A Model to Calculate Natural VOC Emissions from Forests in Europe

A significant portion of the total emissions of volatile organic compounds (VOC) may come from natural sources and, in particular, from forests. It is important to quantify these emissions because their share influences the magnitude of reductions that will have to be undertaken in the anthropogenic emission sectors in order to reduce secondary air pollution problem such as photochemical smog and acid deposition. This paper describes a model to calculate geographically-resolved VOC emissions from forests in Europe for different seasons, months or average days. We review briefly the method on how to calculate biogenic emissions from trees and available emission factor functions, including a discussion of the dependence of emissions on latitude, altitude, time of the day and temperature. Subsequently, the geographically-resolved forest and temperature data bases for Europe, as used in this model to derive the emission estimates, are described. The forest data are verified against other published forest inventories for Europe or parts of Europe. The resulting total VOC emissions are compared with existing country- or region-specific estimates, and some sensitivity analyses are carried out in order to show where the emission model could be simplified or where it needs to be improved. Based on our total forest coverage of approximately 2.2 million km^2, we calculate an average total annual emission rate of VOC's from these forests of 7.5 Megatonnes, based on typical European temperatures averaged over 30 years. This is equivalent to an areal average of 3.4 tonnes per year per km^2 forest or 0.9 tonnes per year per km^2 land area in the modeling domain. Until now, this forest emission model represents the only available basis for geographically-resolved emission calculations of VOC's from forests for all Europe for varying time periods

Calculation of Cause-specific Mortality Impacts of Fine Particulate Matter in GAINS

In the early 2000s, the GAINS (Greenhouse gas - Air pollution Interactions and Synergies) model used emerging epidemiological evidence to estimate premature mortality of the European population that can be attributed to the exposure to fine particulate matter and to identify cost-effective emission control strategies that reduce health impacts at least cost (Amann et al., 2011, p.accepted for publication). Based on the review of available studies on the health effects of PM conducted by the UNECE Task Force on Health (UNECE/WHO, 2003), the GAINS impact assessment employed the associations between population exposure to PM2.5 and all-cause mortality of the American Cancer Society study (Pope et al., 2002). In the meantime, a wealth of new epidemiological studies have sharpened the evidence about health effects of particulate matter and revealed more specific associations between ambient concentrations of PM2.5 and health impacts (e.g., Pope et al., 2009). In particular, new studies establish robust relationships between exposure to fine particles and specific causes of deaths. These new insights should facilitate a more specific estimate of the role of particular death causes that are associated with bad air quality, and a more precise estimate of the total mortality impacts in different countries as baseline death rates from different diseases vary over countries. This background paper describes a revised approach of the health impact assessment in GAINS that employs cause-specific concentration-response relationships for lung cancer, cardio-vascular and respiratory diseases for the European countries. Data on cause-specific deaths in the European countries have been extracted from the 2010 version of the World Health Organization database on mortality indicators by 67 causes of death, age and sex (HFA-MDB) for the latest available year. As a result, the cause-specific approach results in higher impact estimates than the former calculation for all-cause mortality. The difference depends on the relative shares of death causes in the various countries; for the EU-27, cause-specific calculations for the year 2000 result in 16% higher health effects, keeping all other factors constant (i.e., PM exposure, population, etc.). In the non-EU countries, the difference amounts to 54%, essentially due to the higher share of cardio-vascular deaths

Comparison of the RAINS Emission Control Cost Curves for Air Pollutants with Emission Control Costs Computed by the GAINS Model

This paper compares cost curves of SO2, NOx and PM2.5 emission controls generated with the RAINS (Regional Air Pollution Information and Simulation) model with cost estimates obtained from the GAINS (Greenhouse Gas - Air Pollution Interactions and Synergies) model. Based on the same set of input data, results from both models are very similar, and differences are considered as insignificant

On the Optimization Model for Acid Loads on Forest Soils

The emphasis of the model is on the transboundary aspect of air pollution in Europe with the aim to find cost effective environment policies for Europe. The model will be embedded in the IIASA Regional Acidification Information and Simulation (RAINS) model. The spatial coverage of RAINS is all of Europe, and the time horizon begins in 1960 to permit checking of historical calculations, and extends to 2030 to allow examination of long-term consequences of control strategies. In this work we concentrate on soil acidification, which is an important link between air pollution and damage to the terrestrial and aquatic environment. The ability of soil to buffer acid deposition is a key factor in regulating the long-term surface and groundwater acidification. Soil acidification has also been related to forest die-back via its effect in the tree root zone. This work is concentrating on the finding of cost effective pollution control satisfying environment constraints, such as pH-value in forest soils

A Methodology to Estimate Changes in Statistical Life Expectancy Due to the Control of Particulate Matter in Air Pollution

Studies in the United States have shown that those living in less polluted cities live longer than those living in more polluted cities. After adjustments for other factors, an association remained between ambient concentrations of fine particles and shorter life expectancy. This paper presents a methodology to apply the findings of these epidemiological studies to scenarios to control fine particulate matter in Europe and to estimate the resulting losses in statistical life expectancy that can be attributed to particulate matter pollution. Calculations are carried out for all of Europe with a 50*50 km resolution, distinguishing higher PM2.5 levels in urban areas. The methodology uses population statistics and projections from the United Nations, and applies changes in mortality risk identified by the epidemiological studies to the life tables for the individual countries. The preliminary implementation suggests that, for constant 1990 pollution levels, statistical life expectancy is reduced by approximately 500 days (95 percent confidence interval ranging from 168 - 888 days). By 2010, the control measures presently decided for emissions of primary particles and the precursors of secondary aerosols are expected to reduce these losses to about 280 days (94 -497), while the theoretical maximum technically feasible emission reductions could bring reduced life expectancy below 200 (65 -344) days. While the quantifications in this study must be considered as preliminary, the methodology will allow the introduction of health impacts from fine particulate matter into a multi-pollutant/multi-effect framework so that control measures can be explored taking full account of their ancillary benefits for acidification, eutrophication and ground-level ozone

The GAINS Optimization Module as of 1 February 2007

This document describes the optimization framework of the GAINS model for Europe. The approach is compared to the approach used in the RAINS model and a detailed description of the objective function, the constraints and the impact functions is given. Finally a comparison of individual single pollutant cost curves generated from the RAINS model and with the optimization module of GAINS is given to illustrate the consistency of the two approaches for single pollutant measures

The RAINS Optimization Module for the Clean Air For Europe (CAFE) Programme

In 2005 the European Commission developed the Thematic Strategy on Air Quality (COM (2005) 446). IIASA's TAP programme has been instrumental in preparing various emission scenarios for the development of the strategy, and the optimization module of RAINS has been used extensively in the exercise. In this report we document the mathematical formulation and methodological aspects of the optimization module of RAINS

UN/ECE Workshop on Exploring European Sulfur Abatement Strategies

This paper, prepared as a background document for the UN/ECE "Workshop on Exploring European Sulfur Abatement Strategies" (24-26 June 1991, Laxenburg, Austria), provides an analysis of the major approaches presently being explored for further reducing SO2 emissions in Europe. By using an integrated assessment model, the analysis reflects the current stake of various model developments, taking into account the most recent information on energy strategies, emission projections, atmospheric long-range transport and sensitivities of ecosystems in Europe. The paper provides quantitative results from the the "Regional Acidification Information and Simulation" (RAINS) model by analyzing various scenarios. Some more general qualitative conclusions and lessons are drawn from the model results. Further, the paper also attempts to illustrate the current limitations for scenario analysis caused by the limited availability and reliability of present data and models. The paper explores the advantages and disadvantages of alternative approaches by analyzing and evaluating different aspects of the various abatement strategies, such as relative emission reductions (compared to the baseyear 1980); cost of abatement measures; the burden to national economies as implied by emission control expenditures (i.e. the fraction of GDP required for emission reductions); the consequences on acid deposition; and their environmental impacts in terms of critical loads achievement. It should be noted however, that it is not the intention of this paper to perform any value judgments on the various strategies. Such preferences have to be established by negotiators. Undoubtedly, other considerations, which are not incorporated into this formalized analysis, will also influence the decisionmaking on the topic

Modeling of Critical Loads for Acid Deposition in Austria

The author develops an approach to simulate acidification processes in forest soils caused by acid deposition from the atmosphere. Based on a dynamic formulation of the most important processes and external factors leading to soil acificiation the stationary solution of the equation system is derived, which serves as a basis for estimating critical loads for acid deposition. Thereby, critical loads determine the maximum exposure to one or more pollutants, which will not cause chemical changes in the soil leading to long-term harmful effects on the most sensitive ecological systems. This method is applied to derive critical loads for the Austrian forest soils. Results indicate that acid deposition has to be considered as a potential long-term threat for the majority of Austrian forests. The most sensitive ecosystems occur in the north and north-east of Austria. A comparison of the critical loads with current acid deposition shows an excess of the threshold limits in large parts of Austria. Certain ecosystems in the east of Austria, in particular forests in the Waldviertel and the oak forests north and south-east of Vienna, face currently an acid deposition of more than ten times above their critical loads. Finally, a sensitivity analysis identifies the most influential parameters of the model calculations and allows thereby to derive recommendations for further research and monitoring efforts