Environmental Impact Indicators Research Articles

Life Cycle Assessment Introduced by Using Nanorefrigerant of Organic Rankine Cycle System for Waste Heat Recovery

The use of nanorefrigerants in Organic Rankine Cycle (ORC) units is believed to affect the cycle environment performance, but backed with very few relevant studies. For this purpose, a life cycle assessment (LCA) has been performed for the ORC system using nanorefrigerant, the material and energy input, characteristic indicators and comprehensive index of environmental impact, total energy consumption and energy payback time (BPBT) of the whole life cycle of ORC system using Al2O3/R141b nanorefrigerant were calculated. Total environmental comprehensive indexes reveal that ECER-135 index decrease by 1.5% after adding 0.2% Al2O3 nanoparticles to R141b. Based on the contribution analysis and sensitivity analysis, it can be found out ORC system manufacturing is of the most critical stage, where, the ECER-135 index of ORC component production is the greatest, followed by the preparation process of R141b, transportation phase, and that of Al2O3 nanoparticles preparation is small. The retirement phase which has good environmental benefits affects the result significantly by recycling important materials. Meanwhile, the main cause and relevant suggestion for improvement were traced respectively. Finally, the environmental impacts of various power generations were compared, and results show that the power route is of obvious advantage. Among the renewable energy, ORC system using Al2O3/R141b nanorefrigerant with minimal environmental impact is only 0.67% of coal-fired power generation. The environmental impact of current work is about 14.34% of other nations’ PV results.

Innovative technologies of environmentally sound design exemplified by new airport complex in Western Yakutia

The article considers such a relevant problem as innovative technologies of environmentally sound design of Mirny Airport. Mirny Airport provides air communication with the largest cities of Russia. It is also a reserve airport for transcontinental routes from North America and Europe to Asia. The article develops a methodological approach to the environmentally sound design of Mirny Airport, taking into account low-waste and zero waste technologies. Unlike the existing ones, the design is based on the continuous monitoring of the corresponding technology parameters. A system of indicators for assessing the environmental efficiency of sound airport design, taking into account industrial waste treatment, is proposed. The authors imply the system shall include management efficiency indicators, performance indicators and environmental impact indicators of sound airport design. The theoretical basis of the article includes scientific methodological and theoretical developments of domestic and foreign scientists, theorists and practitioners in the area of environmentally sound design revealing issues related to the adoption of management technologies for minimizing the negative environmental impact by airlines. The following research methods were used in the article: analytical, economic-statistical, monographic, computational-constructive, graphical method, abstract-logical.

Life cycle sustainability assessment and circularity of geothermal power plants

Geothermal power generation is expected to increase fivefold worldwide by 2040 compared to 2018. The upcoming growth of geothermal power plants (GPPs) requires assessments of its role in tackling climate change and other impacts within complex environmental, economic and social systems. This study presents the first literature review of GPPs, including comparisons among different GPP technologies, based on life cycle sustainability and circular economy perspectives. A total of 76 core literature studies on geothermal-related topics are reviewed, including technology choices, and critically discussed in terms of their environmental, economic, social and circular economy aspects. Firstly, seven life cycle environmental impact indicators (global warming, acidification, eutrophication, human toxicity, ozone depletion, photochemical oxidation, and cumulative energy demand) are compared both within GPP technologies and to other conventional electricity generation technologies (such as coal and hydro). Secondly, economic sustainability is considered via life cycle costing, and the results show that geothermal could be economically competitive when compared to solar photovoltaic (PV), hydro, and even wind energy sources. Thirdly, social aspects are discussed considering 15 articles that evaluated concerns such as public acceptance, technology safety and local employment rate, although none rigorously considered a life cycle approach. Lastly, a total of 12 articles were found linking the circular economy with GPPs and elaborating on some of the ‘9Rs’ framework. To improve the effectiveness of future research, studies should focus on fulfilling major data gaps in literature such as the lack of detailed documentation for specific materials and background process choices in life cycle assessment databases. The development of GPPs can be an important alternative in efforts to decrease climate change impacts and pursue cleaner energy sources in countries where geothermal energy is more easily available.

Bio-based building material solutions for environmental benefits over conventional construction products – Life cycle assessment of regenerative design strategies (1/2)

The focus in reducing environmental impacts of buildings is shifting from the operational stage to the full life cycle, with particular attention to embodied greenhouse gas (GHG) emissions of construction materials. The application of bio-based construction materials is promoted for potentially reducing material-related embodied GHG and even enabling carbon fixation.In part one of this study (1/2), we apply life cycle assessment (LCA) to critically examine regenerative design strategies, starting by investigating embodied GHG emissions as well as other environmental impact indicators of different bio-based building element variants – assessing timber-, straw- and hemp-based solutions – in a European context.The results show that bio-based building elements tend to have considerably lower embodied GHG emissions than conventional solutions, e.g. brick or concrete-based elements. Analyzing the environmental hotspots across the life cycle of selected bio-based construction options, we identify their most contributing environmental indicators to be global warming potential (GWP), particulate matter (PM) and land use (LU); and the most important life cycle stages to be material production, maintenance and replacement, particularly of finishes. To investigate carbon removal potentials, we calculated biogenic carbon contents of selected bio-based options, identifying straw-based building elements as the most promising solution due to high biogenic carbon content and fast (yearly) re-growth cycles.Our study highlights the environmental potentials of using bio-based construction solutions to substitute conventional building materials. In addition, the study identifies important environmental trade-offs within bio-based material alternatives that demand consideration and further study in future research.

Exploring the Missing Link between Life Cycle Assessment and Circularity Assessment in the Built Environment

The built environment—with its significant environmental impact and long lifespan—is a key sector in which to implement circular economy principles. So far, however, a coherent framework with circularity indicators has not yet been established. While Life Cycle Assessment (LCA) is commonly practiced to quantify the total environmental impact, it is designed and intended to assess linear life cycles, making it unsuitable for circularity assessment. Thus this paper explores an objective method to link LCA to a semi-quantified circularity indicator. Four variants of external wall designs of two case studies are analyzed. The explored possibilities of linking LCA results or mass input flows to the circularity indicator show differences in outcome. Furthermore, the analysis shows that decision-making can be affected by choice of assessing only a circularity indicator, an environmental impact indicator, or mass input flows, as opposed to a scenario in which a linked approach of these parameters is applied.

Testing the sensitivity of stated environmental preferences to variations in choice architecture

We conducted a three-way split sample discrete choice experiment (DCE) to investigate welfare estimates for attributes related to the management of coastal cod stocks in Arctic Norway. In a base DCE design, respondents faced three core attributes: (1) coastal cod spawning biomass as an indicator of the sustainability of the cod stocks, (2) stricter regulations on primary user groups (commercial fishers, local recreational anglers, the marine fishing tourism industry), and (3) annual household cost. In two experimentally varied DCE designs, respondents received a fourth attribute that explicitly describes the expansion of the marine fishing tourism industry in the region. In treatment 1, the expansion is represented by the number of coastal cod caught by marine fishing tourists as an indicator of the industry's environmental impact. In treatment 2, the expansion is represented by the number of new jobs as an indicator of the industry's socioeconomic impact. These two attribute translations, designed to be perfectly correlated, serve as an instrument for testing a choice architecture - value activation framework recently proposed in the management science literature. Mixed logit estimation results indicate that welfare estimates vary significantly across choice architectures, both statistically and economically. Additional regression analyses of conditional welfare estimates and respondents' status quo choices yield mixed evidence of value activation. The overall message of the study is that DCE researchers should be cognizant of their role as choice architects when advising public resource managers and policymakers.

Environmental impacts of corn silage production: influence of wheat residues under contrasting tillage management types

The intensification of specific land management operations (tillage, herbicide, etc.) is increasing land degradation and contributing to ecosystem pollution. Mulches can be a sustainable tool to counter these processes. This is particularly relevant for rural areas in low-income countries where agriculture is a vital sector. In this research, the environmental impact of different rates of wheat residues (no residues, 25, 50, 75, and 100%) in corn silage cultivation was evaluated using the life cycle assessment (LCA) method under conventional tillage (CT) and no-tillage (NT) systems in a semi-arid region in Karaj, Iran. Results showed that in both tillage systems, marine aquatic ecotoxicity (ME) and global warming potential (GWP) had the highest levels of pollution among the environmental impact indicators. In CT systems, the minimum (17,730.70 kg 1,4-dichlorobenzene (DB) eq.) and maximum (33,683.97 kg 1,4-DB eq.) amounts of ME were related to 0 and 100% wheat residue rates, respectively. Also, in the CT system, 0 and 100% wheat residue rates resulted in minimum (176.72 kg CO2 eq.) and maximum (324.95 kg CO2 eq.) amounts of GWP, respectively. However, in the NT system, the 100% wheat residue rate showed the minimum amounts of ME (11,442.39 kg 1,4-DB eq.) and GWP (120.21 kg CO2 eq.). Also, in the NT system, maximum amounts of ME (17,174 kg 1,4-DB eq.) and GWP (175.60 kg CO2 eq.) were observed with a zero wheat residue rate. On-farm emissions and nitrogen fertilizers were the two factors with the highest contribution to the degradation related to environmental parameters at all rates of wheat residues. Moreover, in the CT system, the number of environmental pollutants increased with the addition of a higher wheat residue rate, while in the NT system, increasing residue rates decreased the amount of environmental pollutants. In conclusion, this LCA demonstrates that the NT system with the full retention of wheat residues (100%) is a more environmentally sustainable practice for corn silage production. Therefore, it may be considered one of the most adequate management strategies in this region and similar semi-arid conditions. Further long-term research and considering more environmental impact categories are required to assess the real potential of crop residues and tillage management for sustainable corn silage production.

An environmental and economic assessment of sustained cleaner production for double rice from the combination of controlled-released urea and water-saving irrigation

Controlled-released urea (CRU) and water-saving irrigation are being extensively used to obtain higher rice (Oryza sativa) yields with lower greenhouse gas emissions. However, the environmental impact potential of their combined impacts is still unknown. Two-factor experiments, nitrogen practices with urea and CRU while irrigation practices with conventional irrigation (CI) and alternate wetting-drying water-saving irrigation (AWD), were used to clarify the potential impacts in the Jianghan Plain in China. Life cycle assessment (LCA) methodology was used to examine seven environmental impact categories, including non-renewable energy depletion, global warming potential (GWP), acidification potential, eutrophication potential (EP), human toxicity potential, freshwater toxicity potential (FTP) and soil toxicity potential in addition to an economic assessment. The largest contribution allocated to the comprehensive environmental impact indices included the GWP, EP (>26.28%) and FTP (>62.14%), while the other four indices contributed little, and CRU + AWD had the lowest weighting value (0.7981). The EP was affected by N fertilizer off and on the farm (7% and 68%–71%), nitrous oxide emissions from the planting season and winter fallow (7%–12% and 8%–12%) and the FTP differed slightly among the four treatments. Net ecosystem economic benefits (NEEB) (approximately 15,541 CNY ha−1) and benefit-cost ratio (52%) of CRU + AWD was similar to those of CRU + CI, and were increased by 18%–47% and 11%–41% compared with U + CI and U + AWD, respectively. Trade-off results found the combination of CRU and AWD had the lowest environmental load with a high grain yield, economic benefits and soil organic carbon storage to enable the sustainable production of rice.

Menstrual products: A comparable Life Cycle Assessment

The goal of this paper is to provide a guide for environmentally-friendly menstrual product options for industry, governmental policy makers and consumers. We present the results of comparative analyses of such products—disposable nonorganic and organic tampons (with applicators) and pads, reusable pads, underwear and cups—used for one year across eight environmental impact indicators and three countries, France, India and the U.S. The Life Cycle Assessment (LCA) methodology was applied to estimate the environmental impacts accounting for the entire life cycle beginning with the production of the components and ending with their disposal. Varying consumer habits in the considered countries led to differences in the environmental impacts between countries. Menstrual cups have the lowest impact score across all indicators and countries, with a score 99% lower than those for disposable nonorganic tampons. Menstrual underwear ranked second, given their double functions as underwear and menstrual absorbent. Reusable pads ranked third lowest. Somewhat surprisingly, organic disposable pads had higher scores than their nonorganic counterparts for the majority of indicators. For more realistic use scenarios, we explored combinations of two products (one internal and one external). Menstrual cups in combination with underwear had the lowest scores across all indicators and countries. • Reusable menstrual products have significantly lower environmental impacts than disposable ones. • Disposable organic products have higher environmental impacts than nonorganic ones. • Combining two products (internal and external) ensures more realistic results. • Country-specific behaviors influence environmental impact estimates.

Production of sustainable self-consolidating mortar with low environmental impact.

Reusing industrial by-products and agricultural waste as supplementary cementitious materials for producing sustainable concrete is one of the most promising ways to reduce cement production and the detrimental effects of concrete constructions on the environment. However, when it comes to preparing self-consolidating concrete (SCC) and mortar (SCMO) containing such materials in high volume, bleeding, and segregation of theirfresh mixture are the crucial factors hindering theirlarge-scale application. In this regard, the main aim of this study is to address such issues by designing sustainable SCMO using ground granulated blast furnace slag (GGBS) in high volume and rice husk ash (RHA) with comparatively lower environmental impact and high quality. To achieve this goal, the workability of fresh mixture and all its three main characteristics, including segregation resistance, passing ability, and filling ability, were evaluated with recently developed empirical apparatuses. For this purpose, 12 mixtures with different compositions were prepared to investigate the fresh properties, compressive strength, setting time, and environmental impact index. The results indicate that there are inextricable links between mixing proportions, strength, and carbon emissions of the mixture. Sustainable SCMO with an embodied-CO2 index lower than 4.5kg/MPa.m3, good workability, and compressive strength of 49.7MPa was designed by optimizing cementitious content, while the e-CO2 index of the control mixture was around 8kg/MPa.m3. The addition of GGBFS and RHA not only decreased the e-CO2 index but also increased the unit cement strength contribution index. The results also indicated that by increasing GGBFS, the fluidity and segregation of the mixture increased while adding RHA increased viscosity and modified bleeding and the segregation index. Moreover, the growth rate of the compressive strength in mixtures containing GGBFS was much higher than that of the control mix at the same age. The promising results of this experimental study indicate that utilization of GGBFS and RHA in SCMO mixture can provide a practical way to reduce the environmental effects of cement production and pave the way for friendly disposal of slag and waste products.

Sizing of hybrid microgrids considering life cycle assessment

The sizing of microgrids consists of determining the capacity of its main elements, ensuring financial, technical, reliability and environmental criteria. However, regarding the environmental impact, most of the literature addresses this evaluation by exclusively quantifying the emissions in the microgrid operation stage, which tends to underestimate the life cycle ecological cost of the microgrid’s elements. In this sense, this paper proposes a sizing approach that integrates the life cycle assessment of the implementation and operation stages by adapting a multi-objective function inspired by the well-known life cycle assessment methodology called ReCiPe. For this purpose, information from several sources was compiled and adapted to quantify different environmental impacts in the sizing formulation. A case study of a solar/wind/battery/diesel microgrid is presented, showing that calculating the environmental impact indicators considering only emissions in the operation leads to a value 54.60% lower than the proposed approach. It was also found that the underestimation of environmental indicators can lead to a selection of a more polluting microgrid sizing configuration, which remarks the relevance of an adequate environmental evaluation in the sizing procedure.

Tectonics may affect closed watersheds used to monitor climate change and human activity effects

AbstractPlaya lakes developed in closed watersheds have been used as environmental impact indicators (global warming, water extractions, etc.), but they could be also sensitive to active tectonics. Our study area is located in the main watershed in the western Betics, the northern branch of the Gibraltar arc, which is within the fold‐and‐thrust belt. This area is characterized by an endorheic zone that includes some playa lakes floored by low‐permeable rocks. Our study shows the reduction or disappearance of playa‐lake flooded surfaces due to the reduction in their watershed area. This area reduction is favoured by stream catchments related to knickpoints, which seem to be generated by the quaternary activity of a dextral‐transpressive band within the Betics fold‐and‐thrust belt. χ map also shows the higher erosion power of Mediterranean streams, which will likely catch this endorheic area in tectonics quiescence.Statement of significancePlaya lakes developed in closed watersheds are commonly used to study environmental impacts such as global warming or water extractions. In this work, we analyse how these endorheic systems are sensitive to small water balance variations due to active tectonics. The endorheic area we chose to apply this new approach is located in the main Atlantic‐Mediterranean water divide of the western Betics (northern branch of the Gibraltar arc). The recent tectonics in this fold‐and‐thrust belt segment provoked the Atlantic‐Mediterranean gateway closure and the Messinian Salinity Crisis at 5.6 My. Our study of playa‐lake flooded surface and watershed modifications, together with structural and other geomorphic analyses such as the χ index, never before has it been made to detect active structures. Active tectonics likely influenced in the medium‐term evolution of the studied watersheds and this study is useful to predict both landscape and drainage network evolution in the future. In fact, the possible effect of active tectonic should be taken into account when using closed watersheds to monitor the impacts of climate change and/or local stressors such as water pumping activities.

Association between ecological footprint awareness and health literacy in adults: a population-based study from Turkey

ABSTRACT This study aimed to determine the relationship between health literacy and ecological footprint which is an indicator of sustainability and environmental impact and to examine the factors that may affect them. It was found that 20.3% of individuals have inadequate, 43.7% problematic, 26.1% sufficient and 10.0% excellent health literacy levels. There were differences in age, education level and BMI classification according to Ecological Footprint Awareness Scale score quartiles and health literacy levels (p < 0.05). It was determined that age and Turkey Health Literacy Scale score had effect on ecological footprint awareness. Individuals with a high level of health literacy have a high awareness of their ecological footprint. The increase in people’s health literacy levels and ecological footprint awareness with age can be interpreted as the increase in people’s education and knowledge levels and their awareness levels against the protection of nature and the environment.

Climate change mitigation investigating asphalt pavement solutions made up of plastomeric compounds

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 (HMAPC), b) HMA with neat bitumen and cold-added GRPC (HMAGRPC), c) HMA containing neat bitumen (HMANB) and d) HMA made up of modified bitumen with 5% Styrene Butadiene Styrene (HMAPMB). The mechanical characterization results showed that HMAPC and HMAGRPC increased their crack propagation resistance compared to HMANB, respectively by 35 and 39%, while HMAPMB 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 HMAGRPC 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 HMANB and HMAPMB in the binder layer, respectively) for the overall lower amount of fuels used and lower NOx emissions (−3 kg) during transportation phases and supply of raw materials.

A comparative study on mechanical properties and environmental impact of UHPC with belite cement and portland cement

Developing an eco-friendly UHPC with Belite cement (BC) is a great challenge because the mechanical strength of concrete with BC develops much more slowly than Ordinary Portland cement (alite-rich cement, OPC). However, BC has a lower CO2 footprint than OPC due to a lower calcined temperature and less limestone demand, making it green cement. Besides, concrete with BC has better long-age performance. In this study, the utilization of BC in UHPC was compared to that of OPC. Three curing regimes were used for the designed UHPC. The compressive and flexural strengths of UHPC-BC are lower than of UHPC-OPC at one day but higher after 28 and 90 days of standard curing. After heat curing, the mechanical strength development of UHPC-BC improves noticeably and exceeds UHPC-OPC. UHPC-BC has a higher flexural strength to compressive strength ratio (ff/fcu), and there are more C–S–H, less CH and lower pore coarsening of UHPC-BC paste than UHPC-OPC, especially after heat curing. UHPC-BC has lower environmental impact indices at long age than UHPC-OPC. At 90 days of autoclaved curing, the compressive of UHPC-BC reaches up to 197.5 MPa with the embodied carbon content of 934.37 kg/m3, which is much lower than most UHPCs.

Classical and Process Intensification Methods for Acetic Acid Concentration: Technical and Environmental Assessment

This study aims to investigate, from a technical and an environmental perspective, various alternatives for acetic acid concentration for maximizing acetic acid production, its purity, and in the meantime, minimizing the energy usage and the environmental impact. Liquid–liquid extraction followed by azeotropic distillation using different solvents such as: (i) ethyl acetate, (ii) isopropyl acetate, and (iii) a mixture containing isopropyl acetate and isopropanol were first explored, using process flow modeling software. The three cases were compared considering various technical key performance indicators (i.e., acetic acid flow-rate, acetic acid purity, acetic acid recovery, power consumption, thermal energy used, and number of equipment units involved) leading to the conclusion that the usage of the isopropyl acetate—isopropanol mixture leads to better technical results. The isopropanol-isopropyl acetate mixture was furthermore investigated in other two cases where process intensification methods, based on thermally coupled respectively the double-effect distillation process, are proposed. The highest quantity of pure acetic acid (e.g., 136 kmol/h) and the highest recovery rate (e.g., 97.74%) were obtained using the double-effect method. A cradle-to-gate life cycle assessment, involving ReCiPe method, was used to calculate and compare various environmental impact indicators (i.e., climate change, freshwater toxicity potential, human toxicity, etc.). Several steam sources (i.e., hard coal, heavy fuel oil, light fuel oil, natural gas, and biomass) were considered in the environmental evaluation. The results of the life cycle assessment show a reduction, by almost half, in all the environmental impact indicators when the double effect method is compared to the thermally coupled process. The usage of biomass for steam generation lead to lower impacts compared to steam generation using fossil fuels (i.e., hard coal, heavy fuel oil, light fuel oil, natural gas).

Multi-aspect assessment and multi-objective optimization of sustainable power, heating, and cooling tri-generation system driven by experimentally-produced biodiesels

This paper proposes a tri-generation system based on a diesel engine. An organic Rankine cycle and an ejector refrigerant cycle are employed to recover the diesel engine waste energy and produce cooling and more power. Also, a heat exchanger is installed to supply the heating demand. The mass, energy, exergy, exergoeconomic, and environmental analyses are applied to evaluate the proposed system's performance. Twelve biodiesels and pure Diesel energetic, exergetic, exergoeconomic, and environmental performances are compared to select a proper fuel for the designed system. Furthermore, the system's optimum state is evaluated through the exergy-economic assessment. In this regard, the Canola B20 is chosen as the best fuel for the designed system, which provides 7468 kW net power with 37.96% exergetic efficiency, 1.611 sustainability, and 1.635 environmental impact indexes at the base state. The engine exergetic efficiency is influenced by the engine load, while the total exergetic efficiency is affected by the engine speed. Besides, the ORC flow rate as the subsystem variable criteria has the highest effect on the system performance. Also, the system exergetic efficiency and unit product cost are obtained to be 37.96% and 11.196 $/GJ at the optimum state, respectively.

Accurate Estimation of Chlorophyll-a Concentration in the Coastal Areas of the Ebro Delta (NW Mediterranean) Using Sentinel-2 and Its Application in the Selection of Areas for Mussel Aquaculture

Multispectral satellite remote sensing imagery, together with appropriate modeling, have been proven to provide chlorophyll-a maps that are useful to evaluate the suitability of coastal areas for carrying out shellfish aquaculture. However, current approaches used for chlorophyll-a estimation in very shallow coastal areas often fail in their accuracy. To overcome this limitation, an algorithm that provides an accurate estimation of chlorophyll-a concentration in the coastal areas of the Ebro delta (North Western Mediterranean) using atmospherically corrected Sentinel 2 (S2) remote sensing reflectances (Rrs) has been calibrated and validated. The derived chlorophyll-a maps created have been used in a dynamic carrying capacity model that covers areas from very rich waters inside the embayment to the more oligotrophic waters in the open sea. The use of carrying capacity models is recommended to evaluate the potential of marine coastal areas for bivalve mollusk aquaculture. In this context, the depletion of chlorophyll-a is an indicator of negative environmental impact and thus a continuous monitoring of chlorophyll-a is key. The proposed methodology allows estimation of chlorophyll-a concentration from Sentinel-2 with an accuracy higher than 70% in most cases. The carrying capacity and the suitability of the external areas of the Ebro delta have been determined. The results show that these areas can hold a significant mussel production. The methodology presented in this study aims to provide a tool to the shellfish aquaculture industry.

Alternative Fuels for Agriculture Sustainability: Carbon Footprint and Economic Feasibility

Agriculture is the foremost source of food for humans. Fossil fuels are typically used to operate farm machines, contributing to carbon emissions and accelerating climate change. It is possible to mitigate environmental damage by promoting renewable or alternative fuels, namely biofuels, solar energy, biomass, wind, geothermal, small-scale hydro, and wave power. Biofuels are considered as low carbon-emitting alternatives to conventional fuels. The use of biofuels promotes reduced emissions of greenhouse gases and reduces the related detrimental impact of transport. As an alternative to fossil fuels, renewable fuels seem to present a promising scenario. However, if low carbon products are promoted, analysis of each particular product’s GHG emissions and carbon footprint (CF) is needed. Nowadays, CF is considered as the prime indicator of environmental impact, and its calculation is in utmost demand. Agriculture significantly benefits from the use of renewable resources. The carbon footprint measurement has the potential to assess and compare carbon emissions generated by agricultural products and to identify points for improving environmental performance. Several studies have compared alternative fuels with conventional fuels, and it has been proven that using alternative fuels can significantly reduce traditional fuel consumption. Bioenergy includes a number of socio- economic, technical as well as environmental benefits that helps in achieving the UN sustainable development goals (SDG). The aim to end malnutrition and hunger (SDG 2) requires a sustainable system for food production as well as resilient agriculture practices to improve agricultural productivity. The revenues from bioenergy projects can provide food and a better diet for small farming communities, thereby improving their quality of life. The present review aims to provide a comprehensive outlook of the role of alternative or biofuels in the agriculture sector, in terms of economic feasibility and carbon footprint, for sustainable development. This review also discusses the various generations of biofuels in attaining carbon neutrality, biofuel’s impact on the environment, applications in agriculture, and limitations.

Multi-Phase Environmental Impact Assessment of Marine Ecological Restoration Project Based on DPSIR-Cloud Model.

In order to achieve a comprehensive evaluation of the environmental impact of ecological restoration projects (ERP) under the current destruction and restoration of coastal ecological areas, this paper takes into account the impact of positive and negative indicators on the environment; analyzes the positive and negative benefits of ERP; and establishes a comprehensive environmental impact index system for marine ERP from ecological, economic, and social perspectives through the DPSIR model. On this basis, the cloud model and Monte Carlo simulation are used to obtain the comprehensive assessment grade of the construction period, short-term operation, and long-term operation in the project life cycle. The results show that the benefits of ERP, considering the impact of negative factors, are significantly reduced, and the benefits of ERP will increase remarkably in the long-term operation period. In engineering practice, the environmental pressure factor caused by excessive human activities during construction and operation periods is a key negative factor affecting the overall benefits of ERP. For project decision makers and other stakeholders, the comprehensive assessment grade considering negative impacts is more practical. At the same time, decision makers should take active response measures in the framework of long-term sustainable development, set a tolerance threshold for negative pressure indicators, and strengthen the management of ERP.