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441.
Five years down the road from Kyoto, the Protocol that bears that city’s name still awaits enough qualifying ratifications to come into force. While attention has been understandably focussed on the ratification process, it is time to begin thinking about the next steps for the global climate regime, particularly in terms of a deeper inclusion of developing countries’ concerns and interests. This paper begins doing so from the perspective of the developing countries. The principal argument is that we need to return to the basic principles outlined in the Framework Convention on Climate Change in searching for a north-south bargain on climate change. Such a bargain may be achievable if we can realign the policy architecture of the climate regime to its original stated goals of sustainable development.  相似文献   
442.
Environmental geochemistry of the Guanajuato Mining District, Mexico   总被引:1,自引:0,他引:1  
The Guanajuato Mining District, once one of the major silver producers in the world, has been exploited for silver and gold from low-sulfidation quartz- and calcite-rich epithermal veins since 1548. Currently, there are some 150 million tonnes of low-grade ore piles and mine-waste material (mostly tailings) piles, covering a surface area of 15 to 20 km2 scattered in a 100-km2 region around the city of Guanajuato. Most of the historic tailings piles were not deposited as formal tailings impoundments. They were deposited as simple valley-filling piles without concern for environmental issues. Most of those historical tailings piles are without any vegetation cover and undergo strong eolian and hydrologic erosion, besides the natural leaching during the rainy season (which can bring strong thunderstorms and flash flows). There is public concern about possible contamination of the local aquifer with heavy metals (Fe, Mn, Zn, As and Se) derived from the mining activities.Experimental and field data from this research provide strong geochemical evidence that most of the mine-waste materials derived from the exploitation of the epithermal veins of the region have very low potential for generation of acid mine drainage due to the high carbonate/sulfide ratio (12:1), and very low potential for leaching of heavy metals into the groundwater system. Furthermore, geochemical evidence (experimental and modeled) indicates that natural processes, like metal adsorption onto Fe-oxy-hydroxides surfaces, control the mobility of dissolved metals. Stable isotope data from surface water, groundwater wells (150-m depth) and mine-water (300- to 500-m depth) define an evaporation line (δD=5.93 δ18O=13.04), indicating some deep infiltration through a highly anisotropic aquifer with both evaporated water (from the surface reservoirs) and meteoric water (not evaporated). Zinc concentrations in groundwater (0.03 to 0.5 ppm) of the alluvial aquifer, some 15 km from the mineralized zone, are generally higher than Zn concentrations in experimental tailings leachates that average less than 0.1 ppm. Groundwater travel time from the mineralized area to the alluvial valley is calculated to range from 50 to several hundred years. Thus, although there has been enough time for Zn sourced from the tailings to reach the valley, Zn concentrations in valley groundwater could be due to natural dissolution processes in the deep portions of the epithermal veins.  相似文献   
443.
This in situ study used photosynthetic activity (measured as chlorophyll a fluorescence) and photosynthetic pigment concentrations to assess the effect of copper, cadmium, lead and zinc on the seagrass Zostera capricorni. Custom-made portable in situ exposure (PIE) chambers were developed so seagrasses could be dosed within the meadow. Z. capricorni was exposed to 0.1 and 1 mg l−1 of metal solutions for 10 h. During this time and for the subsequent four-day recovery period, the effective quantum yield of photosystem II (PS II) (ΔF/Fm) was measured. While the results were variable, copper and zinc exposed samples had a depressed ΔF/Fm during the exposure period. Samples exposed to zinc recovered to pre-exposure levels but those exposed to copper did not. Cadmium and lead did not impact on the chlorophyll a fluorescence and the chlorophyll pigment data supported these findings. This study presents an innovative new application of chlorophyll a fluorescence stress assessment.  相似文献   
444.
The year was marked by noteworthy advances in multinational consortia of commercial firms and of forward-looking universities. Again, the tenor of the practice of Engineering Geology has picked up. Not to be in the vanguard does indeed mean that one languishes in the dust raised by those on the move. Engineering geologists must understand an infinity of challenges stemming from land development, environmental protection and cleanup and resource development. This is a profession in which age can bring wisdom and increased competence.Most practitioners were busy in 2001; more than 80% of ASFE member companies report that business has increased or stayed the same for the past 6 months. Sixty percent of practitioners expect that their 2002 revenues will be stable or increase for Year 2002.  相似文献   
445.
北京市经济增长与环境污染水平计量模型研究   总被引:171,自引:10,他引:171  
选取北京市 1985~ 1999年经济与环境数据 ,通过分析经济因子与环境因子相互关系 ,探究北京市经济增长与环境质量演替轨迹 ,以建立北京市经济增长与环境污染水平计量模型 ,为评价北京市环境政策提供依据。实证研究表明 :北京市自 1985年以来随着经济增长其环境恶化程度在下降 ,且已进入经济与环境协调发展后期阶段。北京市各环境指标与人均GDP演替轨迹呈现显著的环境库兹涅茨曲线特征 ,但比发达国家较早实现了其环境库兹涅茨曲线转折点 ,且到达转折点的时间跨度小于发达国家。这主要归功于中国及北京市政府近 10年来 ,尤其 1995年以来有效环境政策和巨额环境投资以及科技后发优势。  相似文献   
446.
A stratigraphic record from a lake in the Central Plateau Regionof northern British Columbia reveals changes in environment and inferredclimate during the Holocene. Upon deglaciation (ca. 11500 BP), Skinny Lakebecame an embayment of an ice-dammed lake. High clastic sedimentationrates, an unstable landscape, and cool, possibly wet conditions likelypersisted until the early Holocene (ca. 9000 BP). From ca. 9000–8300 BPdeclining lake levels coupled with warm and dry conditions resulted in theformation of a prominent marl bed. A colonizing shrub and herb assemblagepersisted from 9000 BP until about 8300 BP when it was replaced by a spruce(Picea) and subalpine fir (Abieslasiocarpa) forest under slightly cooler and moister conditions. Themiddle Holocene was warmer-than-present, however, decreasingtemperature and increasing precipitation trends characterize the period fromca. 6000 BP–3000 BP. The transition to modern climate at 3000 BP isevident primarily in the lithostratigraphic record and corresponds with theinitiation of the Tiedemann glacial advance (ca. 3300 BP) in thesouth-coastal mountains of British Columbia. A significant change infossil pollen occurs at ca. 2400 BP and is characterised by an increase in pinepollen accompanied by decreases in alder (Alnus), spruceand fir. This also coincides with an increase in west-sourced exoticwestern hemlock (Tsuga heterophylla) and cedar type(Cupressaceae) pollen possibly transported by regional changes in air masscirculation patterns associated with Aleutian Low dynamics. This studydemonstrates that both lithostratigraphic and biotic proxies are helpful inreconstructing the timing and nature of climate change and that each may havevarying sensitivities to a particular type of change.  相似文献   
447.
太湖水域氮、磷环境容量评价   总被引:2,自引:0,他引:2       下载免费PDF全文
邓小琴 《江苏地质》2008,32(3):249-253
最近20年来,太湖水质不断恶化,富营养问题日益严重。有效治理太湖当前污染的前提,是查明太湖的污染因子、途径及环境容量。本次研究从生态地质的角度,以太湖水体中水生植物的组成、生态效应分析为依据、以东太湖输出Ⅲ类水为目标,估算太湖水体的N、P环境容量,对太湖水体环境容量问题作初步的尝试和探索。  相似文献   
448.
临汾市在城市发展的过程中,由于自然或人为的原因造成了许多环境地质问题。这些环境地质问题成为临汾市城市进一步发展的制约因素,通过分析临汾市的环境地质条件,进而探讨了临汾市当前的主要环境地质问题。  相似文献   
449.
This paper sets out to evaluate the freedom of voice for Peruvian stakeholders affected by hydrocarbon development. This occurs through the utilization of a political ecology of voice (PEV) theoretical framework based upon the theory of voice by Albert Hirschman and political ecology. PEV can be defined as the study of economic, political, social, and geographical factors over a specific time period and their impact upon the use of voice by stakeholders. Peru’s case study was focused on its main oil-producing Loreto Region and incorporated evaluation of hydrocarbon voice mechanisms (prior consultation and environmental impact assessments) supported by interview testimony of stakeholders and state officials. PEV analysis reveals a political environment which is dangerous, inflexible, and intolerant of Peruvian stakeholders voicing over hydrocarbon development. This is due to the state’s zealous pursuit of its “selva (rainforest) hydrocarbon and development vision” which severely undermines Peruvian stakeholder’s freedom of voice.  相似文献   
450.
青藏高原环境变化对全球变化的响应及其适应对策   总被引:48,自引:0,他引:48  
青藏高原的环境变化对全球变化具有敏感响应和强烈影响。青藏高原的现代环境与地表过程相互作用,引起包括冰冻圈和水资源以及生态系统等方面的一系列变化,对高原本身以及周边地区的人类生存环境和经济社会发展产生重大影响。作为国际研究的热点地区,青藏高原环境变化研究目前出现三个新的科学动向:关注关键地区的关键科学问题的系统研究;关注以现代地表过程为核心的监测研究;关注全球变化影响下的圈层相互作用研究。本项目的研究对青藏高原环境变化科学的发展、国际科学前沿的贡献以及服务于社会经济发展,都具有十分重要的意义。通过项目的研究将揭示青藏高原隆升到现代地貌与环境格局过程中所出现的重大构造事件和环境事件;重建不同区域、不同时间尺度的气候环境变化序列并揭示其时空分布特征;阐明青藏高原冰冻圈、湖泊和主要生态系统与土地覆被在不同气候条件下的变化特征;揭示青藏高原环境变化与地表过程对全球变化的响应特点和高原热力与动力过程对不同气候系统变化的影响。本项目将在高原南北典型区域利用地貌学与沉积学手段,研究青藏高原现代地貌与环境格局的形成过程;利用湖芯、冰芯、树木年轮等手段,研究青藏高原过去环境变化的特征事件、区域分异及其与全球变化的联系;利用冰川、冻土、积雪的时空变化,结合对高原特殊大气边界层的观测,研究青藏高原冰冻圈变化与能量水分循环过程;从冰川、湖泊、大气的监测入手,结合模式方法,研究青藏高原环境变化的机制;利用生态系统碳的源—汇变化,研究青藏高原生态系统对环境变化的响应;综合研究全球变化背景下青藏高原环境变化与水资源变化所产生的区域效应和适应对策。  相似文献   
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