As one input to the revision of the Thematic Strategy on Air Pollution, this report presents an in-depth analysis of the factors that determine the evolution of emissions from mobile sources in Europe.
In 2005, emissions from mobile (road and non-road) sources contributed about 60% to total NOx emissions in the EU, 20% to total PM2.5, and 30% to total VOC emissions. Road vehicles emitted more than 70% of NOx and VOC of all mobile sources, and more than 60% of PM2.5.
From 2005 to 2010, implementation of EU legislation has reduced NOx from mobile sources by 18%, PM by 21% and VOC by 34%. For NOx, the decline is lower than the corresponding reductions from stationary sources (.26%), so that the relative importance of the transport sector has increased despite the EURO legislation. Especially for NOx, the recent drop in emissions is less than what was anticipated by the 2005 Thematic Strategy on Air Pollution. The major reason for this shortfall are problems in the implementation of NOx limit values for light duty diesel vehicles, where changes in real-life emissions did not follow the improvements in the type approval limit values. As a consequence, by 2015 NOx emissions from light duty diesel vehicles will be a factor two higher compared to a situation where real-life emissions of the EURO 2 to EURO 5 standards would have followed the trends in the type approval limit values.
It is estimated that successful implementation of the EURO 6 standards for diesel vehicles (assuming 50% higher real-life emissions than the type approval value to allow for degradation over time and uncertainties in the driving cycles) should lead to a rapid drop of NOx emissions in the next few years. Up to 2020, NOx emissions from road transport would decline by 65% compared to 2005, by 80% in 2025, and by 87% in 2030.
PM emissions from road transport would fall by 62% in 2020 and by 70% in 2030, and VOC by up to 80% until 2030. For PM, the majority of emissions will be caused by non-exhaust sources (tyre and brake wear, road abrasion).
For non-road mobile machinery, implementation of the agreed emission controls according along the current schedule should cut NOx emissions in 2020 by 40% and in 2030 by 60% compared to 2005. Emissions from PM2.5 are projected to drop by 55% in 2020 and by 70% in 2030; the reduction for VOC emissions is estimated at 50% by 2020 and 60% until 2030. Least changes are expected from ships due to their long lifetime and the slow penetration of new technology.
If these changes materialize, emissions from mobile sources would decline faster than those of stationary sources. Especially road transport would lower its share in total emissions, e.g., for NOx from 44% in 2005 to 17% in 2030, for PM from 14% to 7% and for VOC from 23% to 9%.
There is a potential for further emission reductions also for non-road mobile machinery, where the introduction of Stage V controls (equivalent to the EURO VI level for NOx and the EURO V for PM emissions from heavy duty vehicles) in 2020 could cut NOx emissions from NRMM by 15% in 2030 and PM2.5 emissions by 26%. For further reductions ships and aircraft would need to contribute more.
For road vehicles, the introduction of hypothetical EURO 7/VII standards after 2020, with real-world emission factors around 20% below the EURO 6/VI limit values could reduce NOx emissions from road vehicles by 13% below the baseline projection for 2030.
As a big caveat, emission projections for road transport are particularly sensitive against assumptions on the effectiveness and timing of new legislation, especially for NOx from light duty diesel vehicles. For instance, if real-life emissions comply with the EURO 6 type approval values only by 2018 instead of 2015, NOx emissions from diesel light duty vehicles would be 40% higher in 2020. If the type approval limit values were fully achieved in real-life driving cycles, NOx emissions from this source would be 40% lower after 2030. If however, real-world emissions of EURO 6 vehicles would only follow the reduction rate in type approval values relative to real-life EURO 5 emissions, NOx emissions might be by 270 kt and 470 kt above the baseline in 2020 and 2030, respectively, and total NOx emissions would increase by 5% and 13%, respectively.
For PM, non-exhaust emissions (road abrasion, brake and tyre wear) will become the major source in the future, and total mass of PM emissions will critically depend on the development of these sources.
Implications of these further measures on air quality at urban hot spots will be reported in Part 2 of this report at a later stage.
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