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Biofuels are essential to ensure the energy transition and mitigating of climate change. However, understanding the impact of land use change (LUC) and management practices on soil organic carbon (SOC) stocks is fundamental to ensuring well‐founded policymaking and assessing the sector's carbon footprint. Here, we conducted a meta‐analysis (511 pairwise observations) to obtain Brazil's SOC stock change factors (SOCscf) for LUC and management practices in sugarcane fields. Our results showed that converting native vegetation to sugarcane reduced the SOC stock in all assessed periods. The conversion from annual crops to sugarcane showed a reduction in SOC stock in the first 10 years but with a recovery over time. The conversion of pasture to sugarcane reduced the SOC stock only in the 10–20‐year period and had a neutral effect in other periods evaluated. However, our dataset showed high variability in SOCscf, with many observations indicating an increase in SOC stock, which is related to degraded pastures. We observed that the SOC accumulation rate for each ton of sugarcane straw was affected by the interaction between soil texture and precipitation. Regarding straw management, a low removal rate (< 34%) did not affect the SOC stock, while moderate (34%–66%) and high (> 66%) removal resulted in losses of 5.0% (SOCscf 0.950) and 9.9% (SOCscf 0.901), respectively. Our results also showed that reduced tillage and vinasse application increased SOC stocks by 24.0% (SOCscf 1.24) and 10.0% (SOCscf 1.10) respectively, proving to be good strategies to support C sequestration in sugarcane fields. Finally, we highlight that our results can contribute to the improvement of public policies and also be used in future life cycle assessment (LCA) and modeling studies, as they provide robust data to establishing regional SOCscf induced by LUC and management practices, enhancing the reliability of the C footprint assessment of biofuel production. [ABSTRACT FROM AUTHOR]

Purpose: Rice production in Northeastern Vietnam is livelihood-oriented with a small farm size in the northern mountainous and midlands region. This study aims to determine the contribution of agronomic and input factors to the total carbon (C) footprint of rice production to identify solutions that can reduce greenhouse gas (GHG) emissions in agriculture in this region. Methods: We used a life cycle assessment method for the C footprint of rice production from planting to harvesting. Agronomic parameters and input data in both spring and summer crops were collected through interviews conducted with 50 rice-farming households in the Quang Minh commune, Viet Yen district, Bac Giang province, using questionnaires. Additionally, in-depth interviews were conducted to gather information on energy used for land preparation and harvesting. Results and discussion: The C footprint per hectare and per tonne of grain of the summer rice crop (15.6 ± 3.3 t CO2-eq/ha, 2.34 ± 0.54 t CO2-eq/t) was significantly higher than that of the spring crop (9.5 ± 1.8 t CO2-eq/ha, 1.3 ± 0.26 t CO2-eq/t). GHG emissions were due mainly to direct methane emissions during rice growth, accounting for 89.5% of the total C footprint of the summer crop and 80.5% of that of the spring crop. Fertilizer emissions also contributed significantly, accounting for 5.4% and 10.4%, respectively, nearly 75% from N-fertilizer emissions. A higher C footprint (per grain basis) was generally associated with straw incorporation, continuous flooded irrigation, longer rice growth duration, and lower rice yield, indicating the importance of agronomic management of crop residues, water and nutrients, choice of varieties, and growing seasons. Small farm size did not lead to higher carbon intensity. Conclusions: The solutions to avoid direct incorporation of rice straw, to conduct intermittent irrigation, to reduce the amount of N-fertilizer, and to use short-duration rice varieties (especially for summer crop) with high yield potential along with optimal agronomic management practices should be highlighted. Greater adoption of these measures will contribute significantly to reducing the C footprint of rice production in Northeastern Vietnam. [ABSTRACT FROM AUTHOR]

The emerging field of prospective life cycle assessment (pLCA) offers opportunities for evaluating the environmental impacts of possible future consumption shifts. One such shift involves a transition from meat‐based to plant‐forward diets, acknowledged to mitigate environmental impacts of the food system under present day conditions. Current diets are often meat intensive (“meat‐based”), whilst “plant‐forward” diets include mainly plant‐based foods, encompassing flexitarian, vegetarian, and vegan diets. Here we illustrate the application of pLCA in a case study of meal options, implementing shared socio‐economic pathway scenarios in the LCA background system to represent future production conditions. We assess the climate footprints and land‐based biodiversity footprints of a typical meat‐based meal in Germany and Indonesia compared to a plant‐forward meal in both countries (i.e., four meals), now and in 2050. Our findings show that the plant‐forward alternative maintains a lower impact per serving in all future scenarios. At the same time, the reduction in impact for the meat‐based meals is more pronounced in future scenarios due to shifts in the agricultural system. Our findings highlight the importance of supply‐side measures to produce lower‐impact ingredients, complementing demand‐side interventions to reshape food consumption. Results are further evaluated in cultural and nutritional contexts, highlighting the practical decision‐making constraints faced by consumers. We find potential “leakage” effects in calories and nutrition when choosing a lower‐impact, plant‐forward meal. These leakage effects should be considered in future studies seeking to evaluate the environmental implications of meal substitutions in the context of broader dietary requirements. [ABSTRACT FROM AUTHOR]

Background: Offshore wind energy (OWE) will play a significant role in achieving climate neutrality. For example, several scenarios for Germany (e.g., Kopernikus base, Kopernikus 1.5 degree, Prognos CN65, and CN60) depict substantial OWE annual installed capacity additions, especially after 2030. This tendency promotes OWE technology development as deployment expands, allowing manufacturers to gain expertise and optimize wind turbine construction. The global trend towards ever-larger components (e.g., hub height and rotor diameter) is critical to achieving higher-rated capacities. These aspects and others, such as wind quality, influence not only OWE annual electricity production but also its environmental performance. In addition, future supply chains might reduce their environmental impacts and enhance OWE climate change mitigation. In this paper, a prospective life cycle assessment (pLCA) is developed and applied exemplarily for a 9.5-MW offshore wind turbine (OWT) on the North Sea coast of Germany for the years 2030 and 2050. Considering that the current OWTs under construction in Europe have an average capacity of 10 MW, Germany plans to instal OWTs of 9.5-MW. This exemplary OWT describes the potential advances for offshore wind turbines in 2030 and 2050, considering component scale-up and learning effects. Yet, the methodology is adaptable to various installed capacities and regions. This approach allows us to analyse not only the potential future characteristics of wind turbines, but also future developments in OWE supply chains. Therefore, relevant parameters related to OWT construction and operation (e.g., rotor diameter, hub height, distance to the shore, lifetime, etc.) as well as prospective life cycle inventory data for background systems that reflect potential future developments in the broader economy are considered. In this way, scenarios (e.g., optimistic, moderate, and pessimistic) for OWE elucidate the expected environmental impacts, such as climate change, marine eutrophication, and abiotic depletion potential, in 2030 and 2050. Results: The findings describe the variability of the environmental impacts of a 9.5-MW offshore wind turbine representing the technologies expected to be available in Germany in 2030 and 2050 and show that climate change impacts could vary between 7 and 18 g CO2-eq per kWh produced in 2030 and between 5 and 17 g CO2-eq per kWh in 2050. However, marine eutrophication could experience a significant increase (100% increase), depending on the consideration of hydrogen as a fuel in the electricity mix, as demonstrated in the climate-neutral scenarios adopted for Germany. Overall, construction efficiency improvements in 2050 might reduce the required materials, leading to a 6% decrease in abiotic depletion potential compared to 2030 values. Conclusions: This paper highlights the need to consider temporal improvements in LCA studies, particularly when assessing the environmental impacts of offshore wind turbines. The complex nature and rapid growth of offshore wind technology require a comprehensive life cycle approach to deepen our understanding of its potential environmental impacts. [ABSTRACT FROM AUTHOR]

In the pursuit of climate change mitigation, the chemical industry is developing carbon capture and utilization (CCU) processes to eliminate fossil carbon feedstock. Life Cycle Assessment (LCA) of CCU processes is crucial to verify climate change mitigation and identify potential burden shifting to other areas of environmental damage. Preferentially, this knowledge would be available already in early process development. However, LCA expertise is sparse and LCA studies are often data-intensive and complex, limiting the accessibility to non-LCA experts. To bridge this accessibility gap, we present ESTIMATe, an open-source Excel tool automating LCA assumptions and using estimation methods to streamline the LCA of CCU processes. ESTIMATe, designed for non-LCA experts, quickly provides simplified early-stage LCA results before a comprehensive LCA would usually be conducted. Our case studies demonstrate how ESTIMATe guides process development at different levels of process maturity by assessing climate change mitigation potentials, analyzing environmental impacts along the course of process development, and comparing the environmental performance of process alternatives. ESTIMATe is thus designed to complement rather than replace comprehensive LCA software, providing early access to LCA results and enabling process developers to incorporate environmental perspectives into their decision-making. The ESTIMATe tool is available for download at https://doi.org/10.5281/zenodo.11060469. [ABSTRACT FROM AUTHOR]

The research objective is to create a mechanism that generates a valid 'sustainability' metric to enable prospective buyers to confidently identify low carbon footprint computers. The necessity is based upon the hypothesis that current product carbon footprint reports for computers are incomparable between brands. While the inconsistency of use-phase emissions has been addressed in prior associated research, supply chain emissions remain an issue. This is due to multiple scope 3 life cycle assessment methodologies being used by manufacturers that produce differing results even when applied to the same device. To test the theory and generate an alternative approach, the research analyses 244 notebook carbon footprint reports to show inconsistencies caused by five different methodologies. Based on the findings, an alternative approach to comparing supply chain impact is proposed that enables comparison between results. The new metric first generates an average scope 3 carbon footprint baseline value by device type (e.g. notebook). This is then reduced by specific values depending upon actions undertaken by manufacturers when calculating their original carbon footprint report. This includes deductions to the baseline value achieved by including high percentages of production and transport primary data, plus the availability and affordability of offerings that will extend device useful life spans to drive demand displacement. This includes warranty duration and cost plus ease of repair. The research finds that current methodologies create a range of inconsistency of +106% when used to calculate the carbon footprint of the same device and +142% when calculating similar device types. Therefore, the hypothesis of scope 3 emissions being incomparable is validated. Comparatively, the newly proposed mechanism shows a reduced range of inconsistency of 18% when demonstrated. As such, it is recommended that the new approach be applied to the latest version of the world's leading computer eco-label certification, TCO Certified version 10, in 2024. Doing so will enable organisations to confidently select low carbon footprint devices on a global scale and therefore meaningfully support the United Nations sustainable development goals of responsible consumption and production and ultimately climate action. [ABSTRACT FROM AUTHOR]

Low-carbon electricity and heat production is essential for keeping the decarbonization targets and climate mitigation goals. Thus, an accurate understanding of the potential environmental impacts constitutes a key aspect not only for the reduction in greenhouse gas emissions but also for other environmental categories. Life cycle assessment allows us to conduct an overall evaluation of a given process or system through its whole lifetime across various environmental indicators. This study focused on construction, operation and maintenance, and end-of-life phases, which were analyzed based on the ReCiPe 2016 method. Within this work, authors assessed the environmental performance of one of the renewable energy sources—Enhanced Geothermal Systems, which utilize supercritical carbon dioxide as a working fluid to produce electricity and heat. Heat for the process is extracted from hot, dry rocks, typically located at depths of approximately 4–5 km, and requires appropriate stimulation to enable fluid flow. Consequently, drilling and site preparation entail significant energy and material inputs. This stage, based on conducted calculations, exhibits the highest global warming potential, with values between 5.2 and 30.1 kgCO2eq/MWhel, corresponding to approximately 65%, 86%, and 94% in terms of overall impacts for ecosystems, human health, and resources categories, respectively. Moreover, the study authors compared the EGS impacts for the Polish and Norwegian conditions. Obtained results indicated that due to much higher electricity output from the Norwegian plant, which is sited offshore, the environmental influence remains the lowest, at a level of 11.9 kgCO2eq/MWhel. Polish cases range between 38.7 and 54.1 kgCO2eq/MWhel of global warming potential in terms of electricity production. Regarding power generation only, the impacts in the case of the Norwegian facility are two to five times lower than for the installation in the Polish conditions. [ABSTRACT FROM AUTHOR]

The integration of digital technologies into forest management is crucial for the European Union's Green Deal, the Forestry Strategy 2030, and Italy's national forestry strategy, aiming to enhance governance and efficiency. However, sustainable forest management's administrative aspects are often overlooked, despite the potential for digital tools to significantly improve environmental performance. Through a Life Cycle Assessment (LCA) for a case study in the Umbria region, the research quantifies CO2 emissions associated with over-threshold forestry administrative procedures under both current and future digitalisation scenarios. Data were collected from legislative documents, interviews with forestry professionals, and emissions calculated according to ISO standards. The findings reveal a considerable reduction in CO2 emissions through digitalisation, from 75.07 kgCO2 to 38.14 kgCO2, with the implementation of the LIFE FOLIAGE project's digital platform. This underscores digitalisation's role in climate change mitigation, highlighting the significant, albeit modest per procedure, of the cumulative national impact. The main findings support further digitalisation in forest management as a method of increasing resource efficiency and reducing greenhouse gas emissions, thus contributing to the Green Deal's and Italy's forest sustainability goals. [ABSTRACT FROM AUTHOR]

Global concerns about climate change were once again expressed at the COP27 in Sharm El-Sheikh. Seaweed is frequently presented as a solution for climate mitigation. For a proper appraisal of its contribution to mitigating climate change, it is necessary to distinguish between, and critically scrutinize, the various pathways seaweed-based climate mitigations can take. This article identifies four different climate mitigation pathways and critically reflects on each. First, carbon sequestration, occurring when grown seaweed is left in the seas or, second, purposefully sunk. Third, carbon emission reduction, resulting when seaweed-based products replace products with a higher carbon footprint, either fossil based products or other organic material. Fourth, carbon emission avoidance, taking place when seaweed products are used to avoid greenhouse gas emissions in other production processes. Each of these pathways requires specific methods to quantify their magnitude and comes with critical questions to ask. The sequestration pathway requires monitoring of net carbon production and the amount of carbon that is eventually exported to the deep sea. Pathways 3 and 4 require Life Cycle Assessment and/or Carbon Footprint with system boundaries set to include the production system itself and installation thereof. We propose an unequivocal categorization in a belief that confusion on the benefits of seaweed will eventually impede development of seaweedbased solutions. [ABSTRACT FROM AUTHOR]

The study has as its original database the decarbonization process initiated in Mexico by the National Commission for the Efficient Use of Energy (CONUEE) as part of its "Savings Program of Electric Power in Buildings of the Federal Public Administration" (PAEIAPF) of 1999. The primary purpose of PAEIAPF was to reduce the levels of electric power consumption in Federal Government buildings. The program has operated for 20 years; however, its scope only reaches operational carbon. Since 90% of existing buildings will be in use by 2050, the Retrofit Models will be the base to determine solutions for a more resilient living environment that fortifies and extends the grid's capacity and meets climate change mitigation targets. Secondly, significant socioeconomic and profound environmental impacts are not calculated explicitly in existing tools and are often referred to as "secondary" or Non-Energy Benefits (NEB). "The goal is to give them a measurement value to be considered in the decision-making calculus. It is assumed that soon; such factors will enter the general climate change economy, not unlike carbon in the past decade." In this context, the proposed research aims to develop a value-based framework that will support a Building Stock Model and subsequent Retrofit Models, documented in a web-tool platform. The framework has three main steps: A) Building Stock Model: Mapping of selected buildings of the program PAEIAPF in a GIS system. Documentation of the baseline energy consumption and embodied CO2-eq of the existing building. B) Retrofit Models: Involving a Whole Life Cycle Assessment (WLCA) and Non-Energy Benefits (resilience coefficient, health, productivity). C) Web Tool Platform: Application and toolset that allows for consistent documentation, environmental impact evaluation of existing building stock, and solution design in identifying energy reduction concepts. [ABSTRACT FROM AUTHOR]

Construction is an important sector for climate action. The construction, operation and maintenance, demolition and disposal stages of house buildings consume many resources and have a significant impact on society, the economy and the environment. To assess such efforts, we propose the emergy footprint model of house buildings, which can quantitatively analyse the ecological effect in the house buildings life cycle. The research shows the following. China's ecological efficiency of the housing sector is characterized by improvement. In the house building fifty-year life cycle, the emergy footprint of the operation and maintenance stage is the largest (75.92%), followed by the construction stage (21.95%), but the emergy footprint intensity of the latter is 4.82 times that of the former. Reducing energy consumption and carbon dioxide emissions in the operation and maintenance stage is the key to reducing the life cycle emergy footprint of house buildings. The ecological impact coefficient of house buildings is negatively exponentially correlated with their service life. It reaches ecological break-even when the service period of the house building is equal to 36.73 years. If the house building is demolished after less than nine years of service, the impact is extremely unfavourable. [ABSTRACT FROM AUTHOR]

Air pollution in Thailand is regarded as a serious health threat, especially in the northern region. High levels of particulate matter (PM2.5 and PM10) are strongly linked to severe health consequences and mortality. This study analyzed the relationship between exposure to ambient concentrations of PM2.5 and PM10 by using data from the Pollution Control Department of Thailand and the burden of disease due to an increase in the ambient particulate matter concentrations in northern Thailand. This study was conducted using the Life Cycle Assessment methodology considering the human health damage impact category in the ReCiPe 2016 method. The results revealed that the annual average years of life lived with disability from ambient PM2.5 in northern Thailand is about 41,372 years, while from PM10 it is about 59,064 years per 100,000 population. The number of deaths from lung cancer and cardiopulmonary diseases caused by PM2.5 were approximately 0.04% and 0.06% of the population of northern Thailand, respectively. Deaths due to lung cancer and cardiopulmonary diseases caused by PM10, on the other hand, were approximately 0.06% and 0.08%, respectively. The findings expressed the actual severity of the impact of air pollution on human health. It can provide valuable insights for organizations in setting strategies to address air pollution. Organizations can build well-informed strategies and turn them into legal plans by exploiting the study's findings. This ensures that their efforts to tackle air pollution are successful, in accordance with regulations, and contribute to a healthier, more sustainable future guidelines on appropriate practices of air pollution act/policy linkage with climate change mitigation. [ABSTRACT FROM AUTHOR]

Millions of people in Asia and sub-Saharan Africa still lack access to power, which emphasizes the need for sustainable and clean energy solutions. This study attempts to address this issue by integrating a life cycle assessment (LCA) and a multicriteria decision-making (MCDM) analysis to determine the preferred energy technology for electrification. This research focuses on the environmental implications and long-term viability of various energy system options. The LCA evaluates midpoint characterization containing 18 environmental impact categories; the COPRAS and ARAS methods of MCDM analysis are then used to rank the energy alternatives based on their environmental performance. This study's key finding is that the gas-powered power plant is the most preferred energy system alternative, while the geothermal power plant is the least preferred. This midpoint characterization study provides in-depth insights into how various stages contribute to major environmental impact categories like global warming, ozone depletion, and ecotoxicity. By considering environmental impacts and sustainability requirements, informed decisions may be made to encourage clean and cost-effective power generation, thereby contributing to climate change mitigation and supporting economic growth and human development. Future research may include analysis from cradle-to-grave compared to cradle-to-gate. [ABSTRACT FROM AUTHOR]

Rising adverse impact of climate change caused by anthropogenic activities is calling for advanced methods to reduce carbon dioxide emissions. Here, we review adsorption technologies for carbon dioxide capture with focus on materials, techniques, and processes, additive manufacturing, direct air capture, machine learning, life cycle assessment, commercialization and scale-up. [ABSTRACT FROM AUTHOR]

The paper by Kiss and Szalay ([12]) titled I Sensitivity of buildings' carbon footprint to electricity decarbonization: a life cycle-based multi-objective optimization approach i examines how changes in electricity mix impacts GHG emissions. The Intergovernmental Panel on Climate Change (IPCC) emphasizes the need to immediately tackle climate change by significantly reducing greenhouse gas (GHG) emissions and capping global warming at 1.5 °C above pre-industrial levels (IPCC, [8]). The study found that total GHG emissions from maize production were on average 429 ± 27 kg CO2-eq/ton grain, with the highest emissions occurring during the dry season. This SI further contributes to raising awareness to the topic of measuring GHG emissions, decarbonization measures as well as climate neutrality. [Extracted from the article]

The building sector is responsible for a significant portion of global CO2 emissions and any attempt to meet global climate change mitigation goals requires dramatic reductions in CO2 emissions from building construction and use. Among the many green building certification programs intended to reduce the environmental impact of buildings, the passive house standards are one of the most stringent certifications with respect to reducing operational energy. While there is significant research demonstrating the reductions in operational energy use in passive house and passive house inspired buildings, there is comparatively little research into the embodied energy and embodied carbon emissions associated with these buildings. The aim of this research was to evaluate the relationship between embodied carbon emissions, operational carbon emissions, and overall carbon use intensity in passive house certified residential buildings, using a recently completed, multifamily passive house as a case study. First, the case study building was defined, and a partial life cycle assessment (LCA) was performed to evaluate the embodied and operational carbon emissions associated with this base case. Second, a catalog of alternative wall and roof assemblies were defined and the LCA of the case study was updated for each alternative assembly to assess the impact on the embodied carbon, operational carbon, and overall carbon use intensity. The results of this analysis indicate that the material composition of the exterior envelope assemblies can have significant impact on the overall, cumulative carbon impact of a particular building. Moreover, the results also indicate that there are clear scenarios in which operational energy efficiency should be sacrificed in favor of reducing upfront embodied carbon emissions, particularly when evaluated over critical time spans. Based on these results, this study recommends that green building standards and certifications, including passive house but also USGBC LEED, Living Building Challenge, and others, should place greater emphasis on embodied carbon and holistic carbon accounting in addition to operational efficiency. [ABSTRACT FROM AUTHOR]

This paper performs a thorough cradle to tank life cycle assessment to examine environmental impacts of Moringa oleifera derived biodiesel. Attributional LCA according to ISO 14040‐44, using CML‐IA baseline method, was conducted. Furthermore, Biodiesel versus petrodiesel comparison was undertaken. Moringa oleifera derived biodiesel shows a GWP of 39.94 gCO2eq/MJ of biodiesel, which presents a reduction of 52.34%, compared to petrodiesel. It revealed an EROEI value of 1.48, which can reach 3.20 with allocation applying, presenting an energy saving over petrodiesel of 53%. In addition, Ozone layer depletion impact of Moringa based biodiesel is lower than that of petrodiesel. This good performance notwithstanding, Moringa oleifera derived biodiesel exhibits high environmental impacts in terms of Abiotic Depletion of elements, Human Toxicity, Fresh water aquatic ecotoxicity, Marine aquatic ecotoxicity, Terrestrial ecotoxicity, Acidification, Eutrophication, respectively, 96.60%, 60.22%, 82.13%, 64.77%, 98.71%, 35.68% and 76.70% higher than those of petrodiesel. Nevertheless, coproducts valorization and ecofriendly inputs use could contribute efficiently to improve its environmental performances compared to petrodiesel. According to our results and comparison with other feedstocks based biodiesel, Moringa biodiesel could be used as a sustainable biofuel with a high contribution to climate change mitigation and fossil energy savings in addition to reduced environmental impacts. [ABSTRACT FROM AUTHOR]

Direct air capture (DAC) is an essential nexus of CO2 chemistry and climate mitigation. Life cycle assessment (LCA) is often used to validate the environmental potential of emerging technologies. Consequently, an increased number of ex ante LCAs is expected in this field. However, a comprehensive description through parameterized modeling of life cycle inventories of distinct technological pathways, which is essential for transparency, has recently been missing from the international literature. To fill this gap, the present study analyzes three selected DAC technologies to create an inventory. Amine‐based adsorption and absorption, as well as alkali‐based absorption, were modeled. The energy consumption of the operation, cradle‐to‐gate embodied energy, and sensitivity analysis based on parameter variations were carried out. The "cradle‐to‐gate" energy requirement of direct air capture (DAC) often lies in the range or above the formation energy of CO2 (8.94 GJ energy can be obtained by formation of 1 t CO2 from elementary C and O2). This indicates that theoretically more energy is required for capture, as can be obtained during the formation of CO2. Because energy has continuously growing economic and ecological value, this energy intensity of DAC implies that DAC might have important role in CCU to add directly measurable economic value. The parametrized model includes over 60 parameters, resulting in an array of possible energy and material requirements. The use of this wide range of figures in life cycle assessment (LCA) sheds light on real opportunities for DAC in future product systems. The option of varying parameters enables the tailoring of the calculation to a particular situation or design. In this way, the calculator offers a common base for LCA, fostering an early stage analysis of DAC technologies. [ABSTRACT FROM AUTHOR]

We present the results of a study on the climate forcing effects of replacing coal for power generation in the United Kingdom (UK) with wood pellets produced in northern Ontario, Canada. Continuous wood pellet production from two biomass sources were considered: fiber from increased harvesting of standing live trees (stemwood scenario) and from harvest residue provided by ongoing harvesting operations (residue scenario). In both scenarios, biomass was collected from harvesting operations in two forest management units (FMUs) with contrasting harvest residue treatments: natural decay of slash piles in the Hearst FMU and slash pile burning in the Kenora FMU. Life cycle emissions associated with wood pellets were assessed for production, transportation, and combustion to replace coal at a hypothetical power generating station in the UK. Greenhouse gas (GHG) emissions and removals in wood pellet and coal scenarios were assessed using two methods: global warming potential (GWP)-based mass balance and dynamic life cycle assessment (LCA) approaches. In the stemwood scenario, climate change mitigation from replacing coal with wood pellets was not achieved within the study timeline (2020–2100). In the residue scenario, immediate climate change mitigation was achieved with fiber sourced from the Kenora FMU where the current practice is to burn slash piles; for the Hearst FMU, where slash is allowed to decompose in the forest, climate change mitigation occurred 11.6 and 3.1 years after biomass collection began, as assessed by the mass balance and dynamic LCA methods, respectively. Factors affecting mitigation potential in the studied scenarios are discussed. [ABSTRACT FROM AUTHOR]

The mineralization of carbon dioxide offers a way to permanently sequester carbon while producing construction materials, combining the concepts of carbon capture and utilization (CCU) and carbon capture and storage (CSS). However, it is important to evaluate different mineralization processes in terms of their environmental impact. This study provides the first comparative life cycle assessment (LCA) analysis that focuses on the utilization of industrial waste materials. We analyzed the climate and material footprint of six mineralization pathways from cradle to gate using steel slag, concrete waste, municipal solid waste incineration (MSWI) ash, and olivine as feedstock. A sensitivity analysis was used to identify the factors with the greatest impact on environmental performance. Our results show that all processes generate significantly negative values for the global warming impact (GWI) and raw material input (RMI), ranging from −0.6 to −1.3 k g CO 2 eq. kg feed − 1 and −0.6 to −1.6 k g kg feed − 1 , when cement substitute is considered as product. Five out of six processes produce negative values for these factors when sand is considered as a product. When operated as a CCS technology without product use, the processes result in GWI values ranging from −0.13 to 0.01 k g CO 2 eq. kg feed − 1 . Our study confirms that industrial mineralization is a promising technology for reducing carbon dioxide emissions. Future process development should focus on replacing carbon dioxide-intensive products while balancing energy and chemical demand with process efficiency. [ABSTRACT FROM AUTHOR]

Oil palm dominates global oil production, trade, and consumption. Nigeria is one of the leading palm oil producers and consumers. A significant challenge of the palm oil industry is to reduce the environmental impacts (e.g. pollution and carbon footprint) and integrate a circular economy in operation. This study aims to comparatively quantify the environmental impacts of technologies used by different mills. We applied a life cycle assessment in the case of Nigeria. The study covers the reception and processing of fresh fruit bunch (FFB) to end-product palm oil. The inputs include generated empty fruit bunch (EFB), mesocarp fibre, palm kernel shell, palm oil mill effluent, diesel, water and all outputs to the environment for a functional unit of 1-tonne FFB. The results showed that large-scale mills perform worse (468 kg CO2-eq per t FFB) than the semi-mechanised and smallholder mills in effects on climate change but better in the other impact categories, including human toxicity, ecotoxicity, and fine particulate matter formation. In large-scale mills, the climate change impacts decrease by 75% when the raw palm oil mill effluent (POME) is used in composting EFB. Similarly, climate change impacts reduce by 44% when biogas from POME substitutes diesel in the semi-mechanised and smallholder mills. We conclude that regulatory measures are needed to ensure improved management practices in the production processes. Particular attention should be paid to the generation and reuse of biomass and POME. This study provides a handy reference to assist the sustainable energy transition in Nigeria's and other parts of sub-Saharan Africa's oil palm industry to mitigate climate change and form a cleaner bioeconomy. [ABSTRACT FROM AUTHOR]

Stringent climate change mitigation scenarios rely on large-scale drawdown of carbon dioxide from the atmosphere. Amongst drawdown technologies, bioenergy with carbon capture and sequestration (BECCS) has received considerable attention in the climate mitigation literature. Recently, attention has shifted further from a relatively narrow focus on BECCS to a broader focus on Biomass Carbon Removal and Storage (BiCRS). The concept of BiCRS has the potential to enable a future where the climate mitigation value of biomass resources is more valuable than the energy value, due to the potential to remove and sequester large quantities atmospheric CO2. This article provides a qualitative overview of prominent BiCRS technologies from which a set of the most promising technologies are assessed quantitively through life cycle assessment. There are numerous opportunities to incorporate carbon removal and management within the bioeconomy, but the majority of immediate carbon removal potential exists in four bioproducts: bioenergy, bioplastics, biochar, and wood products. We analyze the life cycle greenhouse gas emissions and disposition of sequestered carbon over 10 000 years for four bioproducts representative of each broader category: an advanced BECCS pathway, biopolyethylene, oriented strand board, and biochar soil amendment. We find that the BECCS pathway has the greatest magnitude and durability of CO2 storage over all time horizons. However, non-BECCS pathways achieve 34–64% of the drawdown magnitude relative to BECCS and retain 55–67% of their initial drawdown over 100 years (central estimate). We identify three engineering strategies for enhancing carbon drawdown: reducing biomass supply chain emissions, maximizing carbon stored in long-lived products, and extending the term of carbon storage. Finally, we highlight the need to characterize both the magnitude and permanence of carbon drawdown as a means for policymakers and technology developers to deploy limited biomass resources to maximize mitigation benefits. [ABSTRACT FROM AUTHOR]

Employments of highly durable low carbon technologies are crucial for mitigation of climate change ensuring sustainable infrastructures. In this perspective, a challenging initiative for ultra‐high durability low carbon prestressed concrete bridges utilizing sustainable zero cement concrete (STC‐ZERO) and non‐metallic reinforcement is undertaken. STC‐ZERO exhibiting high strength, low shrinkage, and low creep reduces carbon emission up to 70% compared to the conventional concrete as cement is entirely replaced. Aramid fiber PC tendons have no factor of deterioration of concrete thanks to nonexistence of corrosion. Accordingly, an AASTHO‐PCI BT‐72 PC girder bridge and a butterfly web bridge are designed incorporating this combination and compared with corresponding conventional bridges with respect to whole life carbon emissions. Since there are no repair and rehabilitation requirements, the whole life carbon emissions of next generation non‐metallic bridges are expected to be reduced by around 70%. [ABSTRACT FROM AUTHOR]

• Biogas upgrading is environmentally and energetically favourable over combustion. • Storage or utilisation of the captured CO 2 has larger savings than biogas upgrading. • Upgrading, CO 2 storage or utilisation perform well in all impact categories. • The energy system has a substantial impact on the environmental performance. • Methanation provides large climate change savings only in renewable energy systems. Biogas from anaerobic digestion is an important renewable energy source. Combining its utilisation with carbon capture and storage (CCS) or carbon capture and utilisation (CCU) may improve climate change performance. This study uses life cycle assessment to evaluate the environmental impacts of 17 biogas management technology configurations (TCs). The technologies include biogas combustion, upgrading to natural gas quality, CCS, direct utilisation of CO 2 and methanation. The focus is mainly on energy balances and climate change impacts, and the results are subjected to sensitivity-, uncertainty-, and energy system analysis. The TCs with CCS and CCU provide the largest climate change savings (-1400 to - 2100 kg CO 2 -eq/1000 Nm3 biogas). Specifically, the methanation TCs provide the highest savings, but they also depend strongly on the energy sources. When combustion and upgrading TCs are amended with CCS, the resulting climate change savings are robust across the energy systems. The biogas upgrading TCs exhibit substantial climate change savings, mainly due to the natural gas substitution. Combustion TCs without CCS have the lowest climate change savings and the highest quantified uncertainties. The biogas upgrading TCs with storage or direct utilisation of CO 2 provide a good compromise between climate change savings and energy recovery. In the remaining impact categories, the CCU TCs generally perform best, followed by the upgrading TCs and finally, the combustion TCs. The CCS TCs consistently perform worse than their counterparts without CCS, opposite to the climate change results. Overall, amending biogas utilisation with CCS or CCU can contribute to climate change mitigation. [ABSTRACT FROM AUTHOR]

This study aims to assess the comprehensive energy, environmental and economic performance of a retrofit zero energy building (ZEB). Three life cycle assessments were conducted: life cycle energy (LCE), life cycle carbon emissions (LCCE) and life cycle cost (LCC). Actual building construction cost data and energy use data were used in the assessments. The analysis results indicated that during the whole building life span, the operational life stage (B6) was a major contributor to LCE (82%) and LCCE (77%), but not to LCC (18%). Within the life cycle embodied carbon (LCEC), A3 was the life stage with the highest contribution (56%), which is mainly related to the manufacturing of building assemblies. This case study provides new empirical evidence of ZEB performance in the United States. The findings suggest that to achieve the carbon neutrality goal, current ZEB certifications or designations are not adequate to measure actual building performance. A further reduction of operational energy, in addition to reducing the embodied carbon released during manufacturing, should be the focus. [ABSTRACT FROM AUTHOR]

The concept of net-zero, climate-neutral buildings is attracting global attention, and it is widely recognised as a key solution for achieving climate neutrality targets in the construction sector. However, an increasing and confusing abundance of differing labels, definitions, and approaches is increasing worldwide. This article aims to chart the current progress of national net-zero building pathways and identify gaps and challenges that present a significant barrier to industry uptake and decarbonisation of the built environment worldwide. The national net-zero pathways include an analysis of building legislation, policy and voluntary frameworks in four selected countries, Norway, the United Kingdom, the United States and Singapore, which are all leading regional actors in the race to zero and achieving a climate-neutral construction sector. Firstly, the study provides an overview of each country-specific context and motivation related to climate change adaptation and mitigation in the construction sector. Secondly, a review of the essential features from market-leading net-zero definitions, methodologies, schemes, and tools describing specific building approaches is conducted in each investigated country. Finally, based on the selected net-zero building case studies, the article presents the most promising design strategies for both embodied and operational environmental impact reductions, considering each specific climatic and country context. The research results indicated that the system boundaries for embodied and operational indicators (energy or GHG emissions) presented in investigated net-zero frameworks vary significantly. Consequently, there is an urgent need for a harmonised and transparent standardisation to provide coherence through performed life cycle assessments of buildings. In terms of the design strategies for achieving net-zero ambition according to the investigated frameworks, the common approach is the integration of the passive and active design strategies for operational energy or GHG emission reduction. However, it is evident that in some net-zero building examples, the consideration of the embodied environmental impacts and potential reduction strategies is missing because of not being included and mandatory in the national net-zero framework. This work is built upon the current body of knowledge on existing net-zero building frameworks and already constructed buildings and provides practical indications for building policy development and environmental impact reduction strategies in future climate-neutral, net-zero building projects. • A review of the net-zero building frameworks in Norway, the United Kingdom, the United States and Singapore is presented. • Examines design strategies for embodied and operational environmental impact reductions based on net-zero building cases. • System boundaries and compensation options vary significantly among analysed net-zero frameworks. • Integrating climate mitigation measures with resilience design strategies is missing in the current net-zero frameworks. [ABSTRACT FROM AUTHOR]

Highlights: Among several approaches to circular economy and zero-waste concepts, biochar production is a great example and might be a way to push the economy to a carbon-neutral balance. Overall, despite all the differences in assumptions and methodologies adopted, LCA proved that biochar is a very promising way of contributing to carbon-efficient resource circulation, mitigation of climate change, and economic sustainability. What are the main findings?: Biochar is considered a black porous and carbon-rich matter; Biochar is a promising source of alternative energy. What is the implication of the main finding?: It can be concluded that the costs are closely related to the technologies used in biochar production and also to the feedstock used. Climate change and environmental sustainability are among the most prominent issues of today. It is increasingly fundamental and urgent to develop a sustainable economy, capable of change the linear paradigm, actively promoting the efficient use of resources, highlighting product, component and material reuse. Among the many approaches to circular economy and zero-waste concepts, biochar is a great example and might be a way to push the economy to neutralize carbon balance. Biochar is a solid material produced during thermochemical decomposition of biomass in an oxygen-limited environment. Several authors have used life cycle assessment (LCA) method to evaluate the environmental impact of biochar production. Based on these studies, this work intends to critically analyze the LCA of biochar production from different sources using different technologies. Although these studies reveal differences in the contexts and characteristics of production, preventing direct comparison of results, a clear trend appears. It was proven, through combining life cycle assessment and circular economy modelling, that the application of biochar is a very promising way of contributing to carbon-efficient resource circulation, mitigation of climate change, and economic sustainability. [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]

• Integrating carbon models for forest systems into a LCA of a building for detailed carbon dynamics when using wood in buildings. • Including temporal forest carbon dynamics shift the weight of environmental impacts between current and future emissions. • The results are highly sensitive to the modeling assumptions, in particularly the system boundaries, level of perspective, allocation principles. • Building design incentives remain similar when applying the method from the European standard or this study's approach. • Forest dynamics in LCA alter the environmental impacts of using wood in buildings and should be addressed in future recommendations for building LCAs. The urgent issue of climate change has sparked increasing interest in using wood to reduce buildings' greenhouse gas emissions (GHGe). While attributional life cycle assessment (LCA) methods are commonly employed to estimate GHGe from buildings, they lack a temporal distribution of carbon fluxes from biogenic materials, overlooking forest management impacts on emissions and sequestration. Consequently, we investigated the integration of forest and building systems, examining emissions associated with three different forest management scenarios at stand and landscape levels. Our findings suggest a 6 % to 81 % lower GHGe for the building using this study's approach compared to the static methodology recommended by the European Standard EN16485 in a 50 year perspective. However, the accumulated impact over the building's lifetime remains similar. Hence, both methods incentivize building designers' to use wood to lower GHGe, although the dynamic integration postpones benefits from the forests' carbon sequestration to later stages of the building's lifetime. [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]

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]

• Energy & chemical inputs, biogenic emissions, and product substitutions dominate environmental performance of biorefineries. • More transparency needed for product substitution modelling to avoid misleading conclusions. • Biogenic carbon capture use/storage could enhance future climate mitigation efficacy of biorefineries. • Accurate representation of biogenic carbon cycling essential to identify role of biorefineries in net zero strategies. Anaerobic digestion (AD) has gained attention in the last decade as a strategic component of the circular bioeconomy (CBE), and Life Cycle Assessment (LCA) has been used to explore the environmental performance of prospective AD-biorefineries. A detailed review of 76 studies underpinned systematic evaluation of environmental hotspots and LCA modelling challenges for AD-biorefinery configurations. Crops constitute the most frequently used feedstocks, while electricity, bioethanol, digestate, animal feed, additives, and platform chemicals represent the most reported products. Feedstock cultivation, energy and chemical inputs, biogenic emissions, and avoided burdens due to product substitution are the main drivers of environmental performance. However, modelling of product substitution, biogas upgrading, digestate management and biogenic carbon cycling is patchy, inconsistent, and often inadequately evidenced. Prospective and dynamic LCA coupled with transparent scenario analysis could address some of these shortcomings, and better represent, inter alia , the climate mitigation efficacy of carbon capture use and storage technologies integrated into AD-biorefineries. These findings provide a guide for LCA practitioners and researchers engaged in the study of biorefinery systems and other CBE measures. [ABSTRACT FROM AUTHOR]

Climate change mitigation trade-offs between increasing harvests to exploit substitution effects versus accumulating forest carbon sequestration complicate recommendations for climate beneficial forest management. Here, a time dynamic assessment ascertains climate change mitigation potential from different rotation forest management alternatives across three Swedish regions integrating the forest decision support system Heureka RegWise with a wood product model using life cycle assessment data. The objective is to increase understanding on the climate effects of varying the forest management. Across all regions, prolonging rotations by 20% leads on average to the largest additional net climate benefit until 2050 in both, saved emissions and temperature cooling, while decreasing harvests by 20% leads to the cumulatively largest net climate benefits past 2050. In contrast, increasing harvests or decreasing the rotation period accordingly provokes temporally alternating net emissions, or slight net emission, respectively, regardless of a changing market displacement factor. However, future forest calamities might compromise potential additional temperature cooling from forests, while substitution effects, despite probable prospective decreases, require additional thorough and time explicit assessments, to provide more robust policy consultation. [ABSTRACT FROM AUTHOR]

Three million sheep raised on 10 000 active farms operating in traditional and innovative farming systems in Sardinia, Italy, account for 13% of sheep milk production in the European Union (EU). Almost all of the milk delivered is processed to sheep cheese and is destined for world trade. The Sardinian dairy sheep sector also emits approximately 1600 kt CO2eq/year, approximately 60% of regional livestock greenhouse gas (GHG), prompting the need for regional mitigation plans. The SheepToShip LIFE project (EU‐LIFE Climate Change Action 2014–2020) is a regional case study to test emission mitigation strategies. Based on the SheepToShip LIFE findings, this paper presents a systems perspective against the backdrop of the Sustainable Development Goals (SDGs) framework, with the aim of underlining system interlinkages between environmental, societal, and economic objectives. The project included (i) a life cycle thinking approach featuring environmental and socioeconomic traits of 18 sheep farms, (ii) on‐farm implementation and demonstration of eco‐innovative mitigation techniques indicating the most viable actions to reduce impact, (iii) focus groups discussing beliefs and reactions of the main stakeholders, and (iv) group model building producing a causal loop diagram from a systems thinking approach and exploring insights for regional policy‐making that aligns with the SDGs. Causal links connect public interventions and stakeholder interaction (SDG 17) to boost farm eco‐innovations (SDGs 9 and 8) and education and farmer training (SDG 4), and they foster efficient production (SDG 12) and high‐quality food provisioning (SDG 2). These benefits contribute to climate change mitigation (SDG 13), water quality (SDG 6), and farm ecosystem services (SDG 15). Integr Environ Assess Manag 2022;18:1187–1198. © 2022 SETAC Key Points: The methodological integration of life cycle Assessments and qualitative systems modeling allows an accurate problem definition for complex sustainability challenges.The solutions derived from the introduced methodological journey provides insights for better decision‐making. [ABSTRACT FROM AUTHOR]

The forestry sector is crucial in supporting climate change mitigation, where the mitigation potential is assessed by combining forest carbon analysis and wood product life cycle assessment (LCA). Static LCA (sLCA) is the approach commonly used in national forestry mitigation models worldwide. Static GHG effects are calculated as a running total of emissions and removals, which are often used to imply climate effects. Also, carbon neutrality, a state when the GHG effects equal zero, is used to imply neutral climate effects. However, until carbon neutrality is achieved, the increased emissions contribute to climate warming. Dynamic LCA (dLCA) is an improved method to estimate climate effects by considering the atmospheric dynamics and heat trapping capacity of different GHGs. Climate neutrality is a state when the warming effects caused by increased emissions are fully compensated by warming reduction contributed by removals. We applied dLCA and sLCA to China‐made wood‐based panels produced from 1990 to 2018 by harvesting poplar plantations. Our results suggested that, compared to dLCA results, static GHG effects largely underestimated climate warming effects or overestimated mitigation contributions. Also, decades or longer was required to achieve climate neutrality following carbon neutrality, if achievable. So, within a given timeframe, a forestry mitigation activity can achieve carbon neutrality but increase climate warming, hindering the goal of limiting global temperature rise that was set in the 2015 Paris Agreement. Thus, to assess climate warming effects, using dLCA in addition to GHG effects is essential for forestry mitigation analysis. [ABSTRACT FROM AUTHOR]

In this work, a Carbon Footprint (CF) calculator developed by authors to the tourism sector in Portugal, was validated. The CF calculator self-validation was based on the comparison of the results obtained with two tools available online (Carbon Footprint Ltd-CFL and Climate Care-CC) and with a Life Cycle Assessment (LCA) performed using the SimaPro PhD software. The calculator is based in the CO2e (carbon dioxide equivalent) emissions of 6 components: electricity, water, laundry, fuels, waste and food. These tools were applied to a 3 stars Hotel, located in Viseu region (Portugal) with 50 guests' rooms and an occupied area of 1500m² . CF results attained with calculator developed were slightly higher than CFL and lower than CC results, as it has a different emission from electricity component. For LCA two scenarios were considered, Scenario 1 (same assumptions as CF calculator) and Scenario 2 (assumptions based on LCA methodology) a higher emission was obtained of more than 23975.7 kgCO2e/year and 72680 kgCO2e/year, respectively. For both scenarios the difference was caused by electricity consumption component and additional by fuel consumption in Scenario 2. The emission factors chosen used for each component were the main responsible for these differences. Self-validation process demonstrated that the CO2e emissions from the different tools were very similar when the same assumptions were considered, so the calculator is consistent. [ABSTRACT FROM AUTHOR]

Direct air capture (DAC) is critical for achieving stringent climate targets, yet the environmental implications of its large-scale deployment have not been evaluated in this context. Performing a prospective life cycle assessment for two promising technologies in a series of climate change mitigation scenarios, we find that electricity sector decarbonization and DAC technology improvements are both indispensable to avoid environmental problem-shifting. Decarbonizing the electricity sector improves the sequestration efficiency, but also increases the terrestrial ecotoxicity and metal depletion levels per tonne of CO2 sequestered via DAC. These increases can be reduced by improvements in DAC material and energy use efficiencies. DAC exhibits regional environmental impact variations, highlighting the importance of smart siting related to energy system planning and integration. DAC deployment aids the achievement of long-term climate targets, its environmental and climate performance however depend on sectoral mitigation actions, and thus should not suggest a relaxation of sectoral decarbonization targets. New study concludes that environmental tradeoffs of direct air capture and sequestration technologies are linked to the energy system in which they will operate, and their deployment should not equate to a relaxation of decarbonization or resource use efficiency targets. [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]

Preservation and promotion of agroforestry systems entails the ideology for more ecosystem services, additional biodiversity benefits and climate change mitigation. Furthermore, farmland and forest landscapes and the consequent benefits to the environment from their combination, enhance the importance of agroforestry systems towards sustainable environmental policies. Nevertheless, traditional agroforestry systems face significant adaptation problems, especially in the EU, due to continuous economic reforms and strict agri-environmental measures. In this context our main goal is to assess the current managerial framework of two agroforestry systems and more specifically the olive agroforestry practices in Northern Greece. The economic and environmental implications of four different production plans are highlighted following the Life Cycle Costing and the Life Cycle Assessment protocols. The production plans include the simultaneous cultivation of annual crops, such as vetch and barley, along with olive groves. Potential environmental impacts are depicted in CO2 equivalents, while the economic allocation of costs is divided in targeted categories (e.g., raw materials, labor, land rent, etc.). The results indicate significant deviations among the four production plans, with the combination of olive trees and barley being heavily dependent on fertilization. Furthermore, the open-spaced olive trees intercropped with a mixture of barley and commonly depicted the lowest CO2 eq. emissions, though the economic cost was significantly higher than the other agroforestry system intercropped with barley only. The authors suggest that the formulation of a decision support system for agroforestry systems should be taken into account in order to preserve current agroforestry systems. [ABSTRACT FROM AUTHOR]

The implementation of oxyfuel carbon capture and storage technologies in combination with use of alternative fuels comprising high biogenic shares is promoted as an attractive climate change mitigation option for the cement sector to achieve low or even negative carbon emissions. Here, we perform a prospective life cycle assessment of two state-of-the art cement plants, one in Sweden and one in Germany, under conventional and retrofitted oxyfuel conditions considering alternative fuel mixes with increasing bio-based fractions of forest residues or dedicated bioenergy crops. The analysis also considers effects of the projected changes in the electricity systems up to 2050. Retrofitting the cement plants to oxyfuel reduces climate change impacts between 74 and 91%, while with additional use of biomass as alternative fuel the cement plants reach negative emission between − 24 and − 169 gCO2eq. kgclinker−1, depending on operational condition, location, and biomass type. Additional emission reduction of − 10 (Sweden) and − 128 gCO2eq. kgclinker−1 (Germany) are expected from the decarbonization of the future electricity systems. Retrofitting the cement plants to oxyfuel conditions shows trade-offs with other environmental impacts (e.g., human toxicity, water and energy depletion), which are partially offset with projected changes in electricity systems. Our results illustrate the large climate change mitigation potential in the cement sector that can be achieved by the implementation of oxyfuel carbon capture and storage and biomass use as alternative fuel. [ABSTRACT FROM AUTHOR]

Decision support tools for incentivizing environmentally sound decisions in building design, such as LCA (life cycle assessment), have been highlighted as an essential feature for enhancing the realization of more sustainable buildings. Nevertheless, the use of LCA to support decisions in building design is still limited in practice. A better understanding of the social dynamics and detailed contexts of the decisions leading up to a final building design is therefore critical for better integration of LCA-based information in the decision-making processes. This paper reports a qualitative, semi-structured interview study of single-family home producers in Sweden and their decision-making in relation to climate mitigation, with a particular focus on embodied carbon mitigation. By studying a specific branch of the building and construction sector, a more in-depth record can be obtained of the particularities of implementation contexts and decision-making situations in which LCA may, or may not, have a role in driving climate mitigation. Four primary decision contexts in which LCA may have an influential role to drive embodied carbon reduction include: (1) the development of building systems, (2) development and offering of house models, (3) the selection of construction products for the building system as well as for the offer of add-on products to customers, and (4) the dialogues in the individual house-buyer projects. Decision-making that affects sustainable outcomes in this part of the sector is very much dependent on a supporting regulatory context. Over the years, using building LCA in early design stages, for optimization towards low-impact final buildings, has been a repeatedly promoted recommendation both in academia and practice. This study, however, reveals that such a conclusion is too simplistic. The different overarching decision contexts identified for this particular branch display the variety of needs for life cycle-based information. [ABSTRACT FROM AUTHOR]

This research aims to explore the current evidence on the sustainability of Bioenergy with Carbon Capture and Storage under a life cycle approach and to understand how research on this topic has evolved in the last decade. A systematic literature review was performed, and the main focus was identifying methodological shortcomings and analysing Global Warming Potential results. Forty-seven studies were selected for in-depth revision. Results show that the number of Life Cycle Assessment (LCA) studies on BECCS has increased in the last couple of years and that most of these studies report near-carbon neutral or carbon-negative results for electricity, biofuel energy, and other products. However, in many cases, some aspects have been omitted from the discussion, such as proper accounting of land use impacts, impact allocation procedure, accounting of leakage from storage sites, and impacts related to carbon utilisation. Despite this methodological variability, Global Warming Potential results are mostly carbon-negative and carbon-neutral for both power BECCS and industrial BECCS systems. Consequently, current scientific evidence suggests climate change mitigation benefits from BECCS despite methodological variability. However, it is still insufficient to reach a consensus on the sustainability of this technology as a solution for a global energy transition. It is recommended that further LCA research deals carefully with methodological and product systems variability, which may affect environmental impact results. Moreover, carbon capture approaches with high potential benefits should be further analysed, and the most optimal BECCS typologies should be identified. Finally, additional life cycle impact categories should be reported, along with the assessment of the economic and social dimensions of BECCS. [Display omitted] • Life Cycle Assessment (LCA) of Bioenergy with Carbon Capture and Storage (BECCS) was reviewed. • LCA methodology choices were discussed. • Global Warming Potential ranges between −3.873 and 0.366 kg CO 2 eq per MJ. • Current evidence is insufficient to confirm that BECCS is a sustainable solution for climate change mitigation. [ABSTRACT FROM AUTHOR]

Tackling climate change remains a critical challenge for society. Achieving climate neutrality requires a massive expansion of renewable energies such as wind and photovoltaics (PV). Agriculture plays a key role in this context, especially as the expansion of ground-mounted PV systems often leads to land-use conflicts. Agrivoltaics (AV), which combines agricultural and electricity production, can be a solution, but the synergies are particularly dependent on local agronomic conditions. There is also a knowledge gap in how AV expansion impacts greenhouse gas (GHG) emissions at the landscape level and how it contributes to regional emission reduction targets. In this study, we analysed the economic and climate change mitigation impacts of AV expansion pathways in the German state Baden-Württemberg using an integrated land use model and life cycle assessment under the assumption of general rentability of electricity production by AV. We found that implementing AV on 1%–5% of the regions's arable and grassland area reduced the total agricultural gross margin by a maximum of approximately 0.5%. Concurrently, AV implementation reduced GHG emissions by about 1.2 million to 5.9 million metric tons of CO 2 equivalent (Mt CO 2 -eq). Even if this reduction is almost exclusively accounted for in the energy sector, in absolute terms it amounts to more than the current GHG emissions from Baden-Württemberg's agricultural sector (about 4.4 Mt CO 2 -eq in 2021). In the 5% expansion scenario, almost 90% of the installations were installed on grassland, but this share dropped to 72% when considering landscape quality constraints. Although we found considerable regional disparity, our findings still suggest that AV is an essential component for regional emission reduction targets. These results are particularly relevant for policymakers in spatial planning, agricultural and energy policy. • We analysed impacts of Agrivoltaics (AV) on regional greenhouse gas (GHG) emissions. • Spatial placement was optimised from agricultural and landscape quality perspective. • AV on 5% of Baden-Württemberg's agricultural land reduced up to 5.5 Mt CO 2 -eq. • AV systems were mostly implemented on grassland. • From an agricultural perspective, AV can be a cost-effective GHG mitigation measure. [ABSTRACT FROM AUTHOR]

Existing assessments of climate mitigation technologies, like carbon capture utilisation and storage (CCUS), often rely on life cycle assessments (LCA), which are helpful for quantification but may not always be the most complete tools for decision-making. The novel contribution of this study is to provide the first application of a consequential carbon accounting approach, presented as a time-series analysis, to measure the system-wide change in emissions from CCUS linked to CO 2 -enhanced oil recovery. This method includes emissions from marginal oil production, a variable typically excluded in other LCA methods. The method was applied to a hypothetical CCUS project in Mexico to understand critical factors determining whether such an intervention can effectively contribute to emissions reduction in alignment with net-zero goals. Four intervention scenarios were assessed, comparing two distinct CO 2 injection strategies in oil reservoirs (water alternating gas and continuous gas injection) and two energy policy scenarios (current and sustainability). The findings suggest that the energy grid's role in overall emissions is relatively minor, with only a ∼2% difference between the compared scenarios, in contrast, the injection strategy has a significant impact on emissions. Scenarios 1 and 3 report a total change in emissions of −28.39 and −29.87MtCO 2 e, and scenarios 2 and 4 account for −19.63 and −21.22MtCO 2 e, respectively. The results highlight the importance of conducting system-wide analysis and comparing different scenarios to identify the critical components that drive changes in emissions and, therefore, support decision-making and project planning. • Consequential carbon accounting quantifies the system-wide change caused by CCUS. • A time-series provides decision-relevant information on climate change mitigation. • Market-mediated effects are highly relevant for CCUS projects. • CCUS is not consistent with net zero due to as remaining emissions. [ABSTRACT FROM AUTHOR]

• Solar thermal systems for buildings: environmental life-cycle assessment and policy. • Materials with considerable impacts on human health/ecosystems have been identified. • By involving recycling, appreciable reduction in these impacts can be achieved. • During the phase of usage, solar thermal systems offer considerable avoided impacts. • The avoided impacts based on the electricity mixes of Spain and Italy are presented. Solar thermal systems play a pivotal role in the building sector. However, for the development of sustainable energy systems, different parameters should be taken into account. The present article sets out to present a multidimensional approach. To this end, the first part of the article discusses energy policies, placing emphasis on solar thermal applications. The second part of the article is based on Life Cycle Assessment (LCA) and evaluates the environmental performances of a thermal-energy-storage device and other components appropriate for solar thermal systems for buildings. The analysis has been based on global warming potential, cumulative energy demand, ReCiPe and USEtox. The results show that steel and copper are the materials which are responsible for the major part of the storage-device impact. Based on ReCiPe endpoint/with characterisation, steel and copper present 2.2E-03 DALY (damage to human health) and 5.9E-06 (species.yr) (damage to ecosystems). The results show that the metallic components have the highest environmental impacts. By involving recycling, a remarkable reduction in these impacts can be achieved. Issues related to building-integrated solar systems and future prospects are also discussed. Moreover, the avoided impacts due to the use of a solar thermal system instead of using a conventional electric heater for hot water production have been evaluated, considering multiple environmental indicators. The results based on the Spanish electricity mix have been compared with those based on the Italian electricity mix. In both cases, the findings verify that solar thermal systems offer considerable avoided environmental impacts. [ABSTRACT FROM AUTHOR]

The renewal of old bridges is sometimes restricted to avoid the high carbon emissions caused by materials and construction, which however might not be conductive to climate change mitigation due to their insufficient functions. In order to facilitate the optimization of renewal timing and strategy from the perspective of reducing the comprehensive global warming impacts, we put forward the low-carbon bridge renewal decision method referring to the ideas of consequential life cycle assessment (LCA) and dynamic LCA. In the proposed method, a comparative system boundary matching the bridge renewal characteristics is constructed, where the carbon emission reduction owing to the traffic efficiency improvement by functional updating is incorporated as the low-carbon benefits of renewal, and three types of time-dependent factors, i.e., time-dependent characterization factor, trend factors and changes of traffic demands, are introduced to characterize the influence of renewal timing. The proposed method provided guidance for the renewal of Maogang Bridge, the first long-span cable-stayed bridge in Shanghai. Results illustrate that the global warming impacts of renewal construction activities and the low-carbon benefits from functional updating decrease with the renewal timing. For Maogang Bridge, the rapidly increasing traffic demands inevitably advocated renewal in advance, and the reduction of global warming impacts from emission reduction or carbon uptake could be manifested for renewal in advance. Adopting material recycling in the disposal of old bridge helped reconstructing a new bridge while deconstructing the old one in 2019 becoming the finally selected low-carbon renewal strategy, which is expected to reduce 15.04 kt CO 2 e-2019 compared to the essential renewal in 2050 with the landfill disposal method. The robustness of the strategy choice has been justified, given the variations of analytical time horizon, expected emission trends and repair emissions. In this way, the low-carbon renewal decision method could build a quantitative basis for judging the urgency of functional updating and verifying the low-carbon benefits of immediate concrete recycling in up-coming urban renewals. • Low-carbon bridge renewal decision optimizes renewal timing and strategy. • System boundary is expanded for quantifying benefits from functional updating. • Emission trends and time-dependent characterization factors are explored. [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]