Journal Articles (Peer-Reviewed)
Backes, Jana Gerta., Julian Suer, Nils Pauliks, Sabrina Neugebauer and Marzia Traverso (2021): Life Cycle Assessment of an Integrated Steel Mill Using Primary Manufacturing Data: Actual Environmental Profile, Sustainability, 13 (6).
Abstract: The current dependency on steel within modern society causes major environmental pollution, a result of the product’s life cycle phases. Unfortunately, very little data regarding single steel production processes have been found in literature. Therefore, a detailed analysis of impacts categorized in terms of relevance cannot be conducted. In this study, a complete life cycle assessment of steel production in an integrated German steel plant of thyssenkrupp Steel Europe AG, including an assessment of emissions from the blast furnace, the basic oxygen furnace, and casting rolling, is carried out. The functional unit is set to 1 kg hot-rolled coil, and the system boundaries are defined as cradle-to-gate. This study models the individual process steps and the resulting emitters using the software GaBi. Total emissions could be distributed into direct, upstream, and by-product emissions, where the biggest impacts in terms of direct emissions from single processes are from the power plant (48% global warming potential (GWP)), the blast furnace (22% GWP), and the sinter plant (79% photochemical ozone creation potential (POCP)). The summarized upstream processes have the largest share in the impact categories acidification potential (AP; 69%) and abiotic depletion potential fossil (ADPf; 110%). The results, including data verification, furthermore show the future significance of the supply chain in the necessary reduction that could be achieved.
Neugebauer, Sabrina, Maren Bolz, Rose Mankaa and Marzia Traverso (2020): How sustainable are sustainability conferences? - Comprehensive Life Cycle Assessment of an international conference series in Europe, Journal of Cleaner Production, 242.
Abstract: Scientific conferences are a widely established and a highly important and an indispensable component for knowledge sharing, networking activities, scientific debate etc. What is usually ignored is the resource demand of such an event, putting an enormous burden on the environment. For almost two decades now, there has been an increasing demand for mitigation of environmental impacts of scientific conferences. However, in the field of sustainability science hardly any measures have been taken as only one out of ten sustainability conferences promoted action to reduce environmental impacts. A comprehensive Life Cycle Assessment (LCA) has not been carried out for all phases of a conference. This study therefore strives to conduct a comprehensive LCA of a scientific conference held on sustainability topics. The assessment includes three main parts: 1) preparation of the conference, 2) conference execution, and 3) further pre-/post-conference activities (participants’ travel associated with the conference). The functional unit is defined as: Holding one 3-day international academic conference on sustainability topics. The results display that travel activities of participants dominantly contribute to the overall environmental impact. Further relevant phases are catering, hotel overnight stays as well as environmental burdens associated with the conference venue. It was found that the conference under consideration leaves a carbon footprint of 455 tonnes of CO2 eq., equivalent to an average of 0.57 tonnes of CO2 eq. per participant. A scenario analysis displayed that changes towards train travelling, vegetarian meals and reduction of conference materials can significantly better the environmental profile of a conference. Further measures of environmental optimization could be identified, e.g. digital meetings. It is however unlikely that those will totally replace physical meetings. The social benefits of direct personal and globally-oriented exchange can probably not be outweighed by environmental savings. Future conference planning should thus relate the sustainability benefits with the detrimental impacts.
Sureau, Solene, Sabrina Neugebauer and Achten, Wouter M. J. (2019): Different paths in social life cycle impact assessment (S-LCIA) - a classification of type II impact pathway approaches, International Journal of Life Cycle Assessment, 25: 382-393.
Abstract: Purpose In social life cycle assessment (S-LCA), we can distinguish two main types of impact assessment (LCIA): type I can be seen as a reporting approach with the use of performance reference points and type II aims at including cause-effect chains or impact pathways in the analysis. Given the heterogeneity of those type II approaches, this review provides a classification of existing type II approaches. Methods We reviewed a total of 28 articles against the background of their main purpose, the method used, the issues covered and the origin of data (observation/characterization/ measurement). We checked the articles against (i) the reflection of an impact pathway, (ii) the availability of so-called inventory and impact indicators, and (iii) the presence of characterization models or factors translating correlations or causality. Results and discussion The analysis reveals three main paths to include impact pathways in S-LCA, which differ in authors’ intentions: (1) some studies identify and propose variables composing impact pathways, or frameworks gathering several pathways; (2) other studies investigate or test known pathways empirically, and until now seek mainly to link income data with health impacts at a macro scale, and (3) a last batch applies known and already quantified characterization models or factors from other research works in case studies. Until now, these case studies focus mainly on income-related social effects or on health impacts. Further, each path is further characterized and classified under nine approaches. Our findings highlight not only the heterogeneous nature of approaches, but also their common denominator which is to not consider phenomena or impacts in isolation but to consider them in relation to their sources or further impacts. It should be noted that type II studies are not only limited to quantitative approaches and variables, but can also use more qualitative variables and methods. Conclusions The presented classification may be used as a guidance tool for authors to make their methodological choices. Also, our findings indicate the opportunity of extending future type II S-LCA research to variables tackled in type I studies (e.g., safe and fair employment and working conditions), beyond pathways including incomes and health impacts. This can be done by using theories from social sciences for the identification of impact pathways. Those could then further be investigated through statistical approaches or in the framework of S-LCA case studies, with specific data and potentially more qualitative methods to analyze causality or social mechanisms.
Stark, Rainer, Tom Buchert, Sabrina Neugebauer, Jeremy Bonvoisin and Matthias Finkbeiner (2017): Benefits and Obstacles of Sustainable Product Development Methods: A Case Study in the Field of Urban Mobility, Design Science, 3 (17).
Abstract: In the last few years, numerous approaches have been introduced for supporting design engineers in developing more sustainable products. However, so far, these efforts have not led to the establishment of a commonly acknowledged standard methodology for Sustainable Product Development (SPD). This brings into question the relevance of developing new methods and calls for more efforts in testing the available ones. This article provides a reflection about the benefits and obstacles of applying existing SPD approaches to a real product development project. It reports the results of a project aimed at developing a new mobility solution under the constraints of sustainability-related targets. This project has led to the development of a new pedelec concept, focusing on the substitution of small passenger cars with the help of three SPD methods – Design for Sustainability Guidelines, Product Sustainability Index, and Life Cycle Sustainability Assessment. These methods have proved to be generally beneficial, thanks to a combination of qualitative and quantitative perspectives. However, the multitude of criteria offered by the methods put forth difficulties in evaluating which sustainability aspects are relevant and therefore lead to higher effort for information retrieval analysis and decision processes. Furthermore, the methods still lack an integrated perspective on the product, the corresponding services and the overarching system.
Ward, Hauke, Mia Burger, Ya-Ju Chang, Paul Fürstmann, Sabrina Neugebauer, Alexander Radebach, Gunther Sproesser, Andreas Pittner, Michael Rethmeier, Eckart Uhlmann and Jan Christoph Steckel (2017): Assessing carbon dioxide emission reduction potentials of improved manufacturing processes using multiregional input output frameworks, Journal of Cleaner Production, 163 (1): 154-165.
Abstract: Evaluating innovative process technologies has become highly important within the last decades. As standard tools different Life Cycle Assessment methods have been established, which are continuously improved. While those are designed for evaluating single processes they run into difficulties when it comes to assessing environmental impacts of process innovations at macroeconomic level. In this paper we develop a multi-step evaluation framework building on multi regional input–output data that allows estimating macroeconomic impacts of new process technologies, considering the network characteristics of the global economy. Our procedure is as follows: i) we measure differences in material usage of process alternatives, ii) we identify where the standard processes are located within economic networks and virtually replace those by innovative process technologies, iii) we account for changes within economic systems and evaluate impacts on emissions. Within this paper we exemplarily apply the methodology to two recently developed innovative technologies: longitudinal large diameter steel pipe welding and turning of high-temperature resistant materials. While we find the macroeconomic impacts of very specific process innovations to be small, its conclusions can significantly differ from traditional process based approaches. Furthermore, information gained from the methodology provides relevant additional insights for decision makers extending the picture gained from traditional process life cycle assessment.
Neugebauer, Sabrina, Yasmine Emara, Christine Hellerström and Matthias Finkbeiner (2017): Calculation of Fair wage potentials along products´ life cycle - Introduction of a new midpoint impact category for social life cycle assessment, Journal of Cleaner Production, 143 (1): 1221-1232.
Abstract: Income and wages are among the determinant factors for the living standards and well-being of workers and thus carry a certain degree of relevance for social life cycle assessment (SLCA). Although, fair wages have often been mentioned as a quantitative measure of societal well-being, a defined impact category and quantitative characterization model is missing. Against this background, this paper aims at defining Fair wage as a new midpoint impact category for SLCA and suggests a characterization model to calculate fair wage potentials (FWPs) along a product's life cycle. The characterization model considers the actual wage paid at each process step in comparison to a minimum living wage. It furthermore relates wage to the effective working time and includes an inequality factor to account for income inequalities. The characterization model was tested in a cradle-to-gate case study on tomatoes produced in Germany to ensure its applicability. Results indicate potentially negative social impacts for workers employed in packaging and transport in Turkey and workers in manufacturing and packaging in China. In contrast, low impacts resulted for the Indian workers. No negative impacts are expected for the German and Dutch workers. The midpoint category Fair wage and the associated characterization model facilitate the operationalization of social impact assessment and provide companies with a practical method to quantify and evaluate their products' life cycle.
Mengarelli, Marco, Sabrina Neugebauer, Matthias Finkbeiner, Michele Germani, Patrizia Buttol and Francesca Reale (2016): End-of-life modelling in life cycle assessment - material or product-centered perspective?, The International Journal of Life Cycle Assessment, 22 (8): 1288-1301.
Abstract: Purpose End-of-life (EoL) modelling in life cycle assessment has already been broadly discussed within several studies. However, no consensus has been achieved on how to model recycling in LCA, even though several approaches have been developed. Within this paper, results arising from the application of two new EoL formulas, the product environmental footprint (PEF) and the multi-recycling-approach (MRA) ones, are compared and discussed. Both formulas consider multiple EoL scenarios such as recycling, incineration and landfill. Methods The PEF formula has been developed within the PEF programme whose intent is to define a harmonized methodology to evaluate the environmental performance of products. The formula is based on a 50:50 allocation approach, as burdens and benefits associated with recycling are accounted for a 50% rate. The MRA formula has been developed to change focus from products to materials. Recycling cycles and material losses over time are considered with reference to material pools. Allocation between systems is no longer needed, as the actual number of potential life cycles for a certain material is included in the calculation. Both the approaches have been tested within two case studies. Results and discussion Methodological differences could thereof be determined, as well as applicability concerns, due to the type of data required for each formula. As far as the environmental performance is concerned, impacts delivered by MRA are lower than those delivered by PEF for aluminium, while the opposite happens for plastic and rubber due to the higher share of energy recovery accounted in PEF formula. Stainless steel impacts are almost the same. Conclusions and recommendations The application of the two formulas provides some inputs for the EoL dilemma in LCA. The use of a wider perspective, better reflecting material properties all over the material life cycle, is of substantial importance to properly represent recycling situations. In MRA, such properties are treated and less data are required compared to the PEF formula. On the contrary, the PEF model better accommodates the modelling of products whose materials, at end of life, can undertake the route of recycling or recovery (or landfill), depending on country-specific EoL management practices. However, its application requires more data.
Neugebauer, Sabrina, Silvia Forin and Matthias Finkbeiner (2016): From Life Cycle Costing towards Economic Life Cycle Assessment - Introducing an Economic Impact Pathway, Sustainability, 8 (5).
Abstract: Economic activities play a key role in human societies by providing goods and services through production, distribution, and exchange. At the same time, economic activities through common focus on short-term profitability may cause global crisis at all levels. The inclusion of three dimensions-environment, economy, and society-when measuring progress towards sustainable development has accordingly reached consensus. In this context, the Life cycle sustainability assessment (LCSA) framework has been developed for assessing the sustainability performance of products through Life cycle assessment (LCA), Life cycle costing (LCC), and Social life cycle assessment (SLCA). Yet, the focus of common economic assessments, by means of LCC, is still on financial costs. However, as economic activities may have a wide range of positive and negative consequences, it seems particularly important to extend the scope of economic assessments. Foremost, as the limitation to monetary values triggers inconsistent implementation practice. Further aspects like missing assessment targets, uncertainty, common goods, or even missing ownership remain unconsidered. Therefore, we propose economic life cycle assessment (EcLCA) for representing the economic pillar within the LCSA framework, following the requirements of ISO 14044, and introducing an economic impact pathway including midpoint and endpoint categories towards defined areas of protection (AoPs). We identify important target ratios by means of economic AoPs, which drive economic activities on the macro- and microeconomic level. Furthermore, we provide suggestions for midpoint and endpoint indicators representing the defined categories. With the presented EcLCA framework, a first step towards the inclusion of economic impacts within LCSA has been made. Relations between economic activities and resulting consequences are displayed, going beyond the cost-driven view of classical LCC. Further research and fine-tuning of the identified midpoint and endpoint categories and related indicators is, however, needed to enable a valid and consistent assessment basis for fostering the practical implementation of EcLCA and LCSA.
Neugebauer, Sabrina, Julia Martinez-Blanco, Rene Scheumann and Matthias Finkbeiner (2015): Enhancing the practical implementation of life cycle sustainability assessment - proposal of a Tiered approach, Journal of Cleaner Production, 102: 165-176.
Abstract: Life cycle sustainability assessment has been claimed to be one of the most common methods for assessing sustainability of products and processes. It consists of the three methods life cycle assessment, life cycle costing and social life cycle assessment. However, the life cycle sustainability assessment framework is still under development and its application is still limited. This is substantiated not only by the lack of data and experience, but also by the proliferation of indicators provided by different institutions. Although indicators are available for the three sustainability dimensions, guidance for the indicator selection is missing. The bottleneck is not the lack of good indicators, but rather the lack of a clear indicator selection process. This appears to be one of the most crucial aspects as data availability, method development and interpretation of results heavily depend on this issue. Another obstacle for the practical implementation of life cycle sustainability assessment arises with the relatively high entrance level. Whereas, for the environmental dimension sufficient data and simplified methods are usually available, e.g. carbon footprint, the social and economic dimension are lacking of similar simplifications. Within this study a Tiered approach has been developed providing an indicator hierarchy and proposing a stepwise implementation concept. An indicator review has been performed according to the three criteria practicality, relevance and method robustness. Afterwards the indicators have been ranked in three tiers. The first tier (‘sustainability footprint’) focuses on indicators, which are characterized as easily applicable indicators and as relevant for production processes and on global scales. The second tier reflects current best practice indicators already used in case studies and preferred by institutions. The last tier aims at giving a comprehensive set of sustainability indicators, even if this level may not be applicable immediately. The Tiered approach may not solve all challenges within life cycle sustainability assessment, e.g. the question of how to solve the interpretation dilemma still remains; however it does support the practical application and further development of the framework through the stepwise implementation of sustainability indicators. The application and science related benefits of the Tiered approach result from the undergone comprehensive indicator review, which seems essential as a basis for further developments within the life cycle sustainability assessment framework, and from the proposed indicator hierarchy, which provides directions for further research. The created sustainability footprint facilitates the practical implementation of life cycle sustainability assessment, as the entrance barrier was lowered without neglecting any dimension of sustainability.
Buchert, Tom, Sabrina Neugebauer, Sebastian Schenker, Kai Lindow and Rainer Stark (2015): Multi-Criteria Decision Making as a Tool for Sustainable Product Development - Benefits and Obstacles, Procedia CIRP, 26: 70-75.
Abstract: For developing sustainable products design engineers need to foresee diverse interrelations between a product's characteristics and its economic, social and environmental impacts. In order to support this complex task a wide range of design methods has been developed. Retrospective analytical methods like Life Cycle Sustainability Assessment (LCSA) require a large amount of information and are thus utilized when important design decisions are already made. Prospective methods are rather generic (e.g. checklists) and too broad to be helpful in concrete design decisions. In this paper, the integration of discrete decision trees with LCSA is proposed for shifting multi-criterial quantitative analysis to earlier development. On the basis of sustainability indicators Pareto-optimal decision-paths for given material- and process alternatives along the product lifecycle can be compared up-front. Resulting benefits and obstacles are illustrated by evaluating value creation options of a bicycle frame.
Peukert, Bernd, Stephan Bernecke, Janire Clavell, Sabrina Neugebauer, Nils F. Nissen, Eckart Uhlmann, Klaus-Dieter Lang and Matthias Finkbeiner (2015): Addressing sustainability and flexibility in manufacturing via smart modular machine tool frames to support sustainable value creation, Procedia CIRP, 29: 514-519.
Abstract: Sustainability and flexibility are crucial aspects in todays’ manufacturing processes. Within this study an innovative approach of modular machine tool frames (MMTF) equipped with micro system technology is presented that aims at enhancing flexibility of mutable production processes. This new approach extends the existing reconfigurable manufacturing systems (RMS). MMTF goes beyond the platform approach via minimizing the machine tool frame parts used for the building block system of manufacturing cells. The concept has been realized by integration of modularized microelectronics and actuators enabling for integrity and accuracy of the machine tool frame. In this contribution, sustainable hotspots for the production of the MMTF are identified via a tiered life cycle sustainability assessment. From these findings, new approaches are derived that provide for a reasonable usage of mechanical and electronic components in MMTF for sustainable value creation.
Chang, Ya-Ju, Gunther Sproesser, Sabrina Neugebauer, Kirana Wolf, Rene Scheumann, Andreas Pittner, Michael Rethmeier and Matthias Finkbeiner (2015): Environmental and Social Life Cycle Assessment of Welding Technologies, Procedia CIRP, 26: 293-298.
Abstract: Life Cycle Assessment (LCA) and Social Life Cycle Assessment (SLCA) are applied in evaluating possible social and environmental impacts of the state-of-art welding technologies, such as Manual Metal Arc Welding (MMAW), Manual Gas Metal Arc Welding (GMAW), Automatic GMAW and Automatic Laser-Arc Hybrid Welding (LAHW). The LCA results indicate that for 1 meter weld seam, MMAW consumes the largest amount of resources (like filler material and coating on electrodes) and energy, which contributes to comparatively higher environmental impacts in global warming potential, acidification, photochemical ozone creation potential and eutrophication than other chosen processes. With regard to social aspects, the health issues and fair salary are under survey to compare the relative potential risk on human health caused by fumes in different welding technologies, and to indicate the sufficiency of current salary of welders in Germany. The results reflect that the wage status of welders is still fair and sufficient. The manual processes bring much higher potential risk of welders’ health than the automatic processes, especially MMAW.
Neugebauer, Sabrina, Marzia Traverso, Rene Scheumann, Ya-Ju Chang, Kirana Wolf and Matthias Finkbeiner (2014): Impact Pathways to Address Social Well-Being and Social Justice in SLCA - Fair Wage and Level of Education, Sustainability, 6 (8): 4839-4857.
Abstract: Social well-being and social justice are meant to create a positive outcome meaningful for people and societies. According to the guidelines of social life cycle assessment, especially well-being should be considered as the main area of protection to assess social impacts of products. In addition, equity and equality need to be addressed in terms of social justice to ensure a fair and ethic society. However, even if a lot of studies focused on the definition social indicators to assess resulting impacts, neither have scientific or common agreements been founded to define a valid set of indicators, nor have consistent pathways from inventory towards impact indicators been established. This work, therefore, proposes possible pathways from life cycle inventory to impact assessment of two social midpoint categories: fair wage and level of education. Respective cause-effect-chains are developed based on the environmental life cycle assessment principle. Correspondingly, social inventory indicators throughout direct impacts to midpoint and endpoint categories are defined. Three endpoint categories are included (economic welfare, damage to human health and environmental stability) to address social well-being and social justice. Qualitative characterization factors and a scaling method are proposed to evaluate the impacts according to threshold and reference values from valuable literature.
Finkbeiner, Matthias, Markus Berger and Sabrina Neugebauer (2013): Carbon footprint of recycled biogenic products: the challenge of modelling CO2 removal credits, International Journal of Sustainable Engineering, 6 (1): 66-73.
Abstract: Current carbon footprinting (CF) and life cycle assessment (LCA) methods do not treat recycled biogenic carbon adequately, because the calculation rules for recycled products and biogenic carbon stored in products are defined independently from each other. Therefore, an improved and consistent calculation rule for the CF of product systems containing both recycling processes and carbon stored in products is proposed. The methodological approach consists of the application of the same allocation principles for both greenhouse gas (GHG) releases and GHG removals: (1) explicit accounting of inputs (GHG removals) and outputs (GHG releases) of biogenic carbon flows instead of assuming carbon neutrality per se; (2) consistent application of allocation rules for environmental benefits and environmental burdens. It is shown that the different modelling approaches (e.g. polluter pays, conservative or partitioning) lead to different results in LCA and CF calculations, e.g. the GHG emissions of first life cycle of the product system calculated here range between − 1.6 units in the polluter pays approach and 4 units in the conservative approach. It is shown that the currently common modelling is an average approach for primary biogenic material, a worst-case approach for recycled biogenic material and a best-case approach for disposed biogenic material. This paper proposes to improve the currently developed standards for CF by adding a requirement to the goal and scope definition phase that ensures the consistent and transparent documentation, how biogenic carbon removal credits are allocated between life cycles.
Neugebauer, Sabrina, Matthias Finkbeiner and Wolfgang Volkhausen (2013): Umweltbewertung von Stahl - neue Ökobilanz berücksichtigt Multirecycling des Werkstoffs, Stahl und Eisen, 133 (7): 49-55.
Abstract: Impacts on humans and ecosystems caused by the production of materials and goods are often discussed in nowadays society and policy. The steel industry already implemented several case studies in life cycle assessment. In this connection a new method to assess the environmental profile of steel has been developed in cooperation of TU Berlin and Stahl-Zentrum, which considers the infinite recyclability of steel in a holistic manner. The project aimed on a material pool based evaluation of the material. Within the life cycle assessment model, the two main production routes for steel - the blastfurnace route and the electric arc furnace route - are covered and equally modelled. The method has been explicitly developed in a way that allows its transfer and application to other materials, too.
Neugebauer, Sabrina, Laura Schneider and Matthias Finkbeiner (2012): Carbon Footprint: Treibhausgasemissionen bilanzieren, Umwelt Magazin.
Neugebauer, Sabrina and Matthias Finkbeiner (2012): Ökobilanz nach ISO 14040/44 für das Multirecycling von Stahl: Critical Review Report.
Benoit Norris, Catherine, Marzia Traverso and Neugebauer, Sabrina et al. (2020): Guidelines for Social Life Cycle Assessment of Products and Organizations.
Finkbeiner, Matthias, Robert Ackermann, Vanessa Bach, Markus Berger, Gerhard Brankatschk, Ya-Ju Chang, Marina Grinberg, Annekatrin Lehmann, Julia Martinez-Blanco, Nikolay Minkov, Sabrina Neugebauer, Rene Scheumann, Laura Schneider and Kirana Wolf (2014): Challenges in Life Cycle Assessment: An Overview of Current Gaps and Research Needs, in: Klöpffler, Walter (ed.): Background and Future Prospects in Life Cycle Assessment, 207-258.
Abstract: This chapter provides a comprehensive overview of current gaps of and challenges for LCA structured into inventory, impact assessment, generic and evolving aspects. A total of 34 gaps and challenges were identified. These include challenges like ‘allocation’, ‘uncertainty’ or ‘biodiversity’, as well as issues like ‘littering’, ‘animal well-being’ or ‘positive impacts’ which are not covered as often in the existing LCA literature. Each of these gaps is described by a high-level overview of the topic and its relevance to LCA, and the state of the art in terms of literature and potential solutions, if any, is presented. The motivation for such an overview is two-fold: First, robust, sustainable and credible use of LCA should avoid the over-interpretation of LCA results without proper consideration of its gaps and limitations. Second, these gaps and challenges represent research needs for the scientific LCA community and hopefully inspire further progress in method development.