The influence of durability and recycling on life cycle impacts of window frame assemblies

Purpose

A set of comparative life cycle assessment case studies were undertaken to explore key issues relating to the environmental impacts of building materials. The case studies explore modeling practice for long-life components by investigating (1) recycled content and end-of-life recycling scenarios and (2) service life and maintenance scenarios. The study uses a window unit frames as the object of comparison, allowing for exploration of multiple materials and assembly techniques.

Methods

Four window frame types were compared: aluminum, wood, aluminum-clad wood, and unplasticized PVC (PVCu). These used existing product life cycle inventory data which included primary frame material, coatings, weather stripping sealants, but not glazing. The functional unit was a window frame required to produce 1 m² of visible glazing, with similar thermal performance over a building lifespan of 80 years. The frames were compared using both the end-of-life and recycled content methods for end-of-life scenarios. The models were also tested using custom-use scenarios.

Results and discussion

Well-maintained aluminum window frames proved to be the least impactful option across all categories, in large part due to the credits delivered from recycling and expectations of long-life. Wood window frames had the least variability associated with maintenance and durability. The global warming potential (GWP) of a moderately maintained aluminum assembly was found to be 68 % less than PVCu and 50 % less than aluminum-clad wood. Using a long-life scenario, wood windows were found to have a 7 % lower GWP than the long-life scenario for aluminum-clad woods. Moderately and well-maintained aluminum windows require less energy to be produced and maintained over their lifetime than any of the wood scenarios. Expectations of service life proved to be the most important factor in considering environmental impact of frame materials.

Conclusions

The research shows significant gaps in available data—such as average realized life expectancies of common building components—while further underscoring that recycling rates are a driving factor in the environmental impact of aluminum building products. A modeling shift from the recycled content method to the end-of-life recycling method should promote goals of material recovery over pursuit of material with high recycled content. Hybrid methods, such as the use of Module D, may bridge the divide between these two approaches by providing due credit for use of recycled material, while supporting a design for recycling ethos. Further research is needed on how design and construction decisions affect collection and recovery rates in practice.

     

Geometric service life modelling and discounting,a practical method for parametrised life cycle assessment

Purpose

To evaluate the long-term advantage of reusing building elements, including reduced material consumption and waste production, life cycle assessments are purposeful. To translate these assessments in relevant design advices, it is necessary to model accurately the service life of the considered elements and acknowledge the related uncertainties. Practical methods to do this are nevertheless lacking. In reaction, this paper proposes a new assessment method: geometric service life modelling and discounting.

Methods

The developed method is extensively parametric. Its formulas express an element’s service life in terms of a limited number of variables. This facilitates the evaluation of large series of elements as well as the automation of uncertainty analyses. Further, the method tackles different modelling complexities such as the interaction between replacements and refurbishments. Taking into account these complexities aligns the assessments with realistic service lives. For the presentation of the developed method, a focus on life cycle costing is chosen.

Results and discussion

In this paper, the outcomes of the newly developed method are compared to those of an existing calculation method and benchmarked with the manual modelling and assessment of 390 simplified building elements. This comparison is based on three indicators characterising the methods’ accuracy: the number of interventions, their individual impact and their resulting net present value. For each indicator, geometric discounting led to a considerable increase of accuracy compared to the existing method.

Conclusions

From this comparison, it is concluded that geometric service life modelling and discounting offers not only a well-defined procedure for parametrised life cycle assessment studies, this method is also more accurate than the existing one. Moreover, the uncertainty analyses it facilitates illustrate how detailed assessment outcomes and relevant design advices about the effectiveness of element reuse can be obtained. Nevertheless, further research about the method’s practical implementation is required.

     

Life cycle assessment and life cycle costing of road infrastructure in residential neighbourhoods

Purpose

The built environment consists of a huge amount of infrastructure, such as roads and utilities. The objective of this paper is to assess the life cycle financial and environmental impact of road infrastructure in residential neighbourhoods and to analyse the relative contribution of road infrastructure in the total impact of neighbourhoods.

Methods

Various road sections are analysed based on an integrated life cycle approach, combining life cycle costing and life cycle assessment. To deal with complexity, a hierarchic assessment structure, using the principles of the “element method for cost control”, is implemented. Four neighbourhood models with diverse built densities are compared to gain insight in the relative impact of road infrastructure in neighbourhoods.

Results and discussion

The results reveal important financial and environmental impact differences between the road sections analysed. Main contributors to the life cycle financial and environmental impact are the surface layer and electrical and piped services. The contribution of road infrastructure to the total neighbourhood impact, ranging from 2 to 9 % of the total cost, is relatively limited, compared to buildings, but not negligible in low built density neighbourhoods.

Conclusions

Good spatial planning of the neighbourhood is recommended to reduce the amount of road infrastructure and the related financial and environmental impact. The priority should be to design denser neighbourhood layouts, before decreasing the financial and environmental impact of the road sections.

     

Lightweighting in light commercial vehicles: cradle-to-grave life cycle assessment of a safety-relevant component

Purpose

Currently, the reduction of weight in automotive is a very important topic in order to lower the air pollution. In this context, the purpose of the present paper was to analyze a real case study through a comparison of the environmental sustainability between a conventional steel crossbeam for light commercial vehicles and an innovative lightweight aluminum one.

Methods

For both scenarios, a cradle-to-grave life cycle assessment methodology and a sensitivity analysis has been used through the study of the following phases: mineral extraction, component manufacturing, use on vehicle, and end of life. In particular, many primary data and a complete vehicle model simulation with three different European driving cycles have been used in order to reach the highest possible level of accuracy during the analysis.

Results and discussion

Regarding the manufacturing phase, the aluminum component’s production gave the highest impact because of the high energy required in the mineral reduction. Anyway, this stage of the analysis had a low effect on the entire LCA, because the benefit of weight reduction during vehicle use showed a strongly higher contribution. The urban driving cycle had the most relevant impact, as a consequence of the frequent start and stop operations and the longest time with engine at idle speed, while the extra-urban cycle is the less demanding due to its higher average speed and no start and stop.

Conclusions

In conclusion, the present research demonstrated the environmental importance of the lightweight for an actual case study in the commercial vehicles field.

     

Life cycle assessment in the furniture industry: the case study of an office cabinet

Purpose

In an effort to reduce the environmental impacts of the furniture sector, this study aimed to diagnose the environmental performance of an office cabinet throughout its life cycle.

Methods

An attributional life cycle assessment (LCA) was used, based on the ISO 14044 Standard and ILCD Handbook. The scope of the study considered the entire supply chain, from cradle to grave, including the steps of pre-manufacturing, manufacturing, use, and post-use of the product. The impact assessment method was the International Reference Life Cycle Data System (ILCD) 2011 midpoint.

Results and discussion

The results identified that the most significant environmental impact of the furniture life cycle was due to the distances covered and production of the main raw material, wood medium-density particleboard (MDP). The evaluation of transport scenarios showed environmental tradeoffs for truck fuel switches and environmental gains for the distribution of MDP from closer suppliers by truck, as well as from current supplier by truck and ship in the major categories. Furthermore, evaluation of the office cabinet post-use options showed that reuse, recycling, or energy recovery from waste cause significant environmental gains in the major categories. Wooden furniture is a potential carbon sink if its life cycle does not emit more greenhouse gases than its materials can store. The impacts of substitution scenarios varied depending on the type of product avoided.

Conclusions

The LCA proved a powerful method to diagnose and manage environmental impacts in complex product systems. The sensitivity analysis showed that it is possible to reduce the environmental impacts and, at the same time, make the furniture industry increase its economic gains and net carbon stock in the anthroposphere.

     

Opportunities and challenges of implementing life cycle assessment in seafood certification: a case study for Spain

Purpose

Eco-labelling has become part of the business strategy of companies thanks to numerous advantages in terms of engaging with consumers and gaining market quota. The aim of this article is to present a critical discussion on the development and implementation of a new eco-label named pescaenverde, registered in Spain, as the first type III eco-label in the Spanish fishing sector that is based on life cycle approaches for seafood products.

Methods

More specifically, it aims to complement ecosystem-based eco-labels with the computation of the carbon footprint and the energy return on investment (EROI) of seafood products. Furthermore, it proposes to discuss the ecological criteria, certification process or the opportunities and challenges of the market implementation of this eco-label in detail. Finally, the authors argue that life cycle eco-labels should be considered important complements for more specific sector- or ecosystem-oriented labels already in use, rather than direct competitors.

Results and discussion

There has been much criticism towards the eco-labelling sector as regards the transparency and scientific rigour of its standards. The fishing and seafood sector, which has experienced a boom in eco-labelling in recent years, due mainly to the strength of the Marine Stewardship Council certification scheme, is not alien to this controversy, since critics advocate expanding the concept of sustainable fisheries beyond an ecosystem approach in order to account for global environmental concerns such as greenhouse gas (GHG) emissions or energy use. Not surprisingly, the European Union and other authorities currently encourage eco-labels to base their ecological criteria on life cycle approaches. Therefore, the current study discusses the ecological criteria, certification process or the opportunities and challenges of the market implementation of this eco-label in detail.

Conclusions

The specificity of the life cycle inventory scheme used in pescaenverde delivers an accurate computation of environmental impacts for the specific case of Spanish fisheries. However, the geographical expansion of this scheme to other nations or regions will be conditioned by an important software adaptation to the particular inventory characteristics of the new fisheries, fleets and products.

Recommendations

Adapting ecological criteria to other situations would also need substantial discussion, since the use of this certification scheme is not intended to contrast or compare seafood products against each other but to provide consumers with an easily identifiable label through which they can detect environmentally sustainable practices in terms of GHG emissions and energy use in the fishing fleets supporting the seafood products purchased.

     

Thai national life cycle inventory readiness for product environmental footprint

Purpose

In the near future, the products of Thai industries and companies mainly producing parts and products for export to the European Union (EU) will require the Product Environmental Footprint (PEF) to assess the environmental performance and resource efficiency of products by using a life cycle perspective. The potential generic (often used interchangeably with background data) data have to be modified and improved for mandatory use in the product-specific and country-specific PEF database.

Methods

PEF is used as a tool for assessing the environmental burden of products and services for export to the EU. It requires both specific data from primary sources and generic data to fulfill assessment requirement. Accordingly, the Thai national life cycle inventory (LCI) database plays a key role in generic data that was used to evaluate the environmental performance of products. This paper presents the perspective of Thai data readiness for PEF in which the quality of LCI is the main issue of concern. The current situation of the Thai national LCI database was reviewed. Then, the gaps of data were addressed, and the gaps were also filled. Non-representative data and untreated waste are the selected issues that were presented in this paper.

Results and discussion

Many gaps were revealed for the Thai national LCI database because this database was developed based on ISO 14040/44, which may not be compliant with the PEF guide. The issues that have been selected for improvement are non-representative data and untreated waste because these gaps can offer inaccuracy concerning the environmental burden of products potentially leading to the reliability of products for export to the EU. However, the Thai national LCI database has not achieved the data quality aspects of the PEF, continuously improving the quality of data to meet the requirements of the PEF.

Conclusions

The lessons learned from the real-world situation of data quality development based on PEF requirements were extracted. The practical procedure and recommendations were transparent for drivers and researchers who would like to start with data quality issues and prepare for the EU single market.

     

The application of life cycle assessment to public policy development

Purpose

Despite the potential value it offers, integration of life cycle assessment (LCA) into the development of environmental public policy has been limited. This paper researches potential barriers that may be limiting the use of LCA in public policy development, and considers process opportunities to increase this application.

Methods

Research presented in this paper is primarily derived from reviews of existing literature and case studies, as well as interviews with key public policy officials with LCA experience. Direct experience of the author in LCA projects with public policy elements has also contributed to approaches and conclusions.

Results and discussion

LCAs have historically been applied within a rational framework, with experts conducting the analysis and presenting results to decision-makers for application to public policy development. This segmented approach has resulted in limited incorporation of LCA results or even a broader approach of life cycle thinking within the public policy development process. Barriers that limit the application of LCA within the public policy development process range from lack of technical knowledge and LCA understanding on the part of policy makers, to a lack of trust in LCA process and results. Many of the identified barriers suggest that the failure of LCAs to contribute positively to public policy development is due to the process within which the LCA is being incorporated, rather than technical problems in the LCA itself. Overcoming the barriers to effective use of LCAs in public policy development will require a more normative approach to the LCA process that incorporates a broad group of stakeholders at all stages of the assessment. Specifically, a set of recommendations have been developed to produce a more inclusive and effective process.

Conclusions

In an effort to effectively incorporate LCA within the overall public policy decision-making process, the decision-making process should incorporate a multi-disciplinary approach that includes a range of stakeholders and public policy decision-makers in a collaborative process. One of the most important aspects of incorporating LCA into public policy decisions is to encourage life cycle thinking among policy makers. Considering the life cycle implications will result in more informed and thoughtful decisions, even if a full LCA is not undertaken.

     

Promoting life cycle thinking for sustainability in the mining sector of the Philippines

Purpose

This paper aims to promote life cycle thinking for the mining sector in the Philippines in enhancing the interventions intended for mining as a catalyst of sustainable development in the country. The environmental ills of mining hinder the sector’s acceptability as a catalyst, which is detrimental to its sustainability at the same time.

Methods

Previous works on mining impacts and life cycle thinking and assessment in the country had been reviewed to glean insights on integrating life cycle thinking in mining. Why and how such thinking and approach should be accounted for in mining is examined from these works to figure out the strategies through which mining is helped in mitigating its environmental ills.

Results and discussion

Life cycle thinking helps establish a logical approach in analysing issues associated with mining processes and products. It is of great relevance in preparing for contingencies for the adverse environmental outcomes that arise at any point of mining’s life cycle (exploration to mine closure) and the mining products’ life cycles (extraction to recycling or to accumulation). With its associated assessment procedures, life cycle thinking provides a logical system in obtaining scientific evidence for forward planning particularly on the aspect of sustainable mitigation of mining’s environmental outcomes.

Conclusions

It is apt that life cycle thinking be seriously accounted for in mining to improve the current undertakings of troubleshooting and addressing the adverse environmental outcomes of mining. Important insights from it facilitate the identification of sustainable mitigation strategies and who could take the lead actions, such as in developing business linkages and new markets to capitalize on the wastes and emissions from mining operations. The insights can greatly help the mining sector build its capability to come in harmony with people and nature, and work as a catalyst of sustainable development in the country.

     

Social life cycle assessment of average Irish dairy farm

Purpose

The majority of sustainability studies of dairy farms focused on environmental performance and profitability; however, social aspect has been hardly assessed. This study aims to investigate the social impacts of dairy farm via a case study using a social life cycle assessment framework.

Methods

The assessment was carried out applying the social LCA Guideline by UNEP-SETAC. Nineteen suitable social indicators were selected from four stakeholder categories of the guideline. Characterization and normalization were further developed based on data availability. National farm survey data was used as foreground data for farm activities, supplemented with background data from public database and life cycle working environment (LCWE) data by Gabi database. All indicators were divided into three groups: functional unit-related quantitative indicators, non-functional unit-related quantitative indicators and semi-quantitative indicators.

Results and discussion

Irish dairy farming has positive social impacts on value chain actors and society, predominantly positive impacts for local community and generally positive values for workers. The main negative impacts are health and safety issue, equal opportunity for workers, and safe and healthy living conditions for the local community. Possible actions to improve the social performance include introducing more efficient and robotic milk production systems; applying better handling methods and using real time decision support to operational management for emissions reduction.

Conclusions

This study is the first attempt of social LCA in Ireland. It demonstrated a possible method to carry out SLCA for Irish dairy sector. The results identified the positive and negative social hotspot of dairy farm with recommendation for future improvement.

     

Electric car life cycle assessment based on real-world mileage and the electric conversion scenario

Purpose

While almost all life cycle assessment (LCA) studies published so far are based on generic vehicles, type approval energy consumption as well as emission data, and application scenarios related to standardized laboratory-based driving cycles, this projects aims at quantifying the LCA based on a real-world vehicle composition and energy consumption data measured before and after the electric conversion of a mini class car. Furthermore, consequences of a second life of a vehicle’s glider on the environmental impact were investigated.

Methods

After having driven 100,000 km, a Smart was converted from combustion to electric in a laboratory project. The inventory was developed grounded upon materials data from laboratory measurements during the conversion process as well as on real-world energy consumption data prior and after the conversion. Three base models are compared in this life cycle impact assessment: a conventional new Smart (combustion engine), a new electric Smart, and a Smart converted from combustion engine to electric. Together with two sensitivity analyses (four different electricity mixes as well as urban vs. mixed driving conditions) and two EOL treatments, 36 scenarios have been quantified. The inventory is based on Ecoinvent database v 2.2 as a background system and includes raw material extraction.

Results and discussion

In urban use, the modeled battery electric vehicle has a favorable environmental impact compared to the ICEV even when charged with the German electricity mix of the year 2013. The advantage in summed up endpoints of the converted Smart is 23 % vs. the new electric Smart on average for the mixed driving conditions and 26 % for the urban driving conditions, respectively. Over a variety of impact categories, electricity consumption during battery cell production in China as well as impacts due to microelectronic components dominated the life cycle. Results for 18 midpoint categories, endpoints for damages to human health, to resource quality and to ecosystem quality as well as the Single score endpoints are reported.

Conclusions

This investigation points out that real-world treatments in inventory development can more specifically outline the environmental advantages of the electric car. The electric conversion of a used combustion engine vehicle can save an additional 16 % (CO₂-eq) and 19 % (single score endpoints) of the environmental impact over a lifetime, respectively, when compared with the new BEV.

     

Systematic literature review in social life cycle assessment

Purpose

The main purpose of this review is to investigate the methodology of social life cycle assessment (SLCA) through its application to case studies. In addition, the following research aims to define the trends related to the SLCA by researchers and consultants. This study will help to map the current situation and to highlight the hot spots and weaknesses of the application of the SLCA theory.

Methods

The SLCA could be considered as a useful methodology to provide decision support in order to compare products and/or improve the social effects of the life cycle of a product. Furthermore, the results of the case studies analyzed may influence decision makers significantly. For this reason, a systematic literature review of case studies was carried out in which SLCA was applied in order to analyze closely the application of the stages of this methodology. In this study, the major phases of the technical framework for a SLCA were analyzed. Specific attention was paid to detect the positive impacts that emerged in the case studies, which were also studied by administering a questionnaire to the authors of the analyzed case studies and to a number of experts in the field of SLCA.

Results and discussion

The 35 case studies examined in this paper, even though they do not deviate from the 40 identified by the previous processing, are still significantly different in terms of outcome produced. It is important to clarify that the authors who developed the case studies considered the steps defined in the SETAC/SETAC guidelines, borrowed from the ISO 14044 standard.

Conclusions

The data resulting from this analysis could help both practitioners and researchers to understand what the issues are, on which it is still necessary to investigate and work, in order to solidify the SLCA methodology and define its role in the context of life cycle sustainability assessment (LCSA).

     

Choice of land reference situation in life cycle impact assessment

Purpose

Land use life cycle impact assessment is calculated as a distance to target value—the target being a desirable situation defined as a reference situation in Milà i Canals et al.’s (Int J Life Cycle Assess 12(1):2–4, 2007) widely accepted framework. There are several reference situations. This work aims to demonstrate the effect of the choice of reference situation on land impact indicators.

Methods

Various reference situations are reported from the perspective of the object of assessment in land in life cycle assessment (LCA) studies and the modeling choices used in life cycle land impact indicators. They are analyzed and classified according to additional LCA modeling requirements: the type of LCA approach (attributional or consequential), cultural perspectives (egalitarian, hierarchist or individualist), and temporal preference. Sets of characterization factors (CF) by impact pathway, land cover, and region are calculated for different reference situations. These sets of CFs by reference situation are all compared with a baseline set. A case study on different crop types is used to calculate impact scores from different sets of CFs and compare them.

Results and discussion

Comparing the rankings of the CFs from two different sets present inversions from 5% to 35% worldwide. Impact scores of the case study present inversions of 10% worldwide. These inversions demonstrate that the choice of a reference situation may reverse the LCA conclusions for the land use impact category. Moreover, these reference situations must be consistent with the different modeling requirements of an LCA study (approach, cultural perspective, and time preference), as defined in the goal and scope.

Conclusions

A decision tree is proposed to guide the selection of a consistent and suitable choice of reference situation when setting other LCA modeling requirements.

     

On the boundary between economy and environment in life cycle assessment

Purpose

We investigate how the boundary between product systems and their environment has been delineated in life cycle assessment and question the usefulness and ontological relevance of a strict division between the two.

Methods

We consider flows, activities and impacts as general terms applicable to both product systems and their environment and propose that the ontologically relevant boundary is between the flows that are modelled as inputs to other activities (economic or environmental)—and the flows that—in a specific study—are regarded as final impacts, in the sense that no further feedback into the product system is considered before these impacts are applied in decision-making. Using this conceptual model, we contrast the traditional mathematical calculation of the life cycle impacts with a new, simpler computational structure where the life cycle impacts are calculated directly as part of the Leontief inverse, treating product flows and environmental flows in parallel, without the need to consider any boundary between economic and environmental activities.

Results and discussion

Our theoretical outline and the numerical example demonstrate that the distinctions and boundaries between product systems and their environment are unnecessary and in some cases obstructive from the perspective of impact assessment, and can therefore be ignored or chosen freely to reflect meaningful distinctions of specific life cycle assessment (LCA) studies. We show that our proposed computational structure is backwards compatible with the current practice of LCA modelling, while allowing inclusion of feedback loops both from the environment to the economy and internally between different impact categories in the impact assessment.

Conclusions

Our proposed computational structure for LCA facilitates consistent, explicit and transparent modelling of the feedback loops between environment and the economy and between different environmental mechanisms. The explicit and transparent modelling, combining economic and environmental information in a common computational structure, facilitates data exchange and re-use between different academic fields.

     

Principles for life cycle inventories of land use on a global scale

Purpose

To assess the diverse environmental impacts of land use, a standardization of quantifying land use elementary flows is needed in life cycle assessment (LCA). The purpose of this paper is to propose how to standardize the land use classification and how to regionalize land use elementary flows.

Materials and methods

In life cycle inventories, land occupation and transformation are elementary flows providing relevant information on the type and location of land use for land use impact assessment. To find a suitable land use classification system for LCA, existing global land cover classification systems and global approaches to define biogeographical regions are reviewed.

Results and discussion

A new multi-level classification of land use is presented. It consists of four levels of detail ranging from very general global land cover classes to more refined categories and very specific categories indicating land use intensities. Regionalization is built on five levels, first distinguishing between terrestrial, freshwater, and marine biomes and further specifying climatic regions, specific biomes, ecoregions and finally indicating the exact geo-referenced information of land use. Current land use inventories and impact assessment methods do not always match and hinder a comprehensive assessment of land use impact. A standardized definition of land use types and geographic location helps to overcome this gap and provides the opportunity to test the optimal resolution of land cover types and regionalization for each impact pathway.

Conclusions and recommendation

The presented approach provides the necessary flexibility to providers of inventories and developers of impact assessment methods. To simplify inventories and impact assessment methods of land use, we need to find archetypical situations across impact pathways, land use types and regions, and aggregate inventory entries and methods accordingly.

     

Electric passenger car transport and passenger car life cycle inventories in ecoinvent version 3

Purpose

Due to the large environmental challenges posed by the transport sector, reliable and state-of-the art data for its life cycle assessment is essential for enabling a successful transition towards more sustainable systems. In this paper, the new electric passenger car transport and vehicle datasets, which have been developed for ecoinvent version 3, are presented.

Methods

The new datasets have been developed with a strong modular approach, defining a hierarchy of datasets corresponding to various technical components in the vehicle. A vehicle is therefore modelled by linking together the various component datasets. Also, parameters and mathematical formulas have been introduced in order to define the amount of exchanges in the datasets through common transport and vehicle characteristics. This supports users in the choice of the amount of exchanges and enhances the transparency of the dataset.

Results

The new transport dataset describes the transport over 1 km with a battery electric passenger car taking into account the vehicle production and end of life, the energy consumption due to the use phase, non-exhaust emissions, maintenance and road infrastructure. The dataset has been developed and is suitable for a compact class vehicle.

Conclusions

A new electric passenger car transport dataset has been developed for version 3 of the ecoinvent database which exploits modularisation and parameters with the aim of facilitating users in adapting the data to their specific needs. Apart from the direct use of the transport dataset for background data, the various datasets for the different components can also be used as building blocks for virtual vehicles.

     

An environmental life cycle assessment of forklift operation: a well-to-wheel analysis

Purpose

Among the many publications on the environmental life cycle assessment (LCA) of transport, there are only a few examples of works dedicated to means of internal transport. For this reason, it was decided to gather energy-oriented inventory data and to assess the environmental impact related to the operation of selected forklift trucks, as the most commonly used means of internal transport. This paper presents the main assumptions and the results in relation to the four phases of LCA: the goal and scope definition, the life cycle inventory, the life cycle impact assessment results, and the interpretation.

Methods

Ten forklifts with different engines were selected in order to carry out the life cycle assessment study. The research was based on the results of measuring the operating fuel consumption and exhaust gas emissions, conducted using the SEMTECH-DS mobile device from the PEMS group of devices. In order to make the measurements under a circumstance close to the real conditions of forklift exploitation, it was decided to slightly modify the operating cycle proposed in VDI 2198. The environmental impact of the fuel/electricity usage and exhaust gas emissions was assessed using the ISO 14040x guidelines and the IMPACT 2002+ method.

Results and discussion

The study showed that using an electric forklift to transport 1 t of payload over a distance of 1 km has a significantly smaller environmental impact than using one of the selected forklifts powered by an internal combustion engine. Using forklifts powered by liquefied petroleum gas (LPG) engines leads to a significantly higher environmental impact whilst the use of vehicles with diesel engines has an impact at a level several times lower. In a case of drives without load, where functional unit was defined as covering 1-km distance with no vehicle load, a lower impact for the electric vehicles was also obtained. The analysis includes the influences of the upstream processes of fuel and electrical energy production.

Conclusions

Even when Poland’s production scenario (based almost entirely on fossil fuels) is taken into consideration, the electric forklifts still show a clear advantage. It should be expected that, if the technological mix of electrical energy production for countries with a higher share of renewable or nuclear energy were to be taken into account, the environmental indicators for electric vehicles would be even lower. It is worth noting that only the energy aspects of forklift operation were analysed. Further studies aiming to collect inventory data relating to other exploitation aspects, as well as the production and utilization of the same vehicles, are planned as a continuation of this research.

     

A life cycle assessment framework combining nutritional and environmental health impacts of diet: a case study on milk

Purpose

While there has been considerable effort to understand the environmental impact of a food or diet, nutritional effects are not usually included in food-related life cycle assessment (LCA).

Methods

We developed a novel Combined Nutritional and Environmental Life Cycle Assessment (CONE-LCA) framework that evaluates and compares in parallel the environmental and nutritional effects of foods or diets. We applied this framework to assess human health impacts, expressed in Disability Adjusted Life Years (DALYs), in a proof-of-concept case study that investigated the environmental and nutritional human health effects associated with the addition of one serving of fluid milk to the present average adult US diet. Epidemiology-based nutritional impacts and benefits linked to milk intake, such as colorectal cancer, stroke, and prostate cancer, were compared to selected environmental impacts traditionally considered in LCA (global warming and particulate matter) carried to a human health endpoint.

Results and discussion

Considering potential human health effects related to global warming, particulate matter, and nutrition, within the context of this study, findings suggest that adding one serving of milk to the current average diet could result in a health benefit for American adults, assuming that existing foods associated with substantial health benefits are not substituted, such as fruits and vegetables. The net health benefit is further increased when considering an iso-caloric substitution of less healthy foods (sugar-sweetened beverages). Further studies are needed to test whether this conclusion holds within a more comprehensive assessment of environmental and nutritional health impacts.

Conclusions

This case study provides the first quantitative epidemiology-based estimate of the complements and trade-offs between nutrition and environment human health burden expressed in DALYs, pioneering the infancy of a new approach in LCA. We recommend further testing of this CONE-LCA approach for other food items and diets, especially when making recommendations about sustainable diets and food choices.

     

Social life cycle assessment of first and second-generation ethanol production technologies in Brazil

Purpose

The main goal of this study is to suggest quantitative social metrics to evaluate different sugarcane biorefinery systems in Brazil by exploring a novel hybrid approach integrating social life cycle assessment and input-output analysis.

Methods

Social life cycle assessment is the main methodology for evaluating social aspects based on a life-cycle approach. Using this framework, a hybrid model integrating social life cycle assessment and input-output analysis was introduced to evaluate different social effects of biorefinery scenarios considering workers as the stakeholder category. Job creation, occupational accidents, wage profile, education profile, and gender profile were selected as the main inventory indicators. A case study of three scenarios considering variations in agricultural and industrial technologies (including sugarcane straw recovery and second-generation ethanol production, for instance) was carried out for evaluating present first-generation (1G-basic, 1G-optimized) and future first- and second-generation ethanol production (1G2G).

Results and discussion

The 1G-basic scenario leads to higher job creation levels over the supply chain mainly because of the influence of agricultural stage whose workers are mostly employed in sugarcane manual operations. On the other hand, 1G-optimized and 1G2G present supply chains are more reliant on the manufacturing, trade, and services sectors whose workers are associated with a lower level of occupational accidents, higher average wages, higher education level, and more participation of women in the work force.

Conclusions

The use of a novel hybrid approach integrating social life cycle assessment (SLCA) and input-output analysis (IOA) was useful to quantitatively distinguish the social effects over different present and future sugarcane biorefinery supply chains. As a consequence, this approach is very useful to support decision-making processes aiming to improve the sustainability of sugarcane biorefineries taking social aspects into account.