Life Cycle Assessment of Kerosene Used in Aviation (8 pp)

Goal, Scope, and Background The main goal of the study is a comprehensive life cycle assessment of kerosene produced in a refinery located in Thessaloniki (Greece) and used in a commercial jet aircraft. Methods The Eco-Indicator 95 weighting method is used for the purpose of this study. The Eco-Indicator is a method of aggregation (or, as described in ISO draft 14042, 'weighting through categories') that leads to a single score. In the Eco-indicator method, the weighing factor (We) applied to an environmental impact index (greenhouse effect, ozone depletion, etc.) stems from the 'main' damage caused by this environmental impact. Results and Discussion The dominant source of greenhouse gas emissions is from kerosene combustion in aircraft turbines during air transportation, which contributes 99.5% of the total CO2 emissions. The extraction and refinery process of crude oil contribute by around 0.22% to the GWP. This is a logical outcome considering that these processes are very energy intensive. Transportation of crude oil and kerosene have little or no contribution to this impact category. The main source of CFC-11 equivalent emissions is refining of crude oil. These emissions derive from emissions that result from electricity production that is used during the operation of the refinery. NOx emissions contribute the most to the acidification followed by SO2 emissions. The main source is the use process in a commercial jet aircraft, which contributes approximately 96.04% to the total equivalent emissions. The refinery process of crude oil contributes by 2.11% mainly by producing SO2 emissions. This is due to the relative high content of sulphur in the input flows of these processes (crude oil) that results to the production of large amount of SO2. Transportation of crude oil by sea (0.76%) produces large amount of SO2 and NOx due to combustion of low quality liquid fuels (heavy fuel oil). High air emissions of NOx during kerosene combustion result in the high contribution of this subsystem to the eutrophication effect. Also, water emissions with high nitrous content during the refining and extraction of crude oil process have a big impact to the water eutrophication impact category. Conclusion The major environmental impact from the life cycle of kerosene is the acidification effect, followed by the greenhouse effect. The summer smog and eutrophication effect have much less severe effect. The main contributor is the combustion of kerosene to a commercial jet aircraft. Excluding the use phase, the refining process appears to be the most polluting process during kerosene's life cycle. This is due to the fact that the refining process is a very complicated energy intensive process that produces large amounts and variety of pollutant substances. Extraction and transportation of crude oil and kerosene equally contribute to the environmental impacts of the kerosene cycle, but at much lower level than the refining process. Recommendation and Perspective The study indicates a need for a more detailed analysis of the refining process which has a very high contribution to the total equivalent emissions of the acidification effect and to the total impact score of the system (excluding the combustion of kerosene). This is due to the relative high content of sulphur in the input flows of these processes (crude oil) that results to the production of large amount of SO2.     

Country-dependent Characterisation Factors for Acidification and Terrestrial Eutrophication Based on Accumulated Exceedance as an Impact Category Indicator (14 pp)

Background, Aims and Scope Several authors have shown that spatially derived characterisation factors used in life cycle impact assessment (LCIA) can differ widely between different countries in the context of regional impact categories such as acidification or terrestrial eutrophication. Previous methodology studies in Europe have produced country-dependent characterisation factors for acidification and terrestrial eutrophication by using the results of the EMEP and RAINS models and critical loads for Europe. The unprotected ecosystem area (UA) is commonly used as a category indicator in the determination of characterisation factors in those studies. However, the UA indicator is only suitable for large emission changes and it does not result in environmental benefits in terms of characterisation factors if deposition after the emission reduction is still higher than the critical load. For this reason, there is a need to search for a new category indicator type for acidification and terrestrial eutrophying in order to calculate site-dependent characterisation factors. The aim of this study is to explore new site-dependent characterisation factors for European acidifying and eutrophying emissions based on accumulated exceedance (AE) as the category indicator, which integrates both the exceeded area and amount of exceedance. In addition, the results obtained for the AE and UA indicators are compared with each other. Methods The chosen category indicator, accumulated exceedance (AE), was computed according to the calculation methods developed in the work under the United Nations Economic Commission for Europe (UNECE) Convention on Long-range Transboundary Air Pollution (LRTAP). Sulphur and nitrogen depositions to 150x150 km2 grid cells over Europe were calculated by source-receptor matrices derived from the EMEP Lagrangian model of long-range transport of air pollution in Europe. Using the latest critical load data of Europe, the site-dependent characterisation factors for acidification and terrestrial eutrophication were calculated for 35 European countries and 5 sea areas for 2002 emissions and emissions predicted for 2010. In the determination of characterisation factors, the emissions of each country/area were reduced by various amounts in order to find stable characterisation factors. In addition, characterisation errors were calculated for the AE-based characterisation factors. For the comparison, the results based on the use of UA indicator were calculated by 10% and 50% reductions of emissions that corresponded to the common practice used in the previous studies. Results and Discussion The characterisation factors based on the AE indicator were shown to be largely independent of the reduction percentage used to calculate them.. Small changes in emissions (≤100 t) produced the most stable characterisation factors in the case of the AE indicator. The characterisation errors of those characterisation factors were practically zero. This means that the characterisation factors can describe the effects of small changes in national emissions that are mostly looked at in LCAs. The comparison between country-dependent characterisation factors calculated by the AE and UA indicators showed that these two approaches produce differences between characterisation factors for many countries/areas in Europe. The differences were mostly related to the Central and Northern European countries. They were greater for terrestrial eutrophication because the contribution of ammonia emission differ remarkably between the two approaches. The characterisation factors of the AE indicator calculated by the emissions of 2002 were greater than the factors calculated by the predicted emissions for 2010 in almost all countries/sea areas, due to the presumed decrease of acidifying and eutrophying emissions in Europe. Conclusions and Recommendations. In this study, accumulated exceedance was shown to be an appropriate category indicator in LCIA applications for the determination of site-dependent characterisation factors for acidification and terrestrial eutrophication in the context of integrated assessment modelling. In the future, it would be useful to calculate characterisation factors for emissions of separate parts of large countries and sea areas in Europe. In addition, it would also be useful to compare the approach based on the AE indicator with the method of the hazard index, as recommended in the latest CML guidebook.     

Implications of Uncertainty and Variability in the Life Cycle Assessment of Pig Production Systems(7 pp)

Goal, Scope and Background Calculating LCA outcomes implies the use of parameters, models, choices and scenarios which introduce uncertainty, as they imperfectly account for the variability of both human and environmental systems. The analysis of the uncertainty of LCA results, and its reduction by an improved estimation of key parameters and through the improvement of the models used to convert emissions into regional impacts, such as eutrophication, are major issues for LCA. Methods In a case study of pig production systems, we propose a simple quantification of the uncertainty of LCA results (intra-system variability) and we explore the inter-system variability to produce more robust LCA outcomes. The quantification of the intra-system uncertainty takes into account the variability of the technical performance (crop yield, feed efficiency) and of emission factors (for NH3, N2O and NO3) and the influence of the functional unit (FU) (kg of pig versus hectare used). For farming systems, the inter-system variability is investigated through differentiating the production mode (conventional, quality label, organic (OA)), and the farmer practices (Good Agricultural Practice (GAP) versus Over Fertilised (OF)), while for natural systems, variability due to physical and climatic characteristics of catchments expected to modify nitrate fate is explored. Results and Conclusion For the eutrophication and climate change impact categories, the uncertainty associated with field emissions contributes more to the overall uncertainty than the uncertainty associated with emissions from livestock buildings, with crop yield and with feed efficiency. For acidification, the uncertainty of emissions from livestock buildings is the single most important contributor to the overall uncertainty. The influence of the FU on eutrophication results is very important when comparing systems with different degrees of intensification such as GAP and OA. Concerning the inter-system variability, differences in farmer practices have a larger effect on eutrophication than differences between production modes. Finally, the physical characteristics of the catchment and the climate strongly affect the results for eutrophication. In conclusion, in this case study, the main sources of uncertainty are in the estimation of emission factors, due both to the variability of environmental conditions and to lack of knowledge (emissions of N2O at the field level), but also in the model used for assessing regional impacts such as eutrophication. Recommendation and Perspective Suitable deterministic simulation models integrating the main controlling variables (environmental conditions, farmer practices, technology used) should be used to predict the emissions of a given system as well as their probabilistic distribution allowing the use of stochastic modelling. Finally, our simulations on eutrophication illustrate the necessity of integrating the fate of pollutants in models of impact assessment and highlight the important margin of improvement existing for the eutrophication impact assessment model.     

Life cycle assessment of vegetable products: a review focusing on cropping systems diversity and the estimation of field emissions

Purpose

Recent life cycle assessment studies for vegetable products have identified the agricultural stage as one of the most important contributors to the environmental impacts for these products, while vegetable production systems are characterized by specific but also widely diverse production conditions. In this context, a review aiming at comparing the potential impacts of vegetable products and analyzing the relevance of the methods and data used for the inventory of the farm stage appeared necessary.

Methods

Ten papers published in peer-reviewed scientific journals or ISO-compliant reports were selected. First, a presentation of the selected papers was done to compare the goal and scope and the life cycle inventory data to the related sections in the ILCD Handbook. Second, a quantitative review of input flows and life cycle impact assessment (LCIA) results (global warming, eutrophication, and acidification) was based on a cropping system typology and on a classification per product group. Third, an in-depth analysis of the methods used to estimate field emissions of reactive nitrogen was proposed.

Results and discussion

The heated greenhouse system types showed the greatest global warming potential. The giant bean group showed the greatest acidification and eutrophication potentials per kilogram of product, while the tomato group showed the greatest acidification and eutrophication potentials per unit of area. Main sources of variations for impacts across systems were yields and inputs variations and system expansion rules. Overall, the ability to compare the environmental impact for these diverse vegetable products from cradle-to-harvest was hampered by (1) weaknesses regarding transparency of goal and scope, (2) a lack of representativeness and completeness of data used for the field stage, and (3) heterogeneous and inadequate methods for estimating field emissions. In particular, methods to estimate reactive nitrogen emissions were applied beyond their validity domain.

Conclusions and recommendations

This first attempt at comparing the potential impacts of vegetable products pinpointed several gaps in terms of data and methods to reach representative LCIA results for the field production stage. To better account for the specificities of vegetable cropping systems and improve the overall quality of their LCA studies, our key recommendations were (1) to include systematically phosphorus, water, and pesticide fluxes and characterize associated impacts, such as eutrophication, toxicity, and water deprivation; (2) to better address space and time representativeness for field stage inventory data through better sampling procedures and reporting transparency; and (3) to use best available methods and when possible more mechanistic tools for estimating Nr emissions.     

Uncertainty and spatial variability in characterization factors for aquatic acidification at the global scale

Purpose

Characterization factors (CFs) quantifying the potential impact of acidifying emissions on inland aquatic environments in life cycle assessment are typically available on a generic level. The lack of spatial differentiation may weaken the relevance of generic CFs since it was shown that regional impact categories such as aquatic acidification were influenced by the surroundings of the emission location. This paper presents a novel approach for the development of spatially differentiated CFs at a global scale for the aquatic acidification impact category.

Methods

CFs were defined as the change in relative decrease of lake fish species richness due to a change in acidifying chemicals emissions. The characterization model includes the modelling steps linking emission to atmospheric acid deposition (atmospheric fate factor) change, which lead to lake H⁺ concentration (receiving environment fate factor) change and a decrease in relative fish species richness (effect factor). We also evaluated the significance of each factor (i.e. atmospheric fate, receiving environment fate and effects) to the overall CFs spatial variability and parameter uncertainty.

Results and discussion

The highest CFs were found for emissions occurring in Canada, Scandinavia and the northern central Asia because of the extensive lake areas in these regions (lake areas being one of the parameters of the CFs; the bigger the lake areas, the higher the CFs). The CFs’ spatial variability ranged over 5, 6 and 8 orders of magnitude for NO_x, SO₂ and NH₃ emissions, respectively. We found that the aquatic receiving environment fate factor is the dominant contributor to the overall spatial variability of the CFs, while the effect factors contributed to 98 % of the total parameter uncertainty.

Conclusions

The resulting characterization model and factors enable a consistent evaluation of spatially explicit acidifying emissions impacts at the global scale.     

Feasibility of Applying Site-dependent Impact Assessment of Acidification in LCA (8 pp)

Goal, Scope and Background Taking into account the location of emissions and its subsequent, site-dependent impacts improves the accuracy of LCIA. Opponents of site-dependent impact assessment argue that it is too time-consuming to collect the required additional inventory data. In this paper we quantify this time and look into the added value of site-dependent LCIA results. Methods We recalculated the acidifying impact for three existing LCA studies: linoleum, stone wool, and water piping systems. The amount of time needed to collect the required additional data is reported. The EDIP2003 methodology provides site-generic and site-dependent acidification factors. We used these factors to recalculate acidification for the case studies. We analyzed differences between site-generic and site-dependent acidification and reported problems experienced. Results and Discussion Finding the location of processes and emissions was easy. The reports of the three case studies contained most of this information. Far more time was needed to disaggregate processes to the level where emissions can be localized. Although the overall conclusions with regard to acidification did not change in the case studies, the relative importance of processes shifted when considering sub-levels. This is especially important for improvement analysis. Site-dependent acidification assessment was hampered in the linoleum case study where about 40% of the acidification originates from non-European emissions. However, EDIP2003 provides no site-dependent factors for these countries and site-generic factors had to be used instead. Thus, calculating site-dependent acidification is only feasible for LCA studies in which the majority of the emissions originate in Europe. We could not reproduce all parts of the three case studies using the report and additional public resources. This hindered our recalculation. In fact, any additional analysis will be hampered by this lack of reproducibility. ISO recommends such reproducibility for comparative assertion disclosed to the public. Conclusion Spatially differentiated acidification is feasible for each of the three case studies. Finding the location of processes and emissions was easy, but quite some time was needed to disaggregate processes and emissions to the appropriate level. Overall conclusions on acidification remained the same for the case studies, but the relative contribution of basic processes changed when applying site-dependent impact assessment. Though the three case studies were all rather detailed and complete, none of them was fully reproducible. This complicated recalculation of acidification, and will in fact make any additional analysis difficult.     

Cost-effective emission abatement in europe considering interrelations in agriculture

Agriculture is an important source of ammonia (NH3), which contributes to acidification and eutrophication, as well as emissions of the greenhouse gases nitrous oxide (N2O) and methane (CH4). Controlling emissions of one of these pollutants through application of technical measures might have an impact (either beneficial or adverse) on emissions of the others. These side effects are usually ignored in policy making. This study analyses cost-effectiveness of measures to reduce acidification and eutrophication as well as agricultural emissions of N2O and CH4 in Europe, taking into account interrelations between abatement of NH3, N2O, and CH4 in agriculture. The model used is based on the RAINS (Regional Air pollution INformation and Simulation) model for air pollution in Europe, which includes emissions, abatement options, and atmospheric source-receptor relationships for pollutants contributing to acidification and eutrophication. We used an optimisation model that is largely based on the RAINS model but that also includes emissions of N2O and CH4 from agriculture and technical measures to reduce these emissions. For abatement options for agricultural emissions we estimated side effects on other emissions. The model determines abatement strategies to meet restrictions on emission and/or deposition levels at the least cost. Cost-effective strategies to reduce acidification and eutrophication in Europe were analysed. We found that NH3 abatement may cause an increase in N2O emissions. If total agricultural N2O and CH4 emissions in Europe were not allowed to increase, cost-effective allocation of emission reductions over countries in Europe changed considerably.     

The role of atmospheric dispersion models and ecosystem sensitivity in the determination of characterisation factors for acidifying and eutrophying emissions in LCIA

Background, aim and scope  The methodological choices and framework to assess environmental impacts in life cycle assessment are still under discussion. Despite intensive developments worldwide, few attempts have been made hitherto to systematically present the role of different factors of characterisation models in life cycle impact assessment (LCIA). The aim of this study is to show how European average and country-dependent characterisation factors for acidifying and eutrophying emissions differ when using (a) acidifying and eutrophying potentials alone, (b) depositions from an atmospheric dispersion model or (c) critical loads in conjunction with those depositions. Furthermore, in the latter case, the contributions of emissions, an atmospheric transport model and critical loads to changes in characterisation factors of NO₂ are studied. In addition, the new characterisation factors based on the accumulated exceedance (AE) method are presented using updated emissions, a new atmospheric transport model and the latest critical loads. Materials and methods  In this study, characterisation factors for acidifying and eutrophying emissions are calculated by three different methods. In the ‘no fate’ (NF) methods, acidifying and eutrophying potentials alone are considered as characterisation factors. In the ‘only above terrestrial environment’ (OT) approach, characterisation factors are based on the deposition of the acidifying or eutrophying substances to terrestrial land surfaces. The third method is the so-called AE method in which critical loads are used in conjunction with depositions. The results of the methods are compared both at the European and the country level using weighted mean, weighted standard deviation, minimum and maximum values. To illustrate the sensitivity of the AE method, changes in European emissions, employed atmospheric dispersion model and the critical loads database are conducted step-by-step, and the differences between the results are analysed. Results and discussion  For European average characterisation factors, the three characterisation methods of acidification produce results in which the contributions of NH₃, NO₂ and SO₂ to the acidification indicator do not differ much within each method when 1 kg of each acidifying substance is emitted. However, the NF methods cannot describe any spatial aspects of environmental problems. Both OT and AE methods show that the spatial aspects play an important role in the characterisation factors. The AE method results in greater differentiations between country-dependent characterisation factors than does the OT method. In addition, the results of the AE and OT methods differ from each other for individual countries. A major shortcoming of the OT approach is that it does not consider the sensitivity of the ecosystems onto which the pollutants are deposited, whereas the AE approach does. In the case of the AE method, a new atmospheric dispersion model, new information on emissions and critical loads have a different influence on the characterisation factors, depending on the country. The results of statistics show that the change in the atmospheric dispersion model has a greatest influence on the results, since ecosystem-specific depositions are taken into account for the first time. Conclusions and recommendations  The simple NF methods can be used in a first approximation to assess the impacts of acidification and terrestrial eutrophication in cases where we do not know where the emissions occur. The OT approach is a more advanced method compared with the NF method, but its capability to describe spatial aspects is limited. The AE factors are truly impact-oriented characterisation factors and the information used here represents the current best knowledge about the assessment practice of acidification and terrestrial eutrophication in Europe. The key message of this study is that there is no shortcut to achieving advanced characterisation of acidification and terrestrial eutrophication: an advanced methodology cannot develop without atmospheric dispersion models and information on ecosystem sensitivity.     

An integrated approach for environmental assessments

LCA is a system-wide assessment, and the LCIA phase is confronted with the difficulties of local and regional effects in a number of impact categories. We integrate three different environmental techniques to demonstrate how these effects can be addressed in an environmental assessment. The techniques are life cycle inventory, environmental fate models, and an ecological impact assessment using fuzzy expert systems. Results of the LCI are mass and energy flows. In the environmental fate modelling step these mass flows are transformed into concentration and immission values by dispersion-reaction models. A generalised fuzzy expert system for the environmental mechanisms compares calculated exposure with site specific buffering capacities and formulates a generalised dose-response relationship. This generalised fuzzy expert system is used as a template for the assessment of local and regional environmental impacts. An application of this integrated approach is shown for a practical problem: production of magnesium car components. The environmental fate of nitrogen oxides which are released due to the major combustion source within that production system is simulated. Fuzzy expert models for crop damage, soil acidification and eutrophication determine the possible environmental impact of the immited nitrogen oxides. The important methodological extension of this integrated approach is a regionalised impact assessment depending on the spatial distribution of environmental characteristics.     

Evaluating the variability of aquatic acidification and photochemical ozone formation characterization factors for Canadian emissions

Background, aim, and scope  The Canadian life cycle impact assessment method LUCAS proposes a characterization of the impact categories aquatic acidification and photochemical ozone formation using a resolution scale based on 15 terrestrial ecozones. Each ecozone represents areas of the country which can be identified easily by general living (biotic) and nonliving (abiotic) characteristics. The three main purposes of this research are to improve the characterization models of both impact categories including regional exposure and effect factors, to investigate what is the best resolution scale between Canadian provinces or ecozones, and to analyze the extent of spatial variability. Materials and methods  A model framework accounting for variability in fate, exposure and effect factors has been elaborated. The same fate factor, based on Advanced Statistical Trajectory Regional Air Pollution matrices, applies to both impact categories. For the aquatic acidification impact category, the fate factor also accounts for the fraction of the deposition transferred to the aquatic ecosystem. The exposure factor for this impact category is considered to be 1 and the effect factor is based on the critical load exceedance, where the potential impacts are only considered in provinces or ecozones in which the critical load is exceeded. For the photochemical ozone formation impact category, the exposure factor is considered to be proportional to the population density in each province or ecozone, and the effect factor is represented by the chemical reactivity estimated with the maximum incremental reactivity model. The calculation of the new characterization factors using both a province-based and ecozone resolution scale was performed using a matrix which converts data from one resolution scale to another. Results  Results with the inclusion of the effect and the exposure factors show that the spatial variability between provinces remains within a factor of 10 and 5 for aquatic acidification and photochemical ozone formation, respectively. Discussion  Analysis of the results show that regionalization by province is preferable to regionalization by ecozone. It is more accurate in regard to atmospheric modeling and more representative of population distribution. However, averaging the fate factor and the population density over a whole province results in a serious limitation. Conclusions  The spatial variability of characterization factors between provinces is in the same order of magnitude as the overall range between chemicals for aquatic acidification while much smaller for photochemical ozone formation. Hence, at this stage of knowledge, province-based regionalization seems to be more relevant for the aquatic acidification impact category than for photochemical ozone formation. Recommendations and perspectives  Research must be pursued to integrate a better transport and deposition model with improved spatial capabilities and a successive modeling step properly describing the cause–effect chain up to the damage level, such as the biotic environment and the human population.     

Site-Dependent Life-Cycle Impact Assessment of Acidification

The lack of spatial differentiation in current life-cycle impact assessment (LCIA) affects the relevance of the assessed impact. This article first describes a framework for constructing factors relating the region of emission to the acidifying impact on its deposition areas. Next, these factors are established for 44 European regions with the help of the RAINS model, an integrated assessment model that combines information on regional emission levels with information on long-range atmospheric transport to estimate patterns of deposition and concentration for comparison with critical loads and thresholds for acidification, eutrophication via air; and tropospheric ozone formation. The application of the acidification factors in LCIA is very straightforward. The only additional data required, the geographical site of the emission, is generally provided by current life-cycle inventory analysis. The acidification factors add resolving power of a factor of 1,000 difference between the highest and lowest ratings, while the combined uncertainties in the RAINS model are canceled out to a large extent in the acidification factors as a result of the large number of ecosystems they cover The framework presented is also suitable for establishing similar factors for eutrophication and tropospheric ozone formation for regions outside Europe as well.     

Country-dependent Characterisation Factors for Acidification in Europe - A Critical Evaluation (7 pp)

Goal, Scope and Background Country-dependent characterisation factors for acidification have been derived for use in life cycle assessments to describe the effect on ecosystem protection of a change in national emissions. They have recently also been used in support of European air pollution abatement policies and related cost benefit analyses. We demonstrate that the characterisation factors as calculated to date are unstable due to being derived from the non-smooth and highly varying part of the underlying emission-impact functions. The purpose of this paper is to discuss the currently available characterisation factors and to propose a modification that makes use of the full range of the underlying functions. Method The characterisation factors derived in this paper are based on updates of data used to support European air pollution agreements under the UNECE Convention on Long-range Transboundary Air Pollution (LRTAP) and the European Commission. The focus in this paper is on the analysis of characterisation factors for acidification. The analysis of characterisation factors for terrestrial eutrophication from nitrogen compounds is a simple extension of the methods described here. The analysis is conducted for 25 European nations, i.e. for 23 EU countries plus Norway and Switzerland; Cyprus and Malta are excluded due to lack of data on critical loads. Results and Conclusions We show that a linear model which is calibrated to emission changes of –50% is generally more reliable than characterisation factors which are based on emission changes of plus or minus 10%. Application of these characterisation factors are justified for emission reductions up to 30% in total European emissions, compared to 2000. This is within the range of currently agreed upon emission reductions in 2010 relative to 2000. Therefore, characterisation factors can be used in LCA as well as for the support of the revision of existing European air pollution agreements.     

Product Environmental Life-Cycle Assessment Using Input-Output Techniques

Life-cycle assessment (LCA) facilitates a systems view in environmental evaluation of products, materials, and processes. Life-cycle assessment attempts to quantify environmental burdens over the entire life-cycle of a product from raw material extraction, manufacturing, and use to ultimate disposal. However, current methods for LCA suffer from problems of subjective boundary definition, inflexibility, high cost, data confidentiality, and aggregation.
This paper proposes alternative models to conduct quick, cost effective, and yet comprehensive life-cycle assessments. The core of the analytical model consists of the 498 sector economic input-output tables for the U.S. economy augmented with various sector-level environmental impact vectors. The environmental impacts covered include global warming, acidification, energy use, non-renewable ores consumption, eutrophication, conventional pollutant emissions and toxic releases to the environment. Alternative models are proposed for environmental assessment of individual products, processes, and life-cycle stages by selective disaggregation of aggregate input-output data or by creation of hypothetical new commodity sectors. To demonstrate the method, a case study comparing the life-cycle environmental performance of steel and plastic automobile fuel tank systems is presented.     

Eutrophication as an impact category

State of the art and research needs for the impact category eutrophication are discussed. Eutrophication is a difficult impact category because it includes emissions to both air and water — both subject to different environmental mechanisms — as well as impacts occurring in different types of terrestrial and aquatic ecosystems. The possible fate processes are complex and include transportation between different ecosystems. In some recent approaches, transportation modelling of air emissions has been included. However, in general, the used characterisation methods do not integrate fate modelling, which is a limitation. The definition of the impact indicator needs further research, too. The inclusion of other nutrients than those typically considered should also be investigated.     

Impact Characterization in the Tool for the Reduction and Assessment of Chemical and Other Environmental Impacts

The tool for the reduction and assessment of chemical and other environmental impacts (TRACI) is a set of life-cycle impact assessment (LCIA) characterization methods that has been developed by a series of U.S. Environmental Protection Agency research projects. TRACI facilitates the characterization of stressors that may have potential effects, including ozone depletion, global warming, acidification, eutrophication, tropospheric ozone (smog) formation, eco-toxicity, human particulate effects, human carcinogenic effects, human non-carcinogenic effects, fossil fuel depletion, and land-use effects. This article describes the methodologies developed to address acidification, eutrophication, and smog. Each of these methods offers the ability to take account of differences in expected strength of impact as a function of pollution release location within North America. Specifically, the methods employ regionalized fate and transport modeling. The resulting factors differ regionally by up to more than an order of magnitude.     

Lifecycle assessment of fuel ethanol from sugarcane in Brazil

Background, aim, and scope

This paper presents the lifecycle assessment (LCA) of fuel ethanol, as 100% of the vehicle fuel, from sugarcane in Brazil. The functional unit is 10,000 km run in an urban area by a car with a 1,600-cm³ engine running on fuel hydrated ethanol, and the resulting reference flow is 1,000 kg of ethanol. The product system includes agricultural and industrial activities, distribution, cogeneration of electricity and steam, ethanol use during car driving, and industrial by-products recycling to irrigate sugarcane fields. The use of sugarcane by the ethanol agribusiness is one of the foremost financial resources for the economy of the Brazilian rural area, which occupies extensive areas and provides far-reaching potentials for renewable fuel production. But, there are environmental impacts during the fuel ethanol lifecycle, which this paper intents to analyze, including addressing the main activities responsible for such impacts and indicating some suggestions to minimize the impacts.

Materials and methods

This study is classified as an applied quantitative research, and the technical procedure to achieve the exploratory goal is based on bibliographic revision, documental research, primary data collection, and study cases at sugarcane farms and fuel ethanol industries in the northeast of São Paulo State, Brazil. The methodological structure for this LCA study is in agreement with the International Standardization Organization, and the method used is the Environmental Design of Industrial Products. The lifecycle impact assessment (LCIA) covers the following emission-related impact categories: global warming, ozone formation, acidification, nutrient enrichment, ecotoxicity, and human toxicity.

Results and discussion

The results of the fuel ethanol LCI demonstrate that even though alcohol is considered a renewable fuel because it comes from biomass (sugarcane), it uses a high quantity and diversity of nonrenewable resources over its lifecycle. The input of renewable resources is also high mainly because of the water consumption in the industrial phases, due to the sugarcane washing process. During the lifecycle of alcohol, there is a surplus of electric energy due to the cogeneration activity. Another focus point is the quantity of emissions to the atmosphere and the diversity of the substances emitted. Harvesting is the unit process that contributes most to global warming. For photochemical ozone formation, harvesting is also the activity with the strongest contributions due to the burning in harvesting and the emissions from using diesel fuel. The acidification impact potential is mostly due to the NOx emitted by the combustion of ethanol during use, on account of the sulfuric acid use in the industrial process and because of the NOx emitted by the burning in harvesting. The main consequence of the intensive use of fertilizers to the field is the high nutrient enrichment impact potential associated with this activity. The main contributions to the ecotoxicity impact potential come from chemical applications during crop growth. The activity that presents the highest impact potential for human toxicity (HT) via air and via soil is harvesting. Via water, HT potential is high in harvesting due to lubricant use on the machines. The normalization results indicate that nutrient enrichment, acidification, and human toxicity via air and via water are the most significant impact potentials for the lifecycle of fuel ethanol.

Conclusions

The fuel ethanol lifecycle contributes negatively to all the impact potentials analyzed: global warming, ozone formation, acidification, nutrient enrichment, ecotoxicity, and human toxicity. Concerning energy consumption, it consumes less energy than its own production largely because of the electricity cogeneration system, but this process is highly dependent on water. The main causes for the biggest impact potential indicated by the normalization is the nutrient application, the burning in harvesting and the use of diesel fuel.

Recommendations and perspectives

The recommendations for the ethanol lifecycle are: harvesting the sugarcane without burning; more environmentally benign agricultural practices; renewable fuel rather than diesel; not washing sugarcane and implementing water recycling systems during the industrial processing; and improving the system of gases emissions control during the use of ethanol in cars, mainly for NOx. Other studies on the fuel ethanol from sugarcane may analyze in more details the social aspects, the biodiversity, and the land use impact.     

Life Cycle Impact assessment of pollutants causing aquatic eutrophication

In life cycle impact assessment (LCIA), limited attention is generally given to a consistent inclusion of a fate analysis in the derivation of aquatic eutrophication potentials. This paper includes fate and potential effects in the calculation of aquatic eutrophication potentials of NH₃ and NO_x emitted to the ait, N and P emitted to water, and N and P emitted to soil. These characterisation factors were calculated for the Netherlands, West-Europe and the world, respectively. Implementation in current LCIA practice is further facilitated by calculating normalisation scores for the Netherlands in 1997, West-Europe in 1995 and the world in 1990. Although the results presented may be a step forward, significant improvements are still needed in the assessment of pollutants causing aquatic eutrophication. In particular, the fate factors representing transport of NO_x and NH₃, air emissions via soils to the aquatic environment should be improved. In addition, differences in the biological availability of nutrients and differences in the sensitivity of aquatic environments should be included in the calculation of effect factors for aquatic eutrophication.     

Insights on the Use of Hybrid Life Cycle Assessment for Environmental Footprinting

Establishing a comprehensive environmental footprint that indicates resource use and environmental release hotspots in both direct and indirect operations can help companies formulate impact reduction strategies as part of overall sustainability efforts. Life cycle assessment (LCA) is a useful approach for achieving these objectives. For most companies, financial data are more readily available than material and energy quantities, which suggests a hybrid LCA approach that emphasizes use of economic input‐output (EIO) LCA and process‐based energy and material flow models to frame and develop life cycle emission inventories resulting from company activities. We apply a hybrid LCA framework to an inland marine transportation company that transports bulk commodities within the United States. The analysis focuses on global warming potential, acidification, particulate matter emissions, eutrophication, ozone depletion, and water use. The results show that emissions of greenhouse gases, sulfur, and particulate matter are mainly from direct activities but that supply chain impacts are also significant, particularly in terms of water use. Hotspots were identified in the production, distribution, and use of fuel; the manufacturing, maintenance, and repair of boats and barges; food production; personnel air transport; and solid waste disposal. Results from the case study demonstrate that the aforementioned footprinting framework can provide a sufficiently reliable and comprehensive baseline for a company to formulate, measure, and monitor its efforts to reduce environmental impacts from internal and supply chain operations.     

Cremation,Air Pollution,and Special Use Permitting: A Case Study

Risks to health posed by emissions of hazardous air pollutants from crematories are emerging concerns. The presence of silver–mercury amalgams in bodies results in airborne emissions of mercury; and the combustion of essentially any material results in emissions of polychlorinated dibenzodioxins and furans (PCDD/Fs; “dioxins”). These and other trace emissions from crematories are not regulated at the U.S. federal or (typically) state level, but neighborhood concerns may necessitate quantitative evaluations of potential local impacts, and local officials may need to rely on such evaluations in order to determine whether and under what conditions to grant (or deny) operating permits. Here we present a case study in which these and other issues were evaluated. Using air dispersion models and health risk assessment models, we predicted exposures that would be within health-based guidelines. Concerned citizens provided information that seemed to suggest otherwise. In the end, communication, education, and compromise led to a favorable result.     

Life cycle impact assessment of pesticides

Pesticides are biologically active substances that are directly released to the environment during the use phase of their life cycle. Pesticides are widely used and play an important role in the production of vital goods such as food, feedstuffs and cotton. The Discussion Forum 19 focused on the impact assessment of pesticides applied in agriculture. The discussion forum started with three talks about new approaches to estimate pesticide emissions and to assess their fate in the environment. The following short presentations illustrated the application of some of these methods in case studies and highlighted the problem of data availability. The last two presentations provided insight into risk assessment models used for pesticide registration from a company perspective and from the viewpoint of the authorities.