Comparison of Tools for Quantifying the Environmental Performance of an Urban Territory

To support effective urban policies aimed at decreasing the environmental impacts of cities, it is important to develop robust tools for accounting those impacts. Environmentally extended input‐output analysis (EEIOA) is among the most used tools for this purpose, allowing the quantification of both direct and indirect impacts. Life cycle assessment (LCA) is also a holistic and comprehensive tool that accounts for direct and indirect impacts—but its application to cities is still very recent. This study aims at applying EEIOA and LCA to the municipality of Aveiro (Portugal) in order to compare the outcomes of the two tools in terms of total impacts (climate change and fossil fuel depletion) and hotspots (sectors/products contributing most to the impacts), to identify limitations and advantages of the tools when applied to Aveiro, and to illustrate how LCA can be applied to cities. The total impacts estimated with LCA and EEIOA were similar and the hotspots were also the same: transports, food, construction, and electricity. However, the relative contribution of some sectors was very different in the two tools due to methodological differences mainly in system boundaries, type of activities or products considered in each sector, and geographical coverage of impact data. This study concludes that the analyzed tools can provide complementary results to support decision making concerning urban planning and management.     

Economy‐wide Material Flow Indicators on a Sectoral Level and Strategies for Decreasing Material Inputs of Sectors

The article presents a method for the calculation of selected economy‐wide material flow indicators (namely, direct material input [DMI] and raw material input [RMI]) for economic sectors. Whereas sectoral DMI was calculated using direct data from statistics, we applied a concept of total flows and a hybrid input‐output life cycle assessment method to calculate sectoral RMI. We calculated the indicators for the Czech Republic for 2000–2011. We argue that DMI of economic sectors can be used for policies aiming at decreasing the direct input of extracted raw materials, and imported raw materials and products, whereas sectoral RMI can be better used for justifying support for or weakening the role of individual sectors within the economy. High‐input material flows are associated in the Czech Republic with the extractive industries (agriculture and forestry, the mining of fossil fuels [FFs], other types of mining, and quarrying), with several manufacturing industries (manufacturing of beverages, basic metals, motor vehicles or electricity, and gas and steam supply) and with construction. Viable options for reducing inputs of agricultural biomass include changes in people's diet toward a lower amount of animal‐based food and a decrease in the wasting of food. For FFs, one should think of changing the structure of total primary energy supply toward cleaner gaseous and renewable energy sources, innovations in transportation systems, and improvements in overall energy efficiency. For metal ores, viable options include technological changes leading to smaller and lighter products, as well as consistent recycling and use of secondary metals.     

Emission scenario of non-CO2 gases from energy activities and other sources in China

This paper gives a quantitative analysis on the non-CO2 emissions related to energy demand, energy activities and land use change of six scenarios with different development pattern in 2030 and 2050 based on IPAC emission model. The various mitigation technologies and policies are assessed to understand the corresponding non-CO2 emission reduction effect. The research shows that the future non-CO2 emissions of China will grow along with increasing energy demand, in which thermal power and transportation will be the major emission and mitigation sectors. During the cause of future social and economic development, the control and mitigation of non-CO2 emissions is a problem as challenging and pressing as that of CO2 emissions. This study indicates that the energy efficiency improvement, renewable energy, advanced nuclear power generation, fuel cell, coal-fired combined cycle, clean coal and motor vehicle emission control technologies will contribute to non-CO2 emissions control and mitigation.     

Emission scenario of non-CO2 gases from energy activities and other sources in China

This paper gives a quantitative analysis on the non-CO2 emissions related to energy demand, energy activities and land use change of six scenarios with different development pattern in 2030 and 2050 based on IPAC emission model. The various mitigation technologies and policies are assessed to understand the corresponding non-CO2 emission reduction effect. The research shows that the future non-CO2 emissions of China will grow along with increasing energy demand, in which thermal power and transportation will be the major emission and mitigation sectors. During the cause of future social and economic development, the control and mitigation of non-CO2 emissions is a problem as challenging and pressing as that of CO2 emissions.This study indicates that the energy efficiency improvement, renewable energy, advanced nuclear power generation, fuel cell, coal-fired combined cycle, clean coal and motor vehicle emission control technologies will contribute to non-CO2 emissions control and mitigation.     

The good,the bad,and the future: Systematic review identifies best use of biomass to meet air quality and climate policies in California

California has large and diverse biomass resources and provides a pertinent example of how biomass use is changing and needs to change, in the face of climate mitigation policies. As in other areas of the world, California needs to optimize its use of biomass and waste to meet environmental and socioeconomic objectives. We used a systematic review to assess biomass use pathways in California and the associated impacts on climate and air quality. Biomass uses included the production of renewable fuels, electricity, biochar, compost, and other marketable products. For those biomass use pathways recently developed, information is available on the effects—usually beneficial—on greenhouse gas (GHG) emissions, and there is some, but less, published information on the effects on criteria pollutants. Our review identifies 34 biomass use pathways with beneficial impacts on either GHG or pollutant emissions, or both—the “good.” These included combustion of forest biomass for power and conversion of livestock-associated biomass to biogas by anaerobic digestion. The review identified 13 biomass use pathways with adverse impacts on GHG emissions, criteria pollutant emissions, or both—the “bad.” Wildfires are an example of one out of eight pathways which were found to be bad for both climate and air quality, while only two biomass use pathways reduced GHG emissions relative to an identified counterfactual but had adverse air quality impacts. Issues of high interest for the “future” included land management to reduce fire risk, future policies for the dairy industries, and full life-cycle analysis of biomass production and use.     

Emission scenario of non-CO2 gases from energy activities and other sources in China

This paper gives a quantitative analysis on the non-CO₂ emissions related to energy demand, energy activities and land use change of six scenarios with different development pattern in 2030 and 2050 based on IPAC emission model. The various mitigation technologies and policies are assessed to understand the corresponding non-CO₂ emission reduction effect. The research shows that the future non-CO₂ emissions of China will grow along with increasing energy demand, in which thermal power and transportation will be the major emission and mitigation sectors. During the cause of future social and economic development, the control and mitigation of non-CO₂ emissions is a problem as challenging and pressing as that of CO₂ emissions. This study indicates that the energy efficiency improvement, renewable energy, advanced nuclear power generation, fuel cell, coal-fired combined cycle, clean coal and motor vehicle emission control technologies will contribute to non-CO₂ emissions control and mitigation.

     

Emission scenario of non-CO2 gases from energy activities and other sources in China

This paper gives a quantitative analysis on the non-CO₂ emissions related to energy demand, energy activities and land use change of six scenarios with different development pattern in 2030 and 2050 based on IPAC emission model. The various mitigation technologies and policies are assessed to understand the corresponding non-CO₂ emission reduction effect. The research shows that the future non-CO₂ emissions of China will grow along with increasing energy demand, in which thermal power and transportation will be the major emission and mitigation sectors. During the cause of future social and economic development, the control and mitigation of non-CO₂ emissions is a problem as challenging and pressing as that of CO₂ emissions. This study indicates that the energy efficiency improvement, renewable energy, advanced nuclear power generation, fuel cell, coal-fired combined cycle, clean coal and motor vehicle emission control technologies will contribute to non-CO₂ emissions control and mitigation.     

Bioenergy crops,biodiversity and ecosystem services in temperate agricultural landscapes—A review of synergies and trade-offs

The Paris agreement on climate change requires rapid reductions in greenhouse gas emissions. One important mitigation strategy, at least in the intermediate future, is the substitution of fossil fuels with bioenergy. However, using agriculture- and forest-derived biomass for energy has sparked controversy regarding both the climate mitigation potential and conflicts with biodiversity conservation. The urgency of the climate crisis calls for using forests for carbon sequestration and storage rather than for bioenergy, making agricultural biomass an attractive alternative for fossil energy substitution. However, this calls for comprehensive assessments of its sustainability in terms of consequences for biodiversity and ecosystem services. In this review, we provide a first holistic overview of the impacts on ecosystems of land-use changes from bioenergy crop production in temperate climates, by synthesizing results on both biodiversity and ecosystem service impacts. We found that bioenergy-related land-use changes can have both positive and negative effects on ecosystems, with original land use, bioenergy crop type and scale of bioenergy production being important moderators of impacts. Despite the risk of opportunity cost for food production, perennial crop cultivation on arable land had the lowest occurrence of negative impacts on biodiversity and ecosystem services. Growing biomass for bioenergy on surplus land has been suggested as a way to alleviate competition with food production and biodiversity conservation, but our results demonstrate that utilizing marginal or abandoned land for bioenergy crop production cannot fully resolve these trade-offs. Furthermore, there is a lack of empirical studies of the biodiversity value of marginal and abandoned land, limiting our understanding of the sustainability implications of biomass cultivation on surplus land. We argue that future research and policies for bioenergy production must explicitly consider biodiversity and ecosystem services in combination to avoid potential trade-offs between the two and to ensure sustainable bioenergy production.     

基于多区域投入产出分析的京津冀地区虚拟水核算

通过贸易与消费调控实现区域水资源优化配置已成为缓解地区水资源压力的途径之一。跨区域投入产出分析可为地区间虚拟水贸易战略提供依据。基于2012年京津冀地区投入产出表与生产用水量构建了跨地区虚拟水核算模型,计算了隐含在经济贸易中的虚拟水总量及各地区各部门的直接用水系数、完全用水系数和拉动系数,分析了各部门虚拟水进出口情况,识别了重点耗水部门。结果表明:京津冀地区呈现虚拟水净出口状态,其中净出口部门主要为北京的服务与交通业,河北的农业和制造业。京津冀的农业、矿业和水供应业在生产过程中直接消耗水量大,应注重提升用水效率及节水技术的开发;三地制造业、建筑业和服务与交通业的平均拉动系数较大,这说明其他部门生产活动对该部门依赖性较大,其单位产出的提高将带动整个地区更多虚拟水量的投入。此外,河北的农业和制造业为京津冀各部门输送了大量虚拟水,为各部门生产提供了支撑,是节水的重点部门,应着重调整其产业结构,并从直接和间接用水两方面入手减少水资源消耗。计算了京津冀地区不同部门的直接、间接水资源消耗、水资源消耗拉动系数,以及部门间的虚拟水贸易情况,结果可为该地区部门间水资源配置和虚拟水战略的制定提供基础。     

A regional version of a US economic input-output life-cycle assessment model

Background, Aims and Scope Life cycle assessment models typically use product-specific, plant-level or national aggregate data. However, many decisions by regional policy makers would be better informed by local or regional aggregate data. This research is intended to construct and apply a regional US economic input-output analysis-based life cycle assessment (REIO-LCA) model based upon publicly available datasets. The model uses Gross State Product (GSP) estimates to calculate regional economic multipliers and then link them to regional electricity and fuel use, and air emission factors. Target audiences are governmental decision makers, industry experts and researchers concerned with the regional economic and environmental effects of public and private decisions. Methods A regional version of the existing US EIO-LCA model was developed using regional economic multipliers and state environmental data. The national model is based on the US 491 by 491 economic input-output model, and uses sectoral energy consumption and emission factors to approximate the environmental effects of production and services. The proportion of the regional value added (Gross State Product) to the national value added for each sector was used to develop economic multipliers to allocate the output of industries to individual states and multi-state regions. Inter-sectoral transaction matrices were constructed for eight regions. Regional environmental emission and resource use factors were formed based upon publicly available data of the US Environmental Protection Agency (EPA) and Department of Energy. The Toxics Release Inventory include facility location parameters, enabling the estimation of sectoral toxic emissions for the regions. The national electricity and fuel use, air pollutants (CO, NO_x, PM₁₀, SO₂ and VOC) and greenhouse gas emissions used by the EIO-LCA model were proportioned based upon state totals for each sector. Results A regional economic input-output model was created for US regions, and sectoral energy use and environmental emission factors were estimated for Pennsylvania, the Far West (Alaska, California, Hawaii, Nevada, Oregon and Washington) and the Mideast (Delaware, District of Columbia, Maryland, New Jersey, New York and Pennsylvania) economic areas. The use of the framework for regional IO-LCA model is demonstrated through two case studies. Discussion As a validation exercise, the regional outputs of petroleum refineries were calculated using the regional input-output matrices and the outcomes were compared to the Energy Information Administration’s (EIA) Petroleum State Profile data. The model results show that approximately 70% of the total national sectoral production takes place in three regions, i.e., South West, South East and Far West, which corresponds with the EIA statistics. The REIO-LCA model constructed for the Far West is used to conduct a second case study estimating the annual toxic air emissions of power plants in the region in 2003. The results are evaluated by comparison to data provided by the US EPA. The estimated pollutions do not differ significantly from those presented in the Toxics Release Inventory reports. Conclusions The usefulness of IO LCA models can be improved through the incorporation of local economic and environmental characteristics. Wiht the lack of US regional sectoral data, the allocation of national industrial production to regions can provide a framework to create smaller scale IO models. The results of case studies support the assumption that the GSP multipliers may be used to allocate the sectoral production to the regions, and show that the framework IO LCA model provides a reasonable approximation of supply chain economic activities and environmental effects caused by production and services. Recommendations and Perspectives The quality of data, e.g., age and level of aggregation, and the assumed linearity between sectoral outputs and environmental emissions represent the main sources of uncertainty in the model. The results show that the GSP estimates are appropriate to construct a framework for a regional economic input-output and environmental assessment model. However, further research is recommended to construct more specific state-level input-output matrices incorporating interstate commodity flows, and state environmental factors in order to mitigate the parameter uncertainties. Further, the model might be improved by updating it regularly, as more recent data become available.     

Refurbishment of office buildings in New Zealand: identifying priorities for reducing environmental impacts

Purpose

In recent years, the building sector has highlighted the importance of operational energy and efficient resource management in order to reduce the environmental impacts of buildings. However, differences in building-specific properties (building location, size, construction material, etc.) pose a major challenge in development of generic policy on buildings. The aim of this study was to investigate the relationship between energy and resource management policies, and building-specific characteristics on environmental impacts of refurbished office buildings in New Zealand.

Methods

Life Cycle Assessment (LCA) was performed for 17 office buildings operating under seven representative climatic conditions found in New Zealand. Each building was assessed under four policy scenarios: (i) business-as-usual, (ii) use of on-site photovoltaic (PV) panels, (iii) electricity supply from a renewable energy grid, and (iv) best practice construction activities adopted at site. The influence of 15 building-specific characteristics in combination with each scenario was evaluated. The study adopted regression analysis, more specifically Kruskal-Wallis and General Additive Modeling (GAM), to support interpretation of the LCA results.

Results and discussion

All the chosen policies can significantly contribute to climate change mitigation as compared to business-as-usual. However, the Kruskal-Wallis results highlight policies on increasing renewable energy sources supplying national grid electricity can substantially reduce the impacts across most environmental impact categories. Better construction practices should be prioritized over PV installation as use of on-site PV significantly increases the environmental impacts related to use of resources. The GAM results show on-site PV could be installed in low-rise buildings in regions with long sunshine hours. The results also show the strong influence of façade elements and technical equipment in determining the environmental performance of small and large buildings, respectively. In large multi-storied buildings, efficient HVAC and smaller window area are beneficial features, while in small buildings the choice of façade materials with low embodied impacts should be prioritized.

Conclusions

In general, the study highlighted the importance of policies on increasing renewable energy supply from national grid electricity to substantially reduce most of the impacts related to buildings. In addition, the study also highlighted the importance of better construction practices and building-specific characteristics to reduce the impacts related to resource use. These findings can support policy makers to prioritize strategies to improve the environmental performance of existing buildings in New Zealand and in regions with similar building construction and climate.

     

Resource use and improvement strategy analysis of the livestock and feed production supply chain in Thailand

Purpose

The aim of this research is to reveal the overall money flows and physical flows of the livestock and feed production supply chain in Thailand in order to analyze the resource use and cost and assess material use efficiency of the whole supply chain. Another aim is to evaluate the options to improve and evaluate trade-off between economic and environmental performance.

Methods

This research conducted material and monetary flow modeling using material flow analysis (MFA) and input output analysis (IOA). Data collected from the Thai Input-Output Tables 2005 were employed to develop the monetary flow model. Direct and indirect resource consumption (energy, water, and land use) and turnover along the supply chain were assessed using environmentally extended input-output analysis model (EEIOA). Scenario analysis with improvement options was applied to the model to evaluate the effectiveness of the improvement options.

Results and discussion

One third of energy and water consumption were from the animal farm itself. The rest were from feed production and upstream raw material production. Land use in the system was mainly from maize and paddy field. Feed conversion ratio improvement should play an important role in the strategy for resource efficiency and reduce environmental impact in the whole supply chain. Energy intensity reduction, the best option in overall energy reduction, is the policy that the government is pushing to be implemented in all sectors, and it can also easily be applied along with the other options. Therefore, it should be applied with the other options for improvement.

Conclusions

The results from monetary flow and physical material flow can visually show the holistic view of the Thai livestock production supply chain quantitatively and allow the stakeholders to understand the economic structure of the supply chain system. This can enable the decision makers to analyze the interrelation effect and impact of changing one sector demand or changing resource efficiency to impact other sectors in the system.

     

How City Dwellers Affect Their Resource Hinterland

This article links databases on household consumption, industrial production, economic turnover, employment, water use, and greenhouse gas emissions into a spatially explicit model. The causal sequence starts with households demanding a certain consumer basket. This demand requires production in a complex supply-chain network of interdependent industry sectors. Even though the household may be confined to a particular geographical location, say a dwelling in a city, the industries producing the indirect inputs for the commodities that the household demands will be dispersed all over Australia and probably beyond. Industrial production represents local points of economic activity, employment, water use, and emissions that have local economic, social, and environmental impacts. The consumer basket of a typical household is followed in Australia's two largest cities—Sydney and Melbourne—along its upstream supply chains and to numerous production sites within Australia. The spatial spread is described by means of a detailed regional interindustry model. Through industry-specific emissions profiles, industrial production is then translated into local impacts. We show that annually a typical household is responsible for producing approximately 80 tonnes of greenhouse gas emissions, uses around 3 million liters of water, causes about A$140,000 to circulate in the wider economy, and provides labor worth just under three full-time employment-years. We also introduce maps that visually demonstrate how a very localized household affects the environment across an entire continent. Our model is unprecedented in its spatial and sectoral detail, at least for Australia.     

Characterising the impacts of emerging energy development on wildlife,with an eye towards mitigation

Global demand for energy is projected to increase by 40% in the next 20 years, and largely will be met with alternative and unconventional sources. Development of these resources causes novel disturbances that strongly impact terrestrial ecosystems and wildlife. To effectively position ecologists to address this prevalent conservation challenge, we reviewed the literature on the ecological ramifications of this dominant driver of global land‐use change, consolidated results for its mitigation and highlighted knowledge gaps. Impacts varied widely, underscoring the importance of area and species‐specific studies. The most commonly reported impacts included behavioural responses and direct mortality. Examinations of mitigation were limited, but common easements included (1) reduction of the development footprint and human activity, (2) maintenance of undeveloped, ‘refuge’ habitat and (3) alteration of activity during sensitive periods. Problematically, the literature was primarily retrospective, focused on few species, countries, and ecoregions, and fraught with generalisations from weak inference. We advocate future studies take a comprehensive approach incorporating a mechanistic understanding of the interplay between development‐caused impacts and species ecology that will enable effective mitigation. Key areas for future research vital to securing a sustainable energy future in the face of development‐related global change are outlined.     

能源活动CO2排放不同核算方法比较和减排策略选择

能源活动CO₂排放是温室气体排放的最重要部分,这部分CO₂排放量的核算是温室气体清单编制和减排方案制定的关键和基础。采用直接法、电热终端法和隐含终端法核算了2009年中国能源消费的CO₂排放量,对不同核算法的CO₂排放部门分布、部门排放强度进行了比较,明确不同核算方法的差异和适用范围。采用电热终端法的核算结果定量分析了各产业部门和工业行业的经济增长和排放强度变化对中国能源活动CO₂排放增长的影响。结果表明,中国2009年隐含终端CO₂排放量为65.6亿t,略高于直接和电热终端CO₂排放量62.2亿t。3种核算方法的CO₂排放部门分布和排放强度有明显的差异:电、热力生产与供应业的直接排放占比为45.2%,而电热终端CO₂排放仅占4.5%;制造业的直接法、电热终端法和隐含终端法核算的CO₂排放占比分别为35.3% 、61.1%和65.5%,是终端能源消费CO₂排放最主要的部门;制造业、电热力生产与供应业和交通运输业的电热终端CO₂排放强度分别为2.166、1.72和1.622 t CO₂/万元GDP,是排放强度较高的部门。在产业部门中,制造业的色金属冶炼及压延加工业、非金属矿物制品业等5个行业以9.8%的经济增长贡献,排放了52.4%的CO₂,是产业结构调整、技术和工程减排的重点;服务业以7.2%的CO₂排放,贡献了38.4%的经济增长,应作为中国低碳经济优先发展的产业。     

The Environmental Importance of Energy Use in Chemical Production

In many cases, policy makers and laymen perceive harmful emissions from chemical plants as the most important source of environmental impacts in chemical production. As a result, regulations and environmental efforts have tended to focus on this area. Concerns about energy use and greenhouse gas emissions, however, are increasing in all industrial sectors. Using a life cycle assessment (LCA) approach, we analyzed the full environmental impacts of producing 99 chemical products in Western Europe from cradle to factory gate. We applied several life cycle impact assessment (LCIA) methods to cover various impact areas. Our analysis shows that for both organic and inorganic chemical production in industrial countries, energy‐related impacts often represent more than half and sometimes up to 80% of the total impacts, according to a range of LCIA methods. Resource use for material feedstock is also important, whereas direct emissions from chemical plants may make up only 5% to 10% of the total environmental impacts. Additionally, the energy‐related impacts of organic chemical production increase with the complexity of the chemicals. The results of this study offer important information for policy makers and sustainability experts in the chemical industry striving to reduce environmental impacts. We identify more sustainable energy production and use as an important option for improvements in the environmental profile of chemical production in industrial countries, especially for the production of advanced organic and fine chemicals.     

Generation of an Industry-specific Physico-chemical Allocation Matrix. Application in the Dairy Industry and Implications for Systems Analysis (9 pp)

Background, Aims and Scope Allocation is required when quantifying environmental impacts of individual products from multi-product manufacturing plants. The International Organization for Standardization (ISO) recommends in ISO 14041 that allocation should reflect underlying physical relationships between inputs and outputs, or in the absence of such knowledge, allocation should reflect other relationships (e.g. economic value). Economic allocation is generally recommended if process specific information on the manufacturing process is lacking. In this paper, a physico-chemical allocation matrix, based on industry-specific data from the dairy industry, is developed and discussed as an alternative allocation method. Methods Operational data from 17 dairy manufacturing plants was used to develop an industry specific physico-chemical allocation matrix. Through an extensive process of substraction/substitution, it is possible to determine average resource use (e.g. electricity, thermal energy, water, etc) and wastewater emissions for individual dairy products within multi-product manufacturing plants. The average operational data for individual products were normalised to maintain industry confidentiality and then used as an industry specific allocation matrix. The quantity of raw milk required per product is based on the milk solids basis to account for dairy by-products that would otherwise be neglected. Results and Discussion Applying fixed type allocation methods (e.g. economic) for all input and outputs based on the quantity of product introduces order of magnitude sized deviations from physico-chemical allocation in some cases. The error associated with the quality of the whole of factory plant data or truncation error associated with setting system boundaries is insignificant in comparison. The profound effects of the results on systems analysis are discussed. The results raise concerns about using economic allocation as a default when allocating intra-industry sectoral flows (i.e. mass and process energy) in the absence of detailed technical information. It is recommended that economic allocation is better suited as a default for reflecting inter-industry sectoral flows. Conclusion The study highlights the importance of accurate causal allocation procedures that reflect industry-specific production methods. Generation of industry-specific allocation matrices is possible through a process of substitution/subtraction and optimisation. Allocation using such matrices overcomes the inherit bias of mass, process energy or price allocations for a multi-product manufacturing plant and gives a more realistic indication of resource use or emissions per product. The approach appears to be advantageous for resource use or emissions allocation if data is only available on a whole of factory basis for several plants with a similar level of technology. Recommendation and Perspective The industry specific allocation matrix approach will assist with allocation in multi-product LCAs where the level of technology in an industry is similar. The matrix will also benefit dairy manufacturing companies and help them more accurately allocate resources and impacts (i.e. costs) to different products within the one plant. It is recommended that similar physico-chemical allocation matrices be developed for other industry sectors with a view of ultimately coupling them with input-output analysis.     

Rethinking Environmental Performance from a Public Health Perspective: A Comparative Industry Analysis

To date the most common measures of environmental performance used to compare industries, and by extension firms or facilities, have been quantity of pollution emitted or hazardous waste generated. Discharge information, however, does not necessarily capture potential health effects. We propose an alternative environmental performance measure that includes the public health risks of toxic air emissions extended to industry supply chains using economic input-output life-cycle assessment. Cancer risk to the U.S. population was determined by applying a damage function to the Toxic Release Inventory (TRI) as modeled by CalTOX, a multimedia multipathway fate and exposure model. Risks were then translated into social costs using cancer willingness to pay. For a baseline emissions year of 1998, 260 excess cancer cases were calculated for 116 TRI chemicals, dominated by ingestion risk from polycyclic aromatic compounds and dioxins emitted by the primary aluminum and cement industries, respectively. The direct emissions of a small number of industry sectors account for most of the U.S. population cancer risk. For the majority of industry sectors, however, cancer risk per $1 million output is associated with supply chain upstream emissions. Ranking industries by total (direct + upstream) supply chain risk per economic output leads to different conclusions about the relative hazards associated with these industries than a conventional ranking based on emissions per economic output.     

Assessing uncertainties in land cover projections

Understanding uncertainties in land cover projections is critical to investigating land‐based climate mitigation policies, assessing the potential of climate adaptation strategies and quantifying the impacts of land cover change on the climate system. Here, we identify and quantify uncertainties in global and European land cover projections over a diverse range of model types and scenarios, extending the analysis beyond the agro‐economic models included in previous comparisons. The results from 75 simulations over 18 models are analysed and show a large range in land cover area projections, with the highest variability occurring in future cropland areas. We demonstrate systematic differences in land cover areas associated with the characteristics of the modelling approach, which is at least as great as the differences attributed to the scenario variations. The results lead us to conclude that a higher degree of uncertainty exists in land use projections than currently included in climate or earth system projections. To account for land use uncertainty, it is recommended to use a diverse set of models and approaches when assessing the potential impacts of land cover change on future climate. Additionally, further work is needed to better understand the assumptions driving land use model results and reveal the causes of uncertainty in more depth, to help reduce model uncertainty and improve the projections of land cover.     

城市化流域生态系统服务价值时空分异特征及其对土地利用程度的响应

以南京市九乡河流域为研究区域,以2003与2009年2景QuickBird影像数据为基本信息源,应用空间自相关模型,结合GIS空间分析技术,定量探讨了城市化流域生态系统服务价值时空分异特征,以及土地利用程度对生态服务价值空间分异的影响.结果表明:2003-2009年,九乡河流域生态系统服务总价值减少了2.59％,而流域生态系统服务价值的空间聚集性增强;生态服务价值的高-高区域主要集中在流域上游,低-低区域主要集中在流域下游的仙林大学城一带;九乡河流域生态系统服务价值空间分异发生了明显变化,下游仙林大学城一带低-低分布区快速扩张,而高-高分布区仅在九乡河源头及下游的局部区域有所增加;流域生态服务价值空间自相关表现出明显的尺度效应,随着研究尺度增大,生态服务价值的空间自相关性逐渐增强;九乡河流域生态服务价值的空间分异及其变化主要是由土地开发利用引起,流域土地利用程度对生态服务价值存在明显的负效应.