European scientists press alarm bell on ill effects of diesel cars

A group of 24 scientists from 12 research and scientific organisations across Europe and the US have issued an open letter to sensitise the policy makers and people about the harmful nature of pollution from diesel cars

By Anumita Roychowdhury
Published: Monday 28 December 2015

In a dramatic development on December 11, 2015 a group of 24 scientists from leading scientific institutions in Europe and supported by scientists from the US have issued an open letter to the European policy makers and public expressing strong concern over impact of diesel cars on air quality of Europe. They have appealed to say, “With the help of weaker standards, diesel cars have been granted pollution privileges by EU (European Union) law for over two years. As a result, poor air quality continues to have grave consequences for public health and European policy makers must act to correct this as a matter of urgency.”

Scientists who have signed on to this letter are from institutions across Europe that include Norwegian Institute of Air Research, University of West of England, Bristol, Umea University of Sweden, Trier University of Applied Sciences, Germany,  Leuphana University, Germany, Hermholtz Centre, Munich, Spanish Council for Scientific Research, Barcelona, Institute of Experimental Medicine, Prague, International Society of Doctors for the Environment, Austria, and Ca Foscari University of Venice, Italy. They have been supported by leading scientists from University of California, Berkeley and Stanford University, USA.

Diesel has worsened air quality in Europe

This letter has dispelled all myths that the industry has been spawning about merits of diesel cars. The scientists have stated it categorically that “the EU limit values for nitrogen oxides and air borne fine particles remain difficult to achieve in many cities and promotion of diesel cars has made achievements of these limits more challenging. Most of these emissions in our towns and cities typically come from diesel vehicles”. They have added that the EU emissions limits for diesel cars are less stringent than those for petrol cars.

It is worrying that Europe has continued to face the problem even after graduating to Euro VI emissions standards.  The scientists are in agreement that the “so called ‘clean diesel’ are unlikely to be clean over lifetime.” European legislation requires emissions compliance only for the first 150,000 km, while in the USA it is required for 240,000 km. “For diesel cars to have similar emissions to petrol cars requires a complex five-step chemical process and the engine not to malfunction”. This, they think, is unrealistic expectation in in-use diesel cars. In fact, three-quarters of randomly chosen cars in France were found to be malfunctioning.

The gathering evidences point towards serious concerns around NOx emissions from diesel cars in Europe. The concerned scientists have noted that testing of real world emissions from diesel cars in the United Kingdom in 2011 had shown virtually no improvement in NOx emissions over two decades despite the introduction of increasingly more stringent limit values. Even more dramatic data has come from the studies of the US based International Council on Clean Transportation in 2014 that had also done the expose on high emissions from Volkswagen cars fitted with defeat devices. They found that the average on-road emissions level of NOx from several diesel cars were seven times more than the certified emissions limit for Euro VI vehicles.

This group of scientists has informed that the European regulators are now working to tighten the real world testing of cars and its procedures to address this problem. But the European car industry is lobbying hard to delay its implementation.

Diesel cars – also a climate rogue

The scientists have also taken note of the pressure from the European motor and oil industry to ride on climate mitigation programme. This industry that has launched a pro-diesel car campaign and issued an open letter claimed that “political measures restricting the roll out of the new generation of diesel technology would undermine existing efforts to cut CO emissions”.

But the European scientists have challenged this claim stating that “the environment, climate, and health of the people would benefit from stepping away from the diesel cars.” The scientists have mentioned that Europe has used climate policy and tax measures to promote diesel cars and since 1990 added more than 45 million diesel cars hoping to reduce heat trapping CO for climate mitigation. On the contrary, they have ended up worsening the urban air quality in Europe. Moreover, black carbon emissions from diesel cars especially malfunctioning cars and also those without particulate filters trap more heat than CO and exacerbate global warming.  

The scientists are unanimous that European car industry could have taken other approaches to control CO emissions from car fleet. For instance, Japan Motor Industry has heavily invested in hybrid technologies and succeeded in “reducing CO emissions from new cars faster and more efficiently that European Union.”

Industry lobby has remained strong in Europe. The European oil industry in fact has launched a campaign to promote diesel cars claiming that diesel cars have helped to reduce CO emissions per kilometer. But the scientists do not agree with this and have challenged this claim stating that the industry has invested in diesel cars at the cost of petrol cars over the last 20 years. Their open letter states “Despite this CO emissions of cars with a downsized, charged petrol engine can be comparable with an equivalent diesel car.” The open letter explains that one of the reasons why the European oil industry has pushed diesel cars is the slow-down in sale of diesel fuel due to promotion of natural gas in other sectors.

Stop dieselisation

These are the compelling reasons that have led to the community of scientists to come out against diesel cars. They believe – as they state – “the public should be made aware of the true nature of the pollution from diesel cars.” This alarm bell from the European scientists foreshadows the crisis in India that is battling serious air quality and public health impact of dieselization. India should learn from Europe’s mistake and not repeat the mistake.

Subscribe to Daily Newsletter :

Comments are moderated and will be published only after the site moderator’s approval. Please use a genuine email ID and provide your name. Selected comments may also be used in the ‘Letters’ section of the Down To Earth print edition.