Trends and uncertainties in volatile organic compound emissions from anthropogenic sources

This paper discusses trends and uncertainties in the anthropogenic emission inventory for VOC. EPA's trend analysis indicates that emissions increased almost across the board until about 1970. After 1970, emissions continued to increase for industrial solvents, but declined for transportation, nonindustrial solvents, and combustion and waste disposal. With the current emphasis on using grid models to define NO_x and VOC control strategies, the uncertainty of emission inventories is becoming increasingly important. However, the volume of data in an emissions inventory makes the detailed assessment of uncertainty difficult if not impossible.     

不同地区机械通风式密闭畜禽舍空气氨减排潜力分析

氨气是大气中唯一的碱性气体,减少氨排放对控制大气雾霾有重要作用,畜禽养殖业是重要的氨气排放源,科学评估不同环节的氨气排放量及减排潜力具有重要意义。本文根据文献资料总结了国内外不同畜禽养殖舍的氨排放因子情况、主要减排技术及效率,并结合第二次全国污染源普查获得的全国主要畜禽采用机械通风养殖场的数量和养殖量,对中国分地区、分畜种密闭式畜舍外排空气的氨减排潜力进行了分析。结果表明：中国机械通风畜舍外排空气氨气年减排潜力为26.56万t,主要来自生猪、蛋鸡和肉鸡三种畜禽,其减排潜力分别为10.18万t、7.73万t和6.75万t,三种畜禽舍减排潜力占比92.8%;从地区上看,主要可实施地区为华东区、中南区和华北区,氨气减排潜力分别占全国的35.1%、26.9%和14.9%。建议开展密闭式生猪、蛋鸡和肉鸡舍氨减排设施建设,可为全国氨减排和大气环境质量改善提供保障。     

Emission Inventories,Emission Control Options and Control Strategies: An Overview of Recent Developments

Accurate emission inventories are crucial for informed decisions about emission control strategies. Emission inventory activities are now well established throughout the world and a large body of resources is available to assist in estimating emissions at the global, regional and local scale. Work is ongoing to refine methodologies and to address additional sources and pollutants such as fine particulate matter. During the last decade innovative concepts for emission control legislation were developed. Market based instruments can achieve envisaged emission reductions at lower costs than conventional approaches. Air quality management is now understood as a multi-pollutant, multi-effect task, which offers a significant cost saving potential if synergistic effects are fully utilized. Integrated assessment models proved useful in managing the vast volume of relevant information needed for the design of cost-effective emission control strategies. Europe and North America have embarked on ambitious control strategies that will lead to significant reductions in the emissions of some of the conventional pollutants (e.g., SO₂, NO_x, VOC). There are also first indications of a structural break that could reverse the long-term growth trend of SO₂ emissions also in the fast developing nations of Asia.     

DNDC模型模拟农田温室气体排放研究进展

在简要介绍DNDC模型(脱氮分解模型)及其在中国的应用与改进基础上,综述了中国学者利用该模型模拟与估算农田温室气体排放和减排调控方面的研究进展,提出未来模型在中国的发展应针对中国农业种植体系的特点,增加模型模块,修正模型参数,建立跨尺度农田生态系统综合评估模型,加强大尺度和长时间序列的温室气体排放模拟与预测研究。同时,加强遥感和地理信息系统技术与模型的结合,以提高区域尺度模拟和预测精度,降低模拟结果的不确定性。     

Reduced-Form Modelling of Surface Water and Soil Chemistry for the Tracking and Analysis Framework

A reduced-from modelling approach is used to predict soil and lake acidification as part of an integrated assessment of acid deposition effects and control strategies. The reduced-form model is based upon the mechanistic, lumped parameter watershed chemistry model, MAGIC (Model of Acidification of Groundwater in Catchments). Recent improvements to MAGIC are described, and its reduced-form representation in the Tracking and Analysis Framework (TAF), an integrated assessment model for decision and uncertainty analysis, is presented. Reduced-form models are developed for lake acid neutralising capacity (ANC), calcium, pH, and aluminium; and for soil base saturation. The model for lake ANC incorporates long-term depletion of the watershed acid neutralisation fraction, as is predicted to occur with MAGIC. In test calibrations for 33 representative watersheds in the Adirondacks, the resulting reduced-form model provides a close approximation to MAGIC, with average root mean square errors of 0.79 μeq l^-1 for ANC, 1.09 μeq l^-1 for calcium, 0.16 for pH, 2.52 μeq l^-1 for aluminium, and 0.09% for soil base saturation. In addition, improved fish viability models are incorporated in the integrated assessment model, and predictions are demonstrated for a future deposition reduction scenario for the Adirondack region.     

A review on parameterization and uncertainty in modeling greenhouse gas emissions from soil

The efficacy of mathematical modeling as a tool for estimating greenhouse gas (GHG) emissions from soil depends on the uncertainty. Systematic evaluation of various sources of uncertainties in GHG emission models is limited. This paper reviews the state-of-the-art knowledge on the parameterization and uncertainty analysis of soil GHG emission models. Major recommendations and conclusions from this work include: (a) uncertainties due to model parameters and structure can be quantified by combining the Bayesian theorem and the Markov Chain Monte Carlo (MCMC) method; (b) uncertainty due to event-based model input may also be assessed by regarding each event as a latent variable; however, the necessity of the simultaneous evaluation of uncertainties from model input, parameters, and structure might be negotiable because strong correlations may exist between input errors and model parameters; (c) uncertainty analysis is essential for a successful model parameterization by reducing both the number of undetermined parameters and the parameter space; and (d) model parameterization (calibration) should be conducted on multiple sites towards multiple objectives. Case studies were presented for comparing the model uncertainties of the denitrification components of four models, DAYCENT, DNDC, ECOSYS, and COMP. The methods discussed in this paper can help to evaluate model uncertainties and performances, and to offer a critical guidance for model selection and parameterization.     

碳排放约束下耕地利用推动粮食生产的逻辑关联、现实矛盾与路径优化

耕地利用是国家粮食安全的重要保障,在碳排放约束背景下探究其与粮食生产之间的有机关联有助于揭示“土-碳-粮”三要素复杂的逻辑关系。该研究基于归纳演绎法与理论分析法,在梳理碳约束下耕地利用与粮食生产逻辑关系的基础上,深入分析粮食安全保障与碳减排背景下中国耕地可持续利用面临的挑战,并提出促进耕地绿色转型升级与粮食综合生产能力提高的优化路径。结果表明：1）碳排放约束下耕地利用与粮食生产之间紧密的逻辑关联形成了复杂的“土-碳-粮”要素系统;2）当前农业生产条件下实施耕地利用碳减排对国家粮食安全具有不确定性影响,但粮食稳产与增产仍将造成大量碳排放;3）为有效改善碳排放约束下耕地利用与粮食生产的紧平衡状态,从耕地保护、碳减排、粮食生产三方面通过耕地资源配置优化、碳交易市场构建、粮食生产结构调整等方式实现“土-碳-粮”要素协调路径优化。未来需合理规划耕地空间利用格局,采取多种政策工具,转变耕地利用方式,促进耕地低碳、绿色利用与国家粮食安全的可持续协同发展。     

Methane Emission of the Amsterdam Urban Area

Within the Dutch National Research Programme on Climate Change, the emission of methane from urban areas was considered to be one of the uncertain sources in the national methane budget. Amsterdam was chosen to be a representative urban area for methane emission assessment. An emission inventory was made and concentration fields were calculated using the Danish OML model. Calculated concentration values were compared to concentrations measured continuously at a site near Amsterdam and corrected for background concentrations, The methane emission of the Amsterdam area is low. Main sources are traffic emissions (1.3 ktons y^-1) and the gas distribution network (0.44 ktons y^-1). The background corrected outdoor concentrations are a factor of twenty higher than the calculated outdoor concentrations. The most probable sources for this discrepancy are uncertainty in background concentration and the choice of the roughness length in modelling.     

A Computational Approach Based on GIS Technology for the Development of an Anthropogenic Emission Inventory of Gaseous Pollutants in Greece

This paper describes a computational system developed for the compilation of an anthropogenic emission inventory of gaseous pollutants for Greece. The inventory was developed using a geographical information system integrated with SQL programming language to provide high temporal gridded emission fields for CO, NO₂, NO, SO₂, NH₃ and 23 non-methane volatile organic compounds (NMVOCs) species for the reference year 2003. Activity and statistical data from national sources were used for the quantification of emissions from the road transport, the other mobile sources and machinery sectors and from range activities using top-down or bottom-up methodologies. Annual emission data from existing national and European emission databases were also used. The emission data were spatially and temporally disaggregated using source-specific spatiotemporal indicators. On national scale, the road transport sector produces about 60% of the annual CO and NMVOC total emissions, with gasoline vehicles being the main CO and NMVOC emissions source. The road transport is responsible for approximately half of the higher alkanes and for more than half of the ethene and toluene emissions. The maritime sector accounts for about 40% of the annual total NO_x emissions, most of which are emitted by the international shipping subsector, whilst SO₂ is emitted mainly by the energy sector. The evaluation of the emissions inventory suggests that it provides a good representation of the amounts of gaseous pollutants emitted on national scale and a good characterisation of the relative composition of CO and NO_x emission in the large urban centres.     

北京地区畜禽温室气体排放的时空变化分析

运用IPCC估算农业温室气体排放指南, 对1978-2009年期间畜禽存栏统计数据进行分析, 研究北京地区畜禽养殖温室气体排放的时空分布。结果表明, 北京地区畜禽温室气体排放自20世纪90年代初逐步增长, 到2004年达到顶峰, 之后有所回落。在3类排放的温室气体中, 牲畜肠道发酵产生的甲烷比重最大, 年平均排放量为0.4 Tg CO2-eq, 排放贡献最大的是牛, 占肠道发酵甲烷排放总量的54%; 牲畜粪便排放的甲烷平均值为0.2 Tg CO2-eq, 牲畜粪便排放的氧化亚氮平均值为0.3 Tg CO2-eq, 畜禽粪便管理排放的甲烷和氧化亚氮主要来自猪的排放, 其贡献率分别为73%和46%。从1978-2009年北京畜禽温室气体排放CR4指数(产业集中度指数)逐步增高可以看出, 北京市畜禽产业集约化水平不断提高, 其中顺义、大兴、密云和通州是北京畜禽温室气体排放的主要区域。同时, 对历年畜禽温室气体排放进行了线形回归预测, 结果显示, 北京地区的畜禽温室气体排放仍呈递增走势。结合北京地区畜禽产业温室气体排放的特点与存在问题, 笔者认为应尽快提出适合畜牧业可持续发展的温室气体减排策略及减排目标, 开展温室气体减排技术研发, 从而推进畜禽产业的可持续发展。     

GIS与氮淋溶模型的结合

Geographical information systems(GIS) are increasingly being applied to surface and subsurface flow and transport modling issues,In this paper,more attentions are focused on the methodology and strategies of coupling GIS with non-point pollution models.Suggestions are made on how to best itegrate current available or selected nitrogen leaching models ,especially in the aspect of programming development so as to effectively and fiexibly address the specific tasks.The new possibilities for dealing with non-point pollution problems at a regional scale are provided in the resulting integrated approach,including embedding grid-based GIS components in models.     

碳中和目标下畜牧业低碳发展路径

推动实现碳中和是可持续发展的关键,减少温室气体排放是推动实现碳中和的根本.作为国际低碳行动的引领者和开拓者,中国承诺将力争于2030年前实现二氧化碳排放达峰,努力争取2060年前实现碳中和.农业生产活动是中国温室气体的第三大排放源,其中畜牧业贡献了农业非二氧化碳温室气体排放的80％,是农业主要温室气体排放源.因此,畜牧...     

A gaussian-box modeling approach for urban air quality management in a Northern Chinese City—II. pollutant emission abatement

A modeling framework by linking air quality simulation with system optimization was presented in this paper to develop cost-effective urban air quality management strategies in Fengnan district of China. The relation between the total allowable emission and wind speed as well as the relation between the total allowable emission and air-quality-guideline satisfaction were quantified based on the simulation results of the Gaussian-box modeling system. The area-source emission reduction objective in each functional zone of the study city during the heating and non-heating seasons was calculated based on such relations. A linear programming model was then developed to optimize the emission abatement which was subject to a number of dust and SO₂ control measures. The economic objective of the air quality management strategy was to minimize the total emission control system cost while the environmental objective can still be satisfied. The environmental objective was reflected by the emission reduction objective of TSP, PM₁₀ and SO₂ corresponding to an air-quality-guideline satisfaction percentage of 80%. Consequently, the modeling system comprehensively took into account the information of emission reduction objectives, emission abatement alternatives, emission reduction cost, and related resources constraints. An optimal emission abatement strategy and the related cost were obtained for various pollution control measures. The results would provide sound bases for decision makers in terms of effective urban air quality management and ensuring healthy economic development in the study city.     

农业土壤氧化亚氮排放模型研究进展

农业土壤产生的氧化亚氮气体（N2O）是重要人为N2O源。农业土壤N2O排放模型众多,根据模型建立方法的不同,可分为过程机理模型和经验模型。为探讨产生N2O的具体过程（硝化过程和反硝化过程）和关键因子,着重介绍了DNDC、DAYCENT、Ecosys、WNMM等机理过程模型,指出尽管各个模型的N循环过程类似,但不同侧重因子造成N2O排放量不同,并列出不同模型的特点和应用现状。对目前应用得比较广泛的经验统计模型,如经验归纳模型、回归模型以及其他统计模型等,归纳了其特点并介绍了国内外研究进展。通过对比过程机理模型和经验统计模型的优缺点,指出前者参数较多、过程复杂,用于点位模拟准确度高,后者所需参数少,适用区域范围模拟,点位模拟结果不确定性差。在此基础上指出区域N2O模拟排放量和排放特性将是以后发展的重点方向,并提出区域模拟关键问题的解决方向。     

农作措施对中国稻田氧化亚氮排放影响的研究进展

农业是全球最主要的温室气体排放源之一,稻田不仅是全球重要的甲烷(CH4)排放源,亦是氧化亚氮(N2O)的重要排放源。灌溉、施肥、耕作等农作措施能够改变稻田生态系统土壤微环境,影响土壤硝化与反硝化过程,进而影响N2O的排放。目前,关于农作措施对农田生态系统N2O排放特征研究很多,但系统地综述农作措施对稻田N2O排放影响的研究还比较少。该文着眼于中国的农业发展趋势,基于稻田灌溉、施肥及耕作等方面的新技术,综合分析新型农作措施对中国稻田生态系统N2O排放的影响及其机制,为相关研究提供参考。在此基础上,提出了中国稻田生态系统N2O排放深入研究的方向:1)加强研究新型农作措施下稻田N2O产生及排放途径;2)系统研究稻田生态系统直接与间接N2O排放的影响及其机制;3)开展农作措施集成技术对稻田生态系统N2O排放影响的研究;4)加强模型模拟的调参验证并进行相关预测分析。     

Model for calculating regional energy use,industrial production and greenhouse gas emissions for evaluating global climate scenarios

In the integrated IMAGE 2.0 model the “Energy-Industry System” is implemented as a set of models to develop global scenarios for energy use and industrial processes and for the related emissions of greenhouse gases on a region specific basis. The Energy-Economy model computes total energy use, with a focus on final energy consumption in end-use sectors, based on economic activity levels and the energy conservation potential (“end-use approach”). The Industrial Production and Consumption model computes the future levels of activities other than energy use, which lead to greenhouse gas emissions, based on relations with activities defined in the Energy-Economy model. These two models are complemented by two emissions models, to compute the associated emissions by using emission factors per compound and per activity defined. For investigating energy conservation and emissions control strategy scenarios various techno-economic coefficients in the model can be modified. In this paper the methodology and implementation of the “Energy-Industry System” models is described as well as results from their testing against data for the period 1970–1990. In addition, the application of the models is presented for a specific scenario calculation. Future extensions of the models are in preparation.     

A volatile discourse – reviewing aspects of ammonia emissions,models and atmospheric concentrations in The Netherlands

In the Netherlands, there is a vigorous debate on ammonia emissions, atmospheric concentrations and deposition between stakeholders and research institutions. In this article, we scrutinise some aspects of the ammonia discourse. In particular, we want to improve the understanding of the methodology for handling experimentally determined ammonia emissions. We show that uncertainty in published results is substantial. This uncertainty is under‐ or even unreported, and as a result, data in national emission inventories are overconfident by a wide margin. Next, we demonstrate that the statistical handling of data on atmospheric ammonia concentrations to produce national yearly atmospheric averages is oversimplified and consequently atmospheric concentrations are substantially overestimated. Finally, we show that the much‐discussed ‘ammonia gap’ – either the discrepancy between calculated and measured atmospheric ammonia concentrations or the difference observed between estimated NH₃ emission levels and those indicated by atmospheric measurements – is an expression of the widespread overconfidence placed in atmospheric modelling.     

中国农业碳排放空间格局及影响因素动态研究

研究农业碳排放空间格局及影响因素对中国制定农业分区碳减排政策意义重大。为弥补以往研究中静态分析法难以考察动态影响的缺陷,将动态灰色关联法和回归模型结合,应用2001—2016年统计数据,从分析农业碳排放空间格局入手,深入探讨省际农业碳排放空间格局成因和影响因素与空间差异的数量关系。研究发现:中国农业碳排放强度省际差异大,中部排放等级有所降低,西部排放等级有所升高,农业碳排放省际差异随农业经济水平、农业机械化、农业产业结构和农业人力资本等差异扩大而增加;大部分排放等级上升的省市农业碳排放的长期主导因素为农地利用和农业生产技术(机械),且种植业和畜牧业双发展;大部分排放等级下降的省市农业碳排放的长期主导因素为反刍动物饲养和农业生产技术(人力),且着重发展优势产业。因此,中国未来较长时间内仍应重点关注农地利用减排,进一步推动反刍动物饲养减排技术发展和充分发挥农业产业结构调整对减排的抑制作用等建议。     

A gaussian-box modeling approach for urban air quality management in a northern chinese city—I. model development

A Gaussian-box modeling approach was presented in this paper to examine the urban air quality due to multiple point- and area-source emissions in the northern Chinese city of Fengnan, which is associated with a deteriorated air quality as a consequence of industrialization and rapid urban growth. A 3-D multi-box (3DMB) air quality model was developed to predict air quality due to area-source emissions. It improved upon the conventional box models by allowing consideration of more details in spatial variations of emission sources and meteorological conditions. The modeling domain was divided into various layers within the mixing height, while each layer was associated with a number of sub-boxes. A multi-source and multi-grid Gaussian modeling approach was then applied to predict the air quality in different sub-boxes that are associated with multiple point-source emissions. Thus the Gaussian-box modeling approach could effectively simulate impacts of both area- and point-source emissions but also reflect more details of the spatial variations in source distributions and meteorological conditions. This modeling approach was employed to predict daily average SO₂, TSP and PM₁₀ concentrations for each sub-box during the heating and non-heating seasons, respectively. The analysis of the mean normalized error of the modeling results demonstrates the feasibility and applicability of the developed method, and the presented method could provide more useful and scientific bases for developing effective urban air quality control and management strategies.     

An Emissions Inventory for Regional Atmospheric Modeling of Mercury

Estimates of mercury emissions from individual sources and source categories are needed to understand relationships between the emissions and resulting deposition and to evaluate possible approaches to reducing those emissions. We have developed geographically-resolved estimates of annual average mercury emission rates from current anthropogenic sources in the 48 contiguous United States. These estimates were made by applying emission factors to individual facility operating data and to county-wide source activity levels. We apportioned the emissions to an Eulerian modeling grid system using point source coordinates and the fractions of county areas in each grid cell. Point sources account for about 89% of the 48-state total mercury emissions of 146.4 Mg/yr. Most of the emissions in the inventory are from combustion of mercury-containing fossil fuels and municipal waste, located primarily in the mid-Atlantic and Great Lakes states as well as in the Southeast. The major uncertainties in the emission estimates are caused by uncertainties in the emission factors used to develop the estimates. This uncertainty is likely a result of variability in the mercury content of the combusted materials and in the removal of mercury by air pollution control devices. The greatest research need to reduce uncertainties in mercury emission estimates is additional measurements to improve emission factors.