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Urban activities currently consume 75% of global final energy demand, which is expected to increase given absolute and relative population growth in cities. Assessments of both producer (upstream) and consumer (downstream) ecological and socioeconomic impacts of urban inter-industry exchanges are needed to reduce energy consumption and resource use behind the industrial footprints of cities. Environmental extensions in the input-output analysis are designed from the user side perspective, focusing only on commercial energy supply and use. This study introduced emergy-evaluated supply-extended and use-extended carbon footprint models for Vienna and compared their empirical and conceptual implications. Emergy-evaluated footprints of Vienna's urban consumption were estimated by combining industrial and systems ecology approaches as per the research question, based on previous investigations of GHG emissions and energy supply- and use-extensions. Results showed that the ranking of footprints of final product categories is sensitive to the evaluation method, with products of extractive and manufacturing industries differing by more than 10% depending on whether emergy or carbon evaluation is chosen. The emergy-based comparison further reveals that for products of extractive industries, the difference between use and supply extension results can be more than 20% as opposed to carbon-based comparison with the difference between supply and use extension results for services not even amounting to 5%. Future studies could address the over-estimation of direct energy supply to the economy, under-estimation of product and service, inconsistency in standard use-extension design, and challenges in assembling emergy-evaluated supply and use extensions. Fundings are relevant for unified responsibility assessment of upstream and downstream sectors without prioritising structural features.

Water, energy, and food are indispensable resources for socioeconomic development, and are highly interwoven in urban activities. Clarifying spatial differences in resource consumption is of great significance for coordinated management. However, there is still a lack of a unified assessment for water–energy–food (WEF) nexus flow analysis. This study proposes a comprehensive framework to investigate WEF utilization based on a modified multi-regional input–output (MRIO) analysis. Taking the case of the Yangtze River Delta region, we first inventoried embodied water–energy–food consumption from 2012 to 2017. Then, decoupling analysis and the Logarithmic Mean Divisia Index (LMDI) method were applied to explore decoupling states and identify driving factors. The results show that overall embodied WEF consumption experienced a downward trend from 2012 to 2017, and different provinces varied significantly. Jiangsu had the largest consumption of water and energy, while Anhui contributed a big chunk to food consumption. The manufacturing sector heavily relied on WEF resources and had a great impact on the ecological environment. The decoupling performance indicated a general trend of weak decoupling and strong decoupling in most provinces, with the mining, electricity, and gas supply sectors contributing most to positive decoupling, and the service sectors devoting the most to negative decoupling. As for resource type, water ecological footprint decoupled more than energy and food ecological footprints. Technology level and industrial structure had a major effect on the realization of decoupling, while economic output and population scale were the main restraining factors. Finally, we provide some differentiated policy recommendations for coordinated resource management. [ABSTRACT FROM AUTHOR]

Coordinating the relationship between resources, environmental protection, and economic development is essential for regional sustainable development. Various frameworks and models for quantifying the sustainable development of regional natural–social–economic systems have been produced. This paper focused on measuring regional sustainable development from the perspective of sustainable consumption and production. The study improved the emergy sustainable indices and the evaluation system commonly used in the method of emergy accounting by introducing input and output emergy into the emergy flows. Then, we proposed new subsystem sustainable indexes for evaluating and analyzing the sustainable development trend of the complex natural–social–economic system in Liyang from 2005 to 2020 by adopting the entropy weight method. The results showed that Liyang was generally in a state of sustainable development, with good social sustainability. The economic and natural sustainability indexes were low, which might cause unsustainable risks in the future. From the input structure and production efficiency perspective, the secondary industry with the highest emergy output has a meager net output rate. In contrast, the tertiary industry has a higher net output rate (NOR) and better output efficiency, which should be the core industry in the region's future development. From the perspective of environmental impact and resource and environmental carrying capacity, the natural contribution rate and environmental carrying rate should be improved and the waste emergy rate necessary to be reduced. This study hopes to provide implications for formulating regional land use, industrial planning, and sustainable development policies. [ABSTRACT FROM AUTHOR]

The rapid specialization of livestock production contributes to spatially decoupled crop and livestock production. Relinking croplands and livestock to promote wastes and by-products exchange has been suggested to provide opportunities for sustainable intensification of agriculture systems. However, the environmental and economic performances of such crop–livestock systems remain highly context specific and unclear. This study proposed an emergy-LCA-based framework to study the GHG mitigation and ecological and economic benefits of the integrated crop planting and livestock feeding systems, by taking wheat maize rotation-swine systems (WMRS), tea-swine systems (TS) and citrus alfalfa intercropping-swine systems (CAIS) as the empirical cases. The results showed the three case modes can generally promote GHG mitigation and ecological and economic benefits. CAIS had the lowest carbon footprint per kcal product (0.12 g CO2-eq kcal-1), followed by TS (0.61 g CO2-eq kcal-1) and MWRS (0.66 g CO2-eq kcal-1). The significant difference in this indicator can be attributed to their different upstream input and manure management. Due to the lower dependence on purchased resources, CAIS also had the best performance on emergy-based sustainability and economic benefits. Based on our results, the policy implications, including promoting wastes and by-products exchange, choosing reasonable manure treatment mode and conducting systematic planning have been suggested to provide opportunities for GHG mitigation and sustainable intensification of agro-systems. [ABSTRACT FROM AUTHOR]

Emergy accounting is an environmental assessment tool that accounts for all the energy pathways in production systems. In this regard, the System Thinking Experimental Learning Laboratory Animation (STELLA) with emergy model are used for a retrospective and prospective assessments. Nepal, a country having a relatively small economy but with faster recent growth as well as its geographical position and potentially high vulnerability to climate change was analyzed as a case study using data for 1998-2015 (retrospective) and 2015-2040 (prospective). As per our results, the rising use of non-renewable resources and decreasing use of locally extracted materials caused higher environmental load and reduced emergy sustainability scores. In addition, the effect of natural disasters, such as the Gorkha earthquake, on environmental performance of Nepal was analyzed by emergy accounting. Futuristic emergy analysis for 2015-2040 showed that total and non-renewable emergy would rise considerably, and the emergy sustainability index could further decrease by 33%. Based on these findings, small yet rapidly growing economies, such as Nepal, could improve their environmental management by reducing the material trade deficit (i.e., by increasing domestic material extraction and reducing imports of non-renewable resources), minimizing the use of non-renewables, improving soil fertility, and promoting renewable resource consumption. [ABSTRACT FROM AUTHOR]

Coordinating the relationship between resources, environmental protection, and economic development is essential for regional sustainable development. Various frameworks and models for quantifying the sustainable development of regional natural–social–economic systems have been produced. This paper focused on measuring regional sustainable development from the perspective of sustainable consumption and production. The study improved the emergy sustainable indices and the evaluation system commonly used in the method of emergy accounting by introducing input and output emergy into the emergy flows. Then, we proposed new subsystem sustainable indexes for evaluating and analyzing the sustainable development trend of the complex natural–social–economic system in Liyang from 2005 to 2020 by adopting the entropy weight method. The results showed that Liyang was generally in a state of sustainable development, with good social sustainability. The economic and natural sustainability indexes were low, which might cause unsustainable risks in the future. From the input structure and production efficiency perspective, the secondary industry with the highest emergy output has a meager net output rate. In contrast, the tertiary industry has a higher net output rate (NOR) and better output efficiency, which should be the core industry in the region’s future development. From the perspective of environmental impact and resource and environmental carrying capacity, the natural contribution rate and environmental carrying rate should be improved and the waste emergy rate necessary to be reduced. This study hopes to provide implications for formulating regional land use, industrial planning, and sustainable development policies.

Sustainable tourism development has attracted attention worldwide. A system-based perspective and an interdisciplinary approach are indispensable for evaluating tourism sustainability. The aim of this study is to propose an emergy analysis framework for the Kanas tourism area in Xinjiang, China, by combining emergy accounting and emergetic ternary diagrams. Data from field surveys and literature analysis were used for the sustainability assessment of the Kanas tourism system. The results show the following: (1) the emergy utilization is not efficient according to the indicators of the social subsystem. (2) The emergy investment ratio, net emergy yield ratio, and emergy exchange ratio of tourism, three indicators belonging to the economic subsystem, indicate that the tourism economy in the study area has low efficiency from different perspectives. (3) The environmental loading ratio of tourism indicates that the environmental pressure on the tourism system is low. However, the values of the emergy yield of waste and the ratio of waste emergy to total renewable resources show that tourism waste adversely affects tourism sustainability due to the growing number of tourists. The results of the emergy sustainability indicator of tourism and the emergy indicator of sustainable development of tourism demonstrate that sustainable development may not be possible in the long run due to the low level of economic and social efficiency, although sustainability was achieved for a certain period. (4) The emergetic ternary diagrams of the indicators visualize the increasing ecological pressure and decreasing sustainability of the system, revealing that Kanas should focus on long-term sustainable development based on the sensitivity lines of renewable resources. Finally, suggestions were provided based on the conclusions. [ABSTRACT FROM AUTHOR]

The social and ecological impacts of urbanization require integrated management of cities and their resource metabolism for long-term sustainability and economic prosperity. Traditionally, network models are used to study internal metabolic processes in cities, complementing the traditional “black box” urban models to account for the input of material and energy resources and the output of final products and wastes. This study introduces a multi-criteria assessment framework by integrating a unique hybrid-unit input-output model with the emergy accounting method to estimate the environmental support provided to urban socio-economic systems, applied here to the case of Vienna, Austria. By focusing on the internal organisation and functioning of urban socio-economic systems, the proposed framework strengthens the understanding of ecological and socio-economic flows exchanged among industries and the environment. The results suggest that resources can be saved by applying supply-side and demand-side interventions and improving share of renewables. The multi-criteria assessment framework developed in this study allows to investigate the urban metabolism of cities and regional contexts through the identification of sustainable pathways rooted in material circularity and resource efficiency, supporting the design of policies in line with the “integrated wealth assessment” and “circular economy” principles.

Increasing urbanization day–by–day requires new housing and transportation infrastructures. As a consequence, demand for steel – a basic material for buildings construction as well as for vehicles and railroads – would also increases. This study applies Emergy Accounting (EMA) to assess the Chinás steel industry environmental performance and to identify key application sectors. Subsequently, this study calculates emergy–based indicators capable to assess the present economic performance, environmental sustainability, and land resource appropriate utilization. Building on these indicators, changes of sustainability scenarios in key application sectors are also investigated, with special focus on increased use of recycled steel. The results show that the environmental impacts of steel use in downstream sectors, specially in the Housing and Vehicles Sectors, are significantly higher. Furthermore, the downstream sectors also have a very large requirement for embodied land. Additionally, the Emergy Benefit Ratio (EBR) shows non-negligible advantages to China derived from importing raw iron from abroad at international market prices. Finally, when the recycling rate of scrap steel increases, the performance of downstream sectors improves, with the Vehicle sector showing the most significant changes. Although the benefits of steel-based economy to society are clear, multidimensional sustainability concerns and international competition for primary resources necessitate a transition towards increased recycling and innovative materials within a strictly enforced “circular economy” policy.

Most of the crop production systems have strived for improving crop productivity by increasing various resource inputs; especially water and synthetic nitrogen (N) fertilizer, without considering their environmental consequences. Yet, only few studies have evaluated the sustainability of cropping systems simultaneously using life cycle assessment (LCA) and emergy accounting (EMA) techniques. The former highlights pollutant emissions and environmental impacts, while the latter emphasizes resource consumption and system efficiency. In this three-year field study, the environmental impacts and sustainability of farming systems were estimated under rainfed and irrigated patterns at four N application rates in the Northwest China. Our result indicated that the irrigated pattern enhanced grain yield by 9%, while simultaneously increasing 8% of environmental impact and 12% of emergy input based on per hectare of wheat production. Almost similar results of environmental impact per kg basis of grain production and emergy sustainability index revealed that irrigation practice did not decrease the overall sustainability of a cropping system. Conversely, the higher N levels of 240 and 360 kg N ha−1 did not provide a proportionate yield return and were accompanied by increased environmental impacts of 20% and 69%, respectively on per kg grain production basis, when compared to an N dose of 120 kg N ha−1. Meanwhile, the gross unit emergy value revealed that the production efficiency under 120 kg N ha−1 was enhanced, in comparison with other N levels. Therefore, a moderate N dose of 120 kg N ha−1 under both irrigated and rainfed patterns is highly recommended for adoption due to its overall advantage in terms of yield returns, environmental impact and production efficiency. [ABSTRACT FROM AUTHOR]

High raw material prices and rivalry from the food industry have hampered the adoption of renewable resource-based goods. It has necessitated the investigation of cost-cutting strategies such as locating low-cost raw material supplies and adopting cleaner manufacturing processes. Exploiting waste streams as substitute resources for the operations is one low-cost option. The present study evaluates the environmental burden of biopolymer (polyhydroxyalkanoate) production from slaughtering residues. The sustainability of the PHA production process will be assessed utilising the Emergy Accounting methodology. The effect of changing energy resources from business as usual (i.e., electricity mix from the grid and heat provision utilising natural gas) to different renewable energy resources is also evaluated. The emergy intensity for PHA production (seJ/g) shows a minor improvement ranging from 1.5% to 2% by changing only the electricity provision resources. This impact reaches up to 17% when electricity and heat provision resources are replaced with biomass resources. Similarly, the emergy intensity for PHA production using electricity EU27 mix, coal, hydropower, wind power, and biomass is about 5% to 7% lower than the emergy intensity of polyethylene high density (PE-HD). In comparison, its value is up to 21% lower for electricity and heat provision from biomass.

As an integral part of sponge city construction, permeable brick pavement can effectively alleviate the urban water issues such as urban waterlogging and groundwater resources shortage. The emergy accounting method is employed in this study to comprehensively evaluate the sustainable development capacity of the cement pavement and permeable brick pavement during the construction stage and operation stage. The results showed that the sustainable development capacity of two pavements is very low. This is because the consumption of a large amount of non-renewable resources during the construction stage. On the contrary, the sustainable development capability of the permeable brick pavement is much higher than that of the cement pavement during the operation stage due to its ability to capture rainwater. Indeed, its own Emergy Sustainability Index (ESI) reached 3044.4 times of that during the construction stage. Therefore, it is feasible to use of permeable bricks for sponge city development, which can improve the sustainability performance of the city effectively. In addition, the suitable conditions for the construction of permeable brick pavement are analyzed from the perspective of resource constraints. The design approaches are also proposed to achieve the optimal design of permeable brick pavement and the minimum demand for rainwater in sponge city development. These findings can provide useful references for the development of sponge cities and the formulation of local policies. Image 105658381 • Sustainability performance of pavements is analyzed with emergy accounting. • Sustainable development capacity of permeable brick pavement is optimized. • The suitable conditions of permeable brick pavement application are analyzed. [ABSTRACT FROM AUTHOR]

The linear path "extraction-production-consumption-waste", imposed by humans to natural ecosystems, where all material flows are instead circular, has become unsustainable. Understanding the potential value of some of these "by-products", in order to exploit them effectively in a biorefinery perspective, may help overcoming resource shortages and decrease environmental impacts. This study investigates energy and resource restoration from animal by-products. The slaughterhouse waste undergoes a rendering process to separate residual meal and fat. The latter is combusted in a co-generation plant to produce electricity and heat. The process is carefully assessed using Emergy Accounting approach with the aim of evaluating benefits and environmental load of the process considering the advantages achieved compared with the demand for ecosystem services and natural capital depletion. Moreover, the case aims at exploring three different methodological assumptions referring to the upstream burdens carried by the waste management system, proposing a modified exergy-based allocation rule. The electricity generated shows performances in terms of Unit Emergy Values ranging between 2.7E+05 sej/J, 2.2E+06 sej/J and 3.1E+07 sej/J among the different cases investigated, comparable to power from fossil fuels and renewables sources, and it provides an environmentally sound alternative to conventional waste disposal. • Linear "take-make-dispose" patterns in food production are environmentally unsustainable. • Circular strategies improve the environmental and economic performances of food chain. • Electricity generation out of slaughterhouse waste is suggested as a circular alternative to landfilling. • A modified emergy approach is applied for the evaluation of resource and waste intensive processes. • The emergy approach allows a comprehensive sustainability understanding to integrate monetary and LCA evaluations. [ABSTRACT FROM AUTHOR]

Ecological intensification is a new concept in agriculture that addresses the double challenge of maintaining a level of production sufficient to support needs of human populations and respecting the environment in order to conserve the natural world and human quality of life. This article adapts this concept to fish farming using agroecological principles and the ecosystem services framework. The method was developed from the study of published literature and applications at four study sites chosen for their differences in production intensity: polyculture ponds in France, integrated pig and pond polyculture in Brazil, the culture of striped catfish in Indonesia and a recirculating salmon aquaculture system in France. The study of stakeholders' perceptions of ecosystem services combined with environmental assessment through Life Cycle Assessment and Emergy accounting allowed development of an assessment tool that was used as a basis for co‐building evolution scenarios. From this experience, ecological intensification of aquaculture was defined as the use of ecological processes and functions to increase productivity, strengthen ecosystem services and decrease disservices. It is based on aquaecosystem and biodiversity management and the use of local and traditional knowledge. Expected consequences for farming systems consist of greater autonomy, efficiency and better integration into their surrounding territories. Ecological intensification requires territorial governance and helps improve it from a sustainable development perspective. [ABSTRACT FROM AUTHOR]

In order to respond to rapid urbanization, understanding the relationships between urbanization and ecosystem services (ESs) is of practical importance to move toward sustainable urban development. In this study, an emergy-GIS based method is proposed to evaluate ESs. Spatiotemporal emergy values of water retention (WR), air purification (AP), carbon sequestration (CS), soil conservation (SC), and biodiversity conservation (BC) were quantified and relationships among these ESs were analyzed by taking China’s largest city, Shanghai, as a case. The decoupling analysis was conducted to study the relationship between urbanization and ESs. Results show that the total value of regulating ESs had declined by 8.24% from 2005 to 2010. Chongming had the largest value of ESs, followed by Pudong. There is a synergetic relationship among AP, CS, and SC, while a tradeoff appears between WR and other services. Irregular “U” shape relationships between the decrease of ESs and urbanization indicators were observed. Results from decoupling analysis show that ESs experienced weak decoupling from urbanization in most districts. Finally, policy implications were raised based on the study results.

The worldwide energy consumption shows a significant increasing demand and is still projected to grow in the next years. This is causing increased pollution and environmental degradation. The energy sector is one of the major contributors to the emissions of greenhouse gases and pollutants. A fair access for everyone to energy sources capable of meeting the global needs without further degrading the ecosystems is of paramount importance. In this work, a sustainable medium enthalpy geothermal system to produce electric and thermal energy is assessed. The case study is located in Campania region, Southern Italy, in an area famous for its volcanic activity. The system is composed by an Organic Rankine Cycle for electricity production and a grid for district heating and cooling. The environmental performances are assessed using the Emergy Accounting (EMA) systemic approach. The calculation of the EMA conversion factors, the so-called Unit Emergy Values (UEVs), could benefit from the use of appropriate inventories. The databases used within the Life Cycle Assessment (LCA) method provide a huge amount of reliable, peer reviewed inventories. This work proposes the use of LCA inventories to calculate UEVs, comparing them to literature ones. The performance of the investigated system is calculated and compared to current and improved strategies for heating and cooling and electricity production. The calculated UEVs seem to be reliable when compared to literature values, strengthening the link between LCA and EMA methods. The obtained results confirm the environmental feasibility of the analyzed system and its beneficial environmental performance, when compared to fossil based and other renewable energy production systems. The electricity, heating and cooling produced by the investigated system has UEV values of respectively 1.0E+04, 7.6E+03 and 1.1E+04 sej/J, validating its fitness within a perspective of improved sustainability. [Display omitted] • Unit Emergy Values calculation could benefit from existing Life Cycle Assessment inventories • The Life Cycle Assessment allocation procedure is not allowed in Emergy Accounting • The UEV of the ORC Electricity is 97% lower than the average one of the Italian grid • UEVs of Heating and Cooling are 94% and 97% lower than those of other common processes [ABSTRACT FROM AUTHOR]

Waste management is a serious challenge across many resource constrained countries of the world leading to environmental issues such as pollution and high rates of soil occupation, health issues induced by poor hygienic conditions, and financial problems linked to the high costs associated to waste management, which have high impacts on municipal budget. In this study we determined the environmental impact of different waste disposal scenarios in a major city of Pakistan. Existing studies on the subject of waste management in Pakistan fail to account for the environmental burden of waste processing technologies. To counter this, in this paper we used Emergy based accounting procedures to obtain a donor or nature based perspective for environmental footprinting. Three scenarios were considered for the analysis consisting of the current practice of open dumping as Scenario A; sanitary landfilling with composting and material recycling as Scenario B and incineration with composting and recycling as Scenario C. Results were presented in the form of Emergy based input-output tables as well as greenhouse gas emissions as measured in kg CO 2 equivalent (kCO 2eq /t) per tonne of waste. Scenario A was the worst option due to its high emissions and lack of any useful output. Scenario B was identified as the best alternative as it resulted in similar amount of net emissions as Scenario C but with relatively lower stress on the environment as indicated by the Emergy indicators. In view of the subject city’s resource constraints we recommend inducing waste reduction and minimization practices through public awareness campaigns. Resource contributions from the civic society are also suggested for erecting the necessary waste disposal infrastructure. The results and suggestions presented herein need to be highlighted in a timely manner in order to resolve environmental and public health risks posed by the current practices. [ABSTRACT FROM AUTHOR]

The sustainability of the renowned artistic glass sector of Murano island, in the Venice Lagoon (Italy), has been challenged in recent years by the evolution of several socio-economic dynamics as well as by environmental constraints. Actually, a renewal of the systemic structure of the artistic glass production is increasingly compelling. In this work, the Emergy Accounting method (EMA) is applied to evaluate the environmental sustainability of a Murano factory producing colored glass. The analysis, for which new Unit Emergy Values (UEVs) were calculated for some chemicals, shows that the activity relies mainly upon purchased resources, which is the most evident element of systemic weakness. An evaluation of the downstream ecosystem services required to dilute some heavy metal pollutants is also presented, again addressing the intrinsic fragility of the system. In particular, it is shown how the sustainability of the sector is indissolubly linked to the problems involved in the management of the entire Venice lagoon, underlining how the safeguard of Murano must be part of that of Venice and its lagoon. The UEV of semifinished artistic glasses results 2.31E+10 sej/g (with labor and services), and 1.87E+10 sej/g (without labor and services). [ABSTRACT FROM AUTHOR]

Marine and coastal ecosystems are among the most productive environments in the world and their stocks of natural capital offer a bundle of vital ecosystem services. Anthropogenic pressure seriously threatens health and long-term sustainability of marine environments. For these reasons, integrated approaches capable of combining ecological and socio-economic aspects are needed to achieve nature conservation and sustainability targets. In this study, the value of natural capital of the Egadi Islands Marine Protected Area (EI-MPA) was assessed through a biophysical and trophodynamic environmental accounting model. The emergy value of both autotrophic and heterotrophic natural capital stocks was calculated for the main habitats of the EI-MPA. Eventually, the emergy value of natural capital was converted into monetary units to better communicate its importance to local managers and policy-makers. The total value of natural capital in the EI-MPA resulted in 1.12·10 21 sej, equivalent to about 1.17 billion of euros. In addition, using Marxan software, the results of the environmental accounting were integrated with spatial data on main human uses. This integration took into account the trade-offs between conservation measures and human exploitation by means of two different scenarios, with and without considering human uses in the EI-MPA. The comparison between the scenarios highlighted the importance of taking into account human activities in marine spatial planning (MSP), allowing the identification of key areas for natural capital conservation. In conclusion, this study showed the importance of integrating environmental accounting with conservation planning to support effective strategies for ecological protection and sustainable management of human activities. The results of this study represent a first benchmark useful to explore alternative nature conservation strategies in the EI-MPA, and, more in general, in Mediterranean MPAs. [ABSTRACT FROM AUTHOR]

Although photovoltaic (PV) technology has been projected as one of the most promising candidates to replace conventional fossil based power generation, claims about the potential disadvantages of the PV panels end-of-life (EoL) deserve careful attention in order to fully establish a feasibility and viability baseline and support technological and implementation policies. The current challenge concerning PV technology resides in making them efficient and competitive in comparison with traditional power generation systems, without disregarding the appraisal of EoL impacts. The emergy analysis method proved to be a reliable approach for the evaluation of the efficiency, effectiveness and environmental friendliness of technological processes under a global scale perspective and may likely be applied to the EoL PV investigation as a complement of conventional energy and economic assessments. Therefore, this method was used in this study to evaluate the sustainability of a PV panel recycling process. In addition, this paper aims to explore the implications of methodological assumptions when Emergy Accounting (EMA) tackles waste management systems, in order to address the shortcomings in this field. Results show that the PV panel treatment can generate large environmental benefits not only at the local scale of the process, but also at the larger scale of the industrial manufacture and material recovery, as well as at the even larger scale of the biosphere where resources come from and pollution is released. The comparison between the emergy invested for electricity production via PV and fossil energy sources also including EoL resource and environmental costs, highlights that PV technology is competitive under both energy and environmental points of view. This comparison reveals that the solar technologies imply remarkable emergy savings (1.45E+12 sej/kWh for fossil sources versus 3.57E+11 sej/kWh for crystalline silicon photovoltaic down to 2.31E+11 sej/kWh for cadmium telluride photovoltaic). Results clearly show that PV solar power can be considered a mature technology and can favorably compete with other renewable and non-renewable options for electricity generation. However, efficiency improvements of PV panels thermal recovery are still possible and may lead to further decrease of still too large emergy costs of the treatment process, not to talk of potential recovery alternatives such as chemical treatment for silicon cells and better upstream industrial design. [ABSTRACT FROM AUTHOR]

Urban–rural linkages, which inevitably evolve over time, are influenced by economic, geographic, and demographic factors. In this paper, emergy accounting was used to calculate sustainability indicators and examine the metabolic processes that connect natural environments and rural–urban systems. A map of energy and material flow was visualized with a Sankey diagram, and urban–rural linkages were quantified according to ecological networks. Both rural and urban areas had open metabolic cycles, but the rural system was more dependent on the natural environment and showed better environmental performance. Urban–rural linkages reflected economic transformations during urbanization and formed a complex web of connections. The rural area’s economy and social system were unique in that they were not traditionally self-sufficient. Both rural and urban systems exploited the natural environment. From an ecological perspective, a competitive relationship exists between rural and urban systems, which may result in resource conflict and weaken the sustainability of urban and rural areas. The modern urban–rural linkage indicates a new trans-territorial type of rural system, the town village, which is an emerging phenomenon unique to China and imposes household registration systems. Urbanization has reshaped urban–rural linkages, and thereby influenced system sustainability. The results suggest that new resource management policies should be developed to coordinate the relationship between China’s urban and rural systems during urbanization. [ABSTRACT FROM AUTHOR]

Emergy theory provides a basis for assessing the added value of water resources as a function of their origin and quality. From this perspective, the sustainability of a water system and its supply to end users may be classified according to the products, services, and energy necessary for its operation, which are incorporated from the corresponding socioeconomic system and form an important aspect of its evaluation. In the present study, the development of a geoinformatics tool with an emergy accounting approach and its corresponding methodology are described, focusing on a spatial-temporal analysis of water resources and their allocation to domestic, industrial, and agricultural uses. In addition, different water provision scenarios that involve several levels of infrastructure in the basin of the Upper Course of the Lerma River (UCLR) are evaluated, and existing water deficits are considered in order to assess their economic impact and offer a perspective on regional environmental sustainability. To achieve this, the water supply processes with the greatest relevance for the UCLR basin are evaluated, which include the extraction of groundwater and the treatment of surface and wastewater for subsequent use. The evaluation of the proposed scenarios indicates that the water supply system where treated water is recycled for agricultural, industrial, and urban uses (with restrictions) has the highest value according to the environmental sustainability index. Beyond this, it is possible to establish a series of strategies to transition from the current scenario where the water supply largely comes from an overexploited aquifer, to one where wastewater treatment plants (WWTP) are capable of implementing additional units in their processes to achieve drinking water quality. Finally, the proposed methodology and the geoinformatics tool developed in this study showed their effectiveness as instruments for achieving an integrated management of water resources, which would facilitate a more objective decision making process based on current and projected scenarios. [ABSTRACT FROM AUTHOR]

Environmental flows play an important role in sustaining or enhancing ecosystem services provided by wetlands. In this study, using an improved input-state-output approach, we evaluated ecosystem service values to assess the ability of freshwater releases to improve the ecosystem of China's Yellow River Delta Wetlands. We used emergy analysis to value the inputs, state, and outputs of the ecosystem services from 2001 to 2008, which covered the periods before and after the freshwater releases. From 2001 to 2004, the total emergy input increased from 8.50 × 10 sej to 10.6 × 10 sej, and then decreased to 6.30 × 10 sej in 2008. From 2001 to 2008, the emergy output increased from 9.17 × 10 sej to 10.6 × 10 sej. The emergy yield ratio, representing the ability to supply ecosystem services per unit of inputs, increased by 71.3 %. The results show that freshwater releases improved provisioning, regulating, and cultural ecosystem services from the coastal wetlands. The environmental sustainability index, representing the sustainability of environmental development, decreased from 25.9 × 10 in 2001 to 1.74 × 10 in 2008; both values are much higher than normal for human-dominated ecosystems, indicating that the wetland is still predominantly natural. These results can guide managers in a more holistic evaluation of freshwater releases to support ecosystem restoration. [ABSTRACT FROM AUTHOR]

Dam construction conflicts are typically multidimensional, complex, and dynamic. Until recently, the environmental impact assessment of large dam projects was not fully acknowledged due to the uncertainty of the issue and the current knowledge on the accountability of ecological services. The measurement on the sustainability of the production system with a holistic view are thus of great relevance for the decision makers to implement the sustainable energy policy. In this paper, an integrated EMergy accounting was presented for assessing how the Three Gorges Dam project has performed based on the sustainability criteria. We quantified each EMergy flow component of energy, material and purchased input with available data in an assumed 100-year lifetime run. Special attention is focused on three simplified scenarios for estimating the EMergy cost of sediment. Our results showed that when the EMergy cost of sediment was counted, the Environmental Sustainability Index decreased dramatically with the increasing of the nonrenewable input. The results serve as a reminder of the necessity to apply different transformities for sediment EMergy cost in any hydro project, depending on the unique ecological service of sediment in the local river system. However, due to the high intensity of local renewable EMergy flow, the Environmental Loading Ratios and the Investment Ratios of the Three Gorges Dam system were relatively low. In spite the fluctation, the Environmental Sustainability Index remained higher than that of China in 1996, no matter the sediment EMergy cost was included or not. [ABSTRACT FROM AUTHOR]

While cycles are a very important phenomena of ecosystems, they represent a methodological challenge in emergy accounting. The relevance of feedbacks is acknowledged in emergy evaluations, however they are not considered by the emergy algebra. In this paper, we present supporting arguments in favor of an update in the emergy accounting methodology. We argue that including the contribution of feedback emergy is essential to understand a system's internal functioning, thus studies interested in better capturing these features should consider emergy cycling. Feedbacks represent emergy that entered the system in the past (therefore it is not double counting), and they enable additional organization and work above that supported by input emergy alone. To evaluate the effect upon system properties of including feedbacks, we compared two different methods for calculating transformities using trophic networks as case studies. One method followed the classic emergy rules where feedbacks were not included, and the other included the feedbacks (we refer to them as static and network method, respectively). The comparison between the resulting transformities and system emergy patterns showed that (1) transformities and system emergy were significantly higher with the network method, and (2) this increase affected the network compartments unevenly, altering their position in the emergy hierarchy. Estimating relative importance of the system's components or their true emergy requirements are only possible by evaluating the total emergy that flows through them. [ABSTRACT FROM AUTHOR]

Lignocellulosic ethanol is considered as a good alternative to increase the current amount of first generation ethanol produced, since it does not compete for land with food production. Biochemical technological routes have high potential to be adopted for lignocellulosic ethanol production, in which hydrolysis processes demand cellulase enzymes to convert cellulose and hemicellulose materials into fermentable sugars. Thus, an integral evaluation of lignocellulosic ethanol requires knowledge of the energetic–environmental costs of production of enzymes, which generally occurs off-site of biorefinery plants in specialized companies. The aims of this work are to assess the energetic–environmental costs of cellulase enzyme production and verify their influence on the lignocellulosic ethanol overall cost. For this, the production of industrial enzyme operating under submerged fermentation process was assessed by (i) emergy accounting, (ii) embodied energy analysis, (iii) and emission inventory. Monte Carlo simulation was used for uncertainty analysis. Results show that cellulase enzyme demands 4.06E14 seJ/kg enzyme and 1664 MJ/kg enzyme with a global warming potential of 21.90 kgCO 2-eq. /kg enzyme . These values are equivalent to 0.41%, 0.49%, and 0.02%, respectively, of the emergy, embodied energy, and global warming potential of lignocellulosic ethanol production, making their contribution to the overall energetic–environmental costs negligible when compared to other input resources of the ethanol production chain such as limestone and diesel. [ABSTRACT FROM AUTHOR]

The evolution of maize production patterns in Argentina is evaluated over the last 25 years to compare costs, benefits, environmental performance and sustainability as well as to identify the main driving sources and improvement potential. Results from Argentina cropping systems are compared to other systems worldwide in order to put the Argentina results in a broader context. The study focuses on three farming categories: (1) traditional, low-intensity systems, (2) conventional, high-intensity systems, and (3) GMO-based cropping systems. Low input intensity systems include traditional cropping patterns with seed selection by farmers and conventional hybrid seed coupled to plowing and crop-animal rotation techniques; high input intensity systems use conventional hybrid seeds and recommended chemicals, irrigation and machinery with important soil erosion consequences; and GMO-based cropping systems use herbicide resistant transgenic hybrids, pesticides, higher fertilizer rates, and no-till practices. In each of the three cases, input flows are compared to the achieved yield (in mass and income terms) to better understand relative efficiencies and options for improvement. The study of GMO systems required a preliminary investigation of GMO seed production by seed companies, where a large investment in terms of prior knowledge and high-tech laboratory research is required. The assessments used the Emergy Accounting (EMA) approach. EMA includes material, energy, labor, money, and knowledge flows into the assessment and expands its focus over larger time and spatial scales than conventional economic and cumulative energy demand methods. Emergy-based environmental indicators of grain production for high-intensity hybrid and GMO systems both show a lower performance than low-intensity, traditional patterns in terms of resource return, renewability and sustainability. The fraction of renewability in low-intensity systems is between 28% and 63%, while it is between 8% and 26% for high-intensity hybrid and GMO systems. Calculated indicators also show that GMO-based maize production patterns do not guarantee the expected improvement over conventional high-intensity cropping systems or low-intensity systems in terms of performance and sustainability. Strong reliance on nonrenewable resources and technology, as well as role of direct and indirect labor costs are important factors in determining long-term sustainability and environmental stability of maize production systems. [ABSTRACT FROM AUTHOR]

Greenhouse gas emissions, climate change and the rising energy demand are currently seen as most crucial environmental concerns. With the exploration of renewable energy sources to meet the challenges of energy security and climate change, geothermal energy is expected to play an important role. In this study a LCA (Life Cycle Assessment) and an EMA (Emergy Assessment) of a 20 MW dry steam geothermal power plant located in the Tuscany Region (Italy) are performed and discussed. The plant is able to produce electricity by utilizing locally available renewable resources together with a moderate support by non-renewable resources. This makes the geothermal source eligible to produce renewable electricity. However, the direct utilization of the geothermal fluid generates the release into the atmosphere of carbon dioxide, hydrogen sulfide, mercury, arsenic and other chemicals that highly contribute to climate change, acidification potential, eutrophication potential, human toxicity and photochemical oxidation. The study aims to understand to what extent the geothermal power plant is environmentally sound, in spite of claims by local populations, and if there are steps and/or components that require further attention. The application of the Emergy Synthesis method provides a complementary perspective to LCA, by highlighting the direct and indirect contribution in terms of natural capital and ecosystem services to the power plant construction and operation. The environmental impacts of the geothermal power plant are also compared to those of renewable and fossil-based power plants. The release of CO 2 -eq calculated for the investigated geothermal plant (248 g kWh −1 ) is lower than fossil fuel based power plants but still higher than renewable technologies like solar photovoltaic and hydropower plant. Moreover, the SO 2- eq release associated to the geothermal power plant (3.37 g kWh −1 ) is comparable with fossil fuel based power plants. Results suggest the need for further investigation of other geothermal options (e.g. binary systems) in order to reduce the environmental impacts while taking the maximum advantage of the geothermal resource. [ABSTRACT FROM AUTHOR]

Hydropower has been regarded as a clean energy to replace fossil fuels facing the climate change, while detecting the tradeoffs among renewable energy production, greenhouse gas (GHG) mitigation and ecological impacts still remains challenge. Multi-disciplinary analysis should be adopted to understand these tradeoffs. This study proposed an integrated evaluation framework based on donor-side (emergy analysis) and user-side (economic analysis) which highlighted the impacts on ecosystem services. 8 hydropower plants in Zagunao Basin, Southwest China, were adopted as the study case. The results show that impacts on water supply and biodiversity dominated ecosystem service losses. Plants with higher water head are more efficient in resource utilization, while the efficiency of plants with gravity dams are generally lower than that with grille weirs under the similar installed capacity. Lixian plant had the best performance based on emergy indicators attributed by the benefits to utilize the renewable source from the regulating flow ability of Shiziping plant. Results from fair prices reflect that all the studied plants are not profitable under current grid price. Finally, policy implications were raised based on the results. [ABSTRACT FROM AUTHOR]

Abstract: Emergy accounting (EmA) was applied to a range of dairy systems, from low-input smallholder systems in South Mali (SM), to intermediate-input systems in two regions of France, Poitou-Charentes (PC) and Bretagne (BR), to high-input systems on Reunion Island (RI). These systems were studied at three different levels: whole-farm (dairy system and cropping system), dairy-system (dairy herd and forage land), and herd (animals only). Dairy farms in SM used the lowest total emergy at all levels and was the highest user of renewable resources. Despite the low quality of resources consumed (crop residues and natural pasture), efficiency of their use was similar to that of industrialised inputs by intensive systems in RI, PC and BR. In addition, among the systems studied, SM dairy farms lay closest to environmental sustainability, contradicting the usual image of high environmental impact of cattle production in developing countries. EmA also revealed characteristics of the three intensive systems. Systems from RI and PC had lower resource transformation efficiency and higher environmental impacts than those from BR, due mainly to feeding strategies that differed due to differing socio-climatic constraints. Application of EmA at multiple levels revealed the importance of a multi-level analysis. While the whole-farm level assesses the overall contribution of the system to its environment, the dairy-system level is suitable for comparison of multi-product systems. In contrast, the herd level focuses on herd management and bypasses debates about definition of system boundaries by excluding land management. Combining all levels highlights the contribution of livestock to the global agricultural system and identifies inefficiencies and influences of system components on the environment. [Copyright &y& Elsevier]

• An emergy-based eco-credit is proposed to tackle the obstacles of current accounting methods. • A new accounting framework is established to provide a unified measurement for ecosystem service marketing. • Em-credit strips away differentiated evaluations of people's willingness and makes the accounting results more objective. • It improves the quality of accounting for different types of ecosystem services. • It can provide cross-scale and cross-type ecosystem service accounting. Many nations are taking measures to address the negative impacts of development projects in order to achieve the goal of No Net Loss (NNL) of ecosystem services. It still faces the most fundamental and critical problem— the unified accounting of ecosystem service. To address this problem, we conducted an emergy-based ecosystem service assessment to tackle the challenges and obstacles of current accounting methods and established a new accounting framework to provide a unified measurement for ecosystem service marketing. We adopted the Credit-Debit method of wetland mitigation banking and the emergy-based method to evaluate the ecosystem services of 82 ecological projects. The results have shown that: (1) The emergy-based credit covers more types of ecosystem services, and shows advantages in terms of objectivity, accuracy, dynamic monitoring, and generalization; (2) The new accounting method can provide cross-scale and cross-type ecosystem service; (3) The Em-credit helps to promote the trans-regional eco-bank system in a large scale and at multiple levels, and it can improve the effective supervision and predict the eco-bank in a long period. [Display omitted] [ABSTRACT FROM AUTHOR]