Range Transboundary Air Pollution Research Articles

Have International Pollution Protocols Made a Difference?

Evaluating the effectiveness of international agreements is inherently difficult due to the problems of self-selection, spillovers, and aggregate-level data. In this paper, I provide new and arguably more credible estimates on the effects of the Long Range Transboundary Air Pollution (LRTAP) protocols on three different pollutants: SO2, NOx, and VOCs. I address the problem of non-parallel emission trends by constructing “synthetic” controls that mimic the pre-treatment development of each affected country. Using a new dataset covering more regions and a longer period than previously applied, I find that all three protocols induced emissions reductions well beyond a (synthetic) counterfactual development.

Photochemical smog in China: scientific challenges and implications for air-quality policies

In large areas of China severe air pollution events pose a significant threat to human health, ecosystems and climate. Current reduction of primary emissions will also affect secondary pollutants such as ozone (O3) and particulate matter (PM), but the magnitude of the effects is uncertain. Major scientific challenges are related to the formation of O3 and secondary particulate matter including Secondary Organic Aerosols (SOA). Large uncertainties also remain regarding the interactions of soot, SOA and O3 under the influence of different SO2, NOX and VOC concentrations. To improve the understanding of these secondary atmospheric interactions in China, scientific areas of central importance for photochemically induced air pollutants have been identified. In addition to the scientific challenges, results from research need to be synthesized across several disciplines and communicated to stakeholders affected by air pollution and to policy makers responsible for developing abatement strategies. Development of these science-policy interactions can benefit from experience gained under the UN ECE Convention on Long Range Transboundary Air Pollution (LRTAP)

Performance of European chemistry transport models as function of horizontal resolution

Air pollution causes adverse effects on human health as well as ecosystems and crop yield and also has an impact on climate change trough short-lived climate forcers. To design mitigation strategies for air pollution, 3D Chemistry Transport Models (CTMs) have been developed to support the decision process. Increases in model resolution may provide more accurate and detailed information, but will cubically increase computational costs and pose additional challenges concerning high resolution input data. The motivation for the present study was therefore to explore the impact of using finer horizontal grid resolution for policy support applications of the European Monitoring and Evaluation Programme (EMEP) model within the Long Range Transboundary Air Pollution (LRTAP) convention. The goal was to determine the “optimum resolution” at which additional computational efforts do not provide increased model performance using presently available input data. Five regional CTMs performed four runs for 2009 over Europe at different horizontal resolutions.The models’ responses to an increase in resolution are broadly consistent for all models. The largest response was found for NO2 followed by PM10 and O3. Model resolution does not impact model performance for rural background conditions. However, increasing model resolution improves the model performance at stations in and near large conglomerations. The statistical evaluation showed that the increased resolution better reproduces the spatial gradients in pollution regimes, but does not help to improve significantly the model performance for reproducing observed temporal variability. This study clearly shows that increasing model resolution is advantageous, and that leaving a resolution of 50 km in favour of a resolution between 10 and 20 km is practical and worthwhile. As about 70% of the model response to grid resolution is determined by the difference in the spatial emission distribution, improved emission allocation procedures at high spatial and temporal resolution are a crucial factor for further model resolution improvements.

The effectiveness of international environmental agreements

Many argue that international environmental agreements (IEAs) can alter states’ cost-benefit analyses by providing crucial information about the costs of environmental degradation. Thereby, IEAs may help to effectively curb environmental pollution. However, previous attempts to empirically measure institutional effectiveness found it difficult to provide credible estimates because they have missed to produce convincing counterfactuals. This study empirically estimates the effectiveness of one prominent example of an international environmental institution, the Long Range Transboundary Air Pollution agreement (LRTAP). It sets forth a transparent identification strategy in light of latest advancements in the causal inference literature and presents evidence for the non-effectiveness of the LRTAP in changing member states’ behavior in terms of anthropogenic emissions of two substances (NO x and SO2). By deriving and illustrating the use of difference-in- differences (DID) design in the context of IEAs, this study provides a general methodological tool kit to drawing causal inferences about the effectiveness of international environmental institutions.

Intercontinental transport of persistent organic pollutants: a review of key findings and recommendations of the task force on hemispheric transport of air pollutants and directions for future research

The Task Force on Hemispheric Transport of Air Pollution (TF HTAP) was established under the Convention on Long–range Transboundary Air Pollution (CLRTAP) to improve scientific understanding of the intercontinental transport of air pollutants and to deliver policy–relevant information on this issue. The first comprehensive assessment of POP intercontinental transport made by the TF HTAP was compiled in 2010 and published in 2011. The HTAP assessment was made possible by the contributions of a large network of experts in various national and international organizations and is intended to support further development of international policy and regulation of POPs under the frameworks of the UN ECE CLRTAP and the Stockholm Convention on POPs. By summarizing the outcome of past studies on POPs, the assessment highlights the evidence of POP intercontinental transport and the associated threat to human health and the environment. It presents the current state of knowledge on levels of POPs in the environment, emission inventories and projections, modeling of long–range transport and fate in various compartments, interactions with climate change, as well as harmful effects on human health and ecosystems. Two important outcomes of the HTAP 2010 assessment are the summary of key scientific and policy–relevant findings, and the recommendations for further work which include the need to a more fully developed integrated approach to the pollution assessment. In its next phase, which extends to 2015, the Task Force is planning to cooperate across different thematic areas of scientific activity on intercontinental transport of pollution, and exploit synergies of effort in cases where particulate matter (PM), ozone, mercury, and POPs share common sources. It is recognized that a fully “integrated approach” for building a scientific understanding of POPs in the environment should encompass measurements, modeling results, and emission estimates, and in addition it should more explicitly include assessment of ecosystem effects.

Global multimedia source-receptor relationships for persistent organic pollutants during use and after phase-out

Chemicals that are persistent in the atmosphere can be transported long distances and across international boundaries. Therefore, information about the fraction of local versus imported air pollution is required to formulate regulations aimed at controlling pollutant levels. The objective of this work is to illustrate the capabilities of a dynamic global–scale multimedia model to calculate source–receptor relationships for persistent organic pollutants that cycle between air, water, soil and vegetation in the global environment. As exemplary case studies, we present model calculations of time–evolving source–receptor relationships for PCB28, PCB153, α–HCH and β–HCH over the duration of their usage, phase–out and a post–ban period. Our analysis is geographically explicit, and elucidates the role of primary versus secondary sources in controlling the levels of air pollution. Our case studies consider source–receptor relationships between the four regions defined by the Convention on Long–range Transboundary Air Pollution Task Force on Hemispheric Transport of Air Pollution, as well as the Arctic as a remote receptor region. We find source–receptor relationships that are highly variable over time, and between different regions and chemicals. Air pollution by PCBs in North America and Europe is consistently dominated by local emissions, whereas in East– and South–Asia extra–regional sources are sometimes major contributors. Emissions of α–HCH peak at different times in the four regions, which leads to a phase of high self–pollution in each region, and periods when pollution enters mainly from outside. Compared to α–HCH, air pollution with the less volatile and more persistent β–HCH is more strongly determined by secondary emissions near source areas throughout its use history. PCB concentrations in Arctic air are dominated by emissions transported from North America and Europe from 1930 to 2080, whereas for HCHs each of the source regions contributes a high share at some point between 1950 and 2050.

The EMEP MSC-W chemical transport model – technical description

Abstract. The Meteorological Synthesizing Centre-West (MSC-W) of the European Monitoring and Evaluation Programme (EMEP) has been performing model calculations in support of the Convention on Long Range Transboundary Air Pollution (CLRTAP) for more than 30 years. The EMEP MSC-W chemical transport model is still one of the key tools within European air pollution policy assessments. Traditionally, the model has covered all of Europe with a resolution of about 50 km × 50 km, and extending vertically from ground level to the tropopause (100 hPa). The model has changed extensively over the last ten years, however, with flexible processing of chemical schemes, meteorological inputs, and with nesting capability: the code is now applied on scales ranging from local (ca. 5 km grid size) to global (with 1 degree resolution). The model is used to simulate photo-oxidants and both inorganic and organic aerosols. In 2008 the EMEP model was released for the first time as public domain code, along with all required input data for model runs for one year. The second release of the EMEP MSC-W model became available in mid 2011, and a new release is targeted for summer 2012. This publication is intended to document this third release of the EMEP MSC-W model. The model formulations are given, along with details of input data-sets which are used, and a brief background on some of the choices made in the formulation is presented. The model code itself is available at www.emep.int, along with the data required to run for a full year over Europe.

Multilateral Efforts to Reduce Black Carbon Emissions: A Lifeline for the Warming Arctic?

Rapid reductions in emissions of the short‐lived climate forcers black carbon, tropospheric ozone and methane have been identified as an effective strategy to slow rapid warming and melting in the Arctic and other glaciated areas in the near‐term, and avert abrupt, irreversible changes while strategies to reduce emissions of CO2 are implemented to limit long‐term consequences. Black carbon is a component of fine particulate matter, a traditional air pollutant with significant health impacts; it has a short atmospheric residence time of about a week, thus emissions reductions provide rapid climate benefit. This article analyses the mitigation approaches that are being discussed in multilateral fora including the Arctic Council, the Convention on Long Range Transboundary Air Pollution and the International Maritime Organization. Arctic climate dynamics will affect climate globally, which calls for leadership from Arctic nations to spur faster action to abate emissions.

Health Impacts Estimation of Mineralogical and Chemical Characterization of Suspended Atmospheric Particles over the East Desert

ya Abstract: Problem statement: The small size fraction of aerosols, measured as PM10 and PM2.5, rather than the larger particles, is considered to be responsible for most of the health effects. Such particles have a relatively long residence time in the atmosphere and can therefore travel over long distances. Hence, a large portion of ambient concentrations of PM10 and in particular of particles with an aerodynamic diameter less than 2.5 µm (PM2.5), can be attributed to long range trans boundary air pollution or to other remote sources. The estimates of exposure and of health effects are based on a number of uncertain assumptions and data sets, as described in previous article. Approach: In industrialized Middle East countries, the daily deposition of PM10 particles in the lungs is roughly 250 µg day −1 , which represents a small dose in terms of traditional toxicology studies. Studies of PM10 have considered this total material but have not asked how much its chemical or physical characteristics contribute to its total toxicity. Results: This article focuses on the description of the present knowledge on PM10 concentration fields and predominant sources contributing to PM10 from long range transport of pollution. PM10 is a complex mixture of many known and unknown components; therefore, a short introduction on the composition of PM10 is given. The studies denote to the African dust from mean PM10 levels background levels are still 5-10 mg m 3 higher in the Eastern Basin (EMB) when compared with those in the Western (WMB), mainly due to the higher anthropogenic and sea spray loads. Conclusion: As regards for the seasonal trends, these are largely driven by the occurrence of African dust events, resulting in a spring-early summer maximum over the EMB and a clear summer maximum in the WMB, although in this later region the recirculation of aged air masses play an important role. Furthermore, a marked seasonal trend is still evident when subtracting the African dust load. This is characterized by a high summer maximum (driven by low precipitation, high isolation) and a winter minimum (intense synoptic winds).

Relative Yield Loss Calculations in Wheat (Triticum durumDesf. cv. Camacho) due to Ozone Exposure

In this work, an estimation of the relative yield losses of wheat due to ozone exposure is made by means of two approaches proposed by the CLRTAP (Convention on Long Range Transboundary Air Pollution): the exposure-response approach, which deals with the exposure of plants to ozone during a certain time, and the accumulated uptake approach, which, besides ozone exposure, deals with the velocity of absorption of the contaminant and the environmental factors that modulate that absorption. Once the relative yield losses are calculated by means of the two approaches, the aim is to establish which index (the exposure-response index or the accumulated uptake index) best characterizes the response of wheat plants to ozone. The relative yield losses are compared considering two watering regimes: well watered and nonwatered. The results obtained show that the relative yield losses in wheat due to ozone exposure are much more strongly linked to the real quantity of ozone absorbed by plants than to the environmental ozone exposure, which means that the accumulated uptake approach is much more realistic than the exposure-response approach. Relative yield loss estimations were higher in a crop with no watering; 3% of relative yield losses more than a crop watered until field capacity.

Space, time and nesting Integrated Assessment Models

Integrated Assessment Modelling in the field of air pollution has advanced greatly since the 1985 Helsinki Protocol on the reduction of Sulphur emissions and their transboundary fluxes. With subsequent protocols and increased understanding of the inter-relationships between local air quality, transboundary air pollution and climate change, a variety of spatio-temporal issues must be addressed in order to model the multi-scalar processes involved and nest Integrated Assessment Models. We describe the state-of-the-art in Integrated Assessment Modelling using a conceptual framework which locates the research activities driving integrated assessment in relation both to each other and to flows of information between activities, and identify inter-relationships with scientific and policy domains beyond the scope of the UN/ECE Convention on Long Range Transboundary Air Pollution, recognising the utility of social science in understanding the effects of policy on socio-cultural behaviours. We discuss how the issues identified are being captured by integrated assessment models, with particular focus on the treatment of non-technical pollution abatement measures, noting current developments at the micro-scale addressing the dynamics of behavioural responses to abatement policies. Finally, we identify three key challenges for issue-driven Integrated Assessment Modelling: (i) capturing the dynamics of behavioural responses to value-driven policy mechanisms designed to promote non-technical abatement measures; (ii) the development of new tools to handle the delay times, inter-dependencies and multi-pollutant effects of abatement measures; and (iii) the identification of boundaries between knowledge domains and the effective transfer of multi-disciplinary scientific and socio-cultural knowledge to an increasingly trans-disciplinary policy domain.

Moving boundaries in transboundary air pollution co-production of science and policy under the convention on long range transboundary air pollution

This article focuses on the science–policy interaction in international negotiations in the context of the United Nations Economic Commission for Europe's Convention for Long Range Transboundary Air Pollution (CLRTAP). It addresses the question how participants in the assessment process divide and co-ordinate work between science and policy and how this enhances credibility, legitimacy and relevance with multiple audiences. For this purpose the article combines an analytical framework to approach effectiveness of scientific assessment in policy making, with the notion of boundary work and co-production of science and policy. The article argues that knowledge produced within the CLRTAP process and the institutional setting in which this knowledge production takes place cannot be separated from each other. Furthermore credibility, legitimacy and relevance are to a large extent determined by boundary work in an early stage of the process. At the same time boundary work has to take place continuously in order keep the assessment process credible, legitimate and relevant for new audiences. The application of a combined framework for analysing credibility, legitimacy and relevance and for analysing boundary work turns out to be helpful in describing in detail what happens in practice at the science–policy interface. In particular it helps to address the question of the way participants in the assessment process divide and co-ordinate work, how this shapes design elements and how this enhances credibility legitimacy and relevance of an assessment.

Requirements for developing a regional monitoring capacity for aerosols in Europe within EMEP.

The European Monitoring and Evaluation Programme (EMEP) has been established to provide information to Parties to the Convention on Long Range Transboundary Air Pollution on deposition and concentration of air pollutants, as well as on the quantity and significance of long-range transmission of pollutants and transboundary fluxes. To achieve its objectives with the required scientific credibility and technical underpinning, a close integration of the programme's main elements is performed. These elements are emission inventories, chemical transport modelling, and the monitoring of atmospheric chemistry and deposition fluxes, which further are integrated towards abatement policy development. A critical element is the air pollution monitoring that is performed across Europe with a focus not only on health effect aspects and compliance monitoring, but also on process studies and source receptor relationships. Without a strong observational basis a predictive modelling capacity cannot be developed and validated. Thus the modelling success strongly depends on the quality and quantity of available observations. Particulate matter (PM) is a relatively recent addition to the EMEP monitoring programme, and the network for PM mass observations is still evolving. This article presents the current status of EMEP aerosol observations, followed by a critical evaluation in view of EMEP's main objectives and its model development requirements. Specific recommendations are given for improving the PM monitoring programme within EMEP.

Critical loads for lead in France: First results on forest soils

Within the framework of the United Nation Convention on Long Range Transboundary Air Pollution, France is part of the Working Group on Effect which aims at evaluating the impact of atmospheric deposition on ecosystems by calculating critical loads. The critical loads are the highest deposition of compounds that will not cause chemical changes in soil leading to long-term harmful effects on ecosystem structure and function. A guidance manual for calculation of critical loads for heavy metals (lead and cadmium) has been proposed by the Coordination Center for Effects (executive body of the WGE). French National Focal Center (CNRS and ADEME) aims in this study at evaluating the accuracy of the european methodology for calculation of critical loads for french forest soils. It appears that critical load approach is adapted for France but need to be calibrated at least for calculation of weathering fluxes and determination of critical limits. Stand-still on the contrary is not adequate because of inherent contradictions in the method and too much uncertainties in the transfer functions.

Ecological issues related to ozone: agricultural issues

Research on the effects of ozone on agricultural crops and agro-ecosystems is needed for the development of regional emission reduction strategies, to underpin practical recommendations aiming to increase the sustainability of agricultural land management in a changing environment, and to secure food supply in regions with rapidly growing populations. Major limitations in current knowledge exist in several areas: (1) Modelling of ozone transfer and specifically stomatal ozone uptake under variable environmental conditions, using robust and well-validated dynamic models that can be linked to large-scale photochemical models lack coverage. (2) Processes involved in the initial reactions of ozone with extracellular and cellular components after entry through the stomata, and identification of key chemical species and their role in detoxification require additional study. (3) Scaling the effects from the level of individual cells to the whole-plant requires, for instance, a better understanding of the effects of ozone on carbon transport within the plant. (4) Implications of long-term ozone effects on community and whole-ecosystem level processes, with an emphasis on crop quality, element cycling and carbon sequestration, and biodiversity of pastures and rangelands require renewed efforts. The UNECE Convention on Long Range Trans-boundary Air Pollution shows, for example, that policy decisions may require the use of integrated assessment models. These models depend on quantitative exposure–response information to link quantitative effects at each level of organization to an effective ozone dose (i.e., the balance between the rate of ozone uptake by the foliage and the rate of ozone detoxification). In order to be effective in a policy, or technological context, results from future research must be funnelled into an appropriate knowledge transfer scheme. This requires data synthesis, up-scaling, and spatial aggregation. At the research level, interactions must be considered between the effects of ozone and factors that are either directly manipulated by man through crop management, or indirectly changed. The latter include elevated atmospheric CO 2, particulate matter, other pollutants such as nitrogen oxides, UV-B radiation, climate and associated soil moisture conditions.

Base Cation Removal in Harvesting and Biological Limit Terms for Use in the Simple Mass Balance Equation to Calculate Critical Loads for Forest Soils

The Simple Mass Balance (SMB) equation allows critical loadsto be calculated for forest soils such that all the processesresponsible for acidification and buffering are considered(i.e acidic deposition, deposition of base cations andchloride, mineral weathering, base cation uptake and removalat harvest, nitrogen immobilisation, uptake anddenitrification, and acidity leached). The equation is nowused by 11 UNECE countries in mapping forest critical loadsfor consideration under the Convention on Long RangeTransboundary Air Pollution. In the work described here wehave put together suitable stemwood and bark nutrientconcentrations from the literature with new measurements inorder to calculate species' specific base cation removalterms. Critical loads are then calculated for Quercuspetraea, Pinus sylvestris and Picea sitchensis in order to determine the sensitivity of site critical load values to differences in base cation removal at harvest. The alternativeapproaches of using base cation to aluminium or calcium to aluminium for the biological limit term of the SMB equation arealso examined. Soil critical load values are shown to be influenced by the variability in both these terms, placing priority on the need for species and regional (or perhaps site)specific data similar to those presented here for the UK.

Air quality legislation in the european union

Starting from the 1979 UN Convention on Long Range Transboundary Air Pollution, the European Union has developed both sectoral and national clean air laws. These control individual coating and printing sectors, and set national ceilings for air pollutants from all sources. Some national targets will be very difficult to achieve, but are scheduled for review in 2004, with the Commission and Parliament looking for still lower ceilings. The coatings industry cannot challenge the political drive for cleaner air, or the academic work linking air pollution to human illness and ecological damage. What we can do, in addition to developing cleaner products and technologies, is to review critically the emissions data upon which the decisions on legislation are based. This data can be very poor. Industry needs to support CEPE's work on identifying and quantifying coatings emissions, their composition and the related costs.

Atmospheric deposition at four forestry sites in the Alpine Region of Trentino- South Tyrol, Italy

The Trentino-South Tyrol Region is located in the southern part of the Alpine Chain. The territory is largely mountainous with crystalline rock formations dominant in the north and limestone in the south-east. Most of the land is open to the climatic and atmospheric influence of the River Po, via the mainly N-S oriented valley of the River Adige. The forestry authorities of the region have since the 80s been making an annual assessment of forest decline, particularly as regards parasite attacks, defoliation and crown discoloration, and have found the situation to be better than in most other parts of Europe. The region's forest protection policy is administered by the two provinces of Bolzano/Bozen and Trento in the framework of the European convention on Long Range Transboundary Air Pollution (UN-ECE LRTAP); each province operates two forestry sampling permanent plots. The sites are all constituted according to the standard recommendations, and are located in the central part of the region along the Adige Valley, where most of population live and where most of the agriculture and industry is. Two of the areas are in coniferous stands of the typical Alpine forest, mainly composed of Norway spruce; the other two are located in deciduous stands (both high forest and coppice) and are closer to the urban centres than the first two. Concentration and deposition values for the main ionic components in bulk, wet, throughfall, stemflow and soil water are given separately for the four monitoring sites, with reference to the period 1996- 1999. The major acidifying component in atmospheric precipitation is still sulphate, but as other investigations confirm, the relative importance of the nitrate input is increasing all the time. The effect of these changes is probably positive for terrestrial ecosystems in the short term because of the decrease in total acidifying input and the increase in inorganic fertilisation. The absence of major "forest" damage, outlined in the annual forest damage survey reports issued by the forestry authorities (internal reports since 1983), suggests that the current atmospheric acidic load is in balance with the stational and climatic conditions.

Mapping of Concentrations in Europe Combining Measurements and Acid Deposition Models

Measurements of air and precipitation quality have been carried out within the EMEP programme under the Convention on Long Range Transboundary Air Pollution (LRTAP) since 1978. Approximately 100 rural sites are currently in operation. The Meteorological Synthesising Centre-West (MSC-W) operates two EMEP models estimating transboundary fluxes of air pollutants, a two-dimensional Lagrangian model and a three-dimensional Eulerian model. Traditionally kriging has been used to produce gridded concentration fields from observed data for comparison with modelled data. This paper describes a method for producing optimal fields based on both point measurements and. The difference between modelled and measured values in each measurement point is interpolated to give a smooth two-dimensional expression for the discrepancy between the two data sets. A combined map is derived by adjusting the modelled values with the interpolated difference weighted by the distance to the nearest measurement point. The method has been applied to sulphur and nitrogen measurements in air and precipitation from the EMEP network and modelled results in a 150×150 km grid from the EMEP Lagrangian model. The combined maps give improved regional concentration fields combining characteristics from both the measured and modelled data sets depending on the distance to the measurement points. Comparison with results from the higher resolution Eulerian model shows good agreement.

An Analysis of the Structure of the Simple Mass Balance Equation: Implications for Testing National Critical Loads Maps

The critical loads concept is used by the UN-ECEConvention on Long Range Transboundary Air Pollution(CLRTAP) for setting pollution reduction targets.Increasing numbers of countries are adopting the SimpleMass Balance equation (SMB) to calculate critical loads ofacidifying S and N for forest soils. The equation is madeup of a series of mass balances each of which is used tocalculate a leaching flux. The assumptions in the SMBequation were investigated by testing its ability topredict current sulphur load and by comparing each of thecalculated leaching fluxes to measured rates. It was notpossible to predict current sulphur load at our sites usingthe SMB equation. The leaching tests demonstrated that,primarily due to its steady state assumptions, the SMBequation generates critical loads that are theoretical longterm estimates of risk, and are untestable. Thesimplifying assumptions sometimes lead to illogicalresults. Some of these can be improved by adding a final,simple but dynamic, calculation step to determine theexpected time until effects are observed. Theacceptability of combining annual average data, which bestapproximates steady state, with a biological indicator isquestionable. It is not possible to test critical loadscalculated using the SMB equation when applied with all ofits assumptions but it is possible to test its fundamentalapproach using non steady state data.