How Many Environmental Impact Indicators Are Needed in the Evaluation of Product Life Cycles?

Minimizing the Environmental Impacts of Plastic Pollution through Ecodesign of Products with Low Environmental Persistence

While plastic pollution threatens ecosystems and human health, the use of plastic products continues to increase. Limiting its harm requires design strategies for plastic products informed by the threats that plastics pose to the environment. Thus, we developed a sustainability metric for the ecodesign of plastic products with low environmental persistence and uncompromised performance. To do this, we integrated the environmental degradation rate of plastic into established material selection strategies, deriving material indices for environmental persistence. By comparing indices for the environmental impact of on-the-market plastics and proposed alternatives, we show that accounting for the environmental persistence of plastics in design could translate to societal benefits of hundreds of millions of dollars for a single consumer product. Our analysis identifies the materials and their properties that deserve development, adoption, and investment to create functional and less environmentally impactful plastic products.

Analyzing the relationship between product waste footprints and environmental damage - A life cycle analysis of 1,400+ products

A major problem for the circular economy is monitoring improvements in environmental sustainability. Measuring how much waste reduction efforts contribute to the decrease of environmental impact is difficult, because knowledge on whether life cycle waste amounts correlate with environmental damage is limited. In this article, product waste footprints are used to explore structural similarities and differences in associations with environmental damage. Using the waste flows linked to the production system of 1487 reference products from the Ecoinvent database, we found significant regression equations with R² of 0.75-0.89 between product waste footprints and potential impact on ecosystem diversity, human health and resource availability using log-transformed variables. For each 1 % increase in solid waste, potential impact on the environment increased by 0.75-0.84 %. This strong association between pre-consumer waste and environmental damage is particularly important for advocating for circular economy efforts at the point of consumption, where life cycle waste is invisible to consumers.

Comparative environmental performance of pavement structures considering recycled materials and regional differences

The construction of pavements incorporating reclaimed asphalt pavement (RAP) is taking place around the world, implying the necessity to quantify their net environmental impacts. Life cycle assessment (LCA) is a popular method to analyze the environmental impacts of a product along the whole value chain, providing guidance to practices and technologies from environmental perspectives. However, the LCA research of RAP-modified pavement is seldom performed in Brazil. In addition, as an important source of uncertainties, there is also need of discussion regarding the geographical and technological characteristics in the LCA of pavements. For these motivations, this paper performs a cradle-to-gate LCA to compare the environmental performance of asphalt pavement in Brazil and Switzerland, using the practical rates of RAP use. The functional unit was defined based on the same traffic volume and service life of asphalt pavements, where the mix design and pavement structures follow the standards of the two countries. The results showed that RAP recycling can improve the environmental performance of hot asphalt mixtures in both countries. Binder amount has a high environmental burden and its reduced use by adding RAP has a positive environmental effect. Type of fuel also plays an important role in LCA. In Brazil, it is not recommended to use heavy oils as fuel during the mixing process if other options such as methane gas is available. The results show that the Swiss production of asphalt mixture had lower environmental impact. Nevertheless, a strategic location of material suppliers and mixing plants could lower the transportation distances, improving its environmental performance.

Optimization of endoglucanase-lipase-amylase enzyme consortium from Thermomyces lanuginosus VAPS25 using Multi-Objective genetic algorithm and their bio-deinking applications

In this study, the enzyme consortium of endoglucanase, lipase, and amylase was obtained and optimized using artificial intelligence-based tools. After optimization using a multi-objective genetic algorithm and artificial neural network, the enzyme activity was 8.8 IU/g, 153.68 U/g, and 19.2 IU/g for endoglucanase, lipase, and amylase, respectively, using Thermomyces lanuginosus VAPS25. The highest enzyme activity was obtained at parameters 77.69% moisture content, 52.7 °C temperature, 98 h, and 3.1 eucalyptus leaves: wheat bran ratio. The endoglucanase-lipase-amylase (END-LIP-AMY) enzyme consortium showed reliable characteristics in terms of catalytic activity at 50-80 °C and pH 6.0-9.0. The increase in deinking efficiency of 27.8% and 11.1% were obtained compared to control for mixed office waste and old newspaper, respectively, using the enzyme consortium. The surface chemical composition and fiber morphology of deinked pulp was investigated using Attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR) and Scanning electron microscopy (SEM).

Environmental trade-offs for using low-noise pavements: Life cycle assessment with noise considerations

Noise mitigation is the main advantage of semi-dense asphalt (SDA) pavements compared to traditional pavements such as stone-mastic asphalt (SMA), but noise is not quantitatively considered in traditional life cycle assessment (LCA). This article performs a comprehensive LCA for SMA and SDA including noise considerations. State-of-the-art sound emission and acoustical ageing models were used to determine the road traffic noise. The latest Swiss dose-response curves and current noise exposure data were used to evaluate health impacts due to noise. Additionally, traditional LCA is also included for assessing the greenhouse gas emissions, non-renewable cumulative energy demand and health impacts of non-noise processes. The results show that SDA causes around 70 % higher greenhouse gases and energy demand than SMA, primarily due to its shorter service life. However, the noise impacts in disability adjusted life years (DALYs) are higher by two to three orders of magnitude than non-noise processes, and the use of SDA can reduce 40 % of the total DALYs. It is shown that road traffic noise plays a significant role in the LCA of pavements. The trade-off between greenhouse gas and energy related impacts, on the one hand, and health effects, on the other hand, requires critical consideration by decision makers when promoting low-noise pavements.

Intelligent modeling and optimization of environmentally friendly green enzymatic deinking of printed paper

Nowadays, the paper industry supplies its required fibers either from primary fibers, including wood and plants, or waste papers, called secondary fibers. One of the most challenging recycling processes is deinking of papers digitally printed with electrophotographic ink. In order to produce optically high-quality paper from recycled waste papers, deinking step is required at the desired levels. In this work, the environmentally friendly green enzymatic deinking of printed paper was modeled and optimized via an innovative approach called artificial intelligence method. The effect of treatment temperature, treatment time, and enzyme dosage on mechanical properties (tensile and burst strengths) as well as optical properties (whiteness and brightness) of handsheet was investigated. The developed code can appropriately learn the non-linear behavior of deinking process, and make decisions according to the pattern constructed intelligently. Finally, multi-objective optimization at the specified treatment temperature, treatment time, and enzyme dosage was performed to identify the best conditions for enzyme-deinked handsheet (maximized mechanical and optical properties).

Environmental and Economic Performance of CO2-Based Methanol Production Using Long-Distance Transport for H2 in Combination with CO2 Point Sources: A Case Study for Germany

The use of CO2-based hydrocarbons plays a crucial role in reducing the climate footprint for several industry sectors, such as the chemical industry. Recent studies showed that regions which are favorable for the production of CO2-based hydrocarbons from an energy perspective often do not provide concentrated point sources for CO2, which leads to an increased environmental impact due to the higher energy demand of direct air capture processes. Thus, producing H2 in regions with high renewable power potential and transporting it to industrialized regions with concentrated CO2 point sources could provide favorable options for the whole process chain. The aim of this study is to analyze and compare pathways to produce CO2-based methanol in Germany using a local CO2 point source in combination with the import of H2 per pipeline or per ship as well as H2 produced in Germany. The environmental and economic performance of the pathways are assessed using life cycle assessment and cost analysis. As environmental indicators, the climate, material, water, and land footprints were calculated. The pathway that uses H2 produced with electricity from offshore wind parks in Germany shows the least environmental impacts, whereas the import via pipeline shows the best results among the importing pathways. The production costs are the lowest for import via pipeline now and in the near future. Import via ship is only cost-efficient in the status quo if waste heat sources are available, but it could be more competitive in the future if more energy and cost-efficient options for regional H2 distribution are available. It is shown that the climate mitigation effect is more cost-effective if the H2 is produced domestically or imported via pipeline. Compared to the import of CO2-based methanol, the analyzed H2 import pathways show a comparable (pipeline) or worse environmental and economic performance (ship).

Life Cycle Assessment of Waste Glass Powder Incorporation on Concrete: A Bridge Retrofit Study Case

The construction sector is responsible for some of the highest energy and natural resources consumption. In this context, new materials and solutions are created aimed at developing sustainable alternatives. While the literature presents papers that evaluate the mechanical and durability properties of concrete with glass waste powder and account for its environmental impact, no papers have executed the evaluation considering the retrofit of bridges. Furthermore, no papers evaluating the materials, construction, and maintenance could be found. Hence, this study proposes a technical and sustainable solution for the retrofit of the Third Bridge of Vitoria, an important intercity urban connector. This study evaluates both the technical and the environmental performance of structural concrete elements, considering the partial substitution of cement with glass waste powder and a baseline scenario with conventional concrete. The environmental impacts were evaluated through the life cycle assessment tool. The results indicate that incorporating waste glass powder in the prestressed hollow-core slabs as a partial cement replacement can improve the durability-related properties and mitigate environmental impact. It also shows that the manufacturing phase is the most impactful and that glass powder can significantly reduce the impact of maintenance.

Developing Conversion Factors of LCIA Methods for Comparison of LCA Results in the Construction Sector

The inconsistency caused by different life cycle impact assessment (LCIA) methods is a long-term challenge for the life cycle assessment (LCA) community. It is necessary to systematically analyze the differences caused by LCIA methods and facilitate the fair comparison of LCA results. This study proposes an effective method of conversion factors (CFs) for converting the results of 8 LCIA methods for 14 impact categories and then demonstrates its application in the construction sector. Correlation analyses of the datasets of construction materials are conducted to develop CFs for the impact categories. A set of conversion cards are devised to present the CFs and the associated correlation information for the LCIA methods. It is revealed that the differences between LCIA methods are largely caused by the characterization methods, rather than due to the metrics. A comparison based only on the same metrics but ignoring the underlying LCIA mechanisms is misleading. High correlations are observed for the impact categories of climate change, acidification, eutrophication, and resource depletion. The developed CFs and conversion cards can greatly help LCA practitioners in the fair comparison of LCA results from different LCIA methods. Case studies are conducted, and verify that by applying the CFs the seemingly incomparable results from different LCIA methods become comparable. The CF method addresses the inconsistency problem of LCIA methods in a practical manner and helps improve the comparability and reliability of LCA studies in the construction sector. Suggestions are provided for the further development of LCIA conversion factors.

Development of Streamlined Life-Cycle Assessment for the Solid Waste Management System

Life-cycle assessments (LCAs) of municipal solid waste management (MSWM) systems are time- and data-intensive. Reducing the data requirements for inventory and impact assessments will facilitate the wider use of LCAs during early system planning and design. Therefore, the objective of this study is to develop a systematic framework for streamlining LCAs by identifying the most critical impacts, life-cycle inventory emissions, and inputs based on their contributions to the total impacts and their effect on the rankings of 18 alternative MSWM scenarios. The scenarios are composed of six treatment processes: landfills, waste-to-energy combustion, single-stream recycling, mixed waste recycling, anaerobic digestion, and composting. The full LCA uses 1752 flows of resources and emissions, 10 impact categories, 3 normalization references, and 7 weighting schemes, and these were reduced using the streamlined LCA approach proposed in this study. Human health cancer, ecotoxicity, eutrophication, and fossil fuel depletion contribute 75-83% to the total impacts across all scenarios. It was found that 3.3% of the inventory flows contribute ≥95% of the overall environmental impact. The highest-ranked strategies are consistent between the streamlined and full LCAs. The results provide guidance on which impacts, flows, and inputs to prioritize during early strategy design.

The Timber Footprint of the German Bioeconomy—State of the Art and Past Development

The article gives a comprehensive overview of the roundwood equivalents (RE) consumed in the German bioeconomy from Germany and abroad between 1995 and 2015, i.e., the Timber Footprint of final Consumption (TFPcon). The calculation is based on an adapted version of Exiobase 3.4. The sustainability of roundwood procurement for the TFPcon is assessed. A systematic embedding of the tree compartments considered in the TFP in the context of national forest inventories and material flow analysis is presented. The results show that, in 2015, the total volume of the TFPcon of Germany is 90 Mm3 (slightly above the 1995 level) and is composed of 61% coniferous and 39% non-coniferous wood. Germany is strongly dependent on roundwood sourced from abroad and thus was a net importer of RE in 2015. Among the 17 countries with the largest supply of RE for the TFPcon, around one third very likely include large shares of roundwood procured from deforestation or clear-cutting. The self-sufficiency rate in 2015 was only 76%. It would be possible to increase domestic roundwood production by 8–41% (mainly in the hardwood sector) without exceeding the sustainability limits as defined in the WEHAM scenarios.

The application of life cycle assessment (LCA) to wastewater treatment: A best practice guide and critical review

Life cycle assessment (LCA) has been widely applied in the wastewater industry, but inconsistencies in assumptions and methods have made it difficult for researchers and practitioners to synthesize results from across studies. This paper presents a critical review of published LCAs related to municipal wastewater management with a focus on developing systematic guidance for researchers and practitioners to conduct LCA studies to inform planning, design, and optimization of wastewater management and infrastructure (wastewater treatment plants, WWTPs; collection and reuse systems; related treatment technologies and policies), and to support the development of new technologies to advance treatment objectives and the sustainability of wastewater management. The paper guides the reader step by step through LCA methodology to make informed decisions on i) the definition of the goal and scope, ii) the selection of the functional unit and system boundaries, iii) the selection of variables to include and their sources to obtain inventories, iv) the selection of impact assessment methods, and v) the selection of an effective approach for data interpretation and communication to decision-makers.

Techno-economic and environmental sustainability of biomass waste conversion based on thermocatalytic reforming

The development and design of innovative biomass waste to energy conversion processes is a key issue to pursue the implementation of circular economy and to endorse a sustainable management of agricultural land. Assessing the environmental and economic sustainability of such processes is of paramount importance to prevent the trade-off of their impacts. The present study focused on a novel biomass waste to energy conversion process based on thermocatalytic reforming (TCR). Two different agricultural waste substrates (olive wood pruning and digestate) were selected as reference cases for conversion to energy and valuable material fractions. Mass and energy balances allowed the calculation of environmental and economic indexes considering alternative scenarios for the final use of the energy and of the products obtained from the TCR conversion (i.e. syngas, bio-oil and bio-char). A sensitivity analysis was carried out to assess the robustness of results. The overall performances of the TCR process resulted strongly related to the characteristics of the biomass waste and to the possible use of the product fractions obtained in the TCR process. The use of bio-char for soil amendment, allowed by the high quality of bio-char obtained from the TCR, was a key point to improve the expected environmental and economic sustainability of the conversion process.

Towards Productive Cities: Environmental Assessment of the Food-Energy-Water Nexus of the Urban Roof Mosaic

Cities are rapidly growing and need to look for ways to optimize resource consumption. Metropolises are especially vulnerable in three main systems, often referred to as the FEW (i.e., food, energy, and water) nexus. In this context, urban rooftops are underutilized areas that might be used for the production of these resources. We developed the Roof Mosaic approach, which combines life cycle assessment with two rooftop guidelines, to analyze the technical feasibility and environmental implications of producing food and energy, and harvesting rainwater on rooftops through different combinations at different scales. To illustrate, we apply the Roof Mosaic approach to a densely populated neighborhood in a Mediterranean city. The building-scale results show that integrating rainwater harvesting and food production would avoid relatively insignificant emissions (13.9-18.6 kg CO₂ eq/inhabitant/year) in the use stage, but their construction would have low environmental impacts. In contrast, the application of energy systems (photovoltaic or solar thermal systems) combined with rainwater harvesting could potentially avoid higher CO₂ eq emissions (177-196 kg CO₂ eq/inhabitant/year) but generate higher environmental burdens in the construction phase. When applied at the neighborhood scale, the approach can be optimized to meet between 7% and 50% of FEW demands and avoid up to 157 tons CO₂ eq/year. This approach is a useful guide to optimize the FEW nexus providing a range of options for the exploitation of rooftops at the local scale, which can aid cities in becoming self-sufficient, optimizing resources, and reducing CO₂ eq emissions.

Comparing Life Cycle Assessment (LCA) of Salmonid Aquaculture Production Systems: Status and Perspectives

Aquaculture is the fastest growing food sector worldwide, mostly driven by a steadily increasing protein demand. In response to growing ecological concerns, life cycle assessment (LCA) emerged as a key environmental tool to measure the impacts of various production systems, including aquaculture. In this review, we focused on farmed salmonids to perform an in-depth analysis, investigating methodologies and comparing results of LCA studies of this finfish family in relation to species and production technologies. Identifying the environmental strengths and weaknesses of salmonid production technologies is central to ensure that industrial actors and policymakers make informed choices to take the production of this important marine livestock to a more sustainable path. Three critical aspects of salmonid LCAs were studied based on 24 articles and reports: (1) Methodological application, (2) construction of inventories, and (3) comparison of production technologies across studies. Our first assessment provides an overview and compares important methodological choices. The second analysis maps the main foreground and background data sources, as well as the state of process inclusion and exclusion. In the third section, a first attempt to compare life cycle impact assessment (LCIA) and feed conversion ratio (FCR) data across production technologies was conducted using a single factor statistical protocol. Overall, findings suggested a lack of methodological completeness and reporting in the literature and demonstrated that inventories suffered from incomplete description and partial disclosure. Our attempt to compare LCA results across studies was challenging due to confounding factors and poor data availability, but useful as a first step in highlighting the importance of production technology for salmonids. In groups where the data was robust enough for statistical comparison, both differences and mean equalities were identified, allowing ranking of technology clusters based on their average scores. We statistically demonstrated that sea-based systems outperform land-based technology in terms of energy demand and that sea-based systems have a generally higher FCR than land-based ones. Cross-study analytics also strongly suggest that open systems generate on average more eutrophying emissions than closed designs. We further discuss how to overcome bottlenecks currently hampering such LCA meta-analysis. Arguments are made in favor of further developing cross-study LCA analysis, particularly by increasing the number of salmonid LCA available (to improve sample sizes) and by reforming in-depth LCA practices to enable full reproducibility and greater access to inventory data.

A tool to guide the selection of impact categories for LCA studies by using the representativeness index

Understanding the environmental profile of a product computed from the Life Cycle Assessment (LCA) framework is sometimes challenging due to the high number of environmental indicators involved. The objective here, in guiding interpretation of LCA results, is to highlight the importance of each impact category for each product alternative studied. For a given product, the proposed methodology identifies the impact categories that are worth focusing on, relatively to a whole set of products from the same cumulated database. The approach extends the analysis of Representativeness Indices (RI) developed by Esnouf et al. (2018). It proposes a new operational tool for calculating RIs at the level of impact categories for a Life Cycle Inventory (LCI) result. Impact categories and LCI results are defined as vectors within a standardized vector space and a procedure is proposed to treat issues coming from the correlation of impact category vectors belonging to the same Life Cycle Impact Assessment (LCIA) method. From the cumulated ecoinvent database, LCI results of the Chinese and the German electricity mixes illustrate the method. Relevant impact categories of the EU-standardized ILCD method are then identified. RI results from all products of a cumulated LCI database were therefore analysed to assess the main tendencies of the impact categories of the ILCD method. This operational approach can then significantly contribute to the interpretation of the LCA results by pointing to the specificities of the inventories analysed and for identifying the main representative impact categories.

Methods to Assess the Impacts and Indirect Land Use Change Caused by Telecoupled Agricultural Supply Chains: A Review

The increasing international trade of agricultural products has contributed to a larger diversity of food at low prices and represents an important economic value. However, such trade can also cause social, environmental and economic impacts beyond the limits of the countries directly involved in the exchange. Agricultural systems are telecoupled because the impacts caused by trade can generate important feedback loops, spillovers, rebound effects, time lags and non-linearities across multiple geographical and temporal scales that make these impacts more difficult to identify and mitigate. We make a comparative review of current impact assessment methods to analyze their suitability to assess the impacts of telecoupled agricultural supply chains. Given the large impacts caused by agricultural production on land systems, we focus on the capacity of methods to account for and spatially allocate direct and indirect land use change. Our analysis identifies trade-offs between methods with respect to the elements of the telecoupled system they address. Hybrid methods are a promising field to navigate these trade-offs. Knowledge gaps in assessing indirect land use change should be overcome in order to improve the accuracy of assessments.

Assessing the Environmental Sustainability of Food Packaging: An Extended Life Cycle Assessment including Packaging-Related Food Losses and Waste and Circularity Assessment

Food packaging helps to protect food from being lost or wasted, nevertheless it is perceived as an environmental problem. The present study gives an overview of methods to assess the environmental sustainability of food packaging. Furthermore, we propose a methodological framework for environmental assessment of food packaging. There is a broad consensus on the definition of sustainable packaging, which has to be effective, efficient, and safe for human health and the environment. Existing frameworks only provide general guidance on how to quantify the environmental sustainability of packaging. Our proposed framework defines three sustainability aspects of food packaging, namely direct environmental effects of packaging, packaging-related food losses and waste, as well as circularity. It provides a list of key environmental performance indicators and recommends certain calculation procedures for each indicator. The framework is oriented towards the Product Environmental Footprint initiative and the Circular Economy Package of the European Union. Further research should develop a method to determine the amount of packaging-related food losses and waste. Moreover, future studies should examine the potential environmental benefits of different measures to make food packaging more circular.

Conceptualization of an Indicator System for Assessing the Sustainability of the Bioeconomy

The increased use of biogenic resources is linked to expectations of “green” economic growth, innovation spurts through biotechnology, development options for rural areas, and an increasingly regenerative resource base that is also climate-neutral. However, for several years the signs for unintentional and unwanted side effects have been increasing. In 2015, the 2030 Agenda for Sustainable Development was published at the international level in order to address this problem and deliver a starting point for a comprehensive sustainability criteria evaluation catalogue. Impact indicators to quantify the environmental burden induced by national activities in foreign countries are especially lacking. In this article a comprehensive framework for the evaluation of the sustainability of the bioeconomy, considering key objectives and relevant criteria for environmental, economic, and social sustainability is developed. A special focus is set to the intersection area of the three pillars of sustainability, where the particularly important integrative key objectives and the indicators assigned to them (e.g., resource footprints) apply. This indicator set can be used as a basis for bio-economy monitoring, which uses and produces differently aggregated information on different levels of action, with a focus at the national level but also including global impacts of domestic production and consumption.

Representativeness of environmental impact assessment methods regarding Life Cycle Inventories

Life Cycle Assessment (LCA) characterises all the exchanges between human driven activities and the environment, thus representing a powerful approach for tackling the environmental impact of a production system. However, LCA practitioners must still choose the appropriate Life Cycle Impact Assessment (LCIA) method to use and are expected to justify this choice: impacts should be relevant facing the concerns of the study and misrepresentations should be avoided. This work aids practitioners in evaluating the adequacy between the assessed environmental issues and studied production system. Based on a geometrical standpoint of LCA framework, Life Cycle Inventories (LCIs) and LCIA methods were localized in the vector space spanned by elementary flows. A proximity measurement, the Representativeness Index (RI), is proposed to explore the relationship between those datasets (LCIs and LCIA methods) through an angular distance. RIs highlight LCIA methods that measure issues for which the LCI can be particularly harmful. A high RI indicates a close proximity between a LCI and a LCIA method, and highlights a better representation of the elementary flows by the LCIA method. To illustrate the benefits of the proposed approach, representativeness of LCIA methods regarding four electricity mix production LCIs from the ecoinvent database are presented. RIs for 18 LCIA methods (accounting for a total of 232 impact categories) were calculated on these LCIs and the relevance of the methods are discussed. RIs prove to be a criterion for distinguishing the different LCIA methods and could thus be employed by practitioners for deeper interpretations of LCIA results.

Resource Footprints are Good Proxies of Environmental Damage

Environmental footprints are increasingly used to quantify and compare environmental impacts of for example products, technologies, households, or nations. This has resulted in a multitude of footprint indicators, ranging from relatively simple measures of resource use (water, energy, materials) to integrated measures of eventual damage (for example, extinction of species). Yet, the possible redundancies among these different footprints have not yet been quantified. This paper analyzes the relationships between two comprehensive damage footprints and four resource footprints associated with 976 products. The resource footprints accounted for >90% of the variation in the damage footprints. Human health damage was primarily associated with the energy footprint, via emissions resulting from fossil fuel combustion. Biodiversity damage was mainly related to the energy and land footprints, the latter being mainly determined by agriculture and forestry. Our results indicate that relatively simple resource footprints are highly representative of damage to human health and biodiversity.