Evolution of NOx emissions in Europe with focus on road transport control measures V. Vestreng1,*, L. Ntziachristos2, A. Semb3, S. Reis4, I. S. A. Isaksen5, and L. Tarrasón1 1Air Pollution Section, Research Department, Norwegian Meteorological Institute, Oslo, Norway 2Lab of Applied Thermodynamics, Aristotle University Thessaloniki, Greece 3Norwegian Institute for Air Research, Kjeller, Norway 4Centre for Ecology & Hydrology, Edinburgh, UK 5Department of Geosciences, University of Oslo, Oslo, Norway *now at: The Norwegian Pollution Contorul Authority, Department of Climate and Industry, P.O. Box 8100 Dep, 0032 Oslo, Norway
Abstract. European emission trends of nitrogen oxides since 1880 and up to present are
presented here and are linked to the evolution of road transport emissions.
Road transport has been the dominating source of NOx emissions since
1970, and contributes with 40% to the total emissions in 2005. Five trend
regimes have been identified between 1880 and 2005. The first regime
(1880–1950) is determined by a slow increase in fuel consumption all over
Europe. The second regime (1950–1980) is characterized by a continued steep
upward trend in liquid fuel use and by the introduction of the first
regulations on road traffic emissions. Reduction in fuel consumption
determines the emission trends in the third regime (1980–1990) that is also
characterized by important differences between Eastern and Western Europe.
Emissions from road traffic continue to grow in Western Europe in this
period, and it is argued here that the reason for this continued NOx
emission increase is related to early inefficient regulations for NOx
in the transport sector. The fourth regime (1990–2000) involves a turning
point for road traffic emissions, with a general decrease of emissions in
Europe during that decade. It is in this period that we can identify the
first emission reductions due to technological abatement in Western Europe.
In the fifth regime (2000–2005), the economic recovery in Eastern Europe
imposes increased emission from road traffic in this area. Western European
emissions are on the other hand decoupled from the fuel consumption, and
continue to decrease. The implementation of strict measures to control
NOx emissions is demonstrated here to be a main reason for the
continued Western European emission reductions. The results indicate that
even though the effectiveness of European standards is hampered by a slow
vehicle turnover, loopholes in the type-approval testing, and an increase in
diesel consumption, the effect of such technical abatement measures is
traceable in the evolution of European road traffic emissions over the last
Citation: Vestreng, V., Ntziachristos, L., Semb, A., Reis, S., Isaksen, I. S. A., and Tarrasón, L.: Evolution of NOx emissions in Europe with focus on road transport control measures, Atmos. Chem. Phys., 9, 1503-1520, doi:10.5194/acp-9-1503-2009, 2009.