Global food production is identified as a great threat to the environment. In combination with technical advances in agriculture, dietary change is suggested to be necessary to reduce the ...environmental impact of the food system. In this article a systematic review assessing the environmental impact of dietary change is performed. The aims are to i) evaluate the scientific basis of dietary scenario analysis, ii) estimate the potential environmental effects of dietary change, iii) identify methodological aspects of importance for outcome and iv) identify current gaps in knowledge. The review includes 14 peer-reviewed journal articles assessing the GHG emissions and land use demand of in total 49 dietary scenarios. The results suggest that dietary change, in areas with affluent diet, could play an important role in reaching environmental goals, with up to 50% potential to reduce GHG emissions and land use demand associated with the current diet. The choice of functional unit, system boundaries and methods for scenario development and accounting for uncertainties are methodological aspects identified to have major influence on the quality and results of dietary scenario analysis. Further understanding of dietary change as a measure for more sustainable food systems requires improved knowledge of uncertainty in dietary scenario studies, environmental impact from substitutes and complements to meat and the effect of dietary change in different groups of populations and geographical locations. (C) 2014 Elsevier Ltd. All rights reserved.
Purpose
Abiotic resource is included as an impact category in life cycle impact assessment (LCIA). The most widely accepted LCIA method is abiotic resource depletion potential (ADP). However, ...numerous studies have illustrated the limitations of the ADP method, such as the neglect of resources that can be recycled. This paper aims to develop a comprehensive and objective method for assessing the impact of resource use on future generations, which can be used at different stages of the life cycle.
Methods
Based on the above research objectives, this paper proposes a new method, the abiotic resource expected dissipation potential (AEDP) method, for assessing the impacts of current resource use on the abiotic resource accessibility. The method is divided into four impact categories based on different endpoints of the dissipative flow and replaces the resource extraction rate with the global annual dissipation rate and adds anthropogenic stocks to the total reserves, resulting in the characterization factor AEDPs. Finally, the four impact categories are weighted to obtain a final impact score for resource use.
Results
Results of the new method are presented as a multi-dimensional reflection of natural reserves, dissipation rates, and extraction rates of resources. The comparison between AEDPs and ADPs revealed differences between them, but they were not significant. A higher power of the total reserves in the AEDP formula can overemphasize the effect of natural reserves on the characterization factor. Furthermore, other natural reserve data was used as alternative indicators in the sensitivity analysis.
Conclusion
The new assessment method enables the future impacts of abiotic resource use to be more accurately assessed. It can be used at any life cycle stage to support relevant stakeholder decision-making. However, a broader database is required to be developed to calculate more characterization factors. Moreover, the over-dominance of reserve data in the characterization factors overshadows the influence of other dimensions. Consequently, further research is necessary to improve the operability and plausibility of this method.
Energy, water and food resource scarcity caused by rapid population growth, climate change, imbalanced ecosystems, and economic diversification, is the biggest challenge for today's world. In recent ...decades, the importance of the interdependent relationship between these resources has been recognized as the energy-water-food nexus. Sustainable resource consumption and the capability to ascertain true resource consumption is crucial for modern day development. As such, wide-spread adoption of the energy-water-food nexus methodology for integrated resource modeling can significantly contribute toward resource productivity and continuity. This methodology has expanded over the years, from concept development to application in multiple case studies. The methodology has also enabled the identification of synergies and trade-offs within the sub-systems that constitute the overall energy-water-food nexus system, hence providing a mechanism for optimization in resource consumption and minimization in the total environmental burden in the system under evaluation. This paper has reviewed the interlinkages inherent in the energy-water-food nexus, and the progress in developing suitable quantification methods. Although there is no standardized methodology for analysis involving the energy-water-food nexus, the life-cycle assessment methodology has been used as an enabler for the quantification of environmental burdens of systems evaluated using the ‘Nexus’ approach. As such, this paper will provide an overview of the different applications in which the life cycle assessment methodology has been applied to energy-water-food nexus analysis. The paper concludes that an integrated life cycle assessment and energy-water-food nexus methodology is necessary to determine environmental burdens for different scenarios presented within systems operating within an energy-water-food nexus environment, essentially influencing energy-water-food resource sectors.
•The principles of EWF nexus are increasingly emphasized in research areas.•Environmental challenges of EWF nexus system were addressed.•The regional advances in EWF nexus studies were reviewed.•Existing nexus quantification methods were analyzed, specially highlighting LCA.•Integrated nexus & LCA study ensures wide range of environmental impact scenarios.
Despite a substantial literature using life cycle assessment (LCA) approach, the extent to which second and third generation biofuels are more sustainable than the first generation remains a subject ...of debate. Although the existence of limitations due to LCA variability and uncertainty, this paper intends to determine global tendencies based on a statistic and critical interpretation of previously published study results, reviewing 61 recent papers addressing an environmental evaluation of microalgae biofuels. Such information is compared to the same impact indicators for fossil fuels and for ethanol and biodiesel from terrestrial crops in Europe and Brazil. For each case, the system boundaries and the methodological choices were precisely described. The sustainability potential of all biofuels was evaluated by the Global Warming Potential (GWP), the Energy Ratio (ER) and the Land Use (LU), allowing a broad estimation of the biofuels’ contribution to climate change mitigation, their net energy efficiency and their competiveness with food production chain.
The results highlight that algae-derived biodiesel is, by far, the most efficient alternative in terms of land use compared to other biofuels, avoiding competition with food crops. Some biodiesel pathways can also satisfactorily perform in terms of greenhouse gases emissions reduction, but some others can be even worst than fossil diesel. Nevertheless, in terms of energy efficiency, algae biofuels cannot compete with other biofuels or fossil fuels. They present very low performances, even demanding more energy for its production then the energy they can deliver. Moreover, no pathway can be conclusively selected as preferable between the two main technologies available for microalgae biodiesel due to high uncertainties. However, open raceway pounds technology seems to be preferable as it looks less GHG intensive, requiring lower energy input and land use. Energetic and GWP performances can be improved if production pathways are carefully chosen and optimized.
The selection of an appropriate allocation procedure for co-production and recycling in Life Cycle Assessment (LCA) depends on the goal and scope of the analysis. However, it is not always clear when ...partitioning or system expansion can be applied, or when to conduct an attributional or a consequential LCA, both for LCA practitioners and users of LCA results. In this paper, the influence of the goal and scope on the selected modeling approaches is clarified. The distinction between process-oriented and product-oriented LCAs, between system expansion and substitution, and between the cut-off approach and other allocation procedures are highlighted. Archetypes of goal and scope definitions are developed. These archetypes reflect the minimum amount of information required to select an allocation procedure. It is demonstrated via an illustrative example that the question “what is the environmental impact of a product” can result in at least 15 different research questions requiring at least five different modeling methods. Finally, perspectives are provided on the use of attributional and consequential approaches to evaluate the environmental, social, and economic sustainability of products and processes.
Solid-state batteries (SSBs) are a promising emerging battery technology for electromobility application. Along with new technical opportunities (higher energy density, lower safety risks), they ...introduce new cell chemistry configurations and novel materials in use. This leads to increased complexity of material composition and may reduce the recyclability of SSBs. To ensure circularity of SSB materials, it is important to consider their recyclability at the early stage of SSB development. This paper proposes an approach for identification of target materials for recycling within three types of SSBs with polymer, oxide and sulfide electrolytes. To consider environmental and economic perspectives, interdependencies of material dilution, their cost and environmental material footprint are analyzed using Sherwood and global warming potential (GWP)-plots. Furthermore, a socio-geopolitical aspect of supply risk is considered as a relevant criterion for targeting materials. Li is identified as the main target material for all considered SSBs and Co as a further one for oxide- and sulfide-based cells. Furthermore, an upscaling scenario to a battery pack considered changes in concentration of target materials and revealed direct recycling of composite cathode LLZO and LCO to be very beneficial. Results of this approach can be used by SSB developers and recyclers in order to strive for holistic design enabling recycling of identified target materials.
In this study, we performed a life cycle assessment of the reuse of biomass fly ash as secondary cementitious material in cement mortars as alternative to a reference landfill scenario of the ash. ...Since biomass ash does contain enhanced levels of elements that are of potential concern for the environment or human exposure, the performed Life Cycle Assessment (LCA), in addition to CO2 savings, takes into account the impact on all non-toxic categories and human toxicity/carcinogenicity during service and second life stages. Results showed that utilization of biomass ash in cement is preferable over landfill for all the non-toxic categories at both cement replacements rates of 20 and 40 wt%. In detail, the reduction of CO2-eq. was found to be between 11 and 26% when biomass ash was blended with cement instead of being landfilled. The hydraulic activity of biomass ashes was found to be a critical parameter in this scenario, as it had impacts on the global warming potential (and all other investigated non-toxic categories), and it is therefore crucial to consider the uncertainty related to this aspect in LCA studies. Cement containing biomass ash performed better, on average, when compared with the reference landfill scenario regarding the impact to human toxicity (carcinogenic) category. Contrary, only the utilization in cement for one particular ash type (from paper sludge combustion) showed a better performance than the reference scenario for the ecotoxicity (ET) category. The impact to human toxicity carcinogenic (HTc) and ecotoxicity (ET) was mainly dominated by the leaching of Cr from landfilling of pure biomass fly ash (reference scenario) and the leaching of Ba, Cu, Cr (VI) and Zn from the second life stage of cement products (i.e., reuse of the crushed cement after service life in road base applications). However, this impact was acceptable when emissions are compared to existing EU landfill directive and regulations on the reuse of secondary materials in construction works. The novel LCA approach performed in this study, which includes impacts of leached contaminants during both the service and second life phase of cement, has shown that the reuse of biomass ash as secondary cementitious materials has a beneficial effect on the majority of the impact categories, with no unacceptable leaching risks.
•Environmental impacts associated with reuse of biomass ash in cement were assessed.•The service and second life phases of cement products were considered.•Utilization of biomass ash is preferable over landfill for all non-toxic categories.•Hydraulic activity of ash and cumulative leaching were the most sensitive parameters.•Comparison of leaching values with risk based criteria showed no additional risk.
Purpose
There is a growing concern about the resilience and sustainability of horticultural production in the United Kingdom (UK) as a result of high energy costs and insufficient local labour, ...causing over-reliance on imports. In this study, we present an integrated environmental and economic assessment of organic peri-urban horticulture using primary data from a farm in Sheffield.
Methods
This study includes a farm-to-gate hybrid life cycle assessment (LCA) using the ReCIPE (H) approach for the functional unit of 1-kg tomatoes produced in an unheated polytunnel without supplementary lighting, and 1 kg of field-grown courgettes. All analyses were conducted in SimaPro software using environmental data from the ecoinvent database. Results were compared with those from a systematic literature review of similar studies.
Results
We found that the production of organic tomatoes and courgettes resulted in a global warming potential (GWP) of 0.61 kg CO
2
-eq and 0.11 kg CO
2
-eq respectively using a process-based LCA approach. Using a hybrid LCA approach, however, yielded a GWP of 3.53 kg CO
2
-eq and 1.70 kg CO
2
-eq for the production of organic tomatoes and courgettes respectively. An additional scenario included farmgate-to-warehouse transportation for both domestic and imported produce from Spain, but found that the GWP of tomatoes in the case study was 1.87 times higher than those from Spain. Economic analysis showed that the marginal increase in the prices of tomatoes and courgettes from the case study farm was 4.6 and 5.15 times less than the market prices.
Conclusion
We conclude that the studied production system is both economically and environmentally sustainable as compared to the existing scenario. Other potential benefits of peri-urban organic horticulture include employment, mental health, community cohesion, which remain to be explored in a future qualitative study. The present study is novel as it appears to be the first application of hybrid LCA to UK horticulture. The findings are highly topical given the recent horticultural supply constraints in the UK.
Perovskite photovoltaic cells (PVs) have attracted significant worldwide attention in the past few years. Although the stability of the power conversion is a concern, there is great potential for ...perovskites to enter the global PV market. To determine the future potential of perovskites, we performed a cradle-to-gate environmental life cycle (LCA) for two different perovskite device structures suitable for low cost manufacturing. Rather than examining current laboratory deposition processes like dipping and spinning, we considered spray and co-evaporation methods that are more amenable to manufacturing. A structure with an inorganic hole transport layer (HTL) was developed for both solution and vacuum based processes, and an HTL-free structure with printed with back contact was modeled for solution based deposition. The environmental impact of conventional Si PV technology was used as a reference point. The environmental impacts from manufacturing of perovskite solar cells were lower than that of mono-Si. However, environmental impacts from unit electricity generated were higher than all commercial PV technology mainly because of the shorter lifetime of perovskite solar cell. The HTL-free perovskite generally had the lowest environmental impacts among the three structures studied. Solution based methods used in perovskite deposition were observed to decrease the overall electricity consumption. Organic materials used for preparing the precursors for perovskite deposition were found to cause a high marine eutrophication impact. Surprisingly, the toxicity impacts of the lead used in the formation of the absorber layer were found to be negligible. Energy payback times were estimated as 1.0–1.5 years.
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•We modeled three different perovskite modules, one without a HTL (with printed back contact).•We used TRACI environmental impact assessment model; normalized results to mono-Si.•Environmental impacts from manufacturing perovskite solar cells are lower than those of mono-Si.•Environmental impacts from generating electricity depend on lifetime (6 times) and efficiency (0.70–1.4 times) assumptions.•Not having a HTL can lower the total environmental impact by 25%.
Extra virgin olive-oil (EVO) production is an important economic activity for several countries, especially in the Mediterranean area such as Spain, Italy, Greece and Tunisia. The two major ...by-products from olive oil production, solid-liquid Olive Pomace (OP) and the Olive Mill Waste Waters (OMWW), are still mainly disposed on soil, in spite of the existence of legislation which already limits this practice. The present study compares the environmental impacts associated with two different scenarios for the management of waste from olive oil production through a comparative Life Cycle Assessment (LCA). The two alternative scenarios are: (I) Anaerobic Digestion and (II) Disposal on soil. The analysis was performed through SimaPro software and the assessment of the impact categories was based on International Life Cycle Data and Cumulative Energy Demand methods.
Both the scenarios are mostly related to the cultivation and harvesting phase and are highly dependent on the irrigation practice and related energy demand. Results from the present study clearly show that the waste disposal on soil causes the worst environmental performance of all the impact categories considered here. Important environmental benefits have been identified when anaerobic digestion is chosen as the final treatment. It was consequently demonstrated that anaerobic digestion should be a feasible alternative for olive mills, to produce biogas from common olive oil residues, reducing the environmental burden and adding value to the olive oil production chain.
•The management of wastes from olive oil production was assessed by means LCA.•The two alternative scenarios are: (I) Anaerobic Digestion (II) Disposal on soil.•Scenario I produce biogas and its energy content is recovered.•Results reveal Scenario I reduces all the environmental impact categories assessed.
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