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This study assessed Ghana's sustainability from 2000 to 2019 using emergy synthesis. This research study also explored the relationship between changes in Ghana's socioeconomic metabolism and the expansion of urban areas. The results showed a significant increase of 126% in total emergy use during the study period. This increase was mainly due to a rise in import emergy, which went up from 2.90% to 37.47%, while Ghana's self-sufficiency capacity decreased from 97.10% to 62.53%. This shift in total emergy utilization indicates that Ghana's socioeconomic system is transitioning from relying heavily on indigenous resources to increasingly depending on purchased resources to drive economic growth. The emergy sustainability index (EmSI) suggests that Ghana's socioeconomic system is resource-consuming and has low system performance. To address this situation, this study recommends restructuring Ghana's socioeconomic system to optimize its indigenous renewable resources while reducing import dependency and environmental stress. Expanding urban areas contributes to resource consumption, especially refined fuels and construction materials. This underscores the importance of urban policies that take into account changes in socioeconomic metabolism as a reference for effective urban land administration. [ABSTRACT FROM AUTHOR]

Rapid loss of agricultural land is occurring in fast-growing urbanizing regions in Asia, accompanied by shifts from conventional cultivation practices to cope with changing social and economic demands. To date, comprehensive analyses of the relationship between agricultural land changes and overall regional development remain scarce. In addition, more research is needed to assess the impacts of different cropping practices on the regional agriculture systems from a micro perspective. This study focuses on Changhua County in Taiwan, incorporating its socioeconomic and environmental components into a socio-ecological system model. A hierarchical emergy synthesis framework for the whole county was used to explore the changing role of the agricultural system within the socioeconomic system. We used emergy synthesis to analyze and compare the performance of three cropping practices. The results indicate that the role of these cropping practices in the county's overall socioeconomic system has gradually diminished over time despite improvements in their operational efficiency. Among them, multi-cropping received the highest emergy inflows from the economic system and resulted in the highest energy density, while rice-grain rotation had the lowest. Although higher economic investment in multi-cropping influenced environmental loading and sustainability, its impact was relatively minor in the context of the entire county. We demonstrate the transition of agricultural practices in response to regional land use changes and suggest that regions experiencing severe land use changes should prioritize the adaptation of agricultural practices within the overall regional socioeconomic system. As cropping practices evolve, their functional integration within the system also changes, and their implications for resource efficiency and environmental sustainability should be assessed.

Environmental compensation is a form of payment for pollution of nature and the environment and the destruction of land, plants or animals. One of the challenges in ensuring waste management in Kenya is how to measure the negative effect of industrial activities and waste on the environment, economy, and human health. Although the amount of compensation should be established on the basis of the environmental-economic assessment of the appropriate environment, it should also be sufficient to implement measures aimed at restoring, reproducing and improving this environment. Kenya has not yet developed a clear legal framework for compensation for environmental damage even through it has a clear and elaborate Environmental Management and Coordination Act for the protection of the environment. Previous studies on the cost of environmental damage in Kenya have successfully used two methodologies: emergency costs and soil, air, and water pollution. This works examines the essence of these methods, as well as the possibility of their application in assessing the cost of damage to the environment as a result of human economic activity.

China is rich in oyster resources and has a long history of oyster aquaculture. Various forms of oyster aquaculture coexist in the coastal regions of China, which are dominated by raft aquaculture and long-line aquaculture. The objective of this study is to assess the environmental sustainability of the oyster aquaculture systems located in Jiantiao Bay, Zhejiang province, China. Emergy synthesis is used in the study to quantify the contributions of the natural and economic inputs to the oyster aquaculture systems, in order to better understand the sustainability. The results show that the raft oyster aquaculture system was high in emergy inputs and yield per unit area, whereas the long-line oyster aquaculture system was low in emergy inputs and yield per unit area. However, the transformities of the oysters from the raft oyster aquaculture system and the long-line aquaculture were similar, reflecting that both systems had a similar efficiency in using natural and economic resources. The oyster aquaculture systems had a different impact on the environment as inferred from the emergy indicators. The higher emergy yield ratio and low emergy loading ratio in the long-line oyster aquaculture system suggest that the system could gain more net benefit, and had a lower impact on the surrounding environment, than raft oyster aquaculture system, and can been considered to be more sustainable. Nevertheless, oyster aquaculture was a labor-intensive process and relied highly on purchased resources, such as labor and construction materials. If the construction materials could be used for a longer time, the oyster aquaculture systems might be more sustainable and environmentally friendly. [ABSTRACT FROM AUTHOR]

The application of the emergy approach to analyzing the sustainability of greenhouse systems has resulted in the deployment of adequate management in order to boost the production sustainability of these systems. The goal of this study was to apply the emergy approach to assess the sustainability of greenhouse tomato production systems. The data for this study was collected from greenhouse owners through face-to-face referrals and the completion of a questionnaire. Sixty three tomato greenhouses were chosen for this purpose in Mirjaveh district, Zahedan, Iran. In tomato greenhouse systems, the average total emergy supporting output was 1.06E+16 sej/1000 m2 of greenhouse area. The unit emergy value of economic product (unit emergy value) was calculated to be 9.94E+03 sej/J, indicating that greenhouse systems outperform open field systems of various crops by at least 100 times. The significant proportion of purchased non-renewable resources affected the tomato production system's sustainability in this study. As a result, using productive renewable local environmental inputs, more efficient labor, and technologies to reduce greenhouse building inputs and acquire non-renewable inputs will make the greenhouse tomato production system more sustainable.

Biofloc technology (BFT) has been called an environmentally friendly aquaculture approach. The sustainable characteristics of biofloc-based culture are usually linked to the efficient use of water and nutrients and the minimal discard of effluent to the environment. Given the scarcity of sustainability assessment of biofloc-based systems, it is still unclear whether the positive characteristics of BFT make it a real sustainable approach for aquaculture. This study aimed to investigate and apply the emergy synthesis to assess the sustainability of commercial Nile tilapia fingerlings production in a biofloc-based system. The tilapia fingerlings produced on the BFT farm showed a UEV of 2.04E + 03 sej/J, renewability of 32.73%, EYR of 1.00, EIR, and ELR of 2.05, and ESI of 0.49. Compared to other aquaculture systems, the evaluated BFT farm presented emergy indicators with values characteristic of potentially sustainable production. Electricity has the highest representativeness in the emergy input, making the system dependent on resources from the larger economy. The low UEV indicates that the BFT farm is efficient in terms of converting the invested emergy into the system’s output (tilapia fingerlings). A sensitivity analysis shows that replacing the hydroelectric source of electricity with photovoltaic will not improve the emergy performance of the evaluated BFT farm.

Cities play a crucial role in the development of nations, since they concentrate diverse forms of energy and transform them into higher quality outputs. An alternative for assessing urban agglomerates is the use of the eMergy synthesis method and the Odum's macroscope, which allow understanding and quantifying the energy flows that drive the cities functioning. The macroscope is able to identify the dependence relationships between cities and their surrounding environment that provides energy and resources to be transformed into high-quality products and information. After two decades of developing studies related to urban systems under Odum's macroscope approach, the research team of Paulista University in Brazil acquired experience and maturity to write this conceptual analysis about how Brazilian cities work. Several cases are provided—including anabolic and catabolic pathways involved in the regulation of cities mechanisms—to sustain final insights on the way Brazilian cities work. The results show how these cities add to the development the country transforming low quality energy into higher quality outputs. Cases are discussed under the Odum's macroscope perspective providing understanding on the dependence among cities and their neighborhood and helping to plan for future development.

Bamboo has being used as alternative raw material for construction, reinforcing fibers, paper production, among other applications. Although its recognized potentials as raw material, there are doubts about its environmental performance compared to traditional wood-based products, including paper production, which hinders bamboo-based paper plants in large scales. This study aims to assess the environmental performance of producing office paper from bamboo. Emergy synthesis (with 'm') and global warming potential indicators are calculated and compared with the traditional eucalyptus paper-based production. Results highlights the importance in including the renewability fractions of each input resources into emergy calculations for production systems with high human-labor intensity such as the bamboo agricultural production. Office paper produced from bamboo has similar renewability (28%), moderate environmental load (3.23 vs. 2.49), and emergy unsustainability (0.34 vs. 0.60) compared to paper produced from eucalyptus, but bamboo showed lower performance for global efficiency (568 vs. 442 sej/ton paper), emergy yield (1.09 vs. 1.49), and emergy investment (10.79 vs. 2.05). Focusing on global warming potential, office paper produced from bamboo releases 98 kgCO 2 eq. /ton paper compared to 56–267 kgCO 2 eq. /ton paper for eucalyptus. Notwithstanding, bamboo-based office paper demands four times more land area of agricultural production than eucalyptus, but it has a positive social aspect by requiring higher amount of direct human labor. This work shows the advantages of using eucalyptus rather than bamboo in producing office paper from an emergy and land demand perspectives, while global warming can still be considered inconclusive. Future efforts should consider a quantitative and qualitative analysis of human labor availability in both systems, as well an economic analysis to support discussions towards more sustainable office paper production from different raw materials. • Environmental load of bamboo and eucalyptus for office paper production are compared. • Bamboo has lower emergy performance than eucalyptus. • Including the renewability fraction of labor and services better reflects emergy results. • Bamboo paper emits 98kgCO2eq/ton, eucalyptus paper emits 56–267kgCO2eq/ton. • Bamboo paper needs 4x land compared to eucalyptus and requires more human labor. [ABSTRACT FROM AUTHOR]

The overarching goal of this research was to provide sound strategies to further the development of rapeseed farming and to increase the sustainability and productivity of rapeseed production systems. Progress toward this goal was made by assessing subsistence and commercial rapeseed production systems in Khorramabad, Iran during the 2017–2018 crop year using both emergy and economic indices. The total emergy supporting the systems was estimated to be 4.13E+16 and 2.47E‏+16 sej ha−1 yr−1 for the commercial and subsistence rapeseed production systems, respectively. The calculated values of the modified environmental sustainability index, renewable emergy ratio, environmental loading ratio, and modified environmental loading ratio showed the higher ecological sustainability of the subsistence farming system compared to the commercial system for rapeseed production. According to these indices, the main reason for the lower sustainability of the commercial rapeseed production system was the large amount of soil organic matter that was lost per unit of nonrenewable resources used. A large emergy exchange ratio in favor of the buyer (EER Yield); increased environmental sustainability, when the market impact is considered (Emergy Index of Sustainable Development, EISD); lower emergy required per unit of output (Unit Emergy Value, UEV) and the higher productivity of the production factors (Total Factor Productivity); all reflect the relative advantage of the commercial system over subsistence farming. Our findings revealed that the ecological sustainability of the commercial rapeseed production system can be improved by employing scientific solutions for comprehensive management of the ecosystem, especially through the amelioration of soil organic matter and prevention of its loss. Besides improving the farmers' technical knowledge, the integration of small lots into the overall production system is recommended for improving the economic sustainability of the subsistence farming systems. • The management method chosen determines the quantity of renewable resources used. • Reduction of nonrenewable inputs is essential to make agroecosystems more sustainable. • The subsistence production system is not an ecological system, because of the use of nonrenewable inputs. • Integrated ecological-economic management of agroecosystems can achieve sustainability. [ABSTRACT FROM AUTHOR]

Highlights • The concentration of energy into more valuable forms is the driver for urban growth. • In cities, energy is concentrated in fuels, buildings, institutions, and knowledge. • Total concentration of resources in assets can be measured with emergy synthesis. • Higher population densities do not always produce lower environmental intensity. • There is a strong correlation between emergy intensities and land value. Abstract Energy is the ultimate driver for urban growth, providing the engine for its physical and economic activities, however it is the concentration of energy into more valuable forms—such as fuels, buildings, institutions, and knowledge—that underlies the capacity for development. The goal of the project is to evaluate the interactions between resource flows (renewable and non-renewable) and the spatial distribution of more concentrated assets, using household consumption as the primary lens through which to construct an emergy model of the greater Philadelphia region. [ABSTRACT FROM AUTHOR]

Abstract Urban form is one of the key strategies the IPCC AR5 emphasized in attempting to mitigate greenhouse gases in urban areas. Although there is an abundance of research exploring the relationship linking the elements of urban form, energy consumption, and CO 2 emissions on an urban level, little is known in regards to their relationships at the sub-city level. In addition, the energy consumed and the associated CO 2 emissions during the construction of buildings in urban areas have seldom been assessed. To address these two research areas, this paper uses emergy synthesis to evaluate embodied energy storage of different building types according to construction methods and development intensity and assesses the resources consumed and CO 2 emissions during construction processes across urban space. With the city of Taipei as a case study, five building types were classified according to building materials and stories. The spatial distribution of emergy storage embodied in the urban form of Taipei indicates that neighborhoods with higher emergy storage and building CO 2 emission are dominated by six to twelve stories reinforced concrete (RC) buildings. In contrast, the neighborhoods of low urban development dominated by brick buildings and one to five stories reinforced concrete buildings have lower emergy storage in buildings and building CO 2 emission. The results of the spatial distribution of emergy storage and building CO 2 emission are used to discuss the relationship of the intensity distribution ratio, the building types, the daily consumption of CO 2 , and the effects of urban spatial planning. Highlights • Urban forms and building types were affected by stages of urban development. • The density of building emergy storage are affected by building materials and intensity. • The spatial building-CO 2 emissions are correlated with building emergy storage. • Building-CO 2 emission and urban form are affected by urban spatial planning. • The sub-city scale can provide powerful GHG mitigation leverage points. [ABSTRACT FROM AUTHOR]

Approximately 17% of agricultural lands in the western plain of Taiwan were converted to other uses during 1971–2006 due to rapidly industrial and urban development and high population density. Previous studies on the loss of farmland due to urbanization have focused on changes in the agricultural landscape such as fragmentation and irregular shape of farmlands. The shrinkage and fragmentation of agricultural land due to urbanization not only reduces food production but also results in the decrease and degradation of other agro-ecosystem services. Emergy synthesis has been used to assess land use changes in agricultural lands. However, the relationship between farmland fragmentation and the energy flows in agricultural systems has not been studied. This paper investigates empirically how ecological energetic flows of agricultural land were affected by landscape change in the western coastal plain of Taiwan by using emergy synthesis to assess the changes in ecological energetic flows of agricultural systems in each township from 1971 to 2006. Landscape metrics were also chosen to analyze the agricultural landscape change in each township. These metrics were then correlated with the results of emergy synthesis to study the relationship between farmland fragmentation and energy flows in the agricultural system. The results show that the fragmentation of farmlands tends to intensify the inflows of goods and services from the human economic system for farmland operations. For the counties closer to metropolitan areas, maintaining larger farm sizes and preventing farmland fragmentation decreases the proportion of resource inflows from the economic system and mitigates environmental loading in agricultural systems. [ABSTRACT FROM AUTHOR]

Although endowed with abundant tidal resources, China's tidal power generation industry has been largely lagging behind other renewable energy alternatives such as small hydropower, photovoltaic power, wind power and biomass-based power. To probe the reasons behind this slow pace of development, an emergy evaluation and an economic analysis were conducted on the Jiangxia Tidal Power Station (JTPS), which has an installed capacity of 4.1 MW. The JTPS is the largest tidal power station in China and the fourth largest in the world. The evaluation results exhibited a total power conversion system emergy use of 1.59E+19 sej to generate 5.90E+13 J of electricity in 2014. Tidal energy only accounts for 16.54% of the total energy budget. The rest of the resources were invested to capture and convert tidal energy to electricity, thereby generating a relatively low efficiency or high transformity of 2.69E+05 sej/J. The results revealed a JTPS emergy loading ratio (ELR) and energy sustainability index (ESI) of 3.72 and 0.41, respectively, which indicates poorer environmental performance compared to other renewable energy power plants, with the exception of photovoltaic power. In addition, the economic analysis revealed a JTPS power generation cost of 2.41 CNY/kWh, which is even higher than that of concentrating solar power (CSP). The JTPS is less competitive because tidal energy has a lower quality and is more decentralized when generating electricity compared to other renewable resources. This inefficiency was exacerbated in the JTPS case due to the original multipurpose design and consequential poor site selection with respect to tidal electricity generation. These results further highlight the importance of dam site selection and the tidal range, as they are critical for the improvement of the tidal power generation environmental performance. More importantly, R&D is essential to promote the development of this technology and to ultimately utilize abundant tidal resources in an efficient and sustainable way. [ABSTRACT FROM AUTHOR]

To better understand how cities work, this study performs emergy (spelled with an “m”) synthesis of buildings on Manhattan Island. Conventional emergy studies have focused on much larger unit of analysis; however, architects, urban designers, and policymakers are operating on a smaller scale of building, block, neighborhood, and district. This study contributes to overcoming the scale and resolution mismatch between the macro- and micro-levels. Overall emergy for entire buildings on Manhattan Island is computed by adopting square-foot-base building cost estimation technique to emergy synthesis. We found that high-density and high-rise developments can achieve their maximum empower at the range of 1–5 Floor Area Ratio (FAR; an indicator of development density computed as total building floor area divided by total parcel area) and building height under 40 stories. [ABSTRACT FROM AUTHOR]

An industrial park is characterized as a cluster of industries designed to meet compatible demands of different economic organizations within one location, which is pivotal to drive the regional economic growth of developing countries. The concentrated industrial activities inevitably result in substantial resource consumption and corresponding environmental emissions. Environmental auditing, which is used for the checking and verification of environmental performance, is an effective tool for investigating environmental emissions and resource consumption status and alleviation potential in industrial parks. As one of the environmental auditing technologies, emergy analysis, which provides a systematic approach in identifying the balance between socioeconomic development and natural environment, is employed in this paper. Specifically, a ternary emergetic environmental performance auditing framework was proposed to evaluate the behavior (preliminary work), ecological-economic efficiency (Level 1), environmental impact (Level 2), and mitigation effect (Level 3) of a typical industrial park in Beijing. The result showed that the concerned industrial park mainly depends on labor and service inputs and has a relatively high economic efficiency. However, the large dependence on purchased emergy exerted great pressure on the resource and environment, and affect the stability of the industrial park. The proposed framework may help reveal the value that free environmental services and resources offer to a specific system and thus can be complementary to the existing environmental performance auditing tools. [ABSTRACT FROM AUTHOR]

For ecological economic evaluation based on the unified biophysical matrix this research illustrates an updated emergy synthesis in terms of embodied cosmic exergy instead of embodied solar energy, which successes the foundation of systems ecological theory but changes the starting point for the estimation from simply the sun to the cosmos. According to the modified definition implicating explicit scarcity and strict additivity based on the fundamental thermodynamics laws, the updated emergy approach overcomes the confusable and intractable deficiencies of traditional one and shows firmer theoretical basis as well as better applicability. As a case study for the regional socio-economic ecosystem, a cosmic emergy based ecological economic evaluation of the Beijing urban ecosystem during the period 1978-2004 is presented. The local and external resources supporting the concerned ecosystem are accounted and analyzed in a common unit, i.e., cosmic Joule, according to which a series of indicators are applied to reveal its evolutional characteristics through five aspects as emergy structure, emergy intensity, emergy welfare, environmental impacts, and degree of exploitation and economic efficiency. During the analyzed period, the major emergy source sustaining the operation of the ecosystem had changed from the renewable resources exploited locally to the nonrenewable resources purchased from outside. Emergy intensity for the Beijing urban ecosystem kept rising owing to the continuous investment of resources, which not only improved the living standard but also intensified the environmental pressure. Moreover, the increase of exploitation degree was accompanied with the decline of economic efficiency, while the rising emergy investment ratio implicates that Beijing was at the risks of resources shortage and high dependence on external resources

In this article, the authors quantify uncertainty of the building emergy analysis (BEmA). The emergy accounting considers environmental sources from the most fundamental context: the sun and the geobiosphere. However, due to the variety of large-scale parameters, BEmA suffers from lack of assurance in estimation. Accordingly, a source and quantity of uncertainty need to be clarified for its wide practical use. For this purpose, uncertainty of the major BEmA parameters, i.e., unit emergy values (UEVs) of the primary construction materials, life time of assemblies, and weight of the used materials, have been analyzed through a case study―a typical single-family house in Pennsylvania, United States. Data collected from all available literature was sampled to implement two uncertainty analysis methods: Monte Carlo simulation (MCS) and Fuzzy logic. The experiments were conducted with the following two ways: (1) we assumed that that empirical distributions of all the parameters fit into the normal distribution. The propagation of uncertainty was tested by MCS with hyper-cube sampling. (2) Fuzzy logic was employed to estimate distributions of actural values, because, in the reality, replacement intervals of building components and operational energy use tend to be subject to the building occupants’ contingent decisions or subjective judgments. In this case, data cannot be described by a steady-state normal distribution. The experimental findings showed that Monte Carlo simulation gave the mean of 9.57 × 10 13 sej/m 2 yr with the standard deviation of 3.73 × 10 13 sej/m 2 yr. Meanwhile, Monte Carlo simulation coupled with the Fuzzy logic reduced variability, thereby resulting in the mean of 8.42 × 10 13 sej/m 2 yr and the standard deviation of 0.94 × 10 13 sej/m 2 yr. Above two results were compared to each other through the KS (Kolmogorov–Smirnov) fitness test and the baseline of a point-estimate (7.66 × 10 13 sej/m 2 yr). Sensitivity analysis as a post processing examined the ranked contribution level of each parameter. As a result, it became clear that specific emergy values of the large amount inputs such as electricity and concrete block are the most influential variables to BEmA. [ABSTRACT FROM AUTHOR]

Urban water systems are an example of complex, dynamic human-environment coupled systems which exhibit emergent behaviors that transcend individual scientific disciplines. While previous siloed approaches to water services (i.e., water resources, drinking water, wastewater, and stormwater) have led to great improvements in public health protection, sustainable solutions for a growing global population facing increased resource constraints demand a paradigm shift based on holistic management to maximize the use and recovery of water, energy, nutrients, and materials. The objective of this review paper is to highlight the issues in traditional water systems including water demand and use, centralized configuration, sewer collection systems, characteristics of mixed wastewater, and to explore alternative solutions such as decentralized water systems, fit for purpose and water reuse, natural/green infrastructure, vacuum sewer collection systems, and nutrient/energy recovery. This review also emphasizes a system thinking approach for evaluating alternatives that should include sustainability indicators and metrics such as emergy to assess global system efficiency. An example paradigm shift design for urban water system is presented, not as the recommended solution for all environments, but to emphasize the framework of system-level analysis and the need to visualize water services as an organic whole. When water systems are designed to maximize the resources and optimum efficiency, they are more prevailing and sustainable than siloed management because a system is more than the sum of its parts. [ABSTRACT FROM AUTHOR]

Greenhouse gas emissions and climate change has been partially attributed to agricultural expansion by deforestation, while the pressure to assure food, fiber and energy for the future generations leads to the intensification of agricultural systems. The transition to more efficient systems is actually considered an important strategy to reduce deforestation and to spare land for other uses, including the recovery of environmental services and ecohydrological processes in the drainage basin such as carbon sink and water regulation. The Brazilian Federal Program for Low Carbon Agriculture (ABC Program) intends to reduce carbon emissions by stimulating technological processes that neutralize emissions or enhance the sinking of greenhouse gases. A pilot farm has been established to assess an intensive animal-plant farming system that incorporates anaerobic digestion for biogas, power generation and organic fertilizer production. Emergy Synthesis was chosen as a methodological tool to assess and to diagnosis the farm system design. The modified emergy assessment including externalities (greenhouse gas emissions) improves the understanding of integrated crop–livestock systems efficiency in internal recycling of nutrients and power conversion. The adoption of manure treatment in intensified agricultural systems can effectively contribute to enhance environmental and economic performances. [ABSTRACT FROM AUTHOR]

Sewer systems, over their life cycle, suffer deterioration due to aging, aggressive environmental factors, increased demand, inadequate design, third party intervention, and improper operation and maintenance activities. As a result, their state and overall long-term performance can be affected, which often requires costly and extensive maintenance, repair, and rehabilitation. Furthermore, these pressures can enhance the risk of failures (e.g., sewer leakage) which in turn can have serious impacts on the environment, public safety and health, economics, and the remaining service life of these assets. Effective asset management plans must be implemented to address long-term sustainability principles, i.e., economic growth, human health and safety, and environmental protection, simultaneously. The aim of this paper is to evaluate and compare four typical sewer pipe materials [i.e., concrete, polyvinyl chloride (PVC), vitrified clay, and ductile iron] and identify sustainable solutions. Two comprehensive life cycle sustainability assessment (LCSA) frameworks were applied. The first LCSA framework was based on the integration of emergy synthesis, life cycle assessment (LCA), and life cycle costing (LCC). In this framework, emergy synthesis has been applied to integrate the results from environmental analysis (i.e., LCA) and economic analysis (i.e., LCC) to an equivalent form of solar energy: a solar emergy joule. The second LCSA framework was based on a conventional, multi-criteria decision-making technique, i.e., the analytical hierarchy process, to integrate the results from environmental analysis (i.e., LCA) and economic analysis (i.e., LCC) and find the most sustainable solution over the sewer pipe life cycle. The results demonstrate that PVC pipe is the most sustainable option from both environmental and economic view points and can ensure a more sustainable sewer system. [ABSTRACT FROM AUTHOR]

In this paper, emergy analysis is used in association with the ternary diagrams and geographic information system (GIS) tools to improve the evaluation of sustainability for the Pan-Pearl River Delta (PPRD) region. Emergy accounting of PPRD is estimated, and various emergy-based indicators are reported. Ternary diagrams are drawn to provide a graphical representation of the emergy accounting data. Finally, the GIS tools are employed to assist in the emergy-based spatial analysis, and emergy density based on flat land area is mapped to reflect the intensity of emergy use in human activity areas. Results show the following: (1) the current development path of the PPRD region, with the value of emergy sustainability index (ESI = 0.227) significantly lower than one, is unsustainable in the long run; (2) Guangdong has the lowest ESI value (0.071), and the ESI values of Fujian, Guangxi, Hunan and Jiangxi are lower than 0.5, indicating that the economy in these provinces overly relies on non-renewable and imported resources; (3) Guizhou has a high emergy yield rate and is thus the main energy supplier in PPRD; and (4) among the nine provinces in PPRD, only Hainan has an ESI value (2.145) higher than one. [ABSTRACT FROM AUTHOR]

Highlights: [•] We assess an ecological restoration programme with the dual objectives of environment and poverty alleviation. [•] We use ecological footprint and emergy synthesis for the calculation of the effects and sustainability of this programme. [•] The use of natural resources exceeds the ability of supporting source base both from the perspective of demand and endowment. [Copyright &y& Elsevier]

Abstract: Emergy synthesis is capable of quantifying environmental resources and services, as well as economic and human services, that are used up directly or indirectly to make a product available. However, a controversial aspect of emergy synthesis is the lack of research characterizing and documenting uncertainties in the emergy evaluation process. Uncertainty can arise from analysis of numerous components and flows in a complex environmental system. The reliability of emergy synthesis results may be undermined by both the inherent uncertainty of emergy parameters and models, and by a lack of knowledge regarding the certainty of resulting outputs. This paper explores the utility of fuzzy-based methods in emergy synthesis. Applying fuzzy set theory facilitates the gradual assessment of Unit Emergy Values (UEVs) as a set of possible UEVs. In other words, uncertainty of UEVs is described with the aid of a membership function valued in the real unit interval [0, 1]. The proposed fuzzy-based emergy synthesis has been applied for Life Cycle Assessment (LCA) of a transportation infrastructure system. A paved road, with different pavement options (i.e. asphalt and concrete), has been selected as a case study to highlight the impacts of propagation of different sources of uncertainties in the emergy evaluation process and decision making. Results indicate that fuzzy-based modeling can provide better insight for both emergy and LCA practitioners. The developed methodology provides transparency that should be an integral part of an emergy-based decision making process. [Copyright &y& Elsevier]

Highlights: [•] Integrated emergy and economic evaluation, and statistical analysis of tea production. [•] Tea production chains were classified into three stages for evaluation. [•] Over use of chemical fertilizer and low productivity of labor characterize tea production. [•] One remedy is to decrease the price of organic fertilizer to improve sustainability. [ABSTRACT FROM AUTHOR]

Highlights: [•] The major emergy flows interacting in the Island of Montreal were identified and quantified. [•] The most important emergy flows were the monetary ones and those corresponding to the building materials entering the island. [•] When compared to other selected cities, available space per inhabitant was correlated to empower density. [•] The findings may be used as a guide to propose a methodology for the determination of intensity of development from an environmental perspective. [Copyright &y& Elsevier]

A rising global urban population, increases the demand for natural resources for a certain quality of life. This creates negative impacts on natural ecosystems and the survival of other species. For this reason, it is necessary to measure the state of cities as ecological systems with the purpose of prioritizing environmental management, in accordance to sustainable development. To this end, there exist methods of chrematistic evaluation which exclude the work of nature to provide environmental services that promote environmental sustainability. This study investigated models that foster environmental accounting and that integrate natural and urban ecosystems. The most original proposal came in the form of emergetic synthesis, based on thermodynamic concepts. The municipality of Palmira was chosen as the study area, known as Techno-ecosystem, and applied a five-phase methodology, based on the emergetic synthesis method. Calculating the rate of emergy production - EYR with 1.46, Environmental Load Index - ELR with 3.2 and Environmental Sustainability Index - ESI with 0.46. The analysis indicates that environmental sustainability and the generation of real wealth is limited by current land use, and can be improved with better use of this resource, through a transversal management process. Furthermore the Technoecosystem is subject to the social metabolism of the city of Cali and therefore the demand for imported goods and urban land use will increase, reinforcing the need for environmental management policies , as well as the need to apply to the municipality as Emerging City. [ABSTRACT FROM AUTHOR]

Abstract: Derived from the maximum power principle (MPP), the maximum empower principle (MePP) is considered as the foundation of emergy theory and evaluation methods. However, it has often encountered some doubts since proposed, because of lacking sufficient empirical evidence. To test the validity of the MePP in the self-organization of forest ecosystems, this paper applied a process-based ecosystem model (Biome-BGC) to simulate the dynamics of biomass, litter and soil organic matter (SOM) of three forest plantations in south China during 1985–2007, and attempted to replicate their self-organizing processes. The simulated results and input flows were transformed to emergy as a common basis and, from the viewpoint of emergy synthesis, the dynamics of the production efficiency and empower of the three forest ecosystems were revealed along with their self-organizing developments over time. The results showed that three forest plantations had similar dynamic change patterns of emergy efficiency and empower, but the production efficiencies of them were not always consistent with their empower performances. The production efficiency firstly increased rapidly to maximums, and then decreased to optimal moderate values. However, the empower came to the maximums after the efficiency peaked and then fluctuated up and down, dependent on weather. These results implied that, a forest ecosystem in its self-organizing process tends toward maximum empower at optimal efficiency. Behind the maximum empower of the forest ecosystem is the desynchrony development of different components, e.g., biomass, litter and SOM; leaf, stem and root; biomass and biodiversity. As a whole, the MePP functions like an invisible hand controlling the general self-organizing development of forest ecosystems and pointing out the direction of their development. [Copyright &y& Elsevier]

Abstract: Efficient implementation of recycling networks requires appropriate logistical structures for managing the reverse flow of materials from users to producers. The steel sheet distributor studied had established a protocol for scrap recovery with the steel plant and its customers. The company invested in producing containers, hiring a specialized labor force and in purchasing trucks for container transportation to implement the logistics network for recycling. That network interconnected the company with two kinds of customers: the ones returning scrap and the ones who preferred to continue business-as-usual. The logistical network was analyzed using emergy synthesis, and the data obtained were used to evaluate and compare the system's environmental costs and benefits from the perspective of the distributor and the steel plant operator. The use of emergy ternary diagrams provided a way to assess recycle strategies to compare the relative economic and environmental benefits of the logistical network implemented. The minimum quantity of scrap that the distributor must recover to improve environmental benefits was determined allowing decision on whether it is worth keeping the system running. The new assessment method proposed also may help policy-makers to create strategies to reward or incentive users of reverse logistics, and help to establish regulations, by decreasing taxes or stimulating innovation, for effectively implement the National Policy on Solid Waste. [Copyright &y& Elsevier]

Environmental impact assessment of agriculture has received increased attention over recent decades, leading to development of numerous methods. Among them, three deal with energy use: Energy Analysis (EA), Ecological Footprint (EF) and Emergy synthesis (Em). Based on a review of 197 references applying them to a variety of agricultural systems, this paper evaluates their ability to assess energy use. While EF assesses energy use as land use via a global accounting approach in which energy is only one component of the assessment, EA and Em are energy-focused and appear more appropriate to highlight ways to increase energy-use efficiency. EA presents a clear methodology via fossil energy use and its associated impacts but does not consider all energy sources. With inclusion of natural and renewable resources, Em focuses on other energy resources, such as solar radiation and energy from labour, but does not present impact indicators nor establish a clear link between activities and their environmental impacts. Improvements of the EA and Em methods could increase their ability to perform realistic and unbiased energy analysis or the diversity of livestock systems encountered in the world. First, to consider all energy sources, as Em does, EA could include solar radiation received by farm surfaces and energy expenditure by humans and animals to accomplish farm operations. Second, boundaries of the studied system in EA and Em must include draft animals, humans and communal grazing lands. Third, special attention should be given to update and locally adapt energy coefficients and transformities. [Copyright &y& Elsevier]

Abstract: Energy analysis results confirmed that abandoned rice fields provide a good opportunity for Japan to fulfill its E-3 target by producing ethanol from high-yield rice feedstock. However, to be a viable alternative, a biofuel should not only provide a net energy gain and reduce the emissions of polluting gases, but also be ecologically and economically competitive. Thus, an integrated ecological-economic evaluation was done to determine the viability of the process, the opportunity cost of biodiversity loss and the quality of the energies consumed and produced. The results showed that although ethanol from high-yield rice has a net energy yield, it is currently neither ecologically nor economically feasible to use it to replace gasoline as a transport fuel in Japan. There is a positive effect in that polluting gas emissions are reduced, but this benefit is too small to change the large negative balance in both the emergy and economic accounts. Furthermore, converting an abandoned rice field to the cultivation of intensified high-yield rice feedstock could have a large negative effect on biodiversity at both genetic and species levels, which if fully realized, would be over 300 times the ecological economic value of the rice-ethanol output. [Copyright &y& Elsevier]

Abstract: The biogas-linked agriculture has experienced a rapid development in recent years in rural China, which serves both as part of the country''s developmental strategies of cleaner energy and an important reaction to sustainable agriculture call. This paper provides an overview of the economic and environmental performance of biogas-linked agrosystem (BLAS) in China by focusing on efficiency, emission mitigation effect and sustainability. An emergy synthesis combing emergy accounting and emergetic ternary diagram are utilized to evaluate the overall BLAS and its four subsystems (i.e., planting subsystem, breeding subsystem, aquaculture subsystem and biogas subsystem) in terms of current status and future development. Our findings indicate that despite a high energy transformity at system scale and a great dependence on economic input, BLAS advantages itself with high biogas production efficiency and significant emission mitigation effect. Furthermore, the sustainability zone analysis shows that the overall BLAS, planting and aquaculture subsystems maintain medium-term sustainability under all policy scenarios, despite the fact that breeding and biogas subsystems stay in an unsustainable situation due to their relatively severe environmental load. Among all the studied future options, continual biogas construction and effective technological revolution instead of expanding investment in traditional agriculture are preferable routes to further improve the system performance. Last but not least, emissions mitigation, energy efficiency and system sustainability are unveiled to be positively correlated within BLAS, which entitles it a promising energy alternative to enhance biogas energy utilization in the local agriculture in face of today''s energy crisis. [Copyright &y& Elsevier]

Evaluating the sustainability of a target region for an ecological restoration programme is challenging because it involves different aspects of human society and environment as well as multiple disciplines. Carrying capacity provides a useful measure of the sustainability of a given region where an ecological restoration programme is implemented. In this article, the Yangou catchment, a geomorphic unit, was used as a case study in the Loess Hilly Region of China, where emergy synthesis was used to measure the environmental resources base. The specific standard of living in terms of emergy was employed to calculate carrying capacity over the period 1998–2005 and to assess the sustainability of the Yangou catchment where an ecological restoration programme was carried out. The results of the evaluation indicated that after implementing the ecological restoration programme, there was some improvement in the environmental aspects of the Yangou catchment during the study period, suggesting that the ecological restoration programme alleviated ecological degradation. However, several emergy-based indices and the support areas also illustrated that the ecological restoration programme was not successful enough in terms of preservation and utilisation of environmental resources to enhance sustainability. This indicates that further actions are necessary on conserving environmental resources, improving the emergy input structure for agricultural production and in lifestyle changes for the local people in living in the Yangou catchment. [ABSTRACT FROM AUTHOR]

Abstract: The Chinese government has increasingly turned to agricultural industry policy as a means of promoting rural development, which have not necessarily led to an improvement in rural incomes nor to the achievement of other social and environmental goals. Emergy synthesis methods were applied to four agricultural production systems, i.e., two local traditional production systems as maize plantation and pond fish farming, one scaled Shaoxing duck (Anas Platyrhyncha var. domestica) rearing system, and one newly introduced specialty production system of common mushroom (Agaricus Bisporus) cultivation, in Weishan county of Shandong province of China in the year 2007, to assess and compare their environmental performances. Additionally, aiming at understanding the benefits and driving forces of agricultural diversification, environmental performance results were contrasted with traditional economic indicators. As indicated by EYR, ELR and ESI, it can be clearly shown that the scaled duck rearing and newly introduced common mushroom cultivation alternatives are not in a sustainable pattern, although having better economic performance than maize cropping and pond fish farming. Nevertheless, the development of rural agricultural diversification is also affected by land accessibility, investment ability and even labor availability. Therefore, achieving a profitable and environmental sustainable diversified farming system is not an easy task in Weishan area as well as in whole China. It is unwise to encourage development of agricultural diversification in current manners without too much consideration on environmental degradation. [Copyright &y& Elsevier]

This paper presents a biophysical understanding of the MSW-to-energy facility located at the São João landfill in São Paulo using Emergy synthesis. Accounting for the material inputs and the biogas accumulation Emergy-based indices are calculated to evaluate the environmental load and sustainability level of the concerned biogas project. The study was conducted by combining the analysis of transformities, Emergy indicators and the net Emergy yield ratio to establish long-term sustainability and measure global environmental stress. The implementation of a project for environmental compensation in fulfilment of state's requirements was also assessed. The findings reveal that the Emergy investment to the use of biogas is quite low and, therefore, advantageous. Transformities show that the global productivity of the MSW-to-energy plants can compete with traditional plants. The conclusions justify the effort invested in developing MSW-to-energy plants and are relevant for policy makers in a highly sensitive sector to accomplish sustainability goals. [ABSTRACT FROM AUTHOR]

The cross-boundary environmental effects of urban household metabolism are of increasing interest in the context of global climate change and the sustainability of urban systems. To assess resource exchanges and environmental emissions, urban household metabolism was investigated using an ‘emergy synthesis framework’, with the city of Xiamen providing case study data. Two data sets, one from the highly urbanized Xiamen Island (XI) and the other from the less urbanized Xiamen Mainland (XM), were collected and analyzed using an ‘urban spatial conceptual framework’. Household consumption and its spatial environmental effects are embodied by exchanges of resources, energy, services, and wastes between the urban system's physical footprint (‘Urban Sprawl Region’, USR), and its ecological footprint (‘Urban Footprint Region’, UFR). The results show that Xiamen's USR is connected to its UFRs by approximately 98.74% emergy flows. The distinct emergy indicators identified within the results show that the driving forces, processes, influences, efficiency and sustainability of household metabolism vary dramatically between XI and XM, demonstrating that different urban and social contexts significantly affect household metabolism. The Emergy Sustainability Index reveals that USR households need to make lifestyles changes to sustain development. The employed frameworks (urban spatial conceptual framework and emergy synthesis framework) enable the computation of household consumption and cross-boundary environmental effects. The results may help foster alternative household consumption strategies which could result in more equitable resource allocation and effective mitigation of cross-boundary environmental influences. [ABSTRACT FROM AUTHOR]

Abstract: As the concept of sustainable development is more accepted and incorporated by institutions, it becomes necessary to evaluate the performance of the national economy based on new methods and not only on economic indicators. Despite the importance of sustainability to the preservation of natural ecosystems and services, there is no agreement in the world scientific community concerning a methodology to evaluate that concept. In the last decade, two scientific tools have been extensively used worldwide to measure the human impact on nature: Ecological Footprint and Emergy Synthesis. Papers trying to combine them, and to obtain more accurate results have appeared in scientific literature, of which approach is an important one. Unfortunately, some weak points of the original methods still remain in the new approaches proposed. The objective of this work is to discuss some weak points found in the Ecological Footprint and Emergy Synthesis and to use the positive aspects and potential improvements from both methodologies at a national level. Emergy deals with the notion that all energy that is used directly and indirectly in a process to deliver an output product, flow or service should be accounted for. A new definition for Biocapacity was introduced meaning “the natural area''s capacity of receiving renewable energy”, rather than “usable biomass” as proposed by the conventional Ecological Footprint methodology. The questions to be answered by the proposed methodology are how much land would be equivalent to consumption, if products were generated solely by the use of natural renewable resources (Emergetic Footprint), and how much land would be available in the system considering world''s average capacity of receiving renewable energy (Emergetic Renewable Biocapacity). A new category called “areas not occupied by humans” is included in the Biocapacity. It is composed of open ocean, deserts and frozen land (areas excluded from the conventional Footprint method). Footprint or consumption means the load imposed by humans on the environment and was grouped in categories: cropland, forestry, animal products and energy resources. Ecological Fooptrint using Emergy was used to assess Brazil as a case study, resulting in a Biocapacity of 62.2ghaperson−1 and a Footprint of 41.9ghaperson−1, using data from 2004. The positive aspects of the approach proposed are: (i) its ease of application at global and national scales; (ii) the indicator of consumption (Footprint) accounts for the direct and indirect energy used to generate products and services; (iii) a new category considering areas excluded from the conventional method was included in the Biocapacity calculation, which can be a valid step towards the evaluation and assessment of services provided by nature. On the other hand, the approach has as main limitations: (i) it is not possible to make comparisons between the Biocapacity and Footprint for each category; (ii) there is a need for a handbook with well-explained calculations of emergy intensity factors. [Copyright &y& Elsevier]

Abstract: Indicators of efficiency and environmental performance are fundamental to marking progress toward more sustainable patterns of human development. Central to indicator development is a common framework through which the wide range of environmental assessment methods may make comparative analysis. Clear and consistent definitions of system boundaries and input categories are essential to their interpretation, and form a necessary pre-requisite for meaningful comparisons of competing systems. A common framework of foreground and background categories, consistent with both LCA and Emergy Synthesis, is identified and discussed as the basis for the calculation of performance indicators. In this paper a revised operational definition of the Emergy Yield Ratio (EYR) is introduced, in light of the proposed categorization scheme, for consistent application to technological processes. Two case studies, namely CdTe PV and oil-fired thermal electricity production, are investigated. The Unit Emergy Value (UEV) of electricity generated by the thermal plant was calculated as 5.69E5seJ/J with services and 5.11E5seJ/J without services. The UEV for electricity generated by the PV system is 1.45E5seJ/J with services, and 7.93E4seJ/J without services. The computed EYRs including services are 6.8 for thermal electricity and 2.2 for PV electricity. [Copyright &y& Elsevier]

Large-scale production of biofuels is increasingly touted in national policies and international trade agreements. This global trend is particularly clear in Brazil. However, the sugarcane monocultures promoted in the country depend on a range of fossil fuel derivates, industrial inputs, chemical fertilizers, agrochemicals, machinery, labor exploitation and various other non-renewable resources, making it a questionable alternative to substitute fossil energy sources. In parallel, an alternative approach has recently emerged in southern Brazil, which promotes integrated food and energy production in small-scale, family managed production units, based on agro-ecological principles and local market orientation. This paper explores the potential of this alternative for more environmentally sustainable and socially fair production of food and biofuels. The scope of the paper is interdisciplinary, in combining environmental and social information from participatory fieldwork and interviews with farmers. Resource flows at farm level are identified and illustrated in diagrams, and interactions between farmers and institutions at local and global levels. The paper also explores opportunities for cross-fertilization between the two approaches applied: emergy synthesis (ES) and participatory learning and action (PLA). Integration was operationalized by drawing emergy diagrams together with local farmers, supported by PLA tools. The result is a systems description that adds information provided by farmers to an understanding based on general systems principles. Apart from accounting for the empirical results from this approach, lessons learned are used for proposing a new framework for participatory emergy synthesis (P-ES), which would facilitate more interdisciplinary and participatory evaluation of agricultural systems. [ABSTRACT FROM AUTHOR]

Abstract: The organic agricultural production is regarded as an important way to ensure food safety and achieve sustainable agricultural development. Presented in this paper is an emergy-based analysis of two typical chicken farming systems popular in China, i.e., family-operated organic rearing system and orchard-based field rearing system, from the perspective of production efficiency, environmental impact and the overall sustainability. In addition, the similar evaluation results conducted in Italy (scatter rearing system in grassland and conventional scale rearing system) was also introduced for reference and comparison. The results showed that the emergy yield ratio (EYR) was 1.10 and 1.11 for family-operated organic rearing system and field rearing system respectively. The values are approximately equal and very close to 1, indicating that each process of the two systems only converts resources from outside into product without much addition from local resources. However, the environmental loading ratio (ELR) of orchard-based field rearing system is 3.44, a little bit higher than the family-operated system 3.10, and correspondingly the sustainable index (ESI) is lower than that of family-operated organic rearing system. Despite being close to the concept of organic production practice with respect to rearing space for exercise and feeding patterns, the field chicken farming system has a relative poor performance with regard to environmental pressure and overall sustainability, which is attributable to the large amounts input of external purchased resources, e.g. the building material, drug, feed and so on. Compared with the other two production systems in Italy, the two systems in this study have higher economic cost and heavily rely on the non-renewable resource inputs. It can be concluded that current so-called organic production model in China is far from the essence of real practice and therefore innovations in production techniques and institutional reforms associated with organic pattern are urgently needed in China. [Copyright &y& Elsevier]

Methods and indicators need to be developed to investigate urban ecosystem health to mitigate eco-environmental problems and develop holistic policies for integrated urban ecosystem management. Considering the importance of energy and materials flows in urban ecosystems, the emergy synthesis model was applied to organize the urban ecosystem health indicators from the biophysical perspective in this paper, through which a better understanding of urban ecological patterns and processes can be obtained. Set pair analysis was combined to conduct the data processing of health indicators and promote objectivity of ecosystem health criteria. Set pair analysis defines the approximate degree of a real index set relative to an optimal one, which is evaluated to describe the relative urban ecosystem health levels in view of the emergy-based health indicators. Six cities in the Yangtze River Delta urban cluster in China (Shanghai, Suzhou, Wuxi, Changzhou, Nanjing and Hangzhou) were selected as case studies using 2005 data. The evaluation showed that the urban ecosystem health states of Shanghai and Hangzhou are relatively good, while the health states of Wuxi and Suzhou are relatively poor. The health states of the cities based on the factors (vigor, structure, resilience, ecosystem service maintenance and environmental impact) and individual indicators were also analyzed to identify regulatory directions and measures for improving the health status of those cities with relatively poor ecosystem health. This paper presents a meaningful comparison between different urban ecosystems at different indicator levels and provides a useful framework for urban ecological management with respect to urban ecosystem health status. [ABSTRACT FROM AUTHOR]

Abstract: Peri-urban areas are often characterized by valuable natural environments that provide essential life-support functions and ecosystem services for urban residents. Global environmental change has raised concerns over how urbanization and land use and land cover change affect ecosystem services. This study applied systems ecology theory and ecological energetic analysis to value the worth of natural environment and ecosystem services to a socioeconomic system. We begin with a general discussion of peri-urban areas and their ecosystem services. An emergy approach is applied to establish a framework for evaluating the ecosystem services by identifying systemic roles of each system components. The two-part framework includes: (1) an emergy evaluation of energetic flows of ecosystem services; and (2) an impact matrix to analyze systemic roles of services in the analyzed system. On the basis of the proposed valuation framework and land cover types in the greater Taipei area, this study analyzed ten ecosystems to determine how they interact, via energy flows, to contribute services to human society. By converting all stocks and flows into common emergy units, an impact matrix is constructed to analyze the systemic role of ecosystem components by classifying their status of being active, reactive, critical or indifferent. The analytical results indicate that the soil component of forest ecosystems, upstream rivers and agricultural productivity play critical role of ecosystem services in the study region. The effect of land cover change during 1971–2006 in the study region on ecosystem services is also analyzed. Finally, the implications of biophysical valuation of ecosystem service for spatial planning as related to adapting to global environmental change are discussed. [Copyright &y& Elsevier]

Abstract: As the most active palm industry cluster in the world, Malaysia produces enormous amount of biomass from the industry. This work studies the possibility of creating a renewable and sustainable source of energy by fully utilizing an area of land to provide liquid biofuel for the country. Palm-based biofuel refinery (PBR) proposed in this study has the ultimate goal to displace petroleum fuels and fulfill domestic energy demand. It fully utilizes indigenous palm biomass to fulfill 35.5% of energy demand in the country by using land area of only 8% of current palm cultivation. The operation concept of PBR is similar to petroleum refinery in which a single source feedstock (crude petroleum) can be processed to multiple products. In PBR, products from an oil palm plantation will be converted to various biofuel end products. Renewable biofuel such as biodiesel and bioethanol can be produced from crude palm oil and lignocellulosic residues. Energy and emergy assessment were made in this work to evaluate the sustainability and efficiency of PBR. Biofuel produced from PBR has a high energy equivalent of 31.56MJ/kg as 1ha of land can produce 182,142MJ annually. Although there are still obstacles to be overcome, it is important for Malaysia to develop its own energy supply from indigenous resources as an initiative not only for security but also lower carbon emission. [Copyright &y& Elsevier]

Regarding the basic roles of urban ecosystem health assessment (i.e., discovering the comprehensive health status, and diagnosing the limiting factors of urban ecosystems), the general framework integrating comprehensive evaluation and detailed analysis is established, from both bottom-up and top-down directions. Emergy-based health indicators are established to reflect the urban ecosystem health status from a biophysical viewpoint. Considering the intrinsic uncertainty and relativity of urban ecosystem health, set pair analysis is combined with the emergy-based indicators to fill the general framework and evaluate the relative health level of urban ecosystems. These techniques are favorable for understanding the overall urban ecosystem health status and confirming the limiting factors of concerned urban ecosystems from biophysical perspective. Moreover, clustering analysis is applied by combining the health status with spatial geographical conditions. Choosing 26 typical Chinese cities in 2005, relative comprehensive urban ecosystem health levels were evaluated. The higher health levels of Xiamen, Qingdao, Shenzhen, and Zhuhai are in particular contrast to those of Wuhan, Beijing, Yinchuan, and Harbin, which are relatively poor. In addition, the conditions of each factor and related indicators are investigated through set pair analysis, from which the critical limiting factors of Beijing are confirmed. According to clustering analysis results, the urban ecosystems studied are divided into four groups. It is concluded that the proposed framework of urban ecosystem health assessment, which integrates comprehensive evaluation and detailed analysis and is fulfilled by emergy synthesis and set pair analysis, can serve as a useful tool to conduct diagnosis of urban ecosystem health. [ABSTRACT FROM AUTHOR]