Sustainability assessment of large-scale ethanol production from sugarcane

The present study assesses the sustainability of ethanol produced from sugarcane and examines the environmental feasibility of a large-scale production through the use of: fossil fuel embodied energy and Emergy Assessment including farm and industrial production phases. The study indicates that about 1.82 kg of topsoil eroded, 18.4 l of water and 1.52 m² of land are needed to produce 1 l of ethanol from sugarcane. Also, 0.28 kg of CO₂ is released per liter of ethanol produced. The energy content of ethanol is 8.2 times greater than the fossil-based energy required to produce it. The transformity of ethanol is about the same as those calculated for fossil fuels. The Renewability of ethanol is 30%, a very low value; other emergy indices indicate important environmental impacts as well as natural resources consumption. The results obtained indicate that sugarcane and ethanol production present low renewability when a large-scale system is adopted.     

能值分析理论在耕地可持续利用评价中的应用研究——以南京市为例

评价指标体系是耕地可持续利用评价研究的难点,正确选择评价理论与方法,构建科学、合理的评价指标体系,为正确认识耕地利用的可持续性及制定相应政策提供理论与实践依据。文章引入能值理论,在传统评价方法基础上对耕地利用中物流、能流等以太阳能值为统一衡量标准,建立新的指标体系,并对南京市1995~2004年的耕地利用进行评价。结果表明,研究时段内南京市耕地利用是向可持续方向发展的,且其可持续利用经历了两个阶段:①1995~1998年可持续性下降阶段,综合系数从1995年的1逐渐下降到1998年的0.9570;②1998~2004年可持续性上升阶段,综合系数逐年上升到2004年的1.1123。与传统评价方法相比,引入能值理论后的评价结果更能全面、客观地反映耕地利用的可持续状况。     

Comparison of soil N availability and leaching potential,crop yields and weeds in organic,low-input and conventional farming systems in northern California

Increasing dependence on off-farm inputs including, fertilizers, pesticides and energy for food and fiber production in the United States and elsewhere is of questionable sustainability resulting in environmental degradation and human health risks. The organic (no synthetic fertilizer or pesticide use), and low-input (reduced amount of synthetic fertilizer and pesticide use), farming systems are considered to be an alternative to conventional farming systems, to enhance agricultural sustainability and environmental quality. Soil N availability and leaching potential, crop yields and weeds are important factors related to agricultural sustainability and environmental quality, yet information on long-term farming system effects on these factors, especially in the organic and low-input farming systems is limited. Four farming systems: organic, low-input, conventional (synthetic fertilizer and pesticides applied at recommended rates) 4-year rotation (conv-4) and a conventional 2-year rotation (conv-2) were evaluated for soil mineral N, potentially mineralizable N (PMN), crop yields and weed biomass in irrigated processing tomatoes (Lycopersicon esculentum L.) and corn (Zea mays L.) from 1994 to 1998 in California’s Sacramento Valley. Soil mineral N levels during the cropping season varied by crop, farming system, and the amount and source of N fertilization. The organic and low-input systems showed 112 and 36% greater PMN pools than the conventional systems, respectively. However, N mineralization rates of the conventional systems were 100% greater than in the organic and 28% greater than in the low-input system. Average tomato fruit yield for the 5-year period (1994–1998) was 71.0 Mg ha⁻¹ and average corn grain yield was 11.6 Mg ha⁻¹ and both were not significantly different among farming systems. The organic system had a greater aboveground weed biomass at harvest compared to other systems. The lower potential risk of N leaching from lower N mineralization rates in the organic and low-input farming systems appear to improve agricultural sustainability and environmental quality while maintaining similar crop yields.     

Application of sustainable development concepts to an alluvial mineral extraction project in Lower Caroni River,Venezuela

The Caroni River, a tributary of the Orinoco River in the State of Bolivar, Venezuela, has been subjected to mining since the end of the last century. Until the 1990s, hundreds of artisanal miners operated along a 70 km stretch of the river using rudimentary suction dredges to extract gold and diamonds from sediments. Although artisanal miners created considerable wealth along the river, the local community has also been negatively impacted by the social and environmental effects that characterize this sector. The flooding of many parts of the Lower Caroni River, in conjunction with the development of a large hydroelectric-power complex, changed the conditions for dredging operations.A Canada-based company is proposing to open the recently-created hydro-electrical lakes to a Mineral Dredging Project. The early forecasting of potential socioeconomic and environmental impacts would be a valuable tool to build a sustainable business case that facilitates the integration of the project into a sensitive environment. These strategies, currently used in other economic sectors, would contribute to the identification of opportunities to negotiate mutually beneficial agreements with stakeholders of the Project, and reduce the risk of conflict, in this particular case, with the hydroelectric company (EDELCA), former small-scale miners and other stakeholders.This paper, based on the pre-feasibility study of the Project, assesses the applicability of such tools to the mineral dredging and to junior mining company projects in general.     

Sustainability assessment of a giant bamboo plantation in Brazil: exploring the influence of labour,time and space

Bamboo presents physical and mechanical characteristics, which turn it an alternative option for product development, replacing native or reforested wood. The sustainability assessment of a Dendrocalamus Giganteus species plantation in Brazil through the emergy methodology evidences a great weight of renewable (30% sej/sej) and human labour contributions (33% sej/sej). These contributions account for the great interface with environment and to the intensive work, respectively. The transformity value of bamboo production is 2.42E + 04 sej/J. The influence human labour has on the total emergy flow and on indicators is evaluated by taking into account different country locations (Brazil, Australia and China). Thus, a different transformity value for labour is assumed for each country. A ranking based on emergy sustainability index (ESI) values shows that bamboo production in China was the first placed, followed by Brazil and Australia (values of 1.18, 0.50 and 0.09, respectively). The insertion of indirect renewability embedded in labour results in the ranking modification, leading to plantation in Brazil in the first place, followed by the Australian and Chinese ones. The relative position of the bamboo systems is visualized in the ternary diagram expressed in terms of emergy. In an attempt to explore the relationship between sustainability and time, a graphic of ESI vs. global productivity is discussed in terms of a prospective evaluation. Indirect support areas of the bamboo production are calculated as a way to evaluate the sustainability-space relationship.     

干旱半干旱地域灌区水资源综合效益评价体系研究

干旱半干旱地域灌区农业发展,既受水资源短缺制约,又受生态环境和社会因素的影响。论文基于水资源可持续发展的观点,认为灌区水资源优化配置必须考虑经济效益、生态效益和社会效益的协调和综合影响。文中建立了灌区水资源综合效益评价的数学模型。在分析该区水资源利用特点基础上,提出了综合效益评价的经济效益、社会效益和生态效益类等44项评价指标。应用层次分析法(AHP)原理,对构建的模型进行了研究。并以陕西省宝鸡峡灌区为例,利用所建模型进行了综合评价。评价结果可为灌区水资源评价、管理及节水规划提供决策依据。     

A new tool to map the major worldviews in the Netherlands and USA,and explore how they relate to climate change

For addressing climate change, public support for changes in policy is needed, as well changes in individual lifestyles. Both of these appear to be intimately related with people’s worldviews. Understanding these worldviews is therefore essential. In order to research and ‘map’ them, we translated the theoretical ‘Integrative Worldview Framework’ (IWF) into an empirical, quantitative approach. We constructed a worldview-scale aiming to distinguish between four major worldviews – labeled traditional, modern, postmodern, and integrative – and explored their interface with opinions and behaviors with respect to climate change. The survey was conducted with representative samples of citizens in the Netherlands and the USA (n = 527 and n = 556). The hypothesized worldviews were found in the data with a reasonable degree of reliability, especially in the Dutch sample. We also found consistent relationships between these worldview-clusters and a range of opinions, political priorities, and behaviors. In both countries postmoderns and integratives displayed significantly more concern about climate change as well as more sustainable behaviors, compared with moderns and traditionals. The implications of these findings for environmental policy and social science are noteworthy.     

Use of life cycle assessment methodology for determining phytoremediation potentials of maize-based cropping systems in fields with nitrogen fertilizer over-dose

Using the life cycle assessment (LCA) method, we analyzed the effects of different cropping systems (sole maize (CK), maize + soybean (CST) and maize + groundnut (CGT)) on the environment. The comprehensive index of environmental impacts varied in the order, sole maize > maize + groundnut > maize + soybean, with corresponding intercropping values of 0.1295, 0.1229 and 0.0945, respectively. The results showed that intercropping maize with suitable plants (e.g., groundnut and soybean) could reduce the adverse effects of over-application of nitrogen fertilizer on the environment. The study further showed that the LCA method may be a convenient and effective approach for analyzing the environmental impact of fertilizer management in agricultural fields.     

Environmental and socio-economic impacts of institutional reforms on the agricultural sector of Vietnam: Land suitability assessment for Robusta coffee in the Dak Gan region

After the reunion of North and South Vietnam in 1975, the area under small-holder, irrigated cultivation of Robusta coffee increased by a factor of 10 in the Central Highlands. The actual coffee acreage in Dak Lak province is estimated to be over 260,000 ha, representing 60% of the national production, with 405,000 t year⁻¹ for the world market. Vietnam is presently the second largest exporter worldwide and expansion is still going on. In cooperation with the National Institute for Agricultural Planning and Projection (NIAPP), a 5-year development project “Land Evaluation for Land Use Planning and Development of Sustainable Agriculture in the Central Highlands of South Vietnam” was set up, with a goal of diagnosing the sustainability of the rapidly expanding Robusta coffee sector in Central Vietnam. This paper describes the reasons for this quick expansion and investigates the consequences in ecological and social terms. This is done based on a large-scale natural resources inventory, land suitability analysis for Robusta coffee and participatory rural appraisal combined with secondary statistical records from Dak Gan commune. It is representative of the Central Highlands in terms of geomorphological and pedological variability, ethnic identity and with regard to trade-offs between forest conservation and coffee expansion at the cost of available water stocks. Local institutional reforms in the eighties have accelerated coffee expansion in three ways: demographic resettlement, socio-economic liberalization and legislation towards land ownership. Interaction between these three factors has induced a second spontaneous migration flow towards the Highlands in the nineties. Forest area declined by 19% and was converted to coffee plantations, encouraged by the high economic return of this cash crop. The results indicate that this has happened in an haphazard manner and led to a mismatch between the present land use pattern and the natural resource base. Unsustainable land use manifests itself at four levels. (i) The areal limits for sustainable coffee production have been exceeded. (ii) As a consequence over 74% of the present coffee stand is situated on sub-optimal land units. (iii) An excessive coffee area in combination with over-irrigation is likely to deplete groundwater resources. (iv) And paradoxically 24.3% of suitable soils for coffee production is still under forest in Dak Gan. In turn this leads to large-scale environmental and socio-economic decline: soil erosion, water scarcity and social inequity resulting in conflicts between migrants and the indigenous tribes. Besides local reforms, world trade liberalization changed the global coffee market in the late nineties from a regulated system to a free trade market. This fostered global oversupply, which in combination with a stagnant coffee demand suppressed the world market price. Since Vietnam became the second world producer of Robusta, prices have declined by a factor of 3, not only affecting the local sector but households worldwide.     

城市可持续性发展的不同分析方法对比研究

城市可持续性发展的分析方法有很多种。方法不同,结论也可能不同。文章旨在通过实例研究不同分析方法之间的差别,提出一种城市可持续性发展分析中能够应用的综合评价框架。并以成都市的发展为实例,重点比较分析2种方法,即熵值法和趋势分析方法。分析结果表明熵值法和趋势分析法在分析结果上有很大的区别。如前者侧重于经济发展,因而得出成都市的发展趋势是强可持续的;后者强调经济、能耗、及福利之间的相互关系,得出的结论是成都市的发展属于是能耗型发展,即社会福利和经济增长的同时,能耗也在增加。因而在分析判断城市是否可持续发展时,有必要采取不同类型的方法综合判定城市的可持续发展程度。并在制定政策以确保城市的可持续性发展时,综合考虑环境、经济、社会等各个方面的影响,并进行合理的调整,使之相互协调,共同发展。     

东北老工业区环境与经济可持续发展的研究

为保证我国东北老工业区的社会、经济、环境全面协调可持续发展,从东北老工业区的概况,社会、经济、环境问题的现状入手,对其社会系统、经济系统和环境系统在地区发展中面临的困境和主要问题进行了分析;立足于系统科学的角度,从社会、经济、环境3个系统方面,为东北老工业区提出了协调可持续发展的宏观建议。     

Minimizing greenhouse gas emissions through the application of solar thermal energy in industrial processes

The analysis of industrial energy usage indicates that low temperature processes (20 ≈ 200 °C) are used in nearly all industrial sectors. In principle there is the potential to use solar thermal energy in these lower temperature processes thus, reducing the environmental impact of burning fossil fuels. Using the model of an Austrian dairy plant, this research investigated the potential for, and the economic viability of, using solar energy heat processes in industry.Some industrial sectors such as food, chemistry, plastic processing, textile industry, building materials industry and business establishments can be identified as potential sectors for the application of solar energy heat processes. When assessing the (economic) feasibility of solar thermal energy, the investigation of these industries’ energy systems has to focus on an integrated analysis of cooling and heating demands and to take into account competing technologies. Amongst these are heat integration, cogeneration, new technologies and heat pumps. Pinch analysis was used to investigate industrial energy systems and heat integration possibilities and proved to be a viable tool. Working from the basis of energy balances, Sankey diagrams, pinch analysis and environmental cost accounting, a newly developed investigation tool was applied in the case study of an Austrian dairy plant. This enabled a fast optimization of the system. Two different options for the integration of solar thermal energy into the production line were calculated, option 1 with a solar field of 1000 m² and option 2 with a solar field of 1500 m². Natural gas savings of 85,000 for option 1 and 109,000 m³/a for option 2 can be achieved, resulting in a reduction of 170 tons of CO₂ per year, or 218 tons for options 1 and 2 respectively. Based upon option 1, return on investment is realised after less than three years of implementation. This research thus, indicates promising technical and economical feasibility of using solar thermal energy for industrial processes and provides an important step towards sustainable zero emission production in industry.     

Reducing mercury pollution from artisanal gold mining in Munhena,Mozambique

Artisanal small-scale mining (ASM) is responsible for over 90% of gold production in Mozambique. In 2005, a 15-day pilot training project was held in the village of Munhena, a gold mining community. This intervention aimed at raising awareness related to the environmental and health impacts of mercury amalgamation and introduced alternative practices to reduce mercury release and exposure. In 2007, a 9-day evaluation of the pilot campaign was accomplished and knowledge in regards to mining methods, and the ASM government–community operating relations in Munhena were updated. Miners in Munhena are organized in an association of over 3000 members, work on a 25 year Government granted 143 ha concession and generate a substantial income (producing over 5 kg of gold per month). There remain, however, serious barriers towards sustainable community development. ASM associated environmental and health costs are high, as mercury continues to be used and lost to the environment, and cyanide will be introduced soon. The Government of Mozambique has laid the foundation for supporting this sector; however, resources are limited, and thus restrict ability to fully address these issues. Importantly, malaria and HIV/AIDS are not diagnosed and/or treated effectively within the community, and basic necessities are absent. This paper concludes with recommendations focused on enhancing the ASM sector in Mozambique, and overcoming barriers to sustainability in the community of Munhena.     

Environmental consequences of different beef production systems in the EU

The aim of this paper is to examine the environmental consequences of beef meat production in the EU, using a life cycle approach. Four beef production systems were studied – three from intensively reared dairy calves and one from suckler herds. According to the results of the analysis, the contributions from the production of 1 kg beef meat (slaughter weight) to global warming, acidification, eutrophication, land use and non-renewable energy use were lower for beef from dairy calves than from suckler herds (16.0–19.9 versus 27.3 kg CO₂e, 101–173 versus 210 g SO₂e, 622–1140 versus 1651 g NO₃e, 16.5–22.7 versus 42.9 m²year, and 41.3–48.2 versus 59.2 MJ, respectively). The breakdown analysis helped identify the key areas in the “cradle to farm gate” beef production system where sustainable management strategies are needed to improve environmental performance. The study also included a sensitivity analysis to preliminarily estimate GHG emissions from beef production systems if land opportunity cost and land use change related to grazing and feed crop production for beef were taken into account. If so, the contribution from the production of 1 kg beef to global warming would increase by a factor of 3.1–3.9, based on a depreciation period of 20 years. This highlights the importance of taking into account the impacts of land use in assessing the environmental impacts of livestock production.     

Conceptual chemical process design in a sustainable technological world

Delft University has an established track record in educating MSc students the art of designing chemical processes and products. To foster its future position an experimental conceptual design program has been set up. In this program sustainability requirements are used to stimulate creativity. Our vision is that (designs of) processes, products and systems should fit in a sustainable technological world (STW). The STW is in balance with the other great cycles on Earth, being the exchange of water between hydrosphere and atmosphere and the exchange of carbon dioxide between atmosphere and biosphere. The STW has, like the biosphere and hydrosphere, a certain upper mass (110 Gton) and energy (8800 GW). The STW itself is evolutionary and cannot be designed, yet its content—technological artifacts—is designed. Newly designed artifacts requiring an average life span of 25 years (one human generation), should fit the STW. The total annual product renewal of the STW is 4.4 Gton/year and the energy consumption 64 MJ/kg. These numbers total both industrial production as well as energy spent by consumers using the artifacts. Conceptual designs of chemical processes should fit in this concept of a STW. This means that processes requiring a high energy level are subject to change, for they limit society's patterns of energy consumption. Chemical processes demanding a lot of chemical energy are reduction processes: primary processes (roasting ores and biomass) and secondary processes (dissociations and dehydrogenations). In this article a conceptual design of both types of processes is presented. The first results show that their energy consumption fits the STW and points towards new design solutions for chemical processes, new applications of chemical products and new relationships with other technological sciences.     

Assessing soil chemical and physical property responses to deforestation and subsequent cultivation in smallholders farming system in Ethiopia

In Ethiopia land degradation in the forms of soil erosion and declining soil fertility are serious challenges to agricultural productivity and economic growth. Despite the general recognition of the threat from land degradation on agricultural productivity, few studies have been made to quantify the extent, rate and process of soil fertility depletion under various land use systems and management practices in the country. In this study we assessed soil chemical and physical property responses to deforestation and subsequent cultivation along a chronosequence of closely located farmlands of different ages (7, 10, 26, 34 and 53 years) since conversion from a tropical dry Afromontane natural forest in Ethiopia. These properties were compared with soil properties under an adjacent natural forest. The changes were used as indicators to evaluate the sustainability of the farm management. All the soils in the study were Mollic Andosols/Humic Haplustands. Soil bulk density (g cm⁻³) in the 0–10 and 10–20 cm soil layers increased significantly while percent pore space decreased significantly in a continuum with increasing cultivation period. Soil C and total N contents (g kg⁻¹) in the 0–10 cm soil layer declined significantly and exponentially with increasing years under cultivation. However, in the 10–20 cm soil layer both soil C and total N on the farmlands were significantly higher until after 34 years of continuous cultivation compared to the same soil layer under the natural forest. Consequently, the soil C stock (g m⁻²) of the upper 0.20 m mineral soil was not significantly lower on the farmlands until after 26 years of continuous cultivation compared to the natural forest soil. Available P and K (mg kg⁻¹) in the 0–10 cm layer were higher in the soils of the farmlands throughout the 53 years of continuous cultivation compared to the soil under the natural forest. Exchangeable Ca, CEC and base saturation in the 0–10 cm soil layer declined more or less throughout the cultivation period while in the 10–20 cm soil layer they followed the patterns of soil C of that depth. Generally, the magnitudes and rates of degradation of the soil properties following conversion and subsequent cultivation were lower than expected for a low input tropical farming system as the one investigated. Nevertheless, almost all soil quality attributes showed overall declining trends in the long perspective. This continuous decline, albeit slowly, in soil quality with increasing cultivation period indicated that the present land management is not sustainable. Therefore, improved management is imperative to sustain the soil quality and maintain long-term productivity of the farmlands.     

辽中地区矿业城市生态承载力研究

生态足迹模型是度量可持续发展的一种方法,加入经济因子以提高模型评价的准确性,为辽中地区矿业城市可持续发展提供决策依据。运用生态足迹模型计算了辽中地区矿业城市1985~2005年人均生态足迹、人均生态承载力和生态赤字,利用压力-状态-响应模型耦合生态足迹、生态承载力和经济因子得到综合生态承载力指数,评价了辽中地区矿业城市1985~2005年综合生态承载力水平。结果表明:1985~2005年,辽中地区矿业城市人均生态足迹从1.79 hm²增至3.53 hm²,增长率为97.43%;人均生态承载力从0.78 hm²增至0.81 hm²,生态赤字从-1.01 hm²增至-2.73 hm²,增加了190.17%;综合生态承载力指数先降低,2000年以后略有增加,其中综合生态承载力水平1985年很高,1990年较低,1995、2000年一般,2003、2005年较高。对比生态足迹模型得到的生态承载力和通过压力-状态-响应模型得到的综合生态承载力指数,两者的变化趋势一致,具有很强的相关性。综合生态承载力指数评价指标的丰富在一定程度上增加了评价的公正性和准确性,可以更好地反映区域可持续发展程度,为其它生态足迹研究提供了一定的借鉴。     

Nutrient flows in small-scale peri-urban vegetable farming systems in Southeast Asia—A case study in Hanoi

In many peri-urban areas of Southeast Asia, land use has been transformed from rice-based to more profitable vegetable-based systems in order to meet the increasing market demand. The major management related flows of nitrogen (N), phosphorus (P), potassium (K), copper (Cu) and zinc (Zn) were quantified over a 1-year period for intensive small-scale aquatic and terrestrial vegetable systems situated in two peri-urban areas of Hanoi City, Vietnam. The two areas have different sources of irrigation water; wastewater from Hanoi City and water from the Red River upstream of Hanoi. The first nutrient balances for this region and farming systems are presented. The main sources of individual elements were quantified and the nutrient use efficiency estimated. The environmental risks for losses and/or soil accumulation were also assessed and discussed in relation to long-term sustainability and health aspects.The primary source of nutrient input involved a combination of chemical fertilisers, manure (chicken) and irrigation water. A variable composition and availability of the latter two sources greatly influenced the relative magnitude of the final total loads for individual elements. Despite relatively good nutrient use efficiencies being demonstrated for N (46–86%) and K (66–94%), and to some extent also for P (19–46%), high inputs still resulted in substantial annual surpluses causing risks for losses to surface and ground waters. The surplus for N ranged from 85 to 882 kg ha⁻¹ year⁻¹, compared to P and K which were 109–196 and 20–306 kg ha⁻¹ year⁻¹, respectively. Those for Cu and Zn varied from 0.2 to 2.7 and from 0.6 to 7.7 kg ha⁻¹ year⁻¹, respectively, indicating high risk for soil accumulation and associated transfers through the food chain.Wastewater irrigation contributed to high inputs, and excess use of organic and chemical fertilisers represent a major threat to the soil and water environment. Management options that improve nutrient use efficiency represent an important objective that will help reduce annual surpluses. A sustainable reuse of wastewater for irrigation in peri-urban farming systems can contribute significantly to the nutrient supply (assuming low concentrations of potential toxic or hazardous substances in the water). Nutrient inputs need to be better related to the crop need, e.g. through better knowledge about the nutrient concentrations in the wastewater and improved management of the amount of irrigation water being applied.     

Water footprinting at the product brand level: case study and future challenges

Responding to concerns about the unsustainable use of global freshwater resources, especially in agriculture, the concept of water footprinting has recently been developed and applied to a wide range of commodities. In this paper, water footprints were calculated for two complex agrifood products, 250 g Peanut M&M's^® and 575 g Dolmio^® pasta sauce, in order to evaluate the usefulness of the concept when applied at the product brand level. The process LCA-based methodology took account of blue water appropriated from surface and groundwater resources, green water appropriated from the root zone by plants, and dilution water, being the volume of freshwater needed to assimilate emissions to freshwater. These case studies revealed several issues, namely the lack of correspondence between water footprints and the availability of water for alternative uses in the absence of production, and the difficulty in relating water footprints to potential social and environmental harm. As such, the water footprinting concept requires further development to be useful for promoting sustainable production and consumption.     

无公害农产品土地利用评价体系的研究

土地资源是人类生存最基本的资源，对它的利用与开发必须保持协调的可持续的发展规划。本文以无公害农产品土地利用为例，从环境的角度，构建了产地环境条件子系统、自然条件子系统、经济效益分析子系统和环境影响分析子系统以及各自包含的评价指数集。产地环境条件指标集和自然条件指标集是基于现状的，采用结果指标表达；针对布局规划，环境影响分析和经济效益分析是一种预测评价，对其指标集的构建采用了过程指标的设计。