Strategic Environmental Indicators for Transport and their Evaluation - Qualitative Decision Aiding for SEA

This paper explores to what extent the ordinal multi-criteria decision aid method ELECTRE III can help in strategic assessments of transport’s environmental performance. The method is particularly well suited when data are poor, when heterogeneous input has to be treated, and where strongly different value judgements occur. The qualitative assessment logic appropriately reveals and facilitates compromise on the important issue, but also clearly identifies its limits. Thus the relevant issues for a subsequent quantitative analysis can well be selected. We propose to consider this approach for a first ranking of environmental issues or planning alternatives to identify issues and options that merit detailed investigations

“ARE WE MOVING IN THE RIGHT DIRECTION?” TRANSPORT’S ENVIRONMENTAL IMPACT ASSESSMENT WITH ELECTRE III

“Are we moving in the right direction?” is TERM’s key question on the environmental performance of transport in Europe. Here, we apply ELECTRE III to answer this question, that has been left open ever since. Indicator weights are transferred from Life Cycle Assessment methodology and proposed for discussion. Judging from the indicators provided, the environmental performance from the road vehicles in EU15 may become better if transport’s increasing land take and fragmentation can be halted. Otherwise, improvements do not seem enough to balance the increasing energy consumption and carbon dioxide emissions

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

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

Effect of moisture on leaf litter decomposition and its contribution to soil respiration in a temperate forest

The degree to which increased soil respiration rates following wetting is caused by plant (autotrophic) versus microbial (heterotrophic) processes, is still largely uninvestigated. Incubation studies suggest microbial processes play a role but it remains unclear whether there is a stimulation of the microbial population as a whole or an increase in the importance of specific substrates that become available with wetting of the soil. We took advantage of an ongoing manipulation of leaf litter <sup>14</sup>C contents at the Oak Ridge Reservation, Oak Ridge, Tennessee, to (1) determine the degree to which an increase in soil respiration rates that accompanied wetting of litter and soil, following a short period of drought, could be explained by heterotrophic contributions; and (2) investigate the potential causes of increased heterotrophic respiration in incubated litter and 0–5 cm mineral soil. The contribution of leaf litter decomposition increased from 6 ± 3 mg C m<sup>−2</sup> hr<sup>−1</sup> during a transient drought, to 63 ± 18 mg C m<sup>−2</sup> hr<sup>−1</sup> immediately after water addition, corresponding to an increase in the contribution to soil respiration from 5 ± 2% to 37 ± 8%. The increased relative contribution was sufficient to explain all of the observed increase in soil respiration for this one wetting event in the late growing season. Temperature (13°C versus 25°C) and moisture (dry versus field capacity) conditions did not change the relative contributions of different decomposition substrates in incubations, suggesting that more slowly cycling C has at least the same sensitivity to decomposition as faster cycling organic C at the temperature and moisture conditions studied

Long-term dynamics of soil solution in Bavarian forests: Is there a recovering from acidification?

Acid deposition has damaged soils in Central Europe and has been a major source of disturbance for forest ecosystems in the last century. Although acid deposition decreased continuously since the 1990s, it is not clear how fast the damaged soils will recover. We have analysed time series of up to 20 years of precipitation, throughfall and soil solution of the top- and subsoil from 15 Level II forest monitoring sites in Bavaria (Germany). These sites represent a broad range of tree species and soil conditions. As indicators of soil acidification, we calculated the Bc/Al ratio (the ratio of the nutrient cations K, Mg and Ca to Al) and the alkalinity. Additionally, we analysed the trends in Al and SO4 concentrations. To evaluate the temporal dynamics, we extracted the trend of the time series using the model-free method Empirical Mode Decomposition. Our first results suggest that recovery from acidification, i.e. decrease of Al and increase of Bc/Al and alkalinity, is neither uniform nor continuous. We attribute the distinct responses to differences in soil properties among the studied sites

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

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