Reduction of CO2 emission by optimally tracking a pre-defined target

The recent global financial crisis has highlighted the need for balanced and efficient investments in the reduction of the greenhouse effect caused by emissions of CO₂ on a global scale. In a previous paper, the authors proposed a mathematical model describing the dynamic relation of CO₂ emission with investment in reforestation and clean technology. An efficient allocation of resources to reduce the greenhouse effect has also been proposed. Here, this model is used to provide estimates of the investments needed in land reforestation and in the adoption of clean technologies for an optimum emission and abatement of CO₂, for the period of 1996–2014. The required investments are computed to minimize deviations with respect to the emission targets proposed in the Kyoto Protocol for European Countries. The emission target can be achieved by 2014 with investments in reforestation peaking in 2004, and a reduction of the expected GDP of 42%, relative to 2006. Investments in clean technology should increase between 2008 and 2010 with maximum transfer figures around 70 million American dollars. Total (cumulative) costs are, however, relatively high depending on the price of carbon abatement and the rate at which the expected CO₂ concentration in the atmosphere should be reduced. Results highlight the advantages for policy makers to be able to manage investments in climate policy more efficiently, controlling optimum transfers based on a portfolio of actions that tracks a pre-defined CO₂ concentration target.     

水力帷幕防治海水入侵的数值模拟研究

为比较应用于防治海水入侵工程的水力帷幕效果,利用垂向二维非均质流体的对流-弥散模型,运用伽辽金有限元法求解,并用物理实验结果验证其有效性.将模型应用于模拟广西北海市海城区海水入侵过程及水力帷幕防治海水入侵效果,分别计算了超采地下水、抽水、注水和抽-注水情况下咸淡水界面随时间推移过程,并分析咸淡水界面推移与抽、注水流量及抽、注水孔位置之间关系,通过比较得出注水是北海市防治海水入侵较为理想的措施.     

Controlling Rhododendron ponticum in the British Isles: an economic analysis

What resources should be committed to the control of invasive species? This study is based on a survey of nature conservation and forestry authorities, wildlife trusts and private landowners which investigated the extent of the ecological and economic impacts of the invasive non-native plant Rhododendron ponticum in the British Isles. There are data on 52,000 ha of land affected by R. ponticum, more than 30,000 ha of it in nature reserves. For nearly all nature reserves, displacement of native species and habitat changes were both reported. In 2001, respondents controlled 1275 ha of R. ponticum at a cost of pound 670,924. To test the optimality of this, we apply a model of social expenditure. The external costs of R. ponticum control are estimated from the probability that it will spread to contiguous sites and the damage done on invaded sites. These are then used to calculate the socially optimal level of expenditure on R. ponticum control, and the funding gap it identified by comparing the result with current levels of expenditure. The results suggest that a socially optimal level of control effort requires a significant increase in social funding for R. ponticum control, although the size of the increase varies between landholders.     

The U.S. Experience in Promoting Sustainable Chemistry (9 pp)

- Sustainable chemistry - Section editors: Klaus Günter Steinhäuser, Steffi Richter, Petra Greiner, Jutta Penning, Michael AngrickBackground, Aim and Scope Recent developments in European chemicals policy, including the Registration, Evaluation and Authorization of Chemicals (REACH) proposal, provide a unique opportunity to examine the U.S. experience in promoting sustainable chemistry as well as the strengths and weaknesses of existing policies. Indeed, the problems of industrial chemicals and limitations in current regulatory approaches to address chemical risks are strikingly similar on both sides of the Atlantic. We provide an overview of the U.S. regulatory system for chemicals management and its relationship to efforts promoting sustainable chemistry. We examine federal and state and examine lessons learned from this system that can be applied to developing more integrated, sustainable approaches to chemicals management.Main Features There is truly no one U.S. chemicals policy, but rather a series of different un-integrated policies at the federal, regional, state and local levels. While centerpiece U.S. Chemicals Policy, the Toxic Substances Control Act of 1976, has resulted in the development of a comprehensive, efficient rapid screening process for new chemicals, agency action to manage existing chemicals has been very limited. The agency, however, has engaged in a number of successful, though highly underfunded, voluntary data collection, pollution prevention, and sustainable design programs that have been important motivators for sustainable chemistry. Policy innovation in the establishment of numerous state level initiatives on persistent and bioaccumulative toxics, chemical restrictions and toxics use reduction have resulted in pressure on the federal government to augment its efforts.Results and Conclusions It is clear that data collection on chemical risks and phase-outs of the most egregious chemicals alone will not achieve the goals of sustainable chemistry. These alone will also not internalize the cultural and institutional changes needed to ensure that design and implementation of safer chemicals, processes, and products are the focus of the future. Thus, a more holistic approach of ‘carrots and sticks’ – that involves not just chemical producers but those who use and purchase chemicals is necessary. Some important lessons of the US experience in chemicals management include: (1) the need for good information on chemicals flows, toxic risks, and safer substances.; (2) the need for comprehensive planning processes for chemical substitution and reduction to avoid risk trade-offs and ensure product quality; (3) the need for technical and research support to firms for innovation in safer chemistry; and (4) the need for rapid screening processes and tools for comparison of alternative chemicals, materials, and products.     

城市轨道交通的振动和噪声及其控制的研究

地铁、轻轨等城市轨道交通会给市民和旅客带来便捷 ,同时也会给沿线的居民和建筑物带来振动及噪声等环境污染的公害。笔者分析了振动和噪声的控制与评价标准和预测方法 ,针对城市轨道交通的振动和噪声的特点和传播规律 ,从声源的控制、振动传播与声传播控制以及承受物控制 3个方面 ,提出了相应的控制措施和途径     

Mosquito management: Ecological approaches

This article discusses organism use for management of mosquitoes included are considerations of the introduction and/or manipulation of plants, animals, and microorganisms into breeding habitats in which they act to make conditions less suitable for mosquito production. The importance of foresight and careful planning is stressed with regard to developing mosquito management strategies     

Regional reference sites: a method for assessing stream potentials

Field assessments of impacted streams require a control or at least an unbiased estimate of attainable conditions. Control sites, such as upstream/downstream or wilderness sites, have proven inadequate for assessing attainable ecological conditions where the control streams differ naturally from the impacted streams to a considerable degree or where different disturbances exist than those being studied. Relatively undisturbed reference sites with watersheds in areas having the same land-surface form, soil, potential natural vegetation, and land use as are predominant in large, relatively homogeneous regions are suggested as alternative control sites. These areas are considered typical of the region and therefore the sites also are considered typical of the region because their watersheds exhibit all the terrestrial variables that make that region a region. The logical basis for developing regional reference sites lies in the ability to group watersheds and common stream types into regions by integrating available maps of terrestrial variables that influence streams. Relatively undisturbed reference sites can be selected from typical areas of the regions and from transition zones where one or two of the terrestrial variables are not the predominant one(s) of the region. These reference sites are useful for estimating attainable conditions, for evaluating temporal and spatial changes in ecological integrity, for classifying attainable uses of streams, and for setting biological and environmental criteria.     

Snowblower injuries in Vermont, 1981–1984

The Vermont Department of Health carried out two studies of snowblower injuries in Vermont during the winters of 1982–1983 and 1983–1984. The first was a case-control study in which we assessed risk factors that predisposed operators to injury during snowblower use. We found 20 persons who had been injured by snowblowers and matched 28 controls to these by neighborhood. In this study, owning a snowblower for 1 year or less and having operated a snowblower for 10 days or less in one's lifetime were significantly associated with injury. The second study was population-based. We estimated that approximately 1.5% of Vermont residents owned snowblowers during the winter of 1982–1983 and that, among snowblower owners, injuries occurred at a rate of 1.3/1,000 person-years of ownership (0.1% chance of injury).     

天津市人为源VOCs排放现状及控制对策研究

根据2010年天津市公布的各类排放源活动水平数据,采用排放因子法,估算天津市人为源挥发性有机物排放量。结果表明:天津市人为源VOCs排放量中工业源贡献率最大,其次是流动源,生活源和生物质燃烧源贡献较小。根据天津市人为源挥发性有机物排放现状,提出VOCs控制对策及建议,为大气环境治理提供参考价值。     

我国雾霾成因及防控策略研究

针对近年来我国雾霾频发的现象,通过对我国雾霾现状、污染物来源分析,阐明雾霾成因及危害,并从监测、评价、控制等角度阐述我国雾霾防控策略。