Life Cycle Assessment (LCA) is increasingly used, but studies about the influence on decision making and the actual impact of LCA are so far lacking. The goal of this study is therefore to present a ...first assessment of the influence of LCAs within decision-making and the real-world impact of LCAs. For this purpose, a semi-quantitative questionnaire and several qualitative interviews were performed with decision makers from industry and governmental agencies. The results show that half of the surveyed organizations use LCA frequently in decision-making, while the other half only implement LCA in a few decision situations. In companies, LCA is applied for product development and optimization as well as strategic decisions. The level of integration of LCA in decision-making processes showed a positive correlation with the consideration of LCA results and the impact of LCA results on decision outcomes. In public authorities (analysis restricted to Swiss authorities), environmental aspects are always considered during the development of new regulations, but the LCA results are not the only aspects influencing the decision outcome. Other aspects are the costs and the environmental awareness of the decision-maker. Three quarters of all organizations use climate change as one environmental indicator, mostly (in 68% of the responding organizations) in combination with other environmental indicators. Four main reasons limit the influence of LCA within decision-making: lower priority of environmental aspects compared to other decision criteria, complex LCA methods, complex results, and a lack of data to perform a reliable LCA. Future research could be conducted with a specific focus on an industrial sector, a country, or a specific application area to allow in-depth insights of decision-making practices.
Following life-cycle assessment (LCA) methodology, this study presents a state-level estimation of embodied carbon of wood products harvested in 2019 from California and subsequently processed, ...manufactured, transported, used, and disposed at the end-of-life (EoL). In a conventional static approach to LCA, all GHG emissions were aggregated and considered to occur at year 0 of the given time horizon (500 years in this study) and used a static characterization factor (CF). In dynamic LCA, GHG emissions occurring in different years were considered, and their global warming impact (GWI) was determined using a time-dependent CF over the selected time horizon of 500 years. Four scenarios were developed to examine the impact of EoL choices on GWI. It was found that dynamic GWI for all scenarios ranged from 0.27 to 0.93 million tonne CO₂e, which were 45–73 % lower than those estimated with static LCA approach, indicating that the static LCA approach could lead to an underestimation of the benefits of substituting wood for non-wood products, compared to those based on dynamic LCA approach. This analysis also demonstrated that the choice of EoL treatment option is a key factor affecting the estimated GWI as it directly determines the annual emission of GHGs released into atmosphere and subsequently their warming effect depending on the time harvested wood products (HWPs) spend in the horizon of assessment. Overall, the dynamic LCA performed in this study enabled more robust interpretations of embodied carbon by including temporal boundaries associated with the HWPs life cycle.
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•Assessment of embodied carbon of HWPs manufactured and used in California•Static and dynamic LCA performed for cradle-to-grave life stages•Including timing of GHG emissions helps in better understanding of the impacts.•Global warming impacts were greatly influenced by the end-of-life disposal scenarios.
Digesting the alphabet soup of LCA Guinée, Jeroen B.; Cucurachi, Stefano; Henriksson, Patrik J.G. ...
The international journal of life cycle assessment,
2018/7, Volume:
23, Issue:
7
Journal Article
The building sector has a significant potential to reduce the material resource demand needed for construction and therefore, greenhouse gas (GHG) emissions. Digitalization can help to make use of ...this potential and improve sustainability throughout the entire building’s life cycle. One way to address this potential is through the integration of Life Cycle Assessment (LCA) into the building process by employing Building Information Modeling (BIM). BIM can reduce the effort needed to carry out an LCA, and therefore, facilitate the integration into the building process. A review of current industry practice and scientific literature shows that companies are lacking the incentive to apply LCA. If applied, there are two main approaches. Either the LCA is performed in a simplified way at the beginning of the building process using imprecise techniques, or it is done at the very end when all the needed information is available, but it is too late for decision-making. One reason for this is the lack of methods, workflows and tools to implement BIM-LCA integration over the whole building development. Therefore, the main objective of this study is to develop an integrated BIM-LCA method for the entire building process by relating it to an established workflow. To avoid an additional effort for practitioners, an existing structure for cost estimation in the Swiss context is used. The established method is implemented in a tool and used in a case study in Switzerland to test the approach. The results of this study show that LCA can be performed continuously in each building phase over the entire building process using existing Building Information Modeling (BIM) techniques for cost estimation. The main benefit of this approach is that it simplifies the application of LCA in the building process and therefore gives incentives for companies to apply it. Moreover, the re-work caused by the need for re-entering data and the usage of many different software tools that characterize most of the current LCA practices is minimized. Furthermore, decision-making, both at the element and building levels, is supported.
Purpose
Demand for Environmental Product Declarations (EPDs) is already high and increasing in the construction and building sectors. The overall purpose of EPDs is comparability of product ...environmental performance, and they are thus developed in accordance with product category rules (PCRs): requirements and guidelines for how to make EPDs for one or more product groups. Since several organisations publish PCRs, there is a risk of creating conflicting rules leading to inconsistencies and jeopardising the objective of comparability.
Methods
This study analyses the causes for inconsistency and the consequences in terms of difference in the results across the life cycle assessment (LCA) models underlying the EPDs. Taking four EPD programmes and their actors as cases, first a document analysis was conducted to identify qualitative and quantitative differences in their guidelines. Further focusing on selected quantitative differences, a series of LCA models were designed for the same triple-glazed window product by adhering to the PCRs of each operator, to highlight the differences in results that occur when performing the same assessment via different but all formally selectable operators and compliant EPDs.
Results and discussion
Results show that the EPD of a specific product can return very different impact scores if one or the other guideline is followed. Results can vary more than 10% from the base scenarios, what we consider a significant variation. This is observed across all impact categories. Focusing specifically on the climate change impact, the results show that differences are due to the choice of energy mix, reference service life and other parameters. It is thus the combination of several modelling differences that leads to a overall divergence in results, rather than one single methodological choice.
Conclusions
Numerous different but at the same time compliant EPDs can be obtained for the same product, highlighting a serious harmonisation issue within the EPD system. EPDs are thus not necessarily accurate, and it remains doubtful whether EPD comparability can be achieved. This weakness of the EPD system can in the worst case be exploited by producers to obtain lower results and undermines the system.
Recommendations
Besides recommending using LCA for learning and process improvement rather than just for external communication and compliance, to increase harmonisation in the EPD system, we recommend limiting the number of product-specific PCRs (e.g. complementary PCRs), align default values, learn from verification, use just one background database, increase transparency and move towards one centralized operator.
•Prospective and consequential LCA and LCC are integrated in a PSK BIPV case study.•A prospective methodology links environmental and economic benefits of PSK systems.•Silicon-based PV results as ...more economically valuable than PSK modules in r-BIPV.•PSK f-BIPV systems will become more economically convenient than a glass façade.•f-BIPV results the most attractive PSK systems application to cut GHG emissions.
This paper addresses an integrated economic and environmental assessment where a consequential and prospective life cycle approach is applied to perovskite (PSK) building integrated photovoltaic (BIPV) systems. Two configurations are considered: slanted roof (r-BIPV) installations, and the fenestration of façades (f-BIPV). Concerning r-BIPV, PSK systems are expected to compete with crystalline silicon (c-Si) modules; whereas a glass façade is chosen as an alternative reference for f-BIPV. Assuming economic rationality as the main criteria for the adoption of technologies, a deployment time for the PSK system is estimated and the economic and environmental advantages in the Italian context are evaluated. This assessment is based on three foreground scenarios addressing the gradual development of PSK systems. The results show that while c-Si modules are preferred in the market of r-BIPV systems, PSK modules will find space in f-BIPV applications. Depending on the selected scenario, the economic benefits accumulated by Italian energy users are assessed between −0.5 % and −10.3 %. On the other hand, PSK systems imply a variation of the national GHGs emissions that ranges between + 0.01 % and −7.5 %. Depending on the scenario, the PSK-based f-BIPV systems can provide either environmental benefits (i.e., cumulative energy demand) or burdens (i.e., ecotoxicity indicators).
We developed a physically-based environmental account of US food production systems and integrated these data into the environmental-input-output life cycle assessment (EIO-LCA) model. The extended ...model was used to characterize the food, energy, and water (FEW) intensities of every US economic sector. The model was then applied to every Bureau of Economic Analysis metropolitan statistical area (MSA) to determine their FEW usages. The extended EIO-LCA model can determine the water resource use (kGal), energy resource use (TJ), and food resource use in units of mass (kg) or energy content (kcal) of any economic activity within the United States. We analyzed every economic sector to determine its FEW intensities per dollar of economic output. This data was applied to each of the 382 MSAs to determine their total and per dollar of GDP FEW usages by allocating MSA economic production to the corresponding FEW intensities of US economic sectors. Additionally, a longitudinal study was performed for the Los Angeles-Long Beach-Anaheim, CA, metropolitan statistical area to examine trends from this singular MSA and compare it to the overall results. Results show a strong correlation between GDP and energy use, and between food and water use across MSAs. There is also a correlation between GDP and greenhouse gas emissions. The longitudinal study indicates that these correlations can shift alongside a shifting industrial composition. Comparing MSAs on a per GDP basis reveals that central and southern California tend to be more resource intensive than many other parts of the country, while much of Florida has abnormally low resource requirements. Results of this study enable a more complete understanding of food, energy, and water as key ingredients to a functioning economy. With the addition of the food data to the EIO-LCA framework, researchers will be able to better study the food-energy-water nexus and gain insight into how these three vital resources are interconnected. Applying this extended model to MSAs has demonstrated that all three resources are important to a MSA's vitality, though the exact proportion of each resource may differ across urban areas.
Plastic grocery bags are one of the most ubiquitous single-use packaging products. Recently, ‘eco-friendly’ options of plastic grocery bags have gained traction such as kraft paper, cotton, ...biodegradable, and reusable polypropylene non-woven bags. However, the impact of using various grocery bags in cities with dense population, well-developed infrastructure and thermal treatment as an end-of-life waste management option has been insufficiently documented. In this study, commonly found single-use (HDPE, biodegradable plastic, kraft paper) bags and reusable (cotton, polypropylene non-woven) bags were considered for the life cycle assessment (LCA). The usage characteristics (reusability, dimensions, carrying capacity) of bags, the production process (raw materials extraction, production processes), and emissions were determined as the significant factors contributing to the negative environmental impacts. In a model city with confined waste management, the assessment determined that the reusable polypropylene non-woven bag (PNB) caused the least overall negative environmental impacts when there are 50 instances of reuse, followed by single use HDPE plastic bag (HPB). The global warming potential (excluding biogenic carbon) was 14, 81, 17 and 16 times higher for HDPE plastic, kraft paper, cotton woven and biodegradable polymer bags, respectively, when compared to PNB. Moreover, kraft paper or cotton woven bags demonstrated the highest negative impacts for the impact categories including abiotic fossil depletion, freshwater-, marine- and terrestrial-ecotoxicities, human toxicity, acidification and eutrophication potentials. Further, sensitivity analysis indicated that the inflexion point for the PNB was minimum 4 reuses to avoid emission equivalent to the HPB. Singapore was adopted as the model city with confined waste management structure that imports most of the grocery bags, either as finished goods or as raw materials. Through comprehensive insights based on the new outlook of the integrated LCA model (cradle-to-grave) that included full-scale transportation component, the usage of the real case data from a city to develop the life cycle inventory, and consideration of the existing grocery bags options, the environmental assessment along with critical evaluation was conducted.
•Case specific life cycle assessment of grocery bags in the context of Singapore.•Plastic bags presented lower environmental footprint than paper and cotton bags for Singapore.•Plastics are an environmental friendly option for waste management structures with end-of-life thermal treatment.•Multiple reuse of plastics is a means to minimize environmental footprint.
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