Results from a pilot-scale air quality study in Addis Ababa, Ethiopia

Twenty-one samples were collected during the dry season (26 January–28 February 2004) at 12 sites in and around Addis Ababa, Ethiopia and analyzed for particulate matter with aerodynamic diameter <10 μm (PM₁₀) mass and composition. Teflon-membrane filters were analyzed for PM₁₀ mass and concentrations of 40 elements. Quartz-fiber filters were analyzed for chloride, sulfate, nitrate, and ammonium ions as well as elemental carbon (EC) and organic carbon (OC) content. Measured 24-h PM₁₀ mass concentrations were <100 and 40 μg m⁻³ at urban and suburban sites, respectively. PM₁₀ lead concentrations were <0.1 μg m⁻³ for all samples collected, an important finding because the government of Ethiopia had stopped the distribution of leaded gasoline a few months prior to this study. Mass concentrations reconstructed from chemical composition indicated that 34–66% of the PM₁₀ mass was due to geologically derived material, probably owing to the widespread presence of unpaved roads and road shoulders. At urban sites, EC and OC compounds contributed between 31% and 60% of the measured PM₁₀ while at suburban sites carbon compounds contributed between 24% and 26%. Secondary sulfate aerosols were responsible for <10% of the reconstructed mass in urban areas but as much as 15% in suburban sites, where PM₁₀ mass concentrations were lower. Non-volatile particulate nitrate, a lower limit for atmospheric nitrate, constituted <5% and 7% of PM₁₀ at the urban and suburban sites, respectively. At seven of the 12 sites, real-time PM₁₀ mass, real-time carbon monoxide (CO), and instantaneous ozone (O₃) concentrations were measured with portable nephelometers, electrochemical analyzers, and indicator test sticks, respectively. Both PM₁₀ and CO concentrations exhibited daily maxima around 7:00 and secondary peaks in the late afternoon and evening, suggesting that those pollutants were emitted during periods associated with motor-vehicle traffic, food preparation, and heating of homes. The morning concentration maxima were likely accentuated by stable atmospheric conditions associated with overnight surface temperature inversions. Ozone concentrations were measured near mid-day on filter sample collection days and were in all cases <45 parts per billion.     

探析我国环境税收制度的构建

环境税收制度是未来中国环境政策改革的突破口，相对于其它的环境政策如排污收费与排污权交易等，环境税收其经济效益与环境效益明显，开征环境税收有重要的意义，但在短期内，我国实施环境税收制度的条件尚不成熟，环境政策体系应该采取税费并存并逐步过渡到以环境税为主的方式。     

Mapping and Modeling the Biogeochemical Cycling of Turf Grasses in the United States

Turf grasses are ubiquitous in the urban landscape of the United States and are often associated with various types of environmental impacts, especially on water resources, yet there have been limited efforts to quantify their total surface and ecosystem functioning, such as their total impact on the continental water budget and potential net ecosystem exchange (NEE). In this study, relating turf grass area to an estimate of fractional impervious surface area, it was calculated that potentially 163,800 km² (± 35,850 km²) of land are cultivated with turf grasses in the continental United States, an area three times larger than that of any irrigated crop. Using the Biome-BGC ecosystem process model, the growth of warm-season and cool-season turf grasses was modeled at a number of sites across the 48 conterminous states under different management scenarios, simulating potential carbon and water fluxes as if the entire turf surface was to be managed like a well-maintained lawn. The results indicate that well-watered and fertilized turf grasses act as a carbon sink. The potential NEE that could derive from the total surface potentially under turf (up to 17 Tg C/yr with the simulated scenarios) would require up to 695 to 900 liters of water per person per day, depending on the modeled water irrigation practices, suggesting that outdoor water conservation practices such as xeriscaping and irrigation with recycled waste-water may need to be extended as many municipalities continue to face increasing pressures on freshwater.     

An ecological approach to environmental impact assessment

Carbon cycling analysis is presented as a means for assessing anthropogenic perturbations in an ecosystem. Data from oligotrophic, eutrophic, and dystrophic (bog) lakes are used to show general trends in the lacustrine carbon cycle. The oligotrophic lake is an unstressed system and the eutrophic lake is under nutrient enrichment with high algal standing crops and productivity. The bog lake is a pH-stressed environment that is primarily a grazing ecosystem. It is hoped that a more effective environmental impact assessment will result from the use of carbon cycling as a unifying concept in ecosystem analysis.     

Carbon forestry economic mitigation potential in India,by land classification

Carbon forestry mitigation potential estimates at the global-level are limited by the absence or simplicity of national-level estimates, and similarly national-level estimates are limited by absence of regional-level estimates. The present study aims to estimate the mitigation potential for a large diverse country such as India, based on the GTAP global land classification system of agro-ecological zones (AEZs), as well the Indian AEZ system. The study also estimates the implications of carbon price incentive (US$50 and $100) on mitigation potential in the short-, medium- and long-term, since afforestation and reforestation (A & R) is constrained by lack of investment and financial incentives. The mitigation potential for short and long rotation plantations and natural regeneration was estimated using the GCOMAP global forest model for two land area scenarios. One scenario included only wastelands (29 Mha), and the second enhanced area scenario, included wastelands plus long fallow and marginal croplands (54 Mha). Under the $100 carbon price case, significant additional area (3.6 Mha under the wasteland scenario and 6.4 Mha under the enhanced area scenario) and carbon mitigation is gained in the short-term (2025) compared to the baseline when using the GTAP land classification system. The area brought under A & R increases by 85–100% for the $100 carbon price compared to $50 carbon price in the short-term, indicating the effectiveness of higher carbon price incentives, especially in the short-term. A comparison of estimates of mitigation potential using GTAP and Indian AEZ land classification systems showed that in the short-term, 35% additional C-stock gain is achieved in the $100 carbon price case in the enhanced area scenario of the Indian AEZ system. This difference highlights the role of the land classification system adopted in estimation of aggregate mitigation potential estimates, particularly in the short-term. Uncertainty involved in the estimates of national-level mitigation potential needs to be reduced, by generating reliable estimates of carbon stock gain and losses, and cost and benefit data, for land use sector mitigation options at a scale disaggregated enough to be relevant for national mitigation planning.     

大气痕量气体与全球温室效应

随着工业生产和人类活动的加强，大气中痕量气体含量明显增加。这种增加有可能破坏臭气层、导致全球温室效应。阐述这些气体导致温室效应的机理，总结这些痕量气体近年来在大气中的浓度变化趋势，分析引起这些变化的机理。     

淀山湖水环境管理新模式探讨

10多年来的淀山湖水质监测结果表明，淀山湖水质呈一波高于一波的有机污染趋势。目前环境管理中存在着重排污浓度控制，轻污染物总量控制的问题。文章提出了点源与非点源排污交易是一种合适于湖泊水环境管理的新模式，是总量控制的操作载体，是实施总量控制的充分条件。同时，详细论述了点源与非点源排污交易的实际操作程序。     

在总量控制体系下实施点源与非点源排污交易的理论研究

阐述了点源与非点源排污交易的基本思路，通过边际削减成本的比较，对交易的经济可行性进行了分析，并指出此种交易模式与传统的点源治理模式的成本差异。在给定的简化条件下，提出了单一点源与单一非点源的交易模型。     

CO2 emission reduction for Japanese petrochemicals

Energy efficiency in the Japanese industry is one of the highest in the world. As a consequence, reduction of CO₂ emissions is considered to be difficult and costly. However little attention has been paid as of yet to changes related to so-called non-energy use of fossil fuels. The analysis in this paper suggests that a large number of options exist for emission reduction in the Japanese petrochemical industry. This includes the introduction of biomass feedstocks, the introduction of new catalytic production processes, and changes in waste handling. The use of bioplastics and the use of CO₂ feedstocks seem costly options for GHG emission reduction that should not be applied on the short term. Japanese GHG emissions can be reduced by 7.7% if the optimal set of emission mitigation options is applied. About 60 Mt emission reduction (4.9%) can be achieved by changes on the supply side, another 35 Mt emission reduction (2.8%) can be achieved by changes in waste management. While changes in waste management can be implemented before 2010, biomass introduction on the supply side will probably require a longer lead-time. About half of the emission reduction is cost–effective, but will require further technology development. The other half can be achieved at a cost level of 10,000 yen/t CO₂ (80 US$/t CO₂). The latter part is based on proven technology that is currently not cost–effective.     

滇池水中有机物去除技术探讨

常规水处理工艺，加氯消毒副产物多，饮水中有机卤代物对健康不利。通过臭氧、活性炭及投加粉末活性炭等实验对以滇池水为源水的饮水中有机物的去除有一定效果。根据这一生产性试验，本文讨论了滇池水深度处理结果和应用效果。