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11.
12.
Recycling of household wastes may not contribute as much toward a solution to environmental problems as widely supposed. It runs into practical problems often overlooked by nonspecialists. Recycling can also contribute significantly to pollution. Most important, recycling may use up larger quantities of materials than it saves. The note ends up with a model in which recycling will always cause a net loss in real resources. It is concluded that the subject requires more exploration rather than decision making by prejudgment and emotion.  相似文献   
13.
The construction process contributes to pollutant emissions, particularly through the operation of diesel- and gasoline-powered equipment. In the past decade, a series of investigations were undertaken to quantify these emissions for a variety of non-road construction equipment performing different activities and undergoing different duty cycles, and a model to estimate quantities of six types of pollutant was developed. This paper uses that model to estimate emissions for four street and utility construction projects which no one has done previously. We combined information from company records with standard construction industry manuals to estimate total emissions for the projects and to examine the pollution patterns and magnitudes. The street construction projects all had similar emission profiles with a large peak at the beginning and a steady output of emissions throughout the duration of the project. For example, in two of the projects studied, half of all CO2 emissions were produced before the projects were 40% completed. Results showed that demolition and earthwork are the activities with the largest contribution. The equipment types with the largest contribution are backhoes, front-end loaders, bulldozers and trenchers. Trenchers, for example, produced 30% of all emissions on the projects on which they were used.  相似文献   
14.
Jonathan M. H. Green  Gemma R. Cranston  William J. Sutherland  Hannah R. Tranter  Sarah J. Bell  Tim G. Benton  Eva Blixt  Colm Bowe  Sarah Broadley  Andrew Brown  Chris Brown  Neil Burns  David Butler  Hannah Collins  Helen Crowley  Justin DeKoszmovszky  Les G. Firbank  Brett Fulford  Toby A. Gardner  Rosemary S. Hails  Sharla Halvorson  Michael Jack  Ben Kerrison  Lenny S. C. Koh  Steven C. Lang  Emily J. McKenzie  Pablo Monsivais  Timothy O’Riordan  Jeremy Osborn  Stephen Oswald  Emma Price Thomas  David Raffaelli  Belinda Reyers  Jagjit S. Srai  Bernardo B. N. Strassburg  David Webster  Ruth Welters  Gail Whiteman  James Wilsdon  Bhaskar Vira 《Sustainability Science》2017,12(2):319-331
Delivering access to sufficient food, energy and water resources to ensure human wellbeing is a major concern for governments worldwide. However, it is crucial to account for the ‘nexus’ of interactions between these natural resources and the consequent implications for human wellbeing. The private sector has a critical role in driving positive change towards more sustainable nexus management and could reap considerable benefits from collaboration with researchers to devise solutions to some of the foremost sustainability challenges of today. Yet opportunities are missed because the private sector is rarely involved in the formulation of deliverable research priorities. We convened senior research scientists and influential business leaders to collaboratively identify the top forty questions that, if answered, would best help companies understand and manage their food-energy-water-environment nexus dependencies and impacts. Codification of the top order nexus themes highlighted research priorities around development of pragmatic yet credible tools that allow businesses to incorporate nexus interactions into their decision-making; demonstration of the business case for more sustainable nexus management; identification of the most effective levers for behaviour change; and understanding incentives or circumstances that allow individuals and businesses to take a leadership stance. Greater investment in the complex but productive relations between the private sector and research community will create deeper and more meaningful collaboration and cooperation.  相似文献   
15.
中国特色的城市化问题   总被引:13,自引:3,他引:13  
针对当前社会经济发展中有中国特色的城市化建设问题,展开全方位、多视角的分析阐述,指出了认识对城市化问题的种种误区。提出中国的城市化发展应该与国情国力、工业化发展形势相协调,过程应有序、健康。并认为:(1)在相当长一段时间内、中国城市化水平以界定在50%-55%为宜,而不应该盲目追求西方国家不同国情的高指标、高比例;(2)对城市今后的发展规模应有稳步发展;(4)乡村城镇化必须发展生态农业与生态工业、走集约化、专业化的道路。正确引导中国的城市化进程,把城市发展和农村、工业和农业、人口流动、产业政策、区域平衡、科技进步、外向型经济可持续发展等当作整体一盘棋来统筹制定总体战略。  相似文献   
16.
An international cooperative project on distribution of ozone in the Carpathian Mountains, Central Europe was conducted from 1997 to 1999. Results of that project indicated that in large parts of the Carpathian Mountains, concentrations of ozone were elevated and potentially phytotoxic to forest vegetation. That study led to the establishment of new long-term studies on ecological changes in forests and other ecosystems caused by air pollution in the Retezat Mountains, Southern Carpathians, Romania and in the Tatra Mountains, Western Carpathians on the Polish-Slovak border. Both of these important mountain ranges have the status of national parks and are Man & the Biosphere Reserves. In the Retezat Mountains, the primary research objective was to evaluate how air pollution may affect forest health and biodiversity. The main research objective in the Tatra Mountains was to evaluate responses of natural and managed Norway spruce forests to air pollution and other stresses. Ambient concentrations of ozone (O(3)), sulfur dioxide (SO(2)), nitrogen oxides (NO(x)) as well as forest health and biodiversity changes were monitored on densely distributed research sites. Initial monitoring of pollutants indicated low levels of O(3), SO(2), and NO(x) in the Retezat Mountains, while elevated levels of O(3) and high deposition of atmospheric sulfur (S) and nitrogen (N) have characterized the Tatra Mountains. In the Retezat Mountains, air pollution seems to have little effect on forest health; however, there was concern that over a long time, even low levels of pollution may affect biodiversity of this important ecosystem. In contrast, severe decline of Norway spruce has been observed in the Tatra Mountains. Although bark beetle seems to be the immediate cause of that decline, long-term elevated levels of atmospheric N and S depositions and elevated O(3) could predispose trees to insect attacks and other stresses. European and US scientists studied pollution deposition, soil and plant chemistry, O(3)-sensitive plant species, forest insects, and genetic changes in the Retezat and Tatra Mountains. Results of these investigations are presented in a GIS format to allow for a better understanding of the changes and the recommendations for effective management in these two areas.  相似文献   
17.
Environmental disputes arise due to opposing views of various groups about their environmental concerns and their economic or developmental interests. Development and protection of the environment constitute two main contradictory objectives within the sustainable development paradigm, which are often in conflict. The decision support system, GMCR II, which implements the graph model for conflict resolution, is employed to model and analyze an environmental dispute arising over the construction of a new freeway between the Iranian capital, Tehran, and the city of Chalous located in the north of the country. This study demonstrates that the graph model for conflict resolution can be used as a methodology to promote a reasonable balance between economic development and environmental protection from a strategic viewpoint. In addition to systematically modelling the conflict by putting the existing information into proper perspective, it is shown how conflict analysis can be used for comparing alternative scenarios and predicting possible future outcomes. Readers should send their comments on this paper to: BhaskarNath@aol.com within 3 months of publication of this issue.  相似文献   
18.
A set of biochemical and histological responses was measured in wild gudgeon collected upstream and downstream of urban and pharmaceutical manufacture effluents. These individual end-points were associated to fish assemblage characterisation. Responses of biotransformation enzymes, neurotoxicity and endocrine disruption biomarkers revealed contamination of investigated stream by a mixture of pollutants. Fish from sampled sites downstream of the industrial effluent exhibited also strong signs of endocrine disruption including vitellogenin induction, intersex and male-biased sex-ratio. These individual effects were associated to a decrease of density and a lack of sensitive fish species. This evidence supports the hypothesis that pharmaceutical compounds discharged in stream are involved in recorded endocrine disruption effects and fish population disturbances and threaten disappearance of resident fish species. Overall, this study gives argument for the utilisation of an effect-based monitoring approach to assess impacts of pharmaceutical manufacture discharges on wild fish populations.  相似文献   
19.
The paper describes the results of a study of the impact of the National Energy on the trend towards increased utilization of coal and lignite in Texas with forecasts of increased coal and lignite utilization for the electric utility and industrial sectors. Environmental impacts of this increased coal and lignite use are projected in terms of increased air pollutant emissions and air quality impacts. Economic costs of compliance with alternative source emission regulations are also projected for the electric utility industry.Lignite consumption in Texas under the National Energy Plan is projected to increase from the present 13 million metric tons in 1976 to 57 million metric tons annually by 1985. Sub-bituminous coal consumption in Texas is projected to increase from 1 million metric per year in 1976 to 49 million metric tons per year in 1985. Bituminous coal consumption in Texas is expected to increase from less than one million metric tons per year in 1976 to about 3 million metric tons per year in 1985.Major increases in sulfur oxides emissions from coal and lignite combustion in Texas can be expected by 1985 of up to 1.5 × 109 kg per year without controls and 0.2 × 109 kg per year with controls. Increases in acid precipitation formation will result in north-east Texas from extensive lignite usage for electric power generation as a detriment to agriculture. The photochemical air pollution problem in the Houston area will probably worsen primarily because of increased nitrogen oxides and sulfur oxides emissions because of industrial coal combustion. Capital costs of air pollution controls in Texas for coal-fired utility boilers are estimated as up to U.S. $3.9 billion by 1985, with total operating costs of up to U.S. $1.2 billion per year.  相似文献   
20.
The reasons for developing quantitative estimates of uncertainty in environmental risk assessments are discussed along with a method for developing them which involves scientific judgement. In the situation considered here the regulatory needs are ahead of the science, which makes the development of the estimates on uncertainty more difficult, but not impossible. Quantitative estimates for all uncertainties involved in the estimation of risk resulting from exposure to volatile organic compounds (VOCs) in drinking water are developed and tabulated. By far the largest contribution to the uncertainty in the risk estimates for VOCs in drinking water are due to uncertainty in the extrapolation of the dose-response curve to low levels. The uncertainty due to extrapolation is on the order of 104 and 106. Other components of the analysis may contribute uncertainties of a few orders of magnitude. In general the largest uncertainties are in the toxicological data base and the manipulation of it needed to estimate risk. The data base and manipulations needed to estimate exposure due to VOCs in drinking water were at the more an order to magnitudes in uncertainty.  相似文献   
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