Lifting the ban on Euro 5 diesel vehicles is good for the community

The government isn’t backing down – it’s doubling down. A week after approving the suspension of road tax for 2027 on lower-powered cars, it has decided to postpone the ban on Euro 5 diesel vehicles until next year. A stopgap measure which, in this case, is better than nothing. Let’s see why.

Any restriction on vehicle traffic leads to a reduction in emissions and, consequently, an improvement in air quality. The most effective measure in this regard would be to ban the use of all vehicles from tomorrow: cars, lorries, buses, trams, trains and even underground trains (in older underground trains, the air quality is much worse than outside). Pollution levels could then be reduced even further by halting all industrial activity, energy production and agricultural work, and by switching off heating systems. Pollution would not be eliminated entirely – there would still be pollution caused by natural phenomena such as Saharan sand, which occasionally reaches us and causes concentrations of fine particulate matter to rise – but it could be said that everything possible has been done to minimise the impact of our activities on health.

But would that even be a desirable goal? Even simple common sense tells us it is not. The economic and human consequences of a total ban on transport, and the unavailability of fossil fuels and heating and air-conditioning systems, would have a far more negative impact than the benefit derived from improved air quality (which is already much better today than in the past). There is no such thing as a free lunch – or even clean air. Like all other forms of regulation and public spending, measures concerning environmental impact should only be adopted if the benefits outweigh the costs. This applies just as much to a hypothetical total lockdown as it does to partial measures such as the one postponed for a year.

What is the impact of a Euro 5 car in terms of air pollution? According to estimates from the European Commission’s Handbook on the External Costs of Transport, for every kilometre travelled, a person causes monetary damage amounting to 1.04 euro cents. This figure is 85 per cent lower than that of a Euro 0 car. The figure for a Euro 6 car, which is permitted on the roads, is 0.86 cents. This is a minimal difference – less than two thousandths of a euro – which does not justify the ban: the cost imposed on those affected (the need to change vehicles or longer journey times) is far greater than the benefit gained. Society as a whole therefore suffers a net loss. We can draw the same conclusion if we consider the fact that fuel taxation already more than internalises this and other environmental externalities (such as noise and CO₂ emissions). The ‘polluter pays’ principle – which is fair and efficient, and supported by the European Union itself – is already fully applied. Further policies, such as driving bans, incentives for the purchase of new vehicles or subsidies for public transport, are therefore not justified in terms of environmental sustainability (the subsidy may be justified, but it is not, in any case, the optimal solution for reducing congestion).

The government’s decision is therefore positive, but not a definitive solution. The measures restricting traffic stem from the a priori setting of identical maximum pollution limits for every area of the European Union. A uniform target is set without taking into account that the costs involved in achieving it vary greatly from one region to another: due to unfavourable conditions for the dispersion of pollutants, a much greater effort is required to achieve air quality in the Po Valley that is identical to that in other areas.

If no action is taken on this front, we will find ourselves facing the same situation in the years to come, when restrictions even stricter than the current ones come into force.