Critical evaluation of the European diesel car boom - global comparison, environmental effects and various national strategies

Abstract

Background: On the way to a more sustainable society, transport needs to be urgently optimized regarding energy consumption and pollution control. While in earlier decades, Europe followed automobile technology leaps initiated in the USA, it has decoupled itself for 20 years by focusing research capacity towards the diesel powertrain. The resulting technology shift has led to some 45 million extra diesel cars in Europe. Its outcome in terms of health and environmental effects will be investigated below. Results: Expected greenhouse gas savings initiated by the shift to diesel cars have been overestimated. Only about one tenth of overall energy efficiency improvements of passenger cars can be attributed to it. These minor savings are on the other hand overcompensated by a significant increase of supply chain CO 2 emissions and extensive black carbon emissions of diesel cars without particulate filter. We conclude that the European diesel car boom did not cool down the atmosphere. Moreover, toxic NO x emissions of diesel cars have been underestimated up to 20-fold in officially announced data. The voluntary agreement signed in 1998 between the European Automobile industry and the European Commission envisaging to reduce CO 2 emissions has been identified as elementary for the ensuing European diesel car boom. Four factors have been quantified in order to explain very different dieselization rates across Europe: impact of national car/supplier industry, ecological modernization, fuel tourism and corporatist political governance. By comparing the European diesel strategy to the Japanese petrol-hybrid avenue, it becomes clear that a different road would have both more effectively reduced CO 2 emissions and pollutants.

Global anthropogenic emissions of particulate matter including black carbon

“…At a regional level, the role of transport in BC emissions varies strongly and, for example, in Europe and North America was estimated at over 60 % in 1996 and about 50 % in 2005 and 2010 in this study, while for East Asia its share grew from about 8 to 23 % between 1990 and 2010 (this study). The key source of PM emissions in the transport sector is exhaust emissions from diesel engines with typically light-and heavy-duty trucks playing the largest role; Europe is an exception as policies favouring diesel fuels, in terms of both tax rates and emission limits, resulted in a large share of diesel cars (Cames and Helmers, 2013). Non-exhaust emissions (brake, tyre, and road wear) represent a relatively small share, especially for carbonaceous particles, but their importance grows over time owing to ever more stringent exhaust emission limits.…”

Simulating secondary organic aerosol from missing diesel-related intermediate-volatility organic compound emissions during the Clean Air for London (ClearfLo) campaign

“…The huge dissimilarity in these conclusions, even in the same state in the US, emphasizes the need for continued research into petrol-and diesel-related SOA formation. Furthermore, the US and Europe have very different diesel vehicle profiles: in the US, a negligible proportion of passenger cars are diesel (3 %), whilst on average across Europe 33 % of passenger cars are diesel and this proportion is increasing (Cames and Helmers, 2013). Globally, the demand for diesel fuel is increasing and by 2020 it is expected to overtake petrol as the principal transport fuel used worldwide (Exxon Mobil, 2014).…”

How Does Fuel Taxation Impact New Car Purchases? An Evaluation Using French Consumer-Level Data

“…Figure 2 illustrates this specic position of France among European countries. Outside Europe, policies are even less favorable and dieselengines virtually do not exist: in both in Japan and the US, diesel cars make up about 2% of the overall car eet (Cames & Helmers, 2013 However, over the whole examined period, diesel fuel prices are signicantly lower than gasoline prices (Figure 3) because of the lower tax on diesel fuel. Indeed, fuel tax is a main component of French fuel prices.…”

“…Like many others, Cames & Helmers (2013) argue that environmental benets of diesel cars are overestimated: new technology decreases the spread between CO 2 -emission-eciency of diesel and gasoline cars, but diesel cars continue to produce other greenhouse gases (NOx, ozone, black carbon) and medically hazardous particulate matter.…”