The potential for further controls of emissions from mobile sources in Europe

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

NOx Emissions from Diesel Passenger Cars Worsen with Age

Commonly, the NOx emissions rates of diesel vehicles have been assumed to remain stable over the vehicle’s lifetime. However, there have been hardly any representative long-term emission measurements. Here we present real-driving emissions of diesel cars and light commercial vehicles sampled on-road over 15 years in Zurich/Switzerland. Results suggest deterioration of NOx unit emissions for Euro 2 and Euro 3 diesel technologies, while Euro 1 and Euro 4 technologies seem to be stable. We can exclude a significant influence of high-emitting vehicles. NOx emissions from all cars and light commercial vehicles in European emission inventories increase by 5–10% accounting for the observed deterioration, depending on the country and its share of diesel cars. We suggest monitoring the stability of emission controls particularly for high-mileage light commercial as well as heavy-duty vehicles

GHG Mitigation Potentials and Costs in the Transport Sector of Annex I Countries: Methodology, Version 2

This report documents the specific methodology of IIASA's GAINS model for emissions from transport activities that has been used for comparing mitigation efforts across Annex I Parties. Additional information sources are available at gains.iiasa.ac.at/Annex1.htm

Using snapshot measurements to identify high-emitting vehicles

Policy makers have long been interested in detecting 'high-emitters', a supposedly smallfraction of vehicles that make disproportionally large contributions to total fleet emissions. However, existing identification schemes often exclusively rely on snapshot measurements (i.e. emissions within less than a second), and thus simply identify vehicles with high instantaneous emissions, instead of vehicles with high average emissions over a driving period as regulated by emission standards. We design a comprehensive scheme to address this challenge by combining fleetwide remote sensing measurements with detailed second-by-second emission measurements from individual vehicles. We first determine the trip-average NOx emission rates of individual vehicles in a Euro-5 diesel fleet measured across European locations; this allows, second, to calculate the fraction and emission contributions of high-emitters based on trip-average emission. We demonstrate that the identification of high-emitters is quite uncertain as long as it is based on single snapshots only; but 80% of the high-emitters can be identified with over 75% precision with five or more repeated measurements of the same vehicle. Compared to the conventional detection schemes, our scheme can increase the identified high-emitters and associated emission reductions by over 140%. Our method is validated and shown to be superior to the conventional interpretation of snapshot measurements

European experience in the development of the monitoring, review, and verification (MRV) systems for clean air plans

Over the last decades the European Union has established strict air quality objectives, together with a comprehensive legal framework that should facilitate the achievements of these objectives. As a consequence, air quality has drastically improved in Europe, although the long-term objectives are still not met. The EU clean air legislation played an important role in these air quality improvements. Most importantly, the legal framework provided an effective response mechanism strategy to manage the complex interlinkages between the multitude of pollution sources and the regionally dispersed impacts on air quality which span across different legislation. These connections, which are a direct consequence of the physical nature of the key air pollutants (i.e., their long residence time in the atmosphere), make response strategies that extend beyond individual cities and countries indispensable. In order to implement effective policy responses, the area of the European Union is now considered as one airshed containing 27 Member States, and action needs to be coordinated between countries, regions, and city administrations. The clean air legislation of the EU acknowledges that the European Union as a supra-national institution has to play an important coordinating role in the policy response. It has been found practical to combine three legal pillars into a comprehensive EU clean air legislation framework: • The Ambient Air Quality Directives, • The National Emission Ceilings Directive, and • Source-specific performance standards. One important feature of EU policy that contributed to the success is that, in addition to the key obligations for reaching air quality standards and reducing emissions, all directives contain specific requirements and mechanisms for monitoring, reporting, validation and enforcement. Although the recent nature of some of the directives does not always allow for practical experience, systematic stock-taking on the strengths and weaknesses of older legislation has been recently conducted. This report summarizes the findings emerging from these assessments and indicates options for improvements that could be of interest for the design of effective clean air policies in other parts of the world. While the EU legal framework has obviously been developed for the EU situation, there might be important lessons, particularly on monitoring, review and verification, that could provide relevant insights for other countries which face similar complexities in air quality management, e.g., the need to involve multiple governance levels across State borders

Impact of NOx vehicle emission standards failure on Air Quality in Europe

Vehicle exhaust emission standards have been tightened in the EU for several decades now, in order to protect health and the environment. This has led to a substantial decrease in total pollutant emissions, despite the growing volumes of passenger and freight transport. However, national emissions, particularly of NOx, exceed the ceilings accorded under the Gothenburg Protocol of the UNECE's Convention on Long-Range Transboundary Air Pollution (LRTAP) (EEA 2012) in twelve EU Member States. The main reasons for such exceedances are that more diesel cars have been sold than originally predicted when fixing the targets, and that diesel cars emit much more than expected under real-world driving conditions. The latter appears as a consequence of the effort to achieve high fuel efficiency. While this has largely helped to control CO2 emissions, it was to the detriment of NOx. In this study we estimate what the impact of the different vehicle emission standards has been so far and to predict what the impact of upcoming emission standards will be in the future, using the best current knowledge on road transport activity statistics and emission factors in Europe. We present several sensitivity calculations to reflect the considerable uncertainty about the real-driving NOx emissions of diesel light duty vehicles. The results of this work can be useful in designing both limits for upcoming standards but also in assessing the impact of deviating from such limits. This is necessary in both deciding on the next steps of emission control policy and to relevant air quality prediction models