Search

International audience; Currently, there is no meaningful methodology for the estimation of environmental impacts from long-term heavy metal emissions in a life cycle assessment (LCA) context, when an assessment of landfill and mining technologies is performed. In this paper, the aims are to investigate the main issues hindering the standardisation of a methodology to account for potential impacts from long-term metal emissions, and to describe the characteristics of a robust framework for an operational impact assessment methodology.In order to demonstrate the issues around potential impacts from long-term emissions in LCA and derive a scientific basis for developing an adequate LCA methodology to address these impacts, a two-part review on long-term metal emissions is performed that (a) identifies a suitable time-dependent life cycle inventory (LCI) while underlining the problems in existing emission prediction attempts and (b) describes the existing LCA approaches for accounting of toxic potential impacts from these emissions while explaining the reason that the identified proposals have not been adopted from the LCA community. These approaches are then compared upon the basis of a common LCI and their differences are highlighted.A suitable dynamic LCI is identified for landfill emissions, which calculates Ni, Zn, Cd and Pb emissions as a function of time, based on assumed developments of the leachate pH. The results of the application of the different impact assessment methods on that LCI differ by up to 8 orders of magnitude. Therefore, the decision-making process supported by an LCA becomes very confusing. None of the approaches consider future changes in the receiving environment and are accompanied with any uncertainty considerations.In order to move towards a robust environmental assessment of long-term emissions, it is necessary to (i) represent future potential impacts more accurately by estimating time-dependent characterisation factors (CFs) corresponding to changing environmental conditions, (ii) develop more robust estimations by addressing uncertainty and (iii) refer to actual potential impacts, by taking into account the current and future background concentrations.

Human exposure to indoor pollutant concentrations is receiving increasing interest in Life Cycle Assessment (LCA). We address this issue by incorporating an indoor compartment into the USEtox model, as well as by providing recommended parameter values for households in four different regions of the world differing geographically, economically, and socially. With these parameter values, intake fractions and comparative toxicity potentials for indoor emissions of dwellings for different air tightness levels were calculated. The resulting intake fractions for indoor exposure vary by 2 orders of magnitude, due to the variability of ventilation rate, building occupation, and volume. To compare health impacts as a result of indoor exposure with those from outdoor exposure, the indoor exposure characterization factors determined with the modified USEtox model were applied in a case study on cooking in non-OECD countries. This study demonstrates the appropriateness and significance of integrating indoor environments into LCA, which ensures a more holistic account of all exposure environments and allows for a better accountability of health impacts., Environmental Science & Technology, 49 (21), ISSN:0013-936X, ISSN:1520-5851

International audience; Objectives The environmental assessment of digestate (residue from anaerobic digestion) post-treatment pathways is seen from a new perspective: it is no longer a residue management but an agronomical pathway which is environmentally assessed. LCA is used to compare the post-treatment pathways of four types of digestates. Methodology Pathways are compared in terms of the agronomical value of the produced and spread products. The fertilizer value is based on the amount of available nitrogen for plants and the amendante value is based on the amount of organic matter that remains to the soil. A functional unit based on "to provide X mass of available nitrogen and Y mass of organic matter to the soil, from an annual production of Z mass of raw digestate" has been deployed to the various pathways (farm, territorial, biowaste) applied to each one of the digestates. Results For a given nitrogen fertilization and a given amendante value, adding available nitrogen via mineral fertilizing or organic matter via peat spreading has a low influence on the scenario hierarchy. Moreover, emissions that follow spreading are the main causes of the impacts of the pathways. This is not true regarding the resource depletion category, which is mainly due to the reagents production (for centrifugation and gas treatment). When a raw digestate direct spreading is compared to the spreading of both solid and liquid phases, establishing or not a raw digestate post-treatment does not discriminate the pathways concerning digestates issued from farm biogas plants. The results are more contrasted for the post-treatment of digestates from territorial pathways, when the spreading of both solid and liquid phases is compared to the spreading of a dried product and the liquid products issued from ultrafiltration and reverse osmosis. The environmental assessment is also balanced in the comparison of the spreading of the solid phase towards the spreading of a digestate biowaste compost. Conclusion LCA has shown its limits here as an evaluation tool for agricultural product-providing-pathways, due to the poor grasp of impacts and the benefits of spreading such products on agricultural soils via LCA. This study approaches the aim of a digestate post-treatment via the agronomical view. More investigations should be done on this interest to better reflect the environmental benefits of post-treatment. Authors would like to thank the project partners for having provided the data used in the LCAs.

International audience; Agricultural systems are increasingly subjected to environmental life cycle assessment (LCA) but generating life cycle inventory (LCI) data in agriculture remains a challenge. In Part I, it was suggested that traceability data are a good basis for generating precise LCI with reduced effort, especially when collected by efficient information and communication technologies (ICTs). The aim of this paper is to demonstrate this for wine grape production and generate a list of data to be collected for streamlined LCI generation. The study is carried out in the South of France, on a viticultural farm implementing electronic traceability of each cultivation operation, i.e. tillage, fertilisation, crop protection, weeding, canopy management and harvesting (no irrigation is needed at this vineyard). For each operation, specific emission models which satisfy the trade-off between accuracy and need for data have been identified. Traceability data must be supplemented with data related to the plot, equipment and inputs to feed the models. The sensitivity of the LCA outputs to plot soil type and year of cultivation was studied. Consistent with previous agricultural studies, the results show that operations such as pesticide spraying and fer- tilising have large environmental impacts in this Mediterranean vineyard. Notable variations occur in life cycle impact assessment indicators, principally due to variations in crop yield; however, the influence of secondary factors such as soil type and agricultural practices is also evident and this contribution allows us to better characterise the variability of grape production and to show that streamlined LCI can be created using traceability data. Ultimately, this paper delivers two results. It provides simple models, and relevant data and methodology to enable viticultural LCAs to be undertaken. Additionally, it demon- strates that accurate LCIs can be built based on data already collected for traceability when supplemented with other easily collectable data (weather and farm structural data). Overall, this work paves the way for streamlined LCI in agriculture.

Algae are an attractive, alternative renewable source for biofuel production compared to biomass from food crops or cellulosic materials. Marine algae do not need fresh water or arable land and, thus, production of marine algae does not compete with food production. In contrast to biofuel production from microalgae, the use of macroalgal biomass as feedstock for biofuel production is still in its infancy. This study presents an environmental assessment of bioethanol from onshore grown green seaweed using the life cycle assessment (LCA) methodology. The environmental assessment is based on data from literature and initial laboratory scale experiments, as industrial scale facilities for bioethanol production from macroalgae do not exist. Alternative systems are compared to the reference system and the limits of the LCA are discussed with respect to the co-product management (allocation vs. substitution) in the LCA model. Impact assessment results showed that nutrients for seaweed growth and electricity consumption by the culture system were the main contributors to the environmental burdens of the reference system. Bioethanol from onshore cultivated green seaweed turned out to be an environmentally efficient biofuel compared to fossil fuel and bioethanol from sugarcane. The type of co-product management selected in LCA largely affected the impact assessment results.

L'application d'eau d'irrigation et d'engrais azotés (N) en excès par rapport à la demande des cultures réduit la profitabilité et a de multiples impacts négatifs sur l'environnement. La dynamique de l'azote dans les agrosystèmes est extrêmement complexe, et des modèles mécanistes de culture sont souvent nécessaires pour quantifier l'impact de pratiques de gestion améliorées sur la réduction des pertes en azote. Cette étude utilise la méthodologie de l'Analyse du Cycle de Vie (ACV) combinée à la modélisation mécaniste pour quantifier les bénéfices environnementaux d'une gestion améliorée de l'eau et des fertilisants azotés par des producteurs de canne à sucre, dans une étude de cas à Pongola, Afrique du Sud. Nous avons comparé un scénario de base représentatif des pratiques courantes et intuitives des producteurs en termes d'irrigation, à deux scénarios supplémentaires représentant des pratiques de gestion plus rationnelles de l'eau, et de l'eau et des engrais, respectivement. Les résultats montrent qu'une meilleure gestion de l'eau et de l'azote peut générer une réduction de 20% de la consommation en énergie non-renouvelable, avec des rendements maintenus voire améliorés. Les émissions totales de GES peuvent potentiellement être réduites de 25%. La réduction des applications d'engrais, rendue possible par le moindre lessivage de l'azote sous irrigation raisonnée, résulte en de fortes réductions de ces deux catégories d'impacts. La consommation totale en eau est similaire entre scénario de base et scénarios de meilleure gestion de l'eau; cependant l'utilisation de l'eau de pluie est plus efficiente avec les irrigations raisonnées, réduisant ainsi les besoins d'extraction de la ressource. Par la prise en compte simultanée d'impacts environnementaux multiples, la combinaison de l'ACV et de la modélisation mécaniste de culture montre un potentiel pour identifier les pratiques améliorées et pour développer un accompagnement en éco-conception de systèmes.

Purpose Pesticides are applied to agricultural fields to optimise crop yield and their global use is substantial. Their consideration in life cycle assessment (LCA) is affected by important inconsistencies between the emission inventory and impact assessment phases of LCA. A clear definition of the delineation between the product system model (life cycle inventory—LCI, technosphere) and the natural environment (life cycle impact assessment—LCIA, ecosphere) is missing and could be established via consensus building. Methods A workshop held in 2013 in Glasgow, UK, had the goal of establishing consensus and creating clear guidelines in the following topics: (1) boundary between emission inventory and impact characterisation model, (2) spatial dimensions and the time periods assumed for the application of substances to open agricultural fields or in greenhouses and (3) emissions to the natural environment and their potential impacts. More than 30 specialists in agrifood LCI, LCIA, risk assessment and ecotoxicology, representing industry, government and academia from 15 countries and four continents, met to discuss and reach consensus. The resulting guidelines target LCA practitioners, data (base) and characterisation method developers, and decision makers. Results and discussion The focus was on defining a clear interface between LCI and LCIA, capable of supporting any goal and scope requirements while avoiding double counting or exclusion of important emission flows/impacts. Consensus was reached accordingly on distinct sets of recommendations for LCI and LCIA, respectively, recommending, for example, that buffer zones should be considered as part of the crop production system and the change in yield be considered. While the spatial dimensions of the field were not fixed, the temporal boundary between dynamic LCI fate modelling and steady-state LCIA fate modelling needs to be defined. Conclusions and recommendations For pesticide application, the inventory should report pesticide identification, crop, mass applied per active ingredient, application method or formulation type, presence of buffer zones, location/country, application time before harvest and crop growth stage during application, adherence with Good Agricultural Practice, and whether the field is considered part of the technosphere or the ecosphere. Additionally, emission fractions to environmental media on-field and off-field should be reported. For LCIA, the directly concerned impact categories and a list of relevant fate and exposure processes were identified. Next steps were identified: (1) establishing default emission fractions to environmental media for integration into LCI databases and (2) interaction among impact model developers to extend current methods with new elements/processes mentioned in the recommendations.

The environmental impacts of a water re-circulating system for fish farming were studied through the case study of an inland turbot farm located in Brittany (France). Life Cycle Assessment methodology was used to evaluate the potential environmental impact through the following indicators: Eutrophication Potential, Acidification Potential, Global Warming Potential, Net Primary Production Use and Non Renewable Energy Use. Two methods were used to assess the farm's nitrogen, phosphorus and solids emissions: nutrient measurement accounting and nutrient balance modelling. The two methods gave similar results for solids and phosphorus emissions, while for nitrogen the measurement-based approach resulted in half the emissions predicted by the model. The uncertainty regarding the potential gaseous nitrogen emissions led us to assess impacts according to three scenarios, differing with respect to emissions of N2, N2O and NH3. This approach illustrates that the uncertainty concerning nitrogenous emissions to the atmosphere leads to uncertainty with respect to the production system's Eutrophication Potential and its Global Warming Potential. The comparison of our results with similar results for large rainbow trout production in a flow-through system points out the impacts associated with the high level of energy consumption in the studied re-circulating system (i.e. Non Renewable Energy Use, Global Warming potential, Acidification Potential). The nitrogenous gas emissions of re-circulating systems require further studies, in order to precisely identify the substances involved and the technological solutions allowing reduced impacts.

4th International Seminar in social LCA, Montpellier, FRA, 19-/11/2014 - 21/11/2014; International audience; The social life cycle assessment is a method under construction. It is used to determine the social impacts caused by one change in one life cycle. A crucial question is which categories of impact should be assessed. We must generate a theoretical framework to determine “what is worth in the social world” before answering this question.

In 2010, the president of the Renault-Nissan announces 4 billion dollars in a program to develop electric vehicle and its battery. At that time, the automotive industry is facing a major economic crisis. The success of this engagement is crucial. The electric vehicle is the subject of an innovative design that destabilizes business practices. New protocols should be defined to validate the performance of that product. Given the elimination of emissions during operation, new questions emerge and require a comprehensive assessment of the environmental performance of these vehicles. Therefore, the company must set up a transparent dialogue and manage contested.This work is based in an industrial world, the situation is suitable for intervention. The method of abduction - deduction - induction is used. Collective action is not obvious and needs to be managed. Co-LCA model is designed to facilitate collaboration and building a set of key rules to carry out the study. These rules are still questionable. However, this approach can give more legitimacy to the study. This experience has strengthened the company's practices; it allows many discussions with stakeholders in a structured framework. This process is a platform for knowledge sharing, open discussion and dissemination of information. Finally, we open the way for the LCA tool becomes an instrument for environmental management at the service of a transition in the automotive sector.; En 2010, le président de l'Alliance Renault-Nissan annonce l'investissement de 4 milliards d'euros dans un programme de développement du véhicule électrique et de sa batterie. À cette période, le secteur automobile est confronté à une crise économique importante. Le succès de cet engagement est crucial. Le véhicule électrique fait l'objet d'une conception innovante qui déstabilise les pratiques de l'entreprise. De nouveaux protocoles doivent être définis pour valider les acquis de ce produit. Compte tenu de la suppression des émissions au roulage, de nouvelles questions émergent et réclament une évaluation globale de la performance environnementale de ces véhicules. En conséquence, l'entreprise doit mettre en place un dialogue transparent et gérer une contestation .Ce travail repose sur un monde industriel dont la situation est propice à l'intervention. La méthode d'abduction - déduction – induction est utilisée. L'action collective ne va pas de soi est demande à être pilotée. Le modèle Co-LCA vise à faciliter une collaboration et la construction d'un ensemble de règles clés pour procéder à l'étude. Ces règles sont toujours contestables. Néanmoins, cette approche permet de donner une légitimité plus grande à l'étude. Cette expérience a consolidé les pratiques de l'entreprise, elle autorise de nombreux échanges avec les parties prenantes concernées dans un cadre structuré. Ce processus est une plate-forme pour le partage des savoirs, un débat ouvert et la diffusion d'informations. Enfin, nous ouvrons la voie pour que l'outil ACV devienne un instrument de gestion de l'environnement au service d'une transition dans le secteur automobile.

9th International Conference on Structural Analysis of Historical Constructions, MEXICO, MEXIQUE, 14-/10/2014 - 17/10/2014; Dry-stone technique is a vernacular but worldwide form of construction, appreciated for its simplicity, robustness, and permeability. It consists in interlocking rubble or square stones together without mortar, in order to build a wall or a vault. Dry-stone accounts for 18% of the retaining structures along the French national network, representing more than 1000 walls [1], and for 50% of the walls in Great Britain, stretching over 4500 km [2]. The recent renewal of interest for repair and construction of new dry-stone structures is yet slowed down by the lack of technical and economical knowledge proving their reliability and relevancy. This paper presents recent developments on design methods and sustainability analysis aiming at enhancing the use of dry-stone masonry in retaining wall construction. This study has been undertaken in the framework of the French programme for research PEDRA, which aims at developing analytical and numerical methods as well as decision support tools to assess the performance of vernacular masonry structures during their whole life cycle. First, a structural analysis model based on yield design is exposed. This model provides an analytical expression of the minimal thickness of the wall for a given geometry. Two approaches have been developed, and validated by full-scale experiments: a 2D model for upstream walls and a 3D approach for downstream walls subjected to traffic loading. The 2D approach has been implemented in cross curves of stability, and inserted in a good practice guide [3]. Then, a life cycle analysis and a life cycle cost have been undertaken in order to evaluate the ecological and economical impacts of drystone constructions. Studies on mortared masonry and concrete structures are also provided, as a comparison. As a case of study, the authors focus on the construction of a 50 m long dry-stone retaining wall in the district of Felletin (Creuse, France), built in 2012.

International audience; The FLONUDEP project carried out an environmental LCA « from cradle to grave » of processed tomatoes made in France and Turkey. We compared the environmental impact of tomato sauce made in France with French tomato paste, with that made with Turkish tomato paste. Data have been collected through surveys among a sample of farms (France=4; Turkey=4), processing plants (France= 2; Turkey=4), logistic organization (France=2), 1 supermarket and consumers (n=800), Findings show that French tomato sauce is slightly less impacting than the Turkish one for GHG emissions and human toxicity, whereas results are similar for eutrophication. Critical points are mainly packaging, energy used and steam production at plant level, fertilization and phytosanitary treatments at agricultural level, and finally, consumer behavior (shopping by car) and packaging recycling.

Poster; Besides biofuels from microalgae, an emerging interest in using macroalgae as feedstock for biofuel production is observable. Macroalgae have the advantage that they are much easier to harvest than microalgae so that the problem of low feedstock concentration does not arise. The environmental performance of bioethanol from onshore grown green algae is assessed using literature data and initial laboratory scale data. The optimized system model allows for producing an environmentally efficient biofuel in comparison to fossil fuel and bioethanol from sugar cane. Handling the co-product by substitution instead of energy allocation significantly reduced the environmental impacts of the system and resulted in environmental bonuses in several impact categories. Thus, the management of the co-product in the LCA model (energy allocation vs. substitution) is a key step in the LCA, as it highly influences the impact assessment results.

In a context where husbandries are questioned on their environmental impacts, optimized systems for the future should be devised to pro-vide the milestones. Eight pig systems were constructed by experts by considering the use of best available techniques (BAT), the mod-ernization of buildings and the improvement of technical performances. The kilogram of pig produced from each optimized system was assessed at farm gate using Life Cycle Assessment (LCA) and the results were compared to an average current pig system in conventional production. The results indicate a reduction of impacts which could reach respectively 39, 43, 26, 26 and 45% for climate change, acidifi-cation, eutrophication, land occupation and energy use. The implementation of BATs is limited by their cost. Husbandries should improve their technical performances more than those of the 10% best current husbandries to maintain the current cost of production.

Poster; International audience; Langlois et al. (2012; 2014a) proposed characterization factors (CF) for fish biotic resource extraction impact assessment at the species level. This paper is an improvement of this approach. In the present work, the CF depends on the Maximum Sustainability Yield (MSY), weighted by the ratio of the current total fishing effort to the fishing effort at the MSY value. Because this ratio often cannot be computed from current databases, it is here obtained from the ratio of total catches to MSY and roots of the parabola linking catches to fishing effort. The new version of the CF is proposed for 125 fish stocks. This work allows assessment of fisheries in the LCA formalism. It contributes to a better representation of the depletion of biotic resources.

Environmental impacts of milk production in southern Belgium: estimation for nine commercial farms and investigation of mitigation via better manure application. 9eme International Conference on Life Cycle Assessment in the Agri-Food Sector

International audience

In view of world population increase, the issue is to succeed to feed the planet while knowing that the resources become scarce. Farming is in narrow link with the environment. LCA environmental assessment allows calculating the potential impacts of agricultural practices on the environment. In France, the will to turn to a sustainable farming is taking shape. Through the study of organic beef system of the experimental farm of Thorigné d’Anjou, it is demonstrated that this system can be efficient for both production and environment. These good results are linked to the diverse innovative practices introduced such as multi-species grasslands, the production of cereallegume mixtures, or even horse bean. The system has thus come up with a good balance between productivity and environment. In other systems, either organic or conventional, it is also possible to reduce the environmental impacts, by optimizing their management, while remaining coherent with the implemented practices. The introduction of legumes in crop rotations to reduce the nitrogen inputs, or even the implementation of plant cover to limit the losses towards water, are excellent examples, set up in the farm of Thorigné d’Anjou.; Face à l’augmentation de la population mondiale, l’enjeu est de réussir à nourrir la planète tout en sachant que les ressources se raréfient. L’agriculture est en lien étroit avec l’environnement. L’évaluation environnementale de type ACV permet de chiffrer les impacts potentiels des pratiques agricoles sur l’environnement. En France, la volonté de se tourner vers une agriculture durable se dessine. A travers l’étude du système de bovin viande biologique de la ferme expérimentale de Thorigné d’Anjou, il est démontré que ce système peut être à la fois performant en terme de production et d’environnement. Ces résultats satisfaisants sont en lien avec les diverses pratiques innovantes mises en place telles que les prairies à flore variée, la production de mélanges céréalesprotéagineux, ou encore celle de féverole. Le système a donc su trouver un bon équilibre entre productivité et environnement. Dans d’autres systèmes, aussi bien biologiques que conventionnels, il est également possible de réduire les impacts environnementaux, en optimisant leur conduite, tout en restant cohérent avec les pratiques mises en oeuvre. L’introduction de légumineuses dans les rotations pour réduire les intrants azotés, ou encore la mise en place de couverts végétaux pour limiter les pertes vers l’eau, en sont de bels exemples, appliqués sur la ferme de Thorigné d’Anjou.

International audience; Bulk chemicals and liquid fuels are currently produced almost exclusively from petrochemical feedstock. In the light of emission reduction targets and the dependence on non renewable resources, the production of the same or functionally equivalent chemicals from renewable resources may play an important role [1, 2]. The project BIORARE (Bioelectrosynthesis for the refinery of residual waste) was set up to contribute to this objective. Its purpose is to use microbial electrosynthesis for the direct production of fuels and chemicals from organic waste and CO2 (see figure 1). Ecoconception is used to help to make choices. This is this work which is study.In a first step, we had to determine which parameters of the Bioelectrosynthesis (BES) could be the most impacting ones to define the priorities to be considered to minimize the potential impacts of the entire process. Some flows could be sensitive: the nature and the quantity of outputs, the nature and the quantity of materials, and the amount of energy used. The inventory of these flows had to be the first step. Thanks to databases and literature four have been identified as sensitive: electrodes, membrane, energy and chemicals produced.After determining this, we have to design the model for coupling anaerobic digestion to the BES. This was realized using Life Cycle Assessment approach. The goal of this assessment is to determine the relative influence of various target parameters on the impacts of the process. For example, results will allow assessing if the choice of a material for the electrode could have a significant influence on total impacts. Our methodology illustrates to what extend Life Cycle Assessment could help for the conception of a process, through the evaluation of the contribution of various parameters to the impacts. After, it is possible to integrate them into a model to determine what impacts they could have on the whole production chemicals or fuels from organic waste system.; ACV de production de bioéthanol par bioélectrosynthèse de déchets organiques.

This study aims to propose a holistic, life cycle assessment (LCA) of urban wastewater systems (UWS) based on a comprehensive inventory including detailed construction and operation of sewer systems and wastewater treatment plants (WWTPs). For the first time, the inventory of sewers infrastructure construction includes piping materials and aggregates, manholes, connections, civil works and road rehabilitation. The operation stage comprises energy consumption in pumping stations together with air emissions of methane and hydrogen sulphide, and water emissions from sewer leaks. Using a real case study, this LCA aims to quantify the contributions of sewer systems to the total environmental impacts of the UWS. The results show that the construction of sewer infrastructures has an environmental impact (on half of the 18 studied impact categories) larger than both the construction and operation of the WWTP. This study highlights the importance of including the construction and operation of sewer systems in the environmental assessment of centralised versus decentralised options for UWS ICRA authors also acknowledge the Marie Curie EU Reintegration grants 2010-RG-277050 and PCIG9-GA-2011-293535, the EU-ITN SANITAS (ITN – 289193), the Spanish government (CTM 2011-27163; RYC-2013-14595) and the support from the Economy and Knowledge Department of the Catalan Government through the Consolidated Research Group (2014 SGR 291)

This paper presents the sustainable development analysis undertaken during the recent construction of a new masonry road bridge in the department of Lozère (France). First, the specific construction process of this masonry bridge is exposed. Then, the ecologic and economic impacts of the construction are evaluated through a life cycle assessment and a life cycle cost, and compared to those of a precast concrete bridge solution. Our results show that maintenance consideration is essential to address efficiently the sustainability aspects embedded in stone construction. Recommendations on the use of masonry in modern constructions are finally drawn.

4th European Conference on Sludge Management, Izmir, TUR, 26-/05/2014 - 27/05/2014; International audience; This paper aims to assess the main French sludge treatment and disposal routes using Life Cycle Assessment in order to highlight which system is the most suitable from an environmental point of view. System boundaries include thickening up to the disposal route and the functional unit is one dry matter ton of treated and disposed sludge. Results are provided for thickening, dewatering and stabilization processes coupled with a disposal route. Major points highlighted by this study are the strong impact of the hypotheses used on LCA results as well as the necessity to produce data to fulfil the inventory step.

International audience; Steady-state water-stress based characterisation factors (CFs) for watersheds around the world are already available. CFs for impacts related to water use have proven to be highly spatially dependent. However, the influence of time in the obtained impact factors has not been analysed yet. To this end, this research aimed to calculate water-stress CFs for sub-watersheds in Spain for three temporal scenarios: current situation, short-term future (year 2015) and mid-term future (year 2030). Changing temporal trends in water use due to changing society and economy (ex., population, employment) and modification of regional freshwater resource availability due to already experienced and forecasted effects of climate change have been included in the calculation of the CFs. Statistical uncertainty information of the CFs for each time step is provided, taken into account that uncertainties grow with time horizon. CFs were calculated following the Water Stress Index (WSI) definition of a broadly applied water use impact characterisation method. The WSI was calculated on a yearly basis for 117 sub-watersheds covering Spain. Temporal tendency analysis of the computed CFs shows, in general, a relaxation of water stress in the short-term when compared to the current situation and afterthat a new increment. This is explained by the increase in water availability from now to the near future and then by both water use increment and water availability reduction. Large differences were detected in the comparison of the original WSI CFs at the watershed level for Spain and the WSIs calculated in this research. This may be due to the different time periods for which WSI are calculated and to the use of global maps and models used to figure out the original WSI versus regional data used here. The developed CFs are of usefulness to evaluate water use-related impacts of present and future technologies with life cycle stages located in Spain. We have shown in this study that both temporal and spatial specification matters when assessing impacts of water use.

International audience; This article appeared in a journal published by Elsevier. The attached copy is furnished to the author for internal non-commercial research and education use, including for instruction at the authors institution and sharing with colleagues. Other uses, including reproduction and distribution, or selling or licensing copies, or posting to personal, institutional or third party websites are prohibited. In most cases authors are permitted to post their version of the article (e.g. in Word or Tex form) to their personal website or institutional repository. Authors requiring further information regarding Elsevier's archiving and manuscript policies are encouraged to visit: http://www.elsevier.com/authorsrights a b s t r a c t Reactive nitrogen (N) flows (all forms of N except N 2) are greatly increasing worldwide. This is mainly due to the ever larger use of inorganic N fertilizers used to sustain the growing food production. N flows have major impacts on water, air and soil quality as well as on biodiversity and human health. Reconciling the objectives of feeding the world and preserving the environment is a great challenge for agriculture. One of the main ways to increase food production while reducing its detrimental effects is to increase the efficiency of N use. N use efficiency (NUE) is a commonly used indicator to estimate efficiency of N use at the farm scale. It is defined as the ratio of farm N outputs to N inputs. However, it has some inconsistencies and biases, which raises questions about its reliability for assessing N efficiency of farming systems. As a consequence , we propose a new indicator, called system nitrogen efficiency (SyNE), which is based on NUE and improves upon it in several ways. First, life cycle inventory references are used to estimate N emissions linked to the production of inputs outside the farm. Second, net N flows are calculated by subtracting inputs and outputs of the same product in the farming system. Third, manure is not considered an end product, unlike crop and animal products. Finally, the annual change in N in soil organic matter is estimated. SyNE therefore expresses the efficiency of a farming system in transforming N inputs into desired agricultural products. It takes into account all sources of N, including the annual change in soil N stock as well as N losses occurring during the production and transport of inputs. To test the relevance of this new indicator, 38 mixed farms were surveyed in Brittany, France, and their NUE and SyNE were calculated and compared. Sensitivity analysis was performed to estimate the contribution of each variable to both indicators. We demonstrate SyNE is a useful indicator for comparing the N efficiency of different farming systems. We discuss its use in combination with system N balance (SyNB), a N loss indicator at the system scale. The combination of both indicators gives a more reliable estimate of the productive efficiency and potential environmental impacts of N in various farming systems.

Uncertainty analysis of cattle-based product LCA related to model variables: case study of milk production in Belgium. 9eme International Conference on Life Cycle Assessment in the Agri-Food Sector

International audience; Fossil fuel depletion and attempts of global warming mitigation have motivated the development of biofuels. Several feedstock and transformation pathways into biofuel have been proposed as an alternative to usual fuels. Recently, microalgae have attracted a lot of attention because of the promise of reduced competition with food crop and lowered environmental impacts. Over the last years, several Life Cycle Assessments have been realised to evaluate the energetic benefit and Global Warming Potential reduction of biofuel and bioenergy produced from microalgae. This chapter presents a bibliographic review of fifteen LCA of microalgae production and/or transformation into biofuel. These studies differ often by the perimeter of the study, the functional unit and the production technologies or characteristics. Methods for the environmental impacts assessment and the energy balance computation also diverge. This review aims at identifying the main options and variations between LCAs and concludes by some recommendations and guidelines to improve the contribution of an LCA and to facilitate the comparison between studies.

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 ILCDHandbook. 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-toharvest 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.

Parmi les GES émis en production porcine, les émissions de N2O peuvent être réduites sans perte de performance animale en diminuant les apports en protéines dans les aliments. Pour cela, deux approches complémentaires peuvent être utilisées : améliorer la composition en acides aminés des aliments en apportant des acides aminés alimentaires, et ajuster en dynamique les apports en acides aminés à l’évolution des besoins des animaux. Dans cette étude, nous avons exploré deux options de réduction des émissions GES : l’utilisation accrue des acides aminés alimentaires avec soit une alimentation biphase des porcs à l’engrais (2PAA+), soit une alimentation multiphase (MPAA+). Ces options permettent de réduire les émissions sur l’exploitation de 510 kg CO2e/truie/an pour 2PAA+ et de 692 kg CO2e/truie/an pour MPAA+, soit respectivement une réduction de 29% et 40% par rapport à la situation initiale. Entre 2010 et 2030 et à l’échelle de la France, ces options réduiraient les émissions de 7,4 et 3,7 MTCO2e, pour 2PAA+ et MPAA+, respectivement, soit 22% et 11% relativement à la situation initiale. Avec les efforts de formation et d’aide à la décision engagés, la mise en œuvre de ces pratiques devrait permettre de réduire les émissions de GES et les coûts d’alimentation, de même que les émissions de NH3 et NO3- associées à l’acidification et l’eutrophisation., Among GHG emitted in pig production, N2O emissions can be mitigated without loss of animal performance by reducing crude protein content of feeds. Two complementary approaches can be adopted: improving amino acids composition by incorporating feed-use amino acids and timely adjusting amino acids content of pig feeds to animal requirements. In this study, we investigated two options for mitigating GHG emissions: improved utilisation of feed-use amino acids with either two-phase feeding (2PAA+) or multiphase feeding of growing-finishing pigs (MPAA+). These options mitigate on-farm emissions by 510 kg CO2e/sow/year for 2PAA+ and 692 kg CO2e/sow/year for MPAA+ (i.e. 29% and 40% respectively of the emissions of the control). From 2010 to 2030 at the whole country level, these options would mitigate the emissions by 7.4 and 3.7 MTCO2e, for 2PAA+ and MPAA+ (i.e. 22% and 11% respectively of the emissions of the control situation), respectively. With already engaged actions of training and decision support, the adoption of these practices should allow mitigation of GHG emissions and feeding costs, as well as NH3 and NO3- emissions involved into eutrophication and acidification processes.

National audience

Life cycle assessment is usually an assessment tool, which only considers steady-state processes, as the temporal and spatial dimensions are lost during the life cycle inventory (LCI). This approach therefore reduces the environmental relevance of certain results, as it has been underlined in the case of climate change studies. Given that the development of dynamic impact methods is based on dynamic inventory data, it seems essential to develop a general methodology to achieve a temporal LCI. This study presents a method for selecting the steps, within the whole process network, for which dynamics need to be considered while others can be approximated by steady-state representation. The selection procedure is based on the sensitivity of the impacts on the variation of environmental and economic flows. Once these flows have been identified, their respective timescales are compared to the inherent timescales of the impact categories affected by the flows. The timescales of the impacts are divided into three categories (days, months, years) based on a literature review of the ReCiPe method. The introduction of a temporal dynamic depends on the relationship between the timescale of the environmental and economic flows on the one hand and that of the concerned impact on the other hand. This approach is illustrated by the life cycle assessment of palm methyl ester and ethanol from sugarcane. In both cases, the introduction of a temporal dynamic is limited to a small proportion of the total number of flows: 0.1 % in the sugarcane ethanol production and 0.01 % in the palm methyl ester production. Future developments of time integration in the LCI and in the life cycle impact assessment (LCIA) are also discussed in order to deal with the need of characterization functions and the recurrent problem of waiting times. This work provides a method to select specific flows where the introduction of temporal dynamics is most relevant. It is based on sensitivity analyses and on the relationship between the timescales of the flows and the timescale of the involved impact. The time-distributed LCI generated by using this approach could then be coupled with a dynamic LCIA proposed in the literature.

Le renforcement des préoccupations vis-à-vis des problématiques de développement, de bien-être des populations et de qualité des écosystèmes, génère de nouvelles pressions économiques (labels, cahiers des charges, etc.), normatives (règlements, fiscalité), et de la société civile (consom'action, boycott), et impose aux entreprises de prendre en compte ces problématiques, c'est-à-dire d'identifier, d'évaluer, et d'améliorer leurs impacts. De nombreux outils existent pour évaluer les impacts des chaînes de produits mais seules les méthodes d'Analyse de Cycle de Vie permettent d'avoir une évaluation multicritère et globale, et de rendre compte des transferts d'impacts d'une étape à l'autre du cycle de vie et d'un impact à l'autre. Le développement de l'ACV sociale est vivement souhaité et réclamé par les acteurs. La problématique de cette thèse a consisté à s'interroger sur les principes d'élaboration d'une telle méthode, son cadre conceptuel, théorique et méthodologique. Les besoins de recherche identifiés étant nombreux, les contributions spécifiques de cette thèse ont été triples : i) proposer un nouveau cadre théorique et conceptuel adressant les problématiques de bien-être et de développement, ii) élaborer une relation permettant d'évaluer les impacts de la création d'activité économique et de revenus sur la santé des populations, le " pathway Preston " iii) proposer un cadre méthodologique articulant le Modèle à Capitaux Multiples et le concept de capabilités. Les filières agroalimentaires et plus particulièrement les filières d'importation de fruits et légumes tropicaux, ont servi de cadre empirique à ce travail.

Chapitre 11; International audience; Although the conventional farming system (CV) for apple production remains the common practice worldwide, the organic farming system (OF) is becoming increasingly important. Few global assessments of the environmental impacts of organic orchard systems are currently available. In this work, we analyse the weak and strong points of the environmental performance of the growing phase of two organic and one conventional apple orchard, using a pluri-annual dataset from experimental orchard systems located in the Middle Rhone valley in France, with life cycle analysis (LCA). LCA, also referred to as cradle-to-grave analysis, allows a quantitative and global evaluation of an orchard’s environmental performance. The analysis was performed using the SALCA (Swiss Agricultural Life Cycle Assessment) method (SALCA-Crop V3.1, adapted for pome fruit) and included relevant impact categories based on characterisation models derived mainly from the EDIP97 and CML01 methods, as well as those developed by Agroscope (ART). Seven impact categories that included ecotoxicity and human toxicity, as well as energy consumption and other environmental impact categories, were calculated and are discussed here. The OF systems appeared to have less of an impact than the conventional system, considering the surface-based functional unit (ha/year). However, the basic substitution of conventional with organic inputs or mechanised activities was not sufficient to radically improve the overall environmental performance of the orchard systems. These results need several years of full production to be validated.

absent

Life cycle assessment (LCA) is a tool for evaluating environmental burdens related to a product, process or activity throughout its entire life cycle. In wastewater treatment, LCA can provide, for example, guidance for improving the environmental performance of existing treatment plants. In this study, we applied LCA to assess the environmental impacts of treating washing waters from cheese production by nitrification/denitrification and simultaneous phosphorus precipitation. Wasted sludge was applied as organic fertilizer to farmland to recycle nutrients. LCA results revealed that emissions from biological treatment to air and water, electricity consumption, and consumption of ferric chloride contributed most to the environmental burdens at the level of the treatment plant. Sensitivity analysis of the LCA results regarding the choice of precipitating agent showed that the use of ferrous sulphate instead of ferric chloride reduces the environmental impacts in all impact categories.

Actually biomass-based energy supply is a promising route for renewable energy system and sustainable development strategy. Methane rich gas from biomass can be obtained from gasification (Synthetic Natural Gas, SNG). SNG is very suitable, as it could be an important energy carrier. It could replace natural gas for electricity generation and heating systems and use the existing gas infrastructure. The main objective of this work is to investigate the syngas methanation, and to compare the environmental performance and sustainability for different SNG production systems. The French system (valorization of forest residue) and the Tunisian system (valorization of date palm waste) are analyzed and compared by using the Emergetic Life Cycle Assessment method. The inventory data are obtained mainly through process simulation by Aspen PlusTM software. The results show that increasing the steam ratio in syngas can avoid the carbon deposit during methanation process. The cold gas efficiency of the SNG process is 52%.The environmental analysis results show that high greenhouse gas savings can be obtained for each system. The transformity of the French SNG is lower than the one of the Tunisian SNG. On the other hand, the Tunisian system has the highest percentage of renewability and index of sustainability. The environmental performance and the sustainability of the two systems can be made even more attractive by installing the SNG production units near forests or oasis. Overall, the SNG is expected to contribute favorably to the future renewable energy system, Au regard de la croissance constante de la demande énergétique mondiale et de l'épuisement des ressources fossiles et des problèmes environnementaux, le recours à des sources d'énergie renouvelables est incontournable. La filière biomasse parait une voie prometteuse pour la production d’énergie propre et durable. La production du Gaz Naturel Synthétique (SNG) à partir de biomasse lignocellulosique est en plein essor. L’objectif de ce travail est la comparaison, par le biais d’indicateurs de développement durable, de systèmes de production de SNG à partir des résidus forestiers et des déchets des palmiers dattiers. L’Analyse de Cycle de Vie Emergétique a été choisie comme l’outil le plus judicieux pour cette étude. Elle permet de comparer les deux systèmes afin de déterminer lequel est le plus efficace et le plus durable, et de localiser leurs possibilités d’améliorations environnementales. Les résultats montrent que l'augmentation de la teneur en eau dans le gaz de synthèse peut éviter le dépôt de carbone au cours de la méthanation. Le rendement « Cold Gaz Efficiency » du procédé SNG est de 52%. Les résultats de l'évaluation environnementale montrent de fortes réductions des gaz à effet de serre pour chaque système. La transformité de SNG français est inférieure à celle du SNG tunisien. Par ailleurs, le système tunisien a la plus grande valeur du pourcentage de renouvelabilité et d'indice de durabilité. Le profil environnemental et la durabilité des deux systèmes étudiés peuvent être encore plus intéressants en installant l'unité de SNG à proximité d’oasis ou de forêts. Dans l'ensemble, le SNG devrait contribuer favorablement à l'avenir du mix d'énergie renouvelable

Document élaboré dans le cadre du projet ANR : FLONUDEP Promotion de filières s'inscrivant dans le développement durable à travers un outil d'aide à la décision