Search

This study evaluates the environmental impacts associated with the conversion of garden organic waste into value-added products, namely compost or biochar, employing various processes. Three distinct scenarios are considered: composting garden organic waste followed by screening of oversized materials (CBP), pyrolysis of oversized screenings of compost into biochar AP(I), and in-situ conversion of garden organics into biochar AP(II). A comprehensive Life Cycle Assessment (LCA) was conducted using OpenLCA software and life cycle impact assessment was conducted using Recipe 2016 midpoint methodology. The environmental ramifications of each scenario were assessed, optimising transport distances in AP(II) to achieve a functional unit of one tonne of biochar produced within a cradle-to-gate system boundary. For the first time, this study offers a holistic exploration of the benefits of soil biochar application, extending its scope to climate change mitigation, incorporating the optimisation of transport distance and its influence when scaling up the technology. The results revealed that global warming was increased from 125 kgCO 2 eq during composting of garden waste to 232 kgCO 2 eq where oversized screenings of compost is converted to biochar at an off-site facility. However, direct conversion of the oversized organic waste to biochar, without composting, showed reduced global warming impact of 56 kgCO 2 eq, and is thus the most favourable scenario to limit climate impacts of this fraction of organic garden waste. However, among 18 environmental impact indicators studied, eight indicators were either not influenced or did not significantly increase by transport distance to an off-site pyrolysis facility, while the magnitude of 10 impact indicators increased with transport distance. The insights and methodologies presented in this study hold global relevance, based on an actual case study in regional Australia, offering valuable recommendations for sustainable waste management practices and establishing biochar as a carbon-neutral or carbon-negative solution. The findings contribute to existing waste management knowledge and provide guidance for accessible carbon dioxide removal and soil carbon sequestration technologies. [Display omitted] • A comprehensive LCA for valorisation of garden organics was conducted. • Direct conversion of garden organics to biochar showed least potential environmental impacts. • Biochar provides opportunities for avoided, reduced, and removed carbon from atmosphere. • Maximum transport distance has been identified for individual impact categories. [ABSTRACT FROM AUTHOR]

Developing non-grain forestry woody fuel industries such as Jatropha curcas L. (JCL) aligns with the national conditions of countries with food shortages and large populations, such as some countries in Africa and Asia, and is an ideal alternative to replace fossil fuels. Determining appropriate planting densities suitable for different regions is one of the most critical practices for agriculture and forestry to achieve high yields and sustainability. This study conducted a life cycle assessment (LCA) of the JCL biodiesel's environmental impact, energy balance, and economic analysis (3E) of two densities and three of the most suitable planting regions in China. Findings reveal that the density of 2500 plants/ha had a better 3E performance than 1600 plants/ha, and Yunnan province outperformed Guizhou province and Sichuan province. JCL biodiesel effectively mitigates the greenhouse effect (1141.14–1936.59 kg CO 2 eq/t) compared to conventional fossil diesel in different cases. Key factors influencing environmental performance include seed yield, urea applied during cultivation, methanol for biodiesel conversion, and electricity for irrigation. The Net Energy Balance (NEB) and Net Energy Ratio (NER) demonstrate the superior energy efficiency of JCL biodiesel over fossil diesel. The cost of producing JCL biodiesel decreased with the maturation of the trees, with water use and labor salary accounting for over 80% due to the necessity of the cultivation stage. Although the Financial Net Present Value (FNPV) was negative when considering only JCL biodiesel, it became positive (12111.64–27342.44 CNY) with the inclusion of by-products (glycerine, press-cake, and shells) in high-density cases. Our findings suggest that JCL biodiesel with appropriate density can serve as a sustainable biofuel alternative, replacing a portion of the fossil diesel currently on the market and significantly contributing to climate change mitigation and nonrenewable energy conservation. [Display omitted] • A comprehensive cradle-to-gate LCA of Jatropha curcas L. biodiesel of two densities × three regions was assessed. • Planting density was an important factor influencing the environmental, energy, and economic performance of Jatropha curcas L. • Jatropha curcas L. biodiesel reduced GHG emissions and saved energy compared to fossil diesel. • Emissions from fertilizers, energy consumption from electricity, and the cost of labor contributed the most to 3E of Jatropha curcas L. biodiesel. [ABSTRACT FROM AUTHOR]

We perform an ex-ante life cycle assessment, integrating cradle-to-gate greenhouse gas emissions into an off-grid energy system model. By applying a multi-objective optimization, minimizing both costs and carbon dioxide equivalent (CO 2 e) emissions, we find the Pareto boundary between these two goals. As a case study, we chose the power supply to an astronomical observatory in Chile, using mostly solar power and energy storage in batteries and hydrogen. We compare the ex-ante study to a prior ex-post life cycle assessment, and furthermore dive into sensitivities of our model regarding component lifetimes and costs. We find (i) low-hanging fruit in lowering emissions with small cost increases, (ii) ex-ante life cycle assessments' possibility to find less CO 2 e intensive power systems compared to ex-post conducted studies, (iii) a pronounced sensitivity of the optimization model on assumed lifetimes of energy storage components. This study shows the importance of including life cycle CO 2 e emissions into the optimization objective of energy system models. This method uncovers the environmental and economic trade-offs associated with high shares of renewable energies in off-grid energy systems. • We integrate life cycle assessment (LCA) into an off-grid energy system optimization. • The applied case study powers a remote astronomical telescope in Chile. • A multi-objective optimization finds Pareto curves at varying costs and lifetimes. • Low-hanging fruit shows low additional system costs to reduce CO 2 e impacts. • In contrast, a separate LCA did not find such trade-offs in costs and CO 2 e emissions. [ABSTRACT FROM AUTHOR]

Sustainable fuels and technologies are expected to significantly contribute towards climate change mitigation considering that the transportation sector provides a 23% share out of the total CO 2 emissions. Biodiesel is a green fuel produced by transesterification of triglycerides with an alcohol in the presence of a catalyst. The current study entails modelling and simulation of biodiesel production, through an acid transesterification process, using both classic and intensified methods, coupled with an environmental impact analysis performed following the Life Cycle Assessment methodology. The traditional biodiesel production consists in the synthesis and separation sections, while the intensified method is based on reactive distillation. ChemCAD software was used to simulate and evaluate the processes from a technical point of view. Methanol is generated using CO 2 and H 2 , this method being considered as a new approach for CO 2 utilization. Water electrolysis is employed for H 2 generation, with either biomass or natural gas as power source. A cradle-to-gate environmental analysis is performed within the current research by means of GaBi software, considering the following system boundaries: i) upstream processes: catalyst supply chain, sunflower oil supply chain, natural gas supply chain, limestone extraction and decomposition, ii) main-processes: methanol and biodiesel production, iii) downstream processes: disposal of wastes. ReCiPe method was chosen as the impact assessment method. High purities for the main product and by-product are obtained (i.e., purities higher than 99%). The outcome of the process simulation points to the conclusion that the intensified path gives better performances from technical point of view. The environmental results show that the classic approach performs better when CO 2 and H 2 are used as raw materials, while reactive distillation displays a higher efficiency when natural gas is used as feedstock. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] • Active mobility (AM) contributes to the mitigation of climate change. • The study offers a methodology to measure the street use environmental impacts. • Refurbishment return environmental rates do not exceed seven months. • Sustainable transportation requires strategies: AM, carpooling, and mass transport. • Measuring the impacts of street use could generate sustainable interventions. Active mobility (AM) is a fundamental part of a sustainable mobility system that generates environmental and social advantages; however, its use and operation are understudied using quantitative tools such as life cycle assessment (LCA), especially in the Latin American context. This study aimed to analyze the use stage of a street located in Northern Mexico. Two real scenarios were compared, one conventional (CO-SC-2020) and another sustainable (SU-SC-2022), which incorporated the concept of "complete streets" through a bicycle lane and the improvement of pedestrian spaces. Available data from the "Vía Libre" project and PIMUS, as well as SIMAPRO and Ecoinvent, were used for the LCA. The results indicated that the environmental impacts derived from transportation could be reduced through strategies such as active mobility (6.55%) and carpooling (77%), favoring the conversion of cities that consider the automobile as the guiding axis to more sustainable, inclusive, and safe cities. [ABSTRACT FROM AUTHOR]

In this study, we conducted LCA on the environmental impacts of recycling LDPE films within two system boundaries. System boundary 1 analysed the operations of a recycling company producing recycled LDPE granules. The results were comparable to the literature, yielding 0.44 kg CO 2 -eq./kg LDPE. Polymer testing revealed that recycled LDPE foil products had a higher mass per product than virgin materials to compensate for inferior material properties. System boundary 2 was modelled to analyse existing film products, incorporating both recycled and virgin LDPE and using data from system boundary 1, to fulfil the same function. Due to the incineration at the products' end of life, some recycled products showed higher climate change footprint, due to the additional mass. Accordingly, the idea of a threshold called the environmental break-even was introduced, indicating the maximum surplus of low-quality recyclate usable to achieve the same climate change impact than a purely virgin competitor. [Display omitted] [ABSTRACT FROM AUTHOR]

The greenhouse gas emission reduction potential of harvested wood products (HWPs) is widely recognized and future demand is expected to increase. However, inconsistencies in system boundaries, time horizons, and scenario assumptions in life cycle assessment (LCA) have led to distorted climate impact assessments and misguided policy formulation. To address this, we propose a comprehensive framework covering life cycle, temporal, and spatial dimensions to assist in considering comprehensive factors in evaluating HWPs climate impacts using LCA. Our review of existing studies highlights the significant climate mitigation potential of long-lived HWPs used in construction and furniture, while short-lived products such as bioenergy and paper exhibit uncertainties and can contribute to net emissions. Existing analyses often overlook factors such as indirect land use change emissions, substitution credits, as well as emissions and storage in the end-of-life stage. Moreover, there are misconceptions regarding the selection of time horizons and characterization of climate impacts, as well as emission leakage caused by international trade. Utilizing HWPs for climate mitigation faces challenges such as forest biomass shortages, substitution benefits leakage, and trade-offs between forest protection and utilization, long-term versus short-term goals, and regional versus global benefits. Additionally, extrinsic trade-offs exist between climate impacts and other environmental, economic, and social elements. In formulating future climate policies, we advocate for a holistic assessment from a systematic perspective by the forestry sector, considering both intrinsic and extrinsic challenges, to maximize environmental, economic, and social benefits. [Display omitted] [ABSTRACT FROM AUTHOR]

• A review of the spectrum of emerging Direct Air Capture, DAC technologies. • Several categories are under different levels of development with different working principles. • A widespread data on DAC technical, economic, and environmental performance. • Lack of standardized frameworks for DAC assessment. • Multicriterial assessment frameworks can provide comprehensive guidance for rapid deployment. Direct air capture (DAC) is set to play a crucial role in meeting climate change targets as most recent climate scenarios rely on its large-scale implementation. Nevertheless, despite this widespread consensus, DAC performance and impact have not been sufficiently investigated, which has resulted in hindering its wide-scale deployment for climate change mitigation initiatives. Here, we present a comparative review of different DAC technologies and examine their performance from a holistic perspective by considering different aspects, from technical, commercial, and economic to environmental. We classify DAC technologies into five main categories, namely (i) liquid scrubbing, (ii) solid sorbent, (iii) electrochemical, (iv) cryogenic, and (v) membrane, and within each category, various approaches can be employed. We explore key challenges involved in developing each DAC technology and compare their performance using up-to-date data. We then critically analyze the primary factors contributing to the inconsistencies arising from the economic assessment results and provide valuable guidelines for future studies. Overall, the present review can benefit researchers, engineers, and policymakers in obtaining a holistic understanding of these state-of-the-art technologies in addition to filling key gaps in the DAC field. [ABSTRACT FROM AUTHOR]

• Substitution factors for forest products for the Canadian context were developed. • Substitution factors ranging from 0.51 to 0.91 tC/tC were found. • They will lead to more accurate assessments of the forest GHG mitigation potential. • These factors will help governments to manage forest and fight climate change. Evaluating the climate change mitigation potential of the forest sector requires a holistic approach based on forest carbon (C) sequestration, C storage in harvested wood products (HWP) and substitution on markets. High uncertainty is associated with substitution factors, that express avoided fossil greenhouse gas (GHG) emissions from the use of forest-based products in replacement of GHG-intensive materials and fossil fuels. Few studies have focused on the development of substitution factors in Canada, resulting in the use of unrepresentative generic data. Here, we provide a framework to reduce uncertainties related to substitution factors for primary wood products in a Canadian context. A life cycle assessment framework is used to quantify fossil GHG emissions for a baseline and a wood-intensive scenario. For solid product substitution, we focused on the construction sector and analyzed a range of innovative wood buildings with steel and reinforced concrete as alternative materials. We found non-weighted averages of 0.80 tC/tC for sawnwood and 0.81 tC/tC for panels. For energy substitution, we analyzed cases with different specifications on biomass product, facility type and alternative fossil fuel source in non-residential heat production and biofuel transportation sectors. We found a non-weighted average of 0.80 tC/tC for non-residential heat production and 0.51 tC/tC for biofuel transportation, that can be interpreted as 0.91 tC/tC for heavy fuel oil, 0.69 tC/tC for light fuel oil and 0.68 tC/tC for natural gas substitution. These results provide a benchmark for substitution factors in Canada, to help guide forest management strategies for climate change mitigation. [ABSTRACT FROM AUTHOR]

In the quest for carbon neutrality, the cement industry employs various CO 2 mitigation strategies, including material efficiency, cement plant technologies, and clinker-to-cement ratio reductions. This study reviews the past decade's Life Cycle Assessment (LCA) literature on cement production to assess the feasibility of modeling these strategies. Heating energy is the predominant factor in energy consumption, benefiting from energy efficiency measures. Allocation consistently favors cement in evaluations of secondary fuel-related impacts, leading to significant reductions in energy consumption and Greenhouse Gas (GHG) emissions. However, transparency improvements are necessary to clarify the origin and calculation of combustion-related emissions. Challenges arise from limited data availability when assessing grinding energy, especially for high-quality cement aligned with a material efficiency strategy. In our examination of Ground Granulated Blast Furnace Slag (GGBS) as Supplementary Cementitious Materials (SCMs), we have observed that production process variations and allocation assumptions significantly influence LCA models, while highlighting the absence of waste availability consideration in current substitution-focused LCA methods for both secondary fuels and SCMs. • Cement functionalities are generally not described and should be based on strength. • Existing models overlook impacts of increased cement quality due to grinding energy. • Allocation method choice affects climate change impacts of slag-blended cement. • Excluding allocation methods, slag recovery shows climate change impacts variability. • Substantial variability is also found for heating energy for clinkerization. [ABSTRACT FROM AUTHOR]

Crop residue burning is a common practice in many parts of the world that causes air pollution and greenhouse gas (GHG) emissions. Regenerative practices that return residues to the soil offer a 'no burn' pathway for addressing air pollution while building soil organic carbon (SOC). Nevertheless, GHG emissions in rice-based agricultural systems are complex and difficult to anticipate, particularly in production contexts with highly variable hydrologic conditions. Here we predict long-term net GHG fluxes for four rice residue management strategies in the context of rice-wheat cropping systems in Eastern India: burning, soil incorporation, livestock fodder, and biochar. Estimations were based on a combination of Tier 1, 2, and 3 modelling approaches, including 100-year DNDC simulations across three representative soil hydrologic categories (i.e., dry, median, and wet). Overall, residue burning resulted in total direct GHG fluxes of 2.5, 6.1, and 8.7 Mg CO 2 -e in the dry, median, and wet hydrologic categories, respectively. Relative to emissions from burning (positive values indicate an increase) for the same dry to wet hydrologic categories, soil incorporation resulted in a −0.2, 1.8, or 3.1 Mg CO 2 -e change in emissions whereas use of residues for livestock fodder increased emissions by 2.0, 2.1, or 2.3 Mg CO 2 -e. Biochar reduced emissions relative to burning by 2.9 Mg CO 2 -e in all hydrologic categories. This study showed that the production environment has a controlling effect on methane and, therefore, net GHG balance. For example, wetter sites had 2.8–4.0 times greater CH 4 emissions, on average, than dry sites when rice residues were returned to the soil. To effectively mitigate burning without undermining climate change mitigation goals, our results suggest that geographically-target approaches should be used in the rice-based systems of Eastern India to incentivize the adoption of regenerative 'no burn' residue management practices. • Efforts to build SOC for climate change mitigation, while simultaneously avoiding burning, may have unintended consequences. • Tier 1, 2, and 3 modelling approaches were used to compare no-burn rice residue pathways. • Field hydrology had a dominant effect on methane emissions. • Soil incorporation of residues increased emissions relative to open burning, except in comparatively dry fields. • Biochar is estimated to have the lowest GHG emissions of the evaluated 'no burn' alternatives. [ABSTRACT FROM AUTHOR]

Bioenergy with carbon capture and storage (BECCS) is regarded as a crucial negative emission technology (NET) in many prospective climate change mitigation scenarios that limit global warming below 2 °C. However, there is still insufficient understanding of the overall life cycle environmental performance of different BECCS configurations. Despite the fact that BECCS entails many technological combinations, the technology is still regarded as a single "black box" technology in most climate scenarios. This study presents a critical review of life cycle assessment (LCA) on a wide range of BECCS options: biomass direct-fired power generation, biomass gasification power generation, bio-hydrogen production, biomass application in industry sectors and other biomass conversion processes, such as pyrolysis and fermentation. It is evident from the review that the biomass direct-fired and gasification power plant with a 100% biomass firing ratio and the gasification-based bio-hydrogen processes have a strong potential to achieve negative emissions. However, the net negative life cycle emissions range widely among studies for each configuration due to variations in technology, LCA methodology and assumptions. Additionally, there is an insufficient assessment of comprehensive environmental impacts for BECCS systems other than GWP, making it still unclear about the trade-offs between the benefit from climate change mitigation and potential negative impacts. Main recommendations for improving LCA on BECCS include developing a generalized guideline and standardization for BECCS LCA, conducting LCAs with comprehensive impact categories, focusing on BECCS configurations being overlooked, considering the impact of land use change and the global warming potential of biomass, and extending LCA in both temporal and spatial dimension. [Display omitted] • Systematically review of life cycle assessment on BECCS systems. • Detailed review on various biomass conversion technologies. • Net negative life cycle emissions range widely among studies. • Insufficient studies of some biomass conversion pathways. • Insufficient studies on multi-environmental environment impact categories. [ABSTRACT FROM AUTHOR]

With emphasis on constructing low-carbon cities, the renovation of old communities highlights the importance of renewing rainwater management facilities. Rain garden is an exceptional Nature-based Solution for rainwater management. When applying them to renovate old communities, the carbon footprint should be considered. This study focused on renovating facilities in the Greater Bay Area and utilized the Energy Expert platform to calculate rain garden carbon footprint with the Life Cycle Assessment. The carbon reduction benefits during the operation were estimated. This study accounting the life cycle carbon footprint of the 5455 m2 rain garden was 1117.42 tCO 2 e. The carbon footprint contribution, from highest to lowest was the end-of-life phase, materials production phase, construction phase, use and maintenance phase. Regarding carbon emission inventory, waste soil landfill, fertilizer acquisition, and waste soil recycling ranked high. Transportation also accounted for a remarkable carbon emission. The rain garden showed great potential for climate change mitigation, with a total and net carbon reduction of 1927.41 and 809.99 tCO 2 e, respectively. To reduce the carbon footprint of the rain garden, we should focus on waste soil treatment and transportation. Recommendations included increasing waste soil recycling, in situ recycling and green transportation. [ABSTRACT FROM AUTHOR]

Carbon dioxide valorization into value added products have become subject to much study to reduce industrial CO 2 emissions and fossil energy resource consumption. In this context, the purpose of this study is to evaluate and highlight the interest of CO 2 conversion into methanol through a complete techno-economic and environmental assessment of the entire process chain. The integrated process, successfully implemented in Aspen Plus®, is designed to treat the CO 2 coming from a conventional cement plant. A MEA-based CO 2 capture process is considered, and the captured CO 2 is then directly sent to the conversion unit for its catalytic conversion. Consequently, combining the two units leads to relevant integrations, especially regarding the reuse of the heat provided by the exothermal methanol reactions for the regeneration of the CO 2 capture solvent. An economic assessment is proposed to estimate the operational and investment costs, as well as the net present value, which demonstrates that the economic feasibility strongly depends on electricity and H 2 production costs. A Life Cycle Analysis method is finally performed to identify the main environmental hotspots. The underlying process design offers a significant reduction in greenhouse gases (besides other categories) when compared to the conventional fossil production from natural gas. • An integrated process is studied to produce methanol from industrial CO 2. • Techno-economic and environmental aspects are assessed. • Economics of CO 2 -to-methanol is affected by high renewable H 2 production costs. • Environmental benefits are highlighted compared to conventional production. • CO 2 -to-methanol is a credible substitution alternative in climate change mitigation. [ABSTRACT FROM AUTHOR]

• Building-level hybrid RE systems support net-zero development goals and climate change mitigation. • Energy planning is multi-dimensional, and is affected by uncertainties. • A life cycle thinking based fuzzy decision support model is presented for identifying optimal hybrid building energy mix. • A combinatorial multi-objective optimisation was adopted considering the most viable RE technologies in the local market. • Solar PV and geothermal heating are the optimal residential energy choices for BC, under the selected case study scenario. The increasing concerns about the environmental and economic impacts of conventional centralised energy generation and fossil fuel usage have prompted an interest in renewable-based decentralised energy systems. Implementing such systems at building level can facilitate the development of net-zero energy buildings. Energy system planning is a multi-faceted problem that involves technical, economic, environmental, and social dimensions, and affects multiple stakeholders at different levels. A multi-objective optimisation approach is needed to identify the optimal energy choices at building level, while paying attention to stakeholder priorities and other constraints. The objective of this study is to develop a model to identify the optimal mix of renewable energy (RE) while also accounting for uncertainties, which can be integrated at building level with life cycle thinking. A framework was proposed for planning an optimised hybrid RE system at building level to support the net-zero development goals. The optimisation model was developed considering the objectives of minimising energy system cost, maximising operational cost savings, minimising the life cycle environmental impacts, and maximising the RE fraction. A combinatorial optimisation approach was adopted to reflect the practical engineering aspects of energy planning problems based on technologies available in the market. The developed framework was demonstrated through a case study conducted for an average multi-unit residential buildings (MURB) located in British Columbia, Canada. The results indicated that under the defined stakeholder priorities and constraints, ground source heat pumps and solar photovoltaics (PV) are the optimal energy choices for MURB, and the optimal energy system combination supplied 44% of the building's energy demand through RE. The findings will inform and guide community developers and other stakeholders with an interest in residential buildings, on the most suitable clean energy options for their building project during the pre-project planning stage. [ABSTRACT FROM AUTHOR]

As a secondary energy source, hydrogen produced by water electrolysis is a promising way to sustainably use electricity generated from primary renewable resources. Thereby, hydrogen is not only a highly relevant feedstock for producing chemical products, such as fertilizers and platform chemicals, but also a valuable energy carrier that can be readily transported and stored. This study explores how transporting renewable hydrogen via pipeline from regions with high renewable energy potential to large consumer centers can help overcome current challenges in ensuring a climate-friendly renewable energy supply. To this end, this work assesses the environmental impacts of cross-border hydrogen supply chains relative to the attained operating hours of local hydrogen production and the required hydrogen transport distance via pipeline. Environmental hotspots along the hydrogen supply chain and the main parameters affecting the overall environmental impact were identified. Remarkably, an environmental trade-off emerges: the most suitable local conditions for producing renewable hydrogen need to be balanced against the distance of hydrogen transport to consumers. Nonetheless, the relevance of the transport distance decreases with an increasing share of renewable energies in the electricity mix for operating the compressor stations of the pipeline network. Considering the ongoing transition towards renewable power generation technologies, our results indicate that long-distance hydrogen transport via pipeline is environmentally justified provided that the share of renewable energies used to operate the compressor stations increases. • Renewable hydrogen supply chains are associated with environmental impacts. • Critical parameters focus on hotspots along the hydrogen supply chain. • Regions with high renewable energy potential are ideal for hydrogen production. • Benefits increase as the difference in renewable energy potential increases. • Distance becomes less relevant as energy transition progresses. [ABSTRACT FROM AUTHOR]

Plastics account for 4.5% of global greenhouse gas (GHG) emissions, which are hard-to-abate due to the use of fossil fuels as feedstock. Our study develops a cradle-to-gate life cycle assessment of bioethylene production, exploring 33 pathways across Brazil, the EU, and the US. It aims to understand whether substituting fossil-based ethylene with bioethylene contributes to lowering carbon emissions, and in which of the relevant bioenergy-producing regions/countries the valorisation of biofuels as feedstocks would provide a less carbon-intensive bioethylene production. Results indicate that bioethylene production through catalytic dehydration of sugarcane bioethanol in Brazil presents lowest GHG emission. This pathway could deliver up to −2.1 kg CO 2 e/kg ethylene when accounting for biogenic carbon storage in long-lived applications such as infrastructure. In contrast, beef tallow performs the poorest as a raw material, regardless of whether land-use change (LUC) emissions are considered. When biogenic carbon storage is factored out, none of the pathways outperforms conventional fossil-based steam cracking; however, some are within the fossil-based range indicating potential indirect benefits through reduced refinery utilisation. Our study underscores that biomaterials production as a climate mitigation strategy must be on par with circular economy measures and the conservation of native forestry ecosystems. These results are particularly relevant to policymakers and industries seeking to align polymer manufacturing with sustainability objectives. • Bio-ethylene cradle-to-gate GHG emissions were assessed for 33 pathways. • Sugary, starch, lignocellulosic and oily crops are raw materials for bio-ethylene. • Local specificities such as biogenic carbon storage and land-use are critical to LCA GHG emissions. • Sugarcane bioethanol dehydration route yielded 2.1 kgCO 2 e captured per of kg ethylene. • Climate mitigation and circular economy policies must be designed coherently. [ABSTRACT FROM AUTHOR]

Anthropogenic greenhouse gas emissions (GHGE) are behind climate change. In Chile, food system is the second source of GHGE. Changing Chileans dietary patterns is key to reducing such emissions. There is geographic variability in terms of dietary patterns within the country. Here we investigated the dietary GHGE in five different geographical zones, along with the main contributing food groups and socio-demographic variables. Data for 4676 individuals were obtained from the 2010–2011 National Survey of Food Consumption. The carbon footprint value of each food was obtained from studies using life cycle assessment methodology. Median and percentiles of dietary GHGE were calculated, expressed in kilograms of carbon dioxide equivalent per person per day (kgCO 2 eq/person/d) and compared among zones by Kruskal-Wallis and Dunn's tests. Logistic regression models were fitted to analyzed associations among the variables of interest and quartiles of GHGE. Diet-related GHGE ranged from 3.50 (2.34–5.12) in the North-Central Zone to 4.66 (2.89–6.69) kgCO 2 eq/person/d in the South zone. Meat accounted for 53–58% of the GHGE in all the zones, followed by dairy products with 12–13%. Higher GHGE were significantly associated with energy intake (kcal/d) in all of the zones, with high socioeconomic level in the North-Central, South and Metropolitan zones, and with urban residence in the South-Central zone. Tailored policies considering geographic variability are warranted to promote healthy and sustainable diets among the Chilean population. • Differences in dietary greenhouse gas emissions were determined among five Chilean geographical zones. • South and Metropolitan region showed the highest GHGE while North showed the lowest. • Meat and dairy were the most contributing foods in all zones. • GHGE were positively associated with energy intake in all zones & with high socioeconomic level in three zones. • The promotion of sustainable diets in Chile must consider the geographical specificities. [ABSTRACT FROM AUTHOR]

Lithium-ion batteries (LIBs) play a crucial role in driving energy transitions, particularly in electric vehicles (EVs) and energy storage systems. Forecasting LIB prices has received significant attention due to the tightening of raw material markets. Additionally, the implementation of carbon pricing policies has highlighted the need to incorporate the carbon footprint of LIBs in price evaluation. This study presents a comprehensive analysis of the carbon footprint, pricing trajectories, and forthcoming carbon pricing ramifications associated with LIBs. Firstly, the findings derived from the life-cycle carbon footprint assessment indicate that the global production volume-weighted average carbon footprint of EV battery packs spans 49.2–81.1 kgCO 2 eq/kWh, depending on the chosen end-of-life treatment. Strategic end-of-life selections, aligned with battery chemical composition, can diminish the carbon footprint by up to 46% relative to improper disposal methods. Notably, direct cathode recycling of NCA and NMC622 batteries exhibits superior environmental performance. Secondly, techno-economic analysis predicts that the mean price of EV battery packs with diverse chemical compositions will decline to $75.1/kWh by 2030, factoring in the compound annual growth rate of critical raw material prices over the past decade. LFP batteries emerge as the top economic performers. Lastly, the results reveal that monetizing a battery's carbon footprint may offset battery price reductions through learning effects. This underscores the imperative of effective recycling for curtailing the carbon footprint and ensuring the enduring economic and environmental competitiveness of LIBs. • Life-cycle carbon emissions are integrated into future battery price projections. • Direct cathode recycling provides the greatest potential for carbon reduction. • LFP might be the only lithium-ion battery to achieve the $80/kWh price target. • Cost reductions from learning effects can hardly offset rising carbon prices. • Recycling is needed for climate change mitigation and battery economics. [ABSTRACT FROM AUTHOR]

Future projections indicate an expansion for both food and energy demands, which can increase pressure on land use, while there is an urgent global need for climate change mitigation. Bioenergy is foreseen as key option to meet future energy demands and reduce greenhouse gas (GHG) emissions, however its sustainability depends on locations and regional characteristics. Simultaneously, agricultural production models that co-produce food, feed, and energy offer sustainability synergies and co-benefits, but site-specific sustainability assessments of their large-scale implementation are missing. This study presents a bottom-up approach to assess spatially explicit sustainability aspects of bioenergy-livestock integrated systems (BLI) in Brazil and shed light on their contribution to future energy demands, to climate change mitigation targets, and their impacts on selected ecosystem services, including bioenergy production, climate change mitigation, reduction of food competition, biodiversity conservation, and avoided deforestation. The proposed integration considers livestock intensification and use of biofuels by-products as animal feed supplement, taking advantage of synergies between these two value chains. The expansion of the BLI system in the Center-South region of Brazil produce up to 89 billion liters of ethanol, enough to meet future domestic ethanol demands from multiple shared socioeconomic pathways and generating surpluses for export. This production takes place on 16 million hectares of pastureland within the Sugarcane Agroecological Zoning, excluding the Amazon and Pantanal biomes, and biodiversity hotspots. BLI expansion mitigate up to 250 million tonnes of CO 2 eq and generate 15 billion dollars of profits. The best locations to maximize the selected ecosystem services are west of São Paulo, east of Mato Grosso do Sul, and the south-central region of the states of Goiás. This study may encourage the formulation of enhanced public policies for the integration of bioenergy and livestock value chains and guide a sustainable large-scale deployment of BLI systems. • Bioenergy and livestock integration (BLI): co-production of food, feed and energy. • BLI systems: 89 billion liters of ethanol and 250 million tonnes of CO 2 eq mitigated. • Enough ethanol to meet future Brazilian demands and surplus to be exported. • Biomass expansion only on pastureland inside Sugarcane Agroecological Zoning. • Without land displacement and deforestation of native vegetation. [ABSTRACT FROM AUTHOR]

Abstract The aim of this study is to evaluate and quantify the impacts of different biogas and related policies on the agricultural sector as well as their performance in terms of climate change mitigation and associated costs. To do so we coupled the partial equilibrium approach simulating the market clearing process with the perspective of Life Cycle Assessment of GHG applying it to the well-documented Lombardy case. Results show that the recent Italian biogas policy – prompting manure utilization and reducing the average subsidy per kWh – effectively increased the environmental sustainability of the system, which only now seems able to counteract global warming. Synergies are observed when the recent Common Agricultural Policy greening reform is simultaneously considered by the model. Highlights • Detail the impacts of different biogas and related policies on the agricultural sector as well as their environmental performance in terms of climate change mitigation and associated costs. • Development of partial equilibrium approach simulating the market clearing process in the biogas sector. • Consider agents decisions feedback to the Life Cycle Assessment for consequential analysis. • The latest Italian biogas policy – prompting manure utilization and reducing the average subsidy per kWh – effectively increased the environmental sustainability of the system, regarding global warming. • Synergies are observed when the recent Common Agricultural Policy greening reform is simultaneously considered by the model. [ABSTRACT FROM AUTHOR]

Abstract Strategies for sustainably increasing sugarcane productivity without any negative implications to the environment are challenging. In the present investigation, field trials were conducted to demonstrate the potential of an agro-technique involving foliar applications of Kappaphycus alvarezii seaweed based biostimulant in combination with recommended rate of synthetic fertilizers (RRF) for sustainably enhancing sugarcane production and mitigating environmental impacts. Kappaphycus seaweed extract (KSWE) applied at 5% concentration enhanced cane productivity by 12.5 and 8%, respectively, in plant and ratoon crops. Interestingly, the treatment involving 6.25% KSWE +50% RRF showed yield parity (p < 0.05) with control (water+100% RRF) in ratoon while there was 7.9% reduction over control in plant crop with a concomitant savings of 50% RRF. These results revealed that KSWE application in addition to recommended rate of fertilizer application, can reduce gap between potential and real yield which otherwise requires application of incremental inputs in the form of synthetic fertilizers to obtain similar yields. The findings confirmed our hypothesis that the use of KSWE not only results in hypothetical savings in the incremental application of synthetic fertilizers but also can be used for achieving target yields sustainably. The sugar yield too was enhanced thus increasing the returns on investment. The technique is practically feasibility and scalability. The potential of the KSWE in lowering GHGs is manifested by the way of saving at least 260 kg CO 2 equivalents (Mg cane production)−1 ha−1 when applied at 5% concentration. This would translate in to savings of ca. 9.3 million Mg of CO 2 equivalents if one assumes employing KSWE for at least 10% of the total cane production in India for the year 2015–16. Therefore, the present study advocates a paradigm shift in policy to encourage use of biostimulants in the context of mitigating adverse effects of global climate change and expecting better returns from sugarcane cultivation. Graphical abstract Image 1 Highlights • Kappaphycus seaweed extract (KSWE) at 5% concentration enhanced cane productivity by ca. 10%. • Kappaphycus extract along with 50% RRF showed yield parity with control in ratoon. • Saving of 260 kg per tonne of cane production can be envisaged by use of KSWE. • Kappaphycus seaweed extract can facilitate in mitigating climate change. [ABSTRACT FROM AUTHOR]

The Intergovernmental panel on climate change raised awareness on the urgent need for action to limit climate change. Answers include bioenergy with carbon capture and storage (BECCS), which could theoretically generate negative emissions. The life cycle assessment (LCA) method needs to be applied to BECCS systems to assess their negative emission potential and prevent transfers from one environmental impact category to another. To allow for informed decision-making, the quality of LCA results should be evaluated. The quality of results is related to the quality of the data used. The purpose of this article is thus to review the life cycle inventory data that are used for BECCS LCA. To this end, 35 recent BECCS LCA were selected and the inventory data they used was collected. Synthesis inventory tables were then compiled, including the observed range of variability for each data item. These tables cover biomass harvesting, pre-treatment, combustion, gasification, and carbon dioxide capture with a monoethanolamine (MEA) based solvent. Data quality is also reviewed, through the representativeness, reproducibility and completeness of the life cycle inventories highlighted in the selected articles. Only a third of the articles (13/35) provide life cycle inventory tables. Only half of the articles assess the impact on climate change leading to inventory cut-offs. BECCS systems including combustion followed by MEA-based capture have been most referenced (12/35 articles). More transparency on data quality is recommended. Certain promising BECCS systems should also be further studied. This applies, for instance, to BECCS systems that involve second-generation solvents. • A review of the data quality used in life cycle assessment (LCA) of BECCS is assessed. • Only a third of the studied articles provide their life cycle inventory tables. • Inventory data currently used in LCA of BECCS is compiled into synthesis tables. • BECCS systems including MEA-based capture are most frequently referenced. • BECCS systems that should be further assessed with LCA are identified. [ABSTRACT FROM AUTHOR]

This paper provides pathways of the carbon content of electricity extracted from the Intergovernmental Panel on Climate Change’s fifth Assessment Report scenarios database. It demonstrates three policy-relevant aspects of the carbon content of electricity that are implicit in most integrated assessment model results but under-discussed in academia and the policy debate. First, climate stabilization at any level from 1.5 °C to 3 °C requires the carbon content of electricity to decrease quickly and become almost carbon-free before the end of the century. As such, the question for policy makers is not whether to decarbonize electricity but when and how to do so. Second, decarbonization of electricity is still possible and required if some of the key zero-carbon technologies—such as nuclear power or carbon capture and storage—turn out to be unavailable. Third, progressive decarbonization of electricity is part of every country’s cost-effective means of contributing to climate stabilization. The pathways of the carbon content of electricity reported here can be used to benchmark existing decarbonization targets, such as those set by the European Energy Roadmap or inform new policies in other countries. They can also be used to assess the desirable uptake rates of electric and plug-in hybrid vehicles, electric stoves and heat pumps, industrial electric furnaces, or other electrification technologies. [ABSTRACT FROM AUTHOR]

A variety of climate mitigation strategies is available to mitigate climate impacts of buildings. Several studies evaluating the effectiveness of these strategies have been performed at the building stock level, but do not consider the technological change in building material manufacturing. The objective of this study is to evaluate the climate mitigation effects of increasing the use of biobased materials in the construction of new residential dwellings in Sweden under future scenarios related to technological change. A model to estimate the climate impact from Swedish new dwellings has been proposed combining official statistics and life cycle assessment data of seven different dwelling typologies. Eight future scenarios for increased use of harvested wood products are explored under different pathways for changes in the market share of typologies and in energy generation. The results show that an increased use of harvested wood products results in lower climate impacts in all scenarios evaluated, but reductions decrease if the use of low-impact concrete expands more rapidly or under optimistic energy scenarios. Results are highly sensitive to the choice of climate impact metric. The Swedish construction sector can only reach maximum climate change mitigation scenarios if the low-impact building typologies are implemented together and rapidly. [ABSTRACT FROM AUTHOR]

Generation of goods and services are highly dependent on the use of natural resources. Until very recently, there was an implicit belief that the physical expansion of the economic system could be unlimited, as if the planet would have conditions and time enough to recover and continue to supply resources. This belief implies a confidence in an economic system that would provide whatever is necessary for a continuous growing production and consumption. Even believing that technology alone is not enough to solve the current environmental problems, it is certain that it can collaborate to mitigate climate change and to adaptation to changes in the environment. By bringing environmental aspects into discussions, eco-innovations can affect and transform the innovation system in order to create sustainable processes. However, the main challenge towards the transition to a more sustainable, cleaner and more equitable society is to set innovation in a new context, as until very recently it only considered the economic variables. This change means to value the social and environmental dimension of the innovation. In addition to eco-innovation, Life Cycle Assessment (LCA) is spreading in the industrial environment, offering promising perspectives. LCA is considered a valuable methodology in the environmental sustainability of industry. In this context, the present study addresses LCA and its relationship with the generation of eco-innovations. Drawing on contributions from literature on eco-innovation and LCA, the paper analyses available evidence on this relationship in a context of the transition towards sustainable development. To structure the debate, the paper offers a conceptual approach and an illustrative case on international researchers' and practitioners’ perceptions on the potentially positive relationship between eco-innovation and LCA. The study gathers data in the Web of Science (WoS) Core Collection and in Scopus, in order to provide a picture of the distribution of documents retrieved from these databases, dealing with both eco-innovation and LCA topics. The paper concludes that the convergence of the eco-innovation and LCA studies is quite plausible, but at least in its initial phase, the literature that unites both themes is scarcely found in publications in the area of innovation, being more frequent in the area of engineering and management that usually addresses LCA studies. [ABSTRACT FROM AUTHOR]

Urban environments in Latin America must begin decarbonizing their activities to avoid increasing greenhouse gases (GHGs) emissions rates due to their reliance on fossil fuel-based energy to support economic growth. In this context, cities in Latin America have high potential to convert sunlight into energy. Hence, the main objective of this study was to determine the potential of electricity self-sufficiency production and mitigation of GHG emissions in three medium-sized cities in Peru through the revalorization of underutilized rooftop areas in urban environments. Each city represented a distinct natural area of Peru: Pacific coast, Andean region and Amazon basin. More specifically, photovoltaic solar systems were the technology selected for implementation in these rooftop areas. Data on incident solar energy, temperature and energy consumption were collected. Thereafter, ArcGis10.3 was used to quantify the total usable area in the cities. A series of correction factors, including tilt, orientation or roof profiles were applied to attain an accurate value of usable area. Finally, Life Cycle Assessment was the methodology chosen to calculate the reduction of environmental impacts as compared to the current context of using electricity from the regional grids. Results showed that the cities assessed have the potential to obtain their entire current electricity demand for residential, commercial and public lighting purposes, augmenting energy security and resilience to intermittent natural disasters, with the support of decentralized storage systems. This approach would also translate into substantial reductions in terms of GHG emissions. Annual reductions in GHG emissions ranged from 112 ton CO 2 eq in the city of Ayacucho to over 523 kton CO 2 eq in Pucallpa, showing that cities in the Amazon basin would be the ones that benefit the most in terms of climate change mitigation. [ABSTRACT FROM AUTHOR]

Post-harvest losses of fruits and vegetables during refrigerated storage, transportation and retail are an important contributor to total environmental impacts of food supply chains in Europe. Ultrasonic humidification can reduce these post-harvest losses, but it is currently unknown whether implementing the technology in practice improves the environmental performance of the supply chains. Here, using life cycle assessment we showed that ultrasonic humidification has the potential to reduce environmental impacts, including climate change impacts, of selected fruits and vegetables in Europe by up to 23% compared to conventional supply chains. The greatest potential is obtained when humidifiers are applied to fruits and vegetables chains with total inherent losses higher than 24% and when humidifiers allow reducing post-harvest losses in each post-harvest stage by 20% or more. Our results suggest that humidification may be an attractive technology for making supply chain management more sustainable. [ABSTRACT FROM AUTHOR]

Biomass is an attractive natural energy resource for mitigating climate change. However, the loss of carbon sequestration as an ecosystem service due to biomass harvest has not been considered in previous studies. To assess the impact of biomass harvest on carbon sequestration, carbon dynamics in the forests and the atmosphere were integrated. The impact of forest biomass harvests on carbon sequestration was assessed based on the difference between carbon sequestration after harvest and carbon sequestration without harvest. A Chapman-Richards function and the forest vegetation simulator (FVS) were used to simulate the growth of a forest stand. The carbon dynamics in the atmosphere were simulated by the Bern2.5CC carbon cycle model. Characterization factors of the impact were calculated in three time horizons: 20-, 100- and 500-year. According to the simulations, postponement of harvest and low harvest intensity could prolong the compensation period. The annual impact on carbon sequestration was mostly negative over a short time and became positive in the end of compensation period. The highest characteristic factors of the impact on carbon sequestration were found in rotation length of 100 years with the time horizon of 500-year in the Chapman-Richards simulation and in the lowest harvest intensity with the time horizon of 500-year in the FVS simulation. Based on the results, increasing growth rate, postponing harvest, reducing harvest intensity and increasing length of time horizon could reduce the impact of forest harvest on carbon sequestration. The method proposed in this study is more proper to assess the impact on carbon sequestration, and it has much wider applications in forest management practice. [ABSTRACT FROM AUTHOR]

Malaysian government has advised builders to apply Industrial Building System (IBS) technique in construction due to so many advantages such as productivity, efficiency and cost. This study attempted to reduce greenhouse gas (GHG) emissions from building sector by representing two new building compositions into IBS structures categories. Life cycle assessment (LCA) tool Simapro.8 has been used to identify the environmental performance of buildings from cradle to grave. The full LCA has been run to assess the six different types of prefabricated buildings system, of which four are currently recognized and the other two are designed by current research. The primary result shows that timber prefabricate is the best choice due to having lower emissions toward climate change mitigation of building construction. However, timber houses have rarely been built due to some defects that occurred to its material and structure over time. Rate of applying wood in the construction industry in Malaysia has gone down from about 60% to 7% over the last 40 years. Therefore, this research aims to contribute to the body of knowledge by introducing new composite. First composite is Glued laminated timber (GLT) with steel stud and the second is a combination of laminated veneer lumber (LVL) with steel stud as two new compositions which not only have significantly less global warming potential (GWP) than prefabricated concrete structure or steel framing system, but can be replaced rather than abandoned timber structure. Therefore, new compositions can be suggested to house builders and facilitate the decision making process. [ABSTRACT FROM AUTHOR]

Wood and other bio-based building materials are often perceived as a good choice from a climate mitigation perspective. This article compares the life cycle assessment of the same multi-residential building from the perspective of 16 countries participating in the international project Annex 72 of the International Energy Agency to determine the effects of different datasets and methods of accounting for biogenic carbon in wood construction. Three assessment methods are herein considered: two recognized in the standards (the so-called 0/0 method and −1/+1 method) and a variation of the latter (−1/+1* method) used in Australia, Canada, France, and New Zealand. The 0/0 method considers neither fixation in the production stage nor releases of biogenic carbon at the end of a wood product's life. In contrast, the −1/+1 method accounts for the fixation of biogenic carbon in the production stage and its release in the end-of-life stage, irrespective of the disposal scenario (recycling, incineration or landfill). The −1/+1 method assumes that landfills offer only a temporary sequestration of carbon. In the −1/+1* variation, landfills and recycling are considered a partly permanent sequestration of biogenic carbon and thus fewer emissions are accounted for in the end-of-life stage. We examine the variability of the calculated life cycle-based greenhouse gas emissions calculated for a case study building by each participating country, within the same assessment method and across the methods. The results vary substantially. The main reasons for deviations are whether or not landfills and recycling are considered a partly permanent sequestration of biogenic carbon and a mismatch in the biogenic carbon balance. Our findings support the need for further research and to develop practical guidelines to harmonize life cycle assessment methods of buildings with bio-based materials. [Display omitted] • Life cycle assessments of the same multi-residential building were carried out by experts from 16 countries. • Effects of methods and datasets of biogenic carbon accounting in wood construction were identified. • Different end-of-life scenarios (incineration, landfill, recycling) cause variations in the results. • Different interpretations of the permanence of storing biogenic carbon in landfills also cause variations in the results. • The input and output flows of biogenic carbon must be balanced to correctly assess its climate change impacts. [ABSTRACT FROM AUTHOR]

With building-related greenhouse gas emissions(GHGE) having more than doubled since 1970, they represent one of the largest and most attractive opportunities for climate change mitigation. However, current focus has mainly been on reducing operational GHGE leaving building embodied GHGE (i.e. the GHG emissions associated with the extraction, manufacture and transportation of materials, and the building construction process itself) largely ignored. These embodied emissions have been estimated to represent between 10% to 97% of a buildings total life cycle GHGE. It is thus critical that decision-making in relation to buildings is based on a life cycle perspective. One of the main barriers to this approach is the uncertainty surrounding the financial implications of life cycle GHGE reduction strategies. Despite project cost being a key driver for decision-making, building developers, designers and owners have insufficient knowledge or appropriate tools to adequately consider these life cycle costs and balance them against GHGE savings. Several methods exist for quantifying the costs of a building, such as life cycle costing (LCC). However, LCC and life cycle GHGE assessments are often used in isolation. This study will address the urgent need to move towards integrating these assessments by developing a framework that can be used to ascertain the important relationships and trade-offs between financial and GHGE performance of various building-related GHGE reduction strategies. This framework can be used as part of the building decision-making process and help create a low carbon, affordable built environment. [ABSTRACT FROM AUTHOR]

This paper asks whether after 20years of development, the new discipline of environmental impact assessment and rating has lost its way. The paper shows examples of problems in building environmental rating systems, and corrupted science in Life Cycle Assessment (LCA), Ecolabelling and Environmental Product Declarations (EPD). Comparisons are drawn with carbon accounting and the problems this will cause for government policies aimed at mitigating climate change internationally. The author speculates on possible causes and provides contrasting examples of initiatives that are trying to produce truly credible, scientifically robust outcomes but struggling to find acceptance. The author concludes with suggestions that might tip environmental impact practice back to legitimacy and relevance. [ABSTRACT FROM AUTHOR]

Among the different cereals, rice plays a relevant role in terms of production and dietary intake. Although the highest rice producers are Asian countries, this crop is also cultivated in Europe and, within Europe, Italy is the most relevant country. There are not studies evaluating in detail the environmental load arising from the application of urban sewage sludge in rice fields that, being flooded, are characterized by anaerobic conditions. The goal of this study was to evaluate the environmental performance of rice cultivation fertilised with urban sewage sludge in the Pavia district. Moreover, three mitigation strategies have been proposed and evaluated: the substitution of urban sewage sludge with compost, the introduction of an additional aeration and the collection of straw. The results suggest that the main contributors to the environmental impact of rice are methane emissions associated with the degradation of the organic matter during the flooding period, nitrogen emissions associated with the application of fertilisers, and diesel used for the field operations. The differences among the proposed alternative scenarios are considerable, suggesting that strategies to improve the environmental performance of rice are possible. In more details, in order to reduce the environmental burdens of rice fertilised with urban sewage sludge, the two most effective possibilities are: the substitution of urban sewage sludge with compost and the implementation of an additional aeration period during the cultivation. The first option determines an improvement in all the categories analysed, and particularly in toxicity-related impact categories, with reductions of 99.6%, 78.8% and 68.7% for human toxicity-cancer effects, human toxicity-non cancer effects and freshwater ecotoxicity, respectively, followed by Climate Change (−25.4%) and Mineral Fossil Resource Depletion (−19.2%). The introduction of an additional aeration is beneficial for the Climate Change and Photochemical Oxidant Formation, with a reduction of 9.7% and 1.6%, respectively. Concerning the results of the Climate Change impact category, the use of standard emission factors for the estimation of methane emission involves uncertainty; the development of country-specific emission factors would be instrumental in overcoming this point of weakness. Finally, despite the focus on the Italian context, this study proposes different mitigation strategies, which can be applied to other rice systems in order to reduce their environmental impact. [ABSTRACT FROM AUTHOR]

Wood use is expanding to new markets, driven by the need to substitute fossil-intensive products and energy. Wood products can contribute to climate change mitigation, if they have a lower fossil footprint than alternative products serving the same function. However, the climate change mitigation potential is contingent on the net fossil and biogenic emissions over time, as well as the realism of the counterfactual scenario and market assumptions. This study aims to improve the consistency of assessing the avoided fossil emissions attributed to changes in wood use, and to estimate the additional mitigation potential of increased wood use in construction and textile markets based on wood harvested in Finland. The results show that, compared to baseline, an increase in the market share of wood leads to an increase in atmospheric CO 2 concentration by 2050. Thus, the substitution impacts of wood use are not large enough to compensate for the reduction in forest carbon sinks in the short and medium term. This outcome is further aggravated, considering the decarbonization of the energy sector driven by the Paris Agreement, which lowers the fossil emissions of competing sectors more than those of the forest sector. The expected decarbonization is a highly desirable trend, but it will further lengthen the carbon parity period associated with an increase in wood harvest. This creates a strong motive to pursue shifts in wood uses instead of merely expanding all wood uses. [Display omitted] • Increase in wood use for construction or textiles increases net emissions by 2050 • Substitution impacts will fall remarkably by 2050 due to decarbonization • Results motivate shifts in wood uses as opposed to expanding all wood uses • Substitution assumptions remain oversimplified which causes great uncertainty [ABSTRACT FROM AUTHOR]

• New recycled polymer pellets additioned with graphene nanoplatelets are proposed. • Dynamic tests, such as indirect tensile stiffness modulus, fatigue cracking and rutting tests, were performed. • 12 years-higher service life of the asphalt mixture with recycled polymers and graphene than traditional one LCA of graphene-enhanced asphalt mixture resulted in significantly reduced environmental impacts. Aiming to mitigate climate change effects associated with the construction of asphalt pavements, two different polymers, namely a plastomeric compound (PC) and a graphene-enhanced recycled (hard) plastic compound (GRPC), were introduced into hot mix asphalt (HMA) for binder layers of road pavements. The study revolved around the investigation of the mechanical performance and life cycle environmental impacts of four HMAs: a) HMA with neat bitumen and cold-added PC (HMA PC), b) HMA with neat bitumen and cold-added GRPC (HMA GRPC), c) HMA containing neat bitumen (HMA NB) and d) HMA made up of modified bitumen with 5% Styrene Butadiene Styrene (HMA PMB). The mechanical characterization results showed that HMA PC and HMA GRPC increased their crack propagation resistance compared to HMA NB , respectively by 35 and 39%, while HMA PMB exhibited the lowest rut depth since it is specifically designed to keep the deformation low at high temperature. The rational design of pavement superstructures was carried out by using in turn each designed asphalt mixture for the binder layer; the HMA GRPC resulted in 12 years-longer service life compared to that of a traditional HMA. The application of life cycle assessment methodology highlighted that the solution made up of GRPC resulted in significantly reduced environmental impact indicators; in detail, the greatest reduction was achieved for the marine ecotoxicity (−58% and −22% compared to those with HMA NB and HMA PMB in the binder layer, respectively) for the overall lower amount of fuels used and lower NO x emissions (−3 kg) during transportation phases and supply of raw materials. [ABSTRACT FROM AUTHOR]

Strict energy performance requirements have reduced the building's operational energy use and related environmental impact in the past decades. Consequently, the embodied impacts of buildings gained importance, and hence focussing on the life cycle impacts has become essential to further reduce the environmental impact of buildings. Life cycle assessment (LCA) is an internationally accepted method used for this purpose. Current LCA studies of buildings typically look at their whole life cycle but ignore potential changes in operational energy use due to climate change. However, the latter is expected to influence the operational energy use of buildings to a significant extent. This paper aims to improve the assessment of the operational phase by including variations in the yearly operational energy use caused by climate change and expected changes in the electricity mix as a strategy for climate change mitigation. This adapted dynamic assessment method is used to assess a Belgian office building. The results indicate that a Representative Concentration Pathway (RCP) 8.5 climate change scenario causes a decrease of 18 % for the end use of gas for heating and an increase of 32.4 % for the electricity use for cooling and ventilation. For the case study, the reduction of the environmental impact due to the decrease in gas use compensates the impact increase due to the higher electricity use. An increase in environmental impact in future would however occur if both heating and cooling are provided by electricity. Furthermore, depending on the changes that will occur in the electricity mix, the global warming potential of the office building will change by −13 % for an electricity mix dominated by renewables and by + 10 % for one with mainly production by gas compared to the situation with the current mix. However, the inclusion of a more extended list of environmental indicators shows that the overall environmental impact will only reduce by 4 % or even increase by 7 % compared to the situation with the current mix. [ABSTRACT FROM AUTHOR]

This work evaluates implications of incorporating LCA-GHG (life cycle assessment of GHG emissions) into the optimisation of the power generation mix of Brazil through 2050, under baseline and low-carbon scenarios. Furthermore, this work assesses the impacts of enacting a tax on LCA-GHG emissions as a strategy to mitigate climate change. To this end, a model that integrates regional life cycle data with optimised energy scenarios was developed using the MESSAGE-Brazil integrated model. Following a baseline trend, the power sector in Brazil would increasingly rely on conventional coal technologies. GHG emissions from the power sector in 2050 are expected to increase 15-fold. When enacting a tax on direct-carbon emissions, advanced coal and onshore wind technologies become competitive. GHG emissions peak at 2025 and decrease afterwards, reaching an emission level 40% lower in 2050 than that of 2010. However, if impacts were evaluated through the entire life cycle of power supply systems, LCA-GHG emissions would be 50% higher in 2050 than in 2010. This is due to loads associated with the construction of plant infrastructures and extraction and processing of fossil fuel resources. Thus, taxes might not be as effective in tackling GHG emissions as shown by past studies, if they are only applied to direct emissions. [ABSTRACT FROM AUTHOR]

[Display omitted] • Biofuels are necessary to mitigate the climate impacts in the EU maritime transport. • Impacts of biofuels are heavily dependent on countries' electricity mixes. • Without carbon capture, synthetic natural gas has the highest mitigation potential. • Among carbon-free biofuels, bio-ammonia has the highest mitigation potential. • By 2050, bio-hydrogen can provide the lowest emissions per unit of energy. Alternative fuels are crucial to decarbonize the European maritime transport, but their net climate benefits vary with the type of fuel and production country. In this study, we assess the energy potential and climate change mitigation benefits of using agricultural and forest residues in different European countries for drop-in (Fast Pyrolysis, Hydrothermal Liquefaction, and Gasification to Fischer-Tropsch fuels or Bio-Synthetic Natural Gas) and hydrogen-based biofuels (hydrogen, ammonia, and methanol) with or without carbon capture and storage (CCS). Our results show the combinations of countries and biofuel options that successfully achieve the decarbonization targets set by the FuelEU Maritime initiative for the next years, including a prospective analysis that include technological changes projected for the biofuel supply chains until 2050. With the current technologies, the largest greenhouse gas (GHG) mitigation potential per year at a European scale is obtained with bio-synthetic natural gas and hydrothermal liquefaction. Among carbon-free biofuels, ammonia currently has higher mitigation, but hydrogen can achieve a lower GHG intensity per unit of energy with the projected decarbonization of the electricity mixes until 2050. The full deployment of CCS can further accelerate the decarbonization of the maritime sector. Choosing the most suitable renewable fuels requires a regional perspective and a transition roadmap where countries coordinate actions to meet ambitious climate targets. [ABSTRACT FROM AUTHOR]

Crop breeding has boosted global agricultural productivity over recent decades, but little is known about its contribution to climate change mitigation. Here we assess greenhouse gas emissions per unit land (GHGL) and greenhouse gas emissions per unit harvest product, i.e. carbon footprint (CFP) of winter wheat (Triticum aestivum) and winter rye (Secale cereale) from official German variety trials in the period 1983 to 2019. We assess the life cycle greenhouse gas (GHG) emissions and analyze the data using mixed effects models. We find that breeding progress led to slightly increased GHGL , amounting to ∼4–10%, but to strongly decreasing CFP, amounting to ∼13–23% in wheat and rye since 1983. With a ∼20% lower GHGL and ∼8% lower CFP in rye compared to wheat, the extension of rye production offers viable climate change mitigation potential. Finally, we find that lower CFP are associated with hybrid breeding, chemical plant protection and larger farms. We conclude that with increasing global food demand and limited cropland, breeding progress contributes considerably to climate change mitigation through reduced CFP. • First evidence on the contribution of breeding progress to climate change mitigation. • 27,652 and 10,523 Genotype x Environment x Management-combinations of wheat and rye. • Rye has lower greenhouse gas emissions (∼20%) and carbon footprint (∼8%) than wheat. • Crop breeding decreased carbon footprint in wheat and rye by ∼13–23% since 1983/1985. [ABSTRACT FROM AUTHOR]

The global methanol industry provides a unique supply chain to a plethora of chemicals and processes while also contributing to high quotas of greenhouse gas (GHG) emissions. Hence, as the world focuses on climate change mitigation, green technologies are emerging, allowing for low carbon operations. However, the timeliness and scalability of these technologies limit the sustainable transition of the current methanol industry. Thus, to promote low carbon operations within business-as-usual methanol production, innovative technologies need to be investigated-boasting high resource and energy efficiencies. Here, we examine the effectiveness of novel gas-heated reforming (GHR) over autothermal (ATR) and steam reforming (SMR)- coupled with carbon capture and storage platforms (CCS), in promoting sustainable methanol operations. Our results highlight the GHR as the most efficient flowsheet- with 11 % overall higher energy efficiency and 17 % increase in resource efficiency over ATR and SMR processes. Furthermore, through coupled CCS and electrification, energy and resource efficiencies were improved with GHR systems- achieving 14–41 % reduced GHG emissions compared to ATR and SMR flowsheets. Lastly, considering process economics, GHR flowsheets outperform- producing minimum selling prices up to 24 % lower than the current market. Ultimately, as the world seeks to promote a sustainable transition through the deployment of low carbon energy sources, GHR systems emerge as the preferred technologies- providing both economic and environmental benefits for future low carbon methanol operations. [Display omitted] • Methanol production through Gas-Heated Reforming (GHR) was investigated. • GHR gives 8 % higher energy efficiency over ATR and SMR systems. • Low-carbon electrification sources reduced GHG emissions by 71 %. • CCS integration further lowers GHG emissions by 44 %. • Overall sustainable operations favours GHR and GHR+CCS systems. [ABSTRACT FROM AUTHOR]

Waste-related methane (CH 4) emissions could account for 31% of total UK CH 4 emissions. Waste management strategies in the UK have recently changed as more waste is diverted from landfills to anaerobic digesters (AD) and composting facilities, which can be significant sources of CH 4. In this study, we combined mobile CH 4 emissions data from waste treatment facilities to perform a life cycle assessment of current biowaste treatment and potential future mitigation, including AD, in-vessel composting, incineration, and landfilling scenarios. We found that diverting biowaste from landfill to AD is an effective strategy, but it is not enough to eliminate emissions. The fugitive CH 4 emissions from anaerobic digesters have a significant impact on the environmental sustainability of waste management strategies, with upgrading the biogas into biomethane being the best option for climate change mitigation, in the case where natural gas is replaced. A change in the biowaste strategy can also reduce CH 4 emissions from the waste sub-sector analysed, from 58.2 to 30.3 kilotonnes per year, an emissions saving of approximately 52%. However, with these technologies, net-zero emissions is challenging unless the absolute minimum emissions from the treatment technologies is consistently achieved. Therefore, we strongly recommend a focus on mitigating CH 4 emissions from AD to achieve the goal of net-zero waste management. [Display omitted] • The UK's biowaste strategies are evaluated using seven different scenarios. • Anaerobic digestion, in-vessel composting, incineration and landfill considered. • The range of methane emissions affect technology's environmental sustainability. • Biomethane generation from anaerobic digestion provides the greatest GWP saving. • Meeting the Net Zero goal in the waste sector is challenging. [ABSTRACT FROM AUTHOR]

With the progressive implementation of Low-Carbon Policies based on Life Cycle Assessment (LCA) methodologies to assess climate change mitigation, biofuels' potential environmental advantages could finally be translated into economic revenues, especially for residue-based production chains. This implies, however, tackling environmental hotspots along the Life Cycle, such as the use of enzymes, an important input in cellulosic ethanol production. While relevant, however, aspects of enzyme manufacturing, crucial to the LCA results, are often oversimplified in databases or even undisclosed, which might render the accounting for this flow unreliable. A potential solution for this is to model enzyme production, disclosing aspects such as carbon source uptakes, energy consumption and purification steps, all of which may carry significant environmental burdens, especially for fossil-reliant procedures. Integrating these steps into the biorefinery process design as an on-site operation, however, would allow access to renewable energy and carbon sources for enzyme production, potentially reducing their burden in the final biofuel LCA profile, when compared with off-site supply. This work, then, aims to evaluate the effect of inserting on-site enzyme production within a stand-alone second-generation (2G) biorefinery, using sugarcane straw as feedstock, to produce ethanol and electricity, as opposed to off-site enzyme supply from manufacturers. The results show that adopting on-site production can reduce the overall environmental impact profile for cellulosic ethanol, in comparison to off-site supply, even though off-site data present significant variability among databases and literature. This trend persisted for varied enzyme dosages in the saccharification process and for different inventories to model off-site supply. The reference inventories for off-site supply lack transparency and details, while also displaying large discrepancies between impact indicators, indicating the need to pursue more consistent, reliable, and complete inventories for its modelling in LCA. Compared to first-generation (1G) sugarcane ethanol, 2G-ethanol (with on-site enzyme production) demonstrated a reduction in the Global Warming Potential category of around 80%. However, relevant trade-offs for 2G ethanol (with off-site enzyme supply) were observed – regarding ecotoxicity, mineral scarcity, eutrophication and even the potential GHG reduction – when different enzyme inventories are used. [Display omitted] • On-site enzyme production leads to lower environmental impact. • Enzyme dosage and off-site inventory choice do not alter this previous conclusion. • With on-site production, enzymes cease to be the major hotspot within the life cycle. • On-site production leads to a 53% GHG emissions reduction, compared to off-site. • There are trade-offs among impact categories for cellulosic ethanol production. [ABSTRACT FROM AUTHOR]

[Display omitted] • Midpoint and endpoint environmental profiles for bio-based isobutene are performed. • Pre-treatment represents the largest environmental burden due to steam demand. • From a system approach, co-produce lignin increases the impacts of the biorefinery. • In a product point view, the isobutene profile benefits sharing impacts with lignin. • Allocation method is a relevant decision to declare an environmental profile product. Moving toward a bioeconomy system is fundamental to climate change mitigation, nevertheless, the biotechnological routes should guarantee an environmental sustainability. Isobutene, a precursor in several industrial applications, is one of those chemicals that the environmental effects of its bio-based production have been scarcely explored. This study aims to assess the environmental performance of two biorefinery systems: the first one focuses only on the production of isobutene (I) and the second one on the co-production with lignin (I + L), both from the valorisation of wheat straw. The Life Cycle Assessment methodology is used to determine the environmental impacts considering mid-point and end-point categories. Biorefineries report 0.65 and 1.32 kg CO 2 -eq per kg of biomass processed for I and I + L system, respectively. The most affected endpoint damage category corresponds to Human Health, regardless of the scenarios. Moreover, the pre-treatment stage constitutes the main hotspot of both systems considering midpoint and endpoint perspectives. [ABSTRACT FROM AUTHOR]

This study aims to quantify the environmentally sustainable and economically feasible potentials of agricultural and agro-industrial residues to generate electricity via direct combustion in centralised power plants in Brazil. Further, the energy savings and greenhouse gas (GHG) reduction potential of replacing natural gas-based electricity by bioenergy have been assessed. To this end, a methodology has been developed based on an integrated evaluation, incorporating statistical and geographical information system (GIS)-based analysis, and a life-cycle-assessment approach. Results reveal that the environmentally sustainable generation potential is nearly 141 TWh/year, mainly concentrated in the South, Southeast, and Midwest regions of the country. Sugarcane, soybean and maize crop residues are the major feedstocks for available bioenergy. On the other hand, the economic potential is far lower, accounting to 39 TWh/year. The total GHG mitigation is nearly 18 million tonne CO 2 e and could reach 64 million tonne CO 2 e yearly, if the technical potential is considered. The gap between technical and economic potentials implies that constraints to bioenergy are not related to a lack of resources, but rather associated to economic, logistical, regulatory and political barriers. [ABSTRACT FROM AUTHOR]

• Circular pathway through use of FCS aggregate and fly ash in concrete was explored. • An eco-efficient mix design method based on PPOT was adopted. • Ten types of concrete mixes were prepared using PPOT and conventional mix design. • The techno-environmental performance of all mixes were studied. • FCSAC with 30% fly ash designed by PPOT was ranked as the most sustainable mix. Climate change mitigation and resource efficiency have emerged as crucial challenges for long-term sustainability of concrete. Implementing circular approach through waste valorisation in concrete production with eco-efficient mix design is an efficient mitigation pathway to combat natural resources depletion and environmental issues. This paper investigates techno-environmental sustainability of concrete utilizing 100% ferrochrome slag as alternate coarse aggregate and fly ash as partial cement substitute (0–40%) adopting particle packing optimization technique (PPOT) as a sustainable mix design method. Total of ten types of concrete mixtures were prepared using the alternate materials and mix design methods (PPOT and IS:10262(2009)). Natural aggregate concrete prepared by IS:10262(2009) mix design was considered as the reference mixture. Technical assessment of concrete was performed experimentally in terms of compressive strength and tensile strength. Environmental performance was investigated through life cycle assessment (LCA) as per ISO 14040-44 guidelines using cradle-to-gate system boundary and two functional units: 1 m3 concrete and 1 MPa compressive strength. Results revealed that ferrochrome slag aggregate concrete (FCSAC) containing fly ash up to 30% prepared by PPOT has enhanced strength than reference concrete. Regardless of the functional units used, FCSAC with 30% fly ash designed by PPOT was ranked as the most sustainable mix with significant environmental savings (around 50–70%) without compromising desired requirements. Sensitivity analysis was performed by varying transportation distance, mode of transport and energy mix. Results showed that FCSAC with 30% fly ash is not sensitive to the scenarios investigated. The outcomes will be helpful for decision-makers to develop policy directives and frameworks on synergistic use of ferrochrome slag and fly ash towards concrete sustainability. [ABSTRACT FROM AUTHOR]

One of the main initiatives in the context of global warming brought by the COP26 is global transition to green energy. Bioenergetic utilization of unharnessed renewable resources, such as native rangeland frequently subjected to fires, is a promising alternative to displace fossil fuels. Spartina argentinensis is a native perennial grass that develops in a depressed area of 33,000 km2 in Santa Fe province (Argentine) named "Los Bajos Submeridionales". A life cycle assessment (LCA) was performed analyzing the bioenergetic utilization of S. argentinensis. Two alternative scenarios (AS) were assessed and compared to their business as usual (BAU) counterparts: pellets for i) gasification to deliver electricity to the grid (ASp), contrasted to the Argentinean energy mix (BAUp) and ii) residential heating (ASh) contrasted to natural gas heating (BAUh). Carbon Balance of both AS were negative noticeably lower than BAU and the energy balance was promising considering that the produced energy was higher than that required along the complete system assessed. This is the first LCA of bioenergy from S. argentinensis and according to the results, this biomass resource could collaborate remarkably in climate change mitigation, which is auspicious considering the vast region occupied by this grass and others with similar characteristics. [Display omitted] • Spartina argentinensis can be pelletized without need of an additive. • Pellets can produce syngas for CHP or can be burnt for residential heat. • Renewable energies assessed produce significant lower GHG than fossil counterparts. • Renewable scenarios present high Energy Return on Investment. [ABSTRACT FROM AUTHOR]