中国的生态足迹与绿色发展

从2008年开始,世界自然基金会(WWF)与中国环境与发展国际合作委员会(国合会)联合,通过与国内外智库的合作引入"生态足迹"理念,从自然资源消耗与"生物承载力"之间关系的角度来研究中国经济发展所面临的资源环境问题。研究表明,2007年人类在消耗着1.5个地球。过去半个世纪以来,中国的生态足迹总量2007年已经是1961年的4倍,尽管中国的人均生态足迹水平仍然低于世界平均水平,但是已经突破了1个地球的均衡水平。与全球平均类似,中国生态足迹中最主要的组成部分是碳足迹,占54%。解决中国的生态足迹超支问题,关键是降低碳足迹。目前,中国的能源供给仍然高度依赖于化石能源,超过一半的能源供给来自于煤炭,中国和世界其它国家一样将面临化石能源枯竭问题。中国作为一个处于经济快速发展过程中的能耗大国,应及时调整产业结构和基础设施供给模式,在积极应对气候变化的同时提前应对自身可能面临的能源问题。中国所面临的现实决定了中国不能重复发达国家的高增长高资源消耗的老路,需要转变经济发展方式,发展绿色经济,为全球走向可持续发展道路提供探索的机会。     

基于聚类分析的我国各地化石能源足迹与经济发展定量研究

利用改进后的化石能源足迹公式计算了2000—2009年我国30个地区的人均化石能源足迹,并分别对2000年和2009年中国各地区的数据进行聚类分析,发现我国地区人均化石能源足迹由无明显地域特征转变为东部高于中西部,经济发达地区高于欠发达地区,且能源使用效率和经济发展水平间联系逐渐加强。通过对不同类别代表性地区人均化石能源足迹的分析判断,以北京、上海和广东为代表的发达地区化石能源消耗增长开始趋于缓和甚至出现小幅下降。     

Comparing environmental product footprint for electronic and electric equipment: a multi-criteria approach

Electronic and electric devices are now applied in most human activities: their diffusion is increasing worldwide; furthermore, most of them are characterized by a high replacement rate due to technological obsolescence. Consequently, environmental problems due to their diffusion are increasing; several aspects are involved from the energy consumption derived from their manufacturing processes and their use phases to their end-of-life (EOL) management. Such legislative (e.g. the European Energy Efficiency directive for household appliances) or voluntary interventions (e.g. based on the ISO standards) have been introduced for such devices: the aim is to incorporate environmental considerations in product design and manufacturing in order to benefit the environment. Some attempts are focusing on defining standardized models for the overall lifecycle including waste management. The aim of this paper is to introduce a reference model for comparing environmental product footprint of electrical and electronic equipment (EEE). All life cycles of EEE will be evaluated: a specific focus is on the EOL management process as their waste management represents a complex problem for developed and developing countries. A multi-criteria decision-making model will be developed based on the well-known analytical hierarchy process (AHP) method: differently from traditional AHP applications, an absolute model has been proposed in order to compare EEE effectively from an environmental point of view. A case study validation regarding large household appliances is proposed.     

Enhanced sorption of perfluorooctane sulfonate (PFOS) on carbon nanotube-filled electrospun nanofibrous membranes

Multi-walled carbon nanotube-filled electrospun nanofibrous membranes (MWCNT-ENFMs) were prepared by electrospinning. The addition of MWCNTs (0.5 wt.% vs. ENFMs) doubled the specific surface area and tensile strength of the ENFMs. The MWCNT-ENFMs were used to adsorb perfluorooctane sulfonate (PFOS) in aqueous solutions. The sorption kinetics results showed that the sorption rate of PFOS onto the MWCNT-ENFMs was much higher than the sorption rate of PFOS onto the pure ENFMs control, and the pseudo-second-order model (PSOM) described the sorption kinetics well. The sorption isotherms indicated that the sorption capacity of the MWCNT-ENFMs for PFOS (16.29 ± 0.26 μmol g⁻¹) increased approximately 18 times, compared with the pure ENFMs (0.92 ± 0.06 μmol g⁻¹). Moreover, the solution pH significantly affected the sorption efficiency and sorption mechanism. The MWCNT-ENFMs were negatively charged from pH 2.0–10.0, but the electrostatic repulsion between the MWCNT-ENFMs and PFOS was overcome by the hydrophobic interactions between PFOS and the MWCNTs or nanofibers. The strong hydrophobic interactions between PFOS and the MWCNTs played a dominant role in the sorption process. For the pure ENFMs, the electrostatic repulsion was conquered by the hydrophobic interactions between PFOS and the nanofibers at pH > 3.1. In addition to the hydrophobic interactions, an electrostatic attraction between PFOS and the pure ENFMs was involved in the sorption process at pH < 3.1.     

基于 H＆M 低碳分析及对中国服装产业升级的启示

依据快时尚品牌H＆M的2012年可持续发展报告,对其低碳现状进行研究分析,从碳足迹和产品生命周期的角度对H＆M碳排放情况进行分析,总结了截止到2012年年底,基于服装产业链,H＆M在低碳方面采取的措施与取得的成果,及其对中国服装产业进行低碳升级的启示。     

Is the Water Footprint an Appropriate Tool for Forestry and Forest Products: The Fennoscandian Case

The water footprint by the Water Footprint Network (WF) is an ambitious tool for measuring human appropriation and promoting sustainable use of fresh water. Using recent case studies and examples from water-abundant Fennoscandia, we consider whether it is an appropriate tool for evaluating the water use of forestry and forest-based products. We show that aggregating catchment level water consumption over a product life cycle does not consider fresh water as a renewable resource and is inconsistent with the principles of the hydrologic cycle. Currently, the WF assumes that all evapotranspiration (ET) from forests is a human appropriation of water although ET from managed forests in Fennoscandia is indistinguishable from that of unmanaged forests. We suggest that ET should not be included in the water footprint of rain-fed forestry and forest-based products. Tools for sustainable water management should always contextualize water use and water impacts with local water availability and environmental sensitivity.     

不同情境下桉树碳汇林最佳轮伐期分析

碳汇林具有碳汇价值和木材价值,最佳轮伐期是影响碳汇林收益的重要因素,但目前相关研究较少。以浙江省苍南县桉树碳汇林为研究对象,构建了同时考虑碳汇价值和木材价值的最佳轮伐期模型,并利用桉树生长模型,通过模拟计算,系统地分析了纳入模型的碳价格、贴现率、木材价格和劳动力价格等四个变量,在不同情境下,对碳汇林最佳轮伐期的影响。同时,探讨了上述变量对碳汇林收益净现值的影响。结果表明:当碳价格为55元/t、贴现率为5%、木材价格为700元/m3和劳动力价格为100元/工日时,桉树碳汇林最佳轮伐期为8年,单位面积收益净现值为99 053.80元/hm2,其中碳汇收益净现值只占8.60%;此外,碳价格、贴现率和木材价格对碳汇林最佳轮伐期负相关,而劳动力价格与碳汇林最佳轮伐期正相关。     

关于CCUS技术发展与标准建设的思考

我国CCUS技术发展,迫切需要政策制度的积极引导和技术标准的强力支撑。阐述了我国发展CCUS技术的基本原则和相关政策;跟踪了国内外CCUS技术发展动态及其标准研究现状;重点分析了美国及欧盟在CCS相关政策、法规和标准方面的主要成果;依据我国CCUS发展规划和技术发展路线图,提出了我国CCUS技术发展与标准建设的相关建议。     

The composition, trend and impact of urban solid waste in Beijing

This paper provides an overview of the trend of generation, composition, and management of municipal solid waste, and estimates the carbon emissions arising from municipal solid waste management in Beijing. The correlation analysis conducted shows that the generation of municipal solid waste in Beijing has been growing steadily, showing high correlations (r > 0.9) to the total GDP, per capita income, and the population. Food waste showed an increasing trend since 1990. Compared with the results of an investigation in 1990, ash and woodchips content in 2003 declined from 56% to 17%, while the percentage of paper and plastic increased from 10% to 29% over the same period. The calorific value of the municipal waste also increased, from 2,686 kJ/kg in 1990 to 4,667 kJ/kg in 2003, indicating that the waste is suitable for incineration. Currently, the source separation ratio of municipal waste is approximately 15%. About 94% of all the collected solid waste goes to the landfill while 4% is composted and 2% is incinerated. A moderate garbage collection fee is applied to both permanent and temporary residents in Beijing, but the willingness to pay for solid waste collection and treatment is still low. Under current treatment mode, the total amounts of carbon emission from waste disposal sites and incineration increased with the increase of municipal solid waste, from 29.8 Gg in 1990 to 84.5 Gg in 2003, including 83.3 Gg of CH₄ and 22.0 Gg of CO₂. The data availability and methodological challenges in monitoring the quantity and characteristics of municipal solid waste are discussed.     

Stomatal characteristics and infection biology of Pyrenopeziza betulicola in Betula pendula trees grown under elevated CO2 and O3

Two silver birch clones were exposed to ambient and elevated concentrations of CO₂ and O₃, and their combination for 3 years, using open-top chambers. We evaluated the effects of elevated CO₂ and O₃ on stomatal conductance (g_s), density (SD) and index (SI), length of the guard cells, and epidermal cell size and number, with respect to crown position and leaf type. The relationship between the infection biology of the fungus (Pyrenopeziza betulicola) causing leaf spot disease and stomatal characteristics was also studied. Leaf type was an important determinant of O₃ response in silver birch, while crown position and clone played only a minor role. Elevated CO₂ reduced the g_s, but had otherwise no significant effect on the parameters studied. No significant interactions between elevated CO₂ and O₃ were found. The infection biology of P. betulicola was not correlated with SD or g_s, but it did occasionally correlate positively with the length of the guard cells.