Multi-scale integrated assessment of soybean biodiesel in Brazil

Developing counties are often believed to have excellent conditions for biofuel production, however studies aimed at assessing the sustainability of large scale biofuel programs have generally focused on a few variables related to one scientific domain and one scale. Contrary to this approach, this paper analyzes soybean biodiesel in Brazil using a parallel biophysical and economic assessment at different scales. A Multi-Scale Integrated Analysis of Societal and Ecosystem Metabolism (MuSIASEM) approach is applied as a scenario analysis tool. A soybean biodiesel energy balance for the specific conditions of Brazil is included and the energy ratio turns out to be 1.09. This means that the energy delivered is higher than the energy invested, however the net energy is very low. The economic impacts are analyzed through input-output analysis. The results show that soybean biodiesel increases energy consumption per hour of work without a corresponding increase in economic labor productivity. Consequently the already low energy efficiency of Brazilian production could get worse. Although Brazil has large expanses of land, the substitution of 20% fossil diesel (i.e. just 3.3% of the country's primary energy consumption) with fully renewable biodiesel might destroy protected areas and forests and increase the GHGs emitted.     

城市能源代谢的异质性分析——以北京市为例

充分探究城市能源代谢过程中部门间的内在差异,深入解析并评估其对城市能源代谢过程的影响对于进一步优化城市能源代谢结构,推动节能减排、提质增效具有重要价值。本文基于引力模型分析城市能源代谢过程中能源流两端连接节点的属性差异,选取煤、石油、天然气三种能源,以北京市非首都功能疏解部门为例探究要素差异及部门自身属性差异在能源代谢过程中的影响;利用情景分析法,分析两种能源优化强度和三种部门疏解强度的6种组合情景下四部门的不同种类能源消耗的变化。结果表明,不同要素对部门能源消耗的正负反馈机制以及不同部门对不同能源偏好程度均存在异质性,这种异质性导致不同政策情景对北京市非首都功能疏解部门能源结构优化的作用效果不同。强优化强疏解情景对于制造业部门煤和天然气能源的替代最为有利,低疏解强优化情景对控制交通业及批发和零售业部门的能源消费,改善教育业的能源消费结构最有利。     

Growth in global materials use, GDP and population during the 20th century

The growing industrial metabolism is a major driver of global environmental change. We present an assessment of the global use of materials since the beginning of the 20th century based on the conceptual and methodological principles of material flow accounting (MFA). On the grounds of published statistical data, data compilations and estimation procedures for material flows not covered by international statistical sources, we compiled a quantitative estimate of annual global extraction of biomass, fossil energy carriers, metal ores, industrial minerals and construction minerals for the period 1900 to 2005. This period covers important phases of global industrialisation and economic growth. The paper analyses the observed changes in the overall size and composition of global material flows in relation to the global economy, population growth and primary energy consumption. We show that during the last century, global materials use increased 8-fold. Humanity currently uses almost 60 billion tons (Gt) of materials per year. In particular, the period after WWII was characterized by rapid physical growth, driven by both population and economic growth. Within this period there was a shift from the dominance of renewable biomass towards mineral materials. Materials use increased at a slower pace than the global economy, but faster than world population. As a consequence, material intensity (i.e. the amount of materials required per unit of GDP) declined, while materials use per capita doubled from 4.6 to 10.3 t/cap/yr. The main material groups show different trajectories. While biomass use hardly keeps up with population growth, the mineral fractions grow at a rapid pace. We show that increases in material productivity are mostly due to the slow growth of biomass use, while they are much less pronounced for the mineral fractions. So far there is no evidence that growth of global materials use is slowing down or might eventually decline and our results indicate that an increase in material productivity is a general feature of economic development.     

Effects of food consumption patterns on paddy field use in Taiwan

Societal metabolism and land use are significant and interrelated issues, and play a role in sustainable development. How a society's metabolism relates to local land use is typically affected by the particular context of the society under study, which is usually shaped by many factors, including economic, ecological, cultural, technological, and political factors. This study examines the effects of changes in food consumption patterns – decreasing per capita consumption of rice and increasing per capita consumption of wheat flour and meat – on the use of paddy fields in Taiwan. Although rice is grown domestically, wheat, which is a substitute for rice, is mainly imported. Moreover, the domestic livestock industry depends heavily on imported crops for low-cost feed. Accordingly, dietary changes have significantly decreased the demand for local paddy fields to grow crops. Additionally, the diversion of paddy fields to grow forage crops, which has been promoted by the Taiwanese government by guaranteeing prices for feed maize for 14 years, was discouraged when Taiwan joined the World Trade Organization in 2002, as Taiwan was required at that time to reduce by 20% its aggregate measure of support. The presented Taiwan case provides an empirical example of how a change in input characteristics (supply sources in a spatial dimension) of societal metabolism can, together with other factors, significantly affect local paddy fields, and discusses the underlying implications for sustainable development.     

不同饮食结构对幼年大鼠脂代谢机理的实验研究

20只离乳SD性雄性大鼠随机分为两组,分别对其采用不同干预方式,8周后对两组大鼠进行血脂及相关糖、脂代谢酶指标的检测。实验结果显示,高脂喂养大鼠的体重、体脂含量、胰岛素及血胆固醇(TC)、甘油三脂(TG)、TG/HDL水平均比对照组明显升高,高密度脂蛋白-胆固醇(HDL-C)下降,同时肝脂酶和葡萄糖激酶活性也显著高于对照组,而脂蛋白脂酶活性却明显低于对照组大鼠,且有显著性差异(P<0.05)。研究结果说明高脂饮食条件下,糖、脂代谢酶活性的改变,可能会对脂代谢产生影响,进而引起脂质代谢紊乱,导致肥胖。     

系统性健康教育对2型糖尿病糖代谢的干预作用

目的:探讨健康教育对2型糖尿病患者血糖代谢的干预作用及临床意义。方法:对2型糖尿病患者进行12周的健康教育培训,检测并比较空腹血糖(FBG)、餐后2小时血糖(2hPBG)、糖化血红蛋白等糖代谢指标。结果:实施系统健康教育的患者12周后各项糖代谢指标均有显著性改善。结论:对2型糖尿病患者进行系统健康教育干预,对于改善其糖代谢水平具有积极意义。     

城市化与可持续城市化的理论探讨

快速城市化给我国城市化的健康发展带来巨大挑战。本文从结构、过程和功能三方面分析了城市生态系统的属性,探讨了城市化的概念及其正负两方面的效应,提出了要实现可持续的城市化,必须保证城市生态系统的结构合理、过程高效、功能完善,并从这三方面讨论了可持续城市化的内涵:随着城市化进程的不断推进,城市人均生态足迹增长得到控制,城市代谢效率不断提高,居民福利不断增长。     

Thermal Eco‐cities: Green Building and Urban Thermal Metabolism

Eco‐city projects are becoming increasingly prevalent throughout the globe and are often marketed as ‘new’ urban environments focused on achieving sustainable urban living while promoting environmental–economic transitions towards a low‐carbon technological and industrial base. The article argues for the need to consider the thermal aspects of urban metabolism, while at the same time focusing on the link between individual buildings and eco‐city master plans and wider economic development strategies at a state level. In so doing, the article encourages critical analysis of eco‐city design and planning, while keeping a focus on the role of specific building structures within eco‐cities as examples of the intermeshing of what can be termed a ‘political ecology of scale’ which stretches from specific buildings' climatic characteristics, to the metabolic master plan for eco‐cities, to provincial, regional and state‐level plans for the integration of eco‐cities within wider economic and political development trajectories. The article focuses on Masdar, in Abu Dhabi, an eco‐city under construction at the time of writing.     

Towards an integrated model of socioeconomic biodiversity drivers, pressures and impacts. A feasibility study based on three European long-term socio-ecological research platforms

Effective policies to slow the rate of anthropogenic biodiversity loss should reduce socioeconomic pressures on biodiversity, either directly or by modifying their underlying socioeconomic driving forces. The design of such policies is currently hampered by the limited understanding of socioeconomic drivers of and pressures on biodiversity as well as by lacking data, indicators and models. In order to improve understanding of these issues we here propose a conceptual model of socioeconomic biodiversity drivers and pressures. The model is based on the drivers-pressures-impacts-states-responses (DPSIR) scheme and on the socioeconomic metabolism approach. The aim of the model is to guide research aimed at improving our understanding of socioeconomic biodiversity pressures and drivers and to serve as a basis for the development of formal, quantitative models in that field. Based on three European long-term socio-ecological research (LTSER) platforms, we analyze the model's applicability and suitability as well as data availability and research needs. These platforms are the Danube Delta Wetland System in Romania, the Doñana in Spain and the Eisenwurzen in Austria. An empirical analysis of the relationship between the human appropriation of net primary production (HANPP) and breeding bird richness in the Eisenwurzen demonstrates the ability of HANPP to provide a link between socioeconomic pressures/drivers and biodiversity. The analysis of the case studies underlines the potential utility of the conceptual model to guide future research into socioeconomic biodiversity drivers and pressures. However, considerable investments in monitoring and reconstruction of past trajectories as well as in model development will be required before mathematical (computer) models of the interrelation processes between society and ecosystems can be successfully deployed.     

马克思的新陈代谢断裂理论与新型城市化

新陈代谢断裂是人与自然之间的物质循环断裂,本质就是由于资本的逻辑而导致的城乡社会之间物质循环的断裂,一些食物运输到城市,经消费后在城市造成了环境污染,而另一方面农村土地的肥力无法得到补偿,资本的逐利性是造成资本主义生态断裂的根源.新型城市化应是生态文明的城市,促进城乡的一体化发展,促进城乡之间物质的合理循环.