Life Cycle Assessment

On the use of ordinal scoring scales in social life cycle assessment

Mapping of main research lines concerning life cycle studies on packaging systems in Brazil and in the world Abstract Purpose This article aims to conduct a systematic literature review on the life cycle assessment of packaging in the world and in Brazil. Packaging plays an important role in the preservation and protection of products, and it is an issue of concern all over the world. Many environmental concerns lie on packaging, and life cycle assessment (LCA) is said to be the most comprehensive and complete tool for assessing environmental profiles. Methods The Methodi Ordinatio was used to assist identifying high impact research. The EndNote software was used for reference management and the VOSviewer for clustering terms and authors. The main research themes, institutions, authors, software tools used for impact assessment, and journals were identified in order to draw on the main aspects of the referred body of literature and present an insight on its trends. Results and discussion The line of study has not shown many solid patterns concerning either global or Brazilian research on LCA of packaging, so far. Nevertheless, most research has been dedicated to the food and beverage industries and European countries are leading this theme’s development. Research history shows that recycling has comprised one of the first concerns, whereas the search for alternative materials and end-of-life routes play an important role in the present and future of LCA of packaging. Brazil is the most prominent developing country in this field, featuring among the main contributors to the theme globally. Conclusions There is evidence that the referred body of literature has been increasingly receiving contributions both globally and in Brazil. However, it is not sufficient to state that there are solidly established either drifts or trends, as many research features change over time. The joint interest of public and private sectors can boost this study’s theme’s development and unveil novel alternatives for reducing environmental impacts of packaging systems.

Pathway to domestic natural rubber production: a cradle-to-grave life cycle assessment of the first guayule automobile tire manufactured in the United States Abstract Purpose Guayule (Parthenium argentatum) is a perennial shrub that can be cultivated in the Southwestern US. It produces natural rubber that could be a viable substitute for Hevea natural rubber and synthetic rubbers currently used in tires. Drivers for producing domestic guayule rubber include fluctuations in price and availability of imported Hevea rubber. A tire was manufactured in 2017 where guayule rubber was substituted for all of the Heveaand synthetic rubber in the conventional tire. Methods Life cycle assessment (LCA) from cradle to grave was used to evaluate the environmental and energy sustainability of the guayule tire, and these metrics were benchmarked against those of the conventional tire (CT). Functional units of 1 kg natural rubber for agricultural processes, as well as 1 tire for the cradle-to-grave study were considered. Life cycle inventory (LCI) data were collected directly from primary sources, including guayule field experiments, a rubber-processing company, and a major tire manufacturer. Scenario analysis was used to evaluate alternative processes, such as irrigation options in guayule cultivation, processing scale in rubber extraction, and selection of allocation methodology in LCAs. Model uncertainty was characterized using Monte Carlo analysis. Results and discussion The LC energy consumption of the guayule tire (GT) was 13.7 GJ/tire (including co-product credits, excluding C sequestration during agriculture), compared to 16.4 GJ/tire for the CT. The GT had 6–30% lower emissions than CT in ten different environmental impact categories. Bagasse co-product in energy applications showed benefits of reducing energy consumption by 10% and decreasing environmental impacts by up to 11%. GT’s use-phase resulted in the highest energy consumption (95%) and environmental impacts ranging between 81 and 99%. Variables in use phase, i.e., rolling resistance coefficient, vehicle efficiency, and tire lifetime, and those in guayule cultivation i.e., rubber and biomass yields, were key model parameters. The effect of excluded but potentially important model parameters, i.e., guayule carbon sequestration and resin co-product were tested via sensitivity analyses. Conclusions Based on these results that factored in the lower rolling resistance coefficient of a guayule tire—a significant element that improves the fuel economy of an automobile—the guayule rubber tire shows promise in its ability to replace current conventional tires. The first commercially manufactured guayule rubber passenger tire will most likely substitute components, which are either partially or fully guayule, instead of guayule replacing 100% of the existing rubbers as shown in this study.

Responsibility in life cycle assessment practice

Variable impact transportation (VIT) model for energy and environmental impact of hauling truck operation Abstract Purpose Fuel economy and emissions of heavy-duty trucks greatly vary based on vehicular/environmental conditions. Large-scale infrastructure construction projects require a large amount of material/equipment transportation. Single-parameter generic hauling models may not be the best option for an accurate estimation of hauling contribution in life cycle assessment (LCA) involving construction projects; therefore, more precise data and parameterized models are required to represent this contribution. This paper discusses key environmental/operational variables and their impact on transportation of materials and equipment; a variable-impact transportation (VIT) model accounting for these variables was developed to predict environmental impacts of hauling. Methods The VIT model in the form of multi-nonlinear regression equations was developed based on simulations using the U.S. Environmental Protection Agency (EPA)’s Motor Vehicle Emission Simulator (MOVES) to compute all the impact categories in EPA’s TRACI 2.1 and energy consumption of transportation. Considering actual driving cycles of hauling trucks recorded during a pavement rehabilitation project, the corresponding environmental impacts were calculated, and sensitivity analyses were performed. In addition, an LCA case study based on historical pavement reconstruction projects in Illinois was conducted to analyze the contribution of transportation and variability of its impacts during the pavements’ life cycle. Results and discussion The importance of vehicle driving cycles was realized from simulation results. The case study results showed that considering driving cycles using the VIT model could increase the contribution of hauling in total life cycle Global Warming Potential (GWP) and total life cycle GWP itself by 2–4 and 3–5%, respectively. In addition to GWP, ranges of other hauling-related impact categories including Smog, Ozone Depletion, Acidification, and Primary Energy Demand from fuel were presented based on the case study. Ozone Depletion ranged from 9 to 45%, and Smog ranged from 11 to 48% of the total relevant life cycle impacts. The GWP contribution of hauling in pavement LCA ranged between 5 and 32%. The results indicate that the contribution of hauling transportation can be significant in pavement LCA. Conclusions For large-scale roadway infrastructure construction projects that need a massive amount of material transportation, high fidelity models and data should be used especially for comparative LCAs that can be used as part of decision making between alternatives. The VIT model provides a simple analytical platform to include the critical vehicular/operational variables without any dependence on an external software; the model can also be incorporated in those studies where some of the transportation activity data are available.

Preface

The 9th International Conference on Life Cycle Management 2019—Poznań, Poland, 1–4 September 2019 (www.lcm2019.org)

Development of human health damage factors for tropospheric ozone considering transboundary transport on a global scale Abstract Purpose Air pollutants such as tropospheric ozone and PM2.5 travel through large areas. The damage factors (DFs) presented by existing researches in life cycle impact assessment do not take into consideration transboundary movement. A previous study used a global chemistry transport model (CTM), to develop health damage factors for ten different regions around the world by considering the transboundary movement of PM2.5. Under the same assessment procedure, this research is designed to calculate the ozone DFs by region and to find the effects of wide range movement on the DFs. Methods The DFs by regions are defined as changes in disability-adjusted life years (DALYs) derived from changes in tropospheric ozone concentration around the world which is induced by an increase in emissions of the unit amount of nitrogen oxides (NOx) and non-methane volatile organic compounds (NMVOC). DFs for ten regions are calculated as follows. Firstly, the concentration change of worldwide ozone caused by a change in emission of a substance from one region is estimated with a global scale CTM for both NOx and NMVOC. Secondly, DALY changes on the world due to a change in concentration of ozone are estimated by using population data and epidemiological concentration-response functions for mortality and morbidity. Finally, the above calculations are done for all targeted ten regions. Results and discussion DFs of NOx and NMVOC for ten regions were calculated as 0.3–4.2 × 10−5 DALY/kg and 0.2–5.6 × 10−6 DALY/kg, respectively. It was found DFs might be underestimated around 10 to 70 % by region if the transboundary movement is not taken into consideration. In many regions in the northern hemisphere, about 60 % of damage occurs outside the emission area, which is larger than that of southern hemispheric regions due to a larger population exposed to downwind places. In regions of China and India, however, the influence on other regions accounted for only 10 % because these regions involve larger influences in the source region. The impact of NO titration effect can be seen in cold seasons in many regions, but it was found that the effect is remarkable on an annual average only in Europe, a cold region with large emissions. Conclusions The human health DFs of NOx and NMVOC considering effects of transboundary movement of tropospheric ozone are estimated for ten regions by using a global CTM. As a future work, it is important to show the interannual sensitivity of the DFs through chronological assessments.

Development of human health damage factors for PM 2.5 based on a global chemical transport model Abstract Purpose Health damage from ambient fine particulate matter (PM2.5) shows large regional variations and can have an impact on a global scale due to its transboundary movement. However, existing damage factors (DFs) for human health in life cycle assessments (LCA) are calculated only for a few limited regions based on various regional chemical transport models (CTMs). The aim of this research is to estimate the human health DFs of PM2.5originating from ten different regions of the world by using one global CTM. Methods The DFs express changes in worldwide disability-adjusted life years (DALYs) due to unit emission of black carbon and organic carbon (BCOC), nitrogen oxides (NO x ), and sulfur dioxide (SO2). DFs for ten regions were calculated as follows. Firstly, we divided the whole world into ten regions. With a global CTM (MIROC-ESM-CHEM), we estimated the concentration change of PM2.5 on the world caused by changes in the emission of a targeted precursor substance from a specific region. Secondly, we used population data and epidemiological concentration response functions (CRFs) of mortality and morbidity to estimate changes in the word’s DALYs occurring due to changes in the concentration of PM2.5. Finally, the above calculations were done for all ten regions. Results and discussion DFs of BCOC, NO x , and SO2 for ten regions were estimated. The range of DFs could be up to one order of magnitude among the ten regions in each of the target substances. While population density was an important parameter, variation in transport of PM2.5 on a continental level occurring due to different emission regions was found to have a significant influence on DFs. Especially for regions of Europe, Russia, and the Middle East, the amount of damage which occurred outside of the emitted region was estimated at a quarter, a quarter, and a third of their DFs, respectively. It was disclosed that the DFs will be underestimated if the transboundary of PM2.5 is not taken into account in those regions. Conclusions The human health damage factors of PM2.5 produced by BCOC, NO x , and SO2 are estimated for ten regions by using one global chemical transport model. It became clear that the variation of transport for PM2.5 on a continental level greatly influences the regionality in DFs. For further research to quantify regional differences, it is important to consider the regional values of concentration response function (CRF) and DALY loss per case of disease or death.

Development of weighting factors for G20 countries. Part 2: estimation of willingness to pay and annual global damage cost Abstract Purpose This paper is the second part of a series of articles presenting the results of research on monetary weighting factors (MWFs) for the G20 countries, which together account for approximately 90% of the global GDP. We developed their MWFs with regard to Life Cycle Impact Assessment (LCIA) and evaluated them via a large-scale questionnaire survey. We estimated the economic value of one unit of damage caused by human activities. Methods To ensure that the MWFs covered all areas of protection as defined by the LCIA method based on Endpoint Modeling (human health, social assets, biodiversity, and primary production), we conducted a choice experiment in all G20 countries. We conducted face-to-face interviews to minimize survey bias and ensure that the questions were understood by the emerging G20 countries’ respondents. Internet surveys were adopted to collect samples from the developed G20 countries’ respondents, where Internet diffusion rates are generally high. We obtained response data from 200 to 250 and 500 to 600 households of all the emerging and all the developed G20 countries, respectively. We gathered 6400 responses in all. We estimated preference intensities using the random parameter logit model. We calculated MWFs based on each respondent’s willingness to pay. Results and discussion We devised MWFs providing the costs of damage to four safeguard subjects. All the estimated values are statistically significant at the 1% level, with the exception of monetary attributes from Mexico. The MWFs for the G20 are 23,000 USD for human health (per year), 2.5 USD for social assets (per USD of resources), 11 billion USD for biodiversity (per species), and 5.6 billion USD for primary production (per 100 million tons). The differences between the developed and emerging G20 countries are considerable, with the values generally being smaller for the latter in purchasing power parity (USD) terms. The estimated global total economic annual impact was approximately 5.1 trillion USD (6.7% of the world’s total GDP). Conclusions We obtained reasonable and conservative global-scale MWFs compared with previous studies. Moreover, the cross-country heterogeneity in this study potentially helps extrapolate future/global value developments from current/local estimates. The variations in human health and social asset MWFs are small enough within developed countries to allow international transfers among them, while significant variations in biodiversity and primary production MWFs are a caveat to up-front international transfers even within developed countries.