club in place and a relatively quick and easy win for councils is to ask their local car club operator to do more. Car clubs' raison d'etre is to provide a sustainable and viable alternative to car ownership, and this is a perfect area for operators to demonstrate this.

Councils can and should ask car clubs to provide detailed information on their emissions on both a fleet wide and local basis, and then ask what operators can do to reduce these emissions further. For example, through careful fleet selection we've successfully reduced nitrogen oxide emissions from our cars by 43% in the last year, but we're still looking to do more.

We are also keen to work with councils to ensure we communicate these changes effectively to the local community, so together councils and car clubs can play a crucial part in ensuring that the importance of controlling nitrogen oxide levels is more widely recognised by the general public.

James Finlayson is managing director of the UK's largest independent car club, City Car Club