To improve air quality in the long term diesel vehicles must be subject to the same emissions standards as other vehicles and the tax advantages that diesel enjoys must be abolished.

At the recent ‘Diesel Summit’ in Berlin, politicians, car manufacturers and others met to discuss possible ways out of the current diesel mess. The measures on the table include banning diesel vehicles from cities, introducing a ‘blaue Plakette’, and retrofitting older models. But none of these will suffice. This is because the 20-year boom in diesel passenger vehicles in Europe and its devastating consequences for health have deep roots. For many years diesel vehicles have had strong political backing in Europe, and this has given them an unfavourable advantage over competing technologies in the European car market. State subsidies for diesel technologies should therefore be abolished at the soonest possible opportunity. This is the only way to force diesel technologies to compete on a level playing field with alternative motor technologies.

Since signing up to the Kyoto Protocol in 1998, the EU has promoted and subsidised diesel engines. The reason for this preferential treatment lies in the alleged climate benefits of diesel vehicles. Yet this completely overlooks the fact that diesel vehicles emit far more harmful pollutants than petrol-driven cars. Indeed, EU emission norms for air quality even allow them to do so. Most diesel vehicles currently driven on European roads are permitted by law to emit up to three times as many oxides of nitrogen (NO_x) per kilometre as petrol-driven cars. With drastic consequences: NOx is responsible for tens of thousands of premature deaths each year in Europe. The EU’s compromise between meeting its Kyoto committments and protecting its citizens is yielding alarming results.

So much for climate protection: the car industry is riding roughshod over even lax standards

Car manufacturers have chosen to ignore even the lax air quality standards set by the EU. The diesel vehicles they produced can emit up to 20 times more than the legally permitted amount of NOx. Even the most modern Euro 6 vehicles emit around five times more NOx than allowed under real-world driving conditions. This cheating has worsened air pollution in major European cities to such an extent that some of them are now considering – or being forced to consider – a ban on diesel vehicles.

Yet the car manufacturers and regulators that failed to set and enforce appropriate emissions norms are not the only culprits here. Many European countries, including Germany, offer motorists incentives to purchase diesel vehicles by taxing diesel at a significantly lower rate than other fuels and thus making it more affordable. In Germany, this costs taxpayers about eight billion euro every year.

A diesel boom thanks to fuel subsidies and absent controls

This combination of fuel subsidies and the absence of effective emissions controls has resulted in a rapid increase in the number of new registrations for diesel vehicles in Europe in the last two decades. In the mid-1990s just over 20 per cent of all newly registered vehicles ran on diesel; today that share is over 50 per cent. In the two other major car manufacturing regions of the world – Japan and the USA – diesel vehicles account for significantly less than five per cent of all new car registrations. The diesel boom is a purely European phenomenon that has resulted from an excessively close relationship between car manufacturers and governments.

Twenty years ago, diesel passenger vehicles did indeed emit less CO₂ than petrol-driven vehicles, but since then the gap between diesel and petrol technologies has closed significantly in this regard. Per kilometre, modern petrol-driven cars emit almost the same amount of CO₂ as diesel vehicles. And the CO₂ emissions of hybrid petrol vehicles are even lower. That means that there are no longer justifiable grounds for the preferential treatment of diesel cars in emissions regulations and taxation law. On the contrary, this favouring of diesel is exacting a huge toll on health and human life and must be stopped as soon as possible.

A mobility transition where the same conditions apply to all vehicles

A radical mobility transition is necessary if the EU is to meet not just its committments under the Paris Climate Agreement but also its own air quality goals. The future European car fleet must run with almost zero CO₂ and pollutant emissions. A range of different motor technologies at different stages of development could play an important role in the transition to a low-emission future, for example, natural gas, fuel cells, hybrids, and battery-fuelled vehicles. While some of these technologies will ultimately fall by the wayside, others will form the basis of sustainable mobility and stimulate job creation.

France – the country where the Paris Climate Agreement was born – recently announced that it will no longer permit the sale of diesel- and petrol-driven vehicles after 2040. Great Britain followed suit, and other EU countries are considering similar measures. A blanket ban on internal combustion engines would significantly improve air quality in inner cities. However, the climate benefits of such a ban would depend on the technology chosen to replace these engines. For example, electric vehicles only result in climate benefits when powered by electricity from low-carbon sources such as solar, wind, and nuclear energy. In France, where 80 per cent of electricity is generated in nuclear power plants, electric vehicles make more sense from a climate protection point of view than in Germany, where coal is still the main source of electrical power. Yet increased dependence on nuclear energy brings the risk of accidents as well as the problem of nuclear waste. To be truly sustainable, electromobility must proceed hand in hand with the energy transition.

Stop-gap solutions are not enough

In the case of the current diesel mess, stop-gap measures such a ban on diesel vehicles in city centres or expensive retrofitting are probably necessary to ensure cleaner air in cities. Citizens who bought their diesel cars without realising their harmful effects should not have to foot the bill for such measures on their own. The issue of responsibility is complicated since car manufacturers and governments created this problem together. However, the eight billion euro that could be saved each year in Germany alone if diesel were subject to the same tax rate as petrol would certainly help.

In the longer term, a complete rethinking of the entire mobility sector is inevitable. European governments should think long and hard about favouring one specific motor technology over others in the future, since that decision could prove to be just as short-sighted as the promotion of diesel technologies in the last 20 years has been. Regardless of their power source, when it comes to their influence on the climate and air quality all vehicles must be subject to the same regulations and the same taxes – taking account of both their life cycles and real-world driving conditions. There is no environmental reason why diesel vehicles should not be subject to the same emission norms as petrol-run cars. But it is vital that these emissions norms then need to be enforced, with appropriately high fines for infringements. This will help to ensure that diesel vehicles eventually find their true niche in the European car market.

This article was published in German in Tagesspiegel Background Energie & Klima on 2 August 2017.

Header image: istock/ssuaphoto