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.