Global warming contributions from wheat,sheep meat and wool production in Victoria,Australia – a life cycle assessment

This paper compares the life cycle global warming potential of three of Australia’s important agricultural production activities – the production of wheat, meat and wool in grazed subterranean clover (sub-clover) dominant pasture and mixed pasture (perennial ryegrass/phalaris/sub-clover/grass and cape weed) systems. Two major stages are presented in this life cycle assessment (LCA) analysis: pre-farm, and on-farm. The pre-farm stage includes greenhouse gas (GHG) emissions from agricultural machinery, fertilizer, and pesticide production and the emissions from the transportation of these inputs to paddock. The on-farm stage includes GHG emissions due to diesel use in on-farm transport and processing (e.g. seeding, spraying, harvesting, topdressing, sheep shearing), and non-CO₂ (nitrous oxide (N₂O), and methane (CH₄)) emissions from pastures and crop grazing of lambs.The functional unit of this life cycle analysis is the GHG emissions (carbon dioxide equivalents – CO₂ -e) from 1 kg of wheat, sheep meat and wool produced from sub-clover, wheat and mixed pasture plots. The GHG emissions (e.g. CO₂, N₂O and CH₄ emission) from the production, transportation and use of inputs (e.g. fertilizer, pesticide, farm machinery operation) during pre-farm and on-farm stages are also included. The life cycle GHG emissions of 1 kg of wool is significantly higher than that of wheat and sheep meat. The LCA analysis identified that the on-farm stage contributed the most significant portion of total GHG emissions from the production of wheat, sheep meat and wool. This LCA analysis also identified that CH₄ emissions from enteric methane production and from the decomposition of manure accounted for a significant portion of the total emissions from sub-clover and mixed pasture production, whilst N₂O emissions from the soil have been found to be the major source of GHG emissions from wheat production.     

Resource consumption and emissions from olive oil production: a life cycle inventory case study in Cyprus

“Cradle to gate” life cycle analysis (LCA) has been used to evaluate the consumption of raw materials and emissions of pollutants from olive oil production in Lythrodontas region in Cyprus, in order to identify the processes which give rise to the most significant environmental burdens. The system investigated includes the production of the chemical inputs used (fertilisers and pesticides), agricultural processes, the industrial processing and the transportation and waste management associated with olive oil production. Raw material and energy use as well as emissions were quantified on the basis of a functional unit of 1 l of extra virgin olive oil. The production of the inorganic fertilisers used in the agricultural stage of olive oil production and the disposal of liquid effluent from olive mills to evaporation ponds were found to be “hot-spot” processes not only in terms of resource consumption but also in terms of emissions into the environment.     

我国典型露地蔬菜生产中的温室气体排放

基于国家农业统计数据,以露地番茄、黄瓜、大白菜和萝卜为研究对象,应用生命周期评价(life cycle assessment,LCA)方法,定量化我国4种典型露地蔬菜生产中的净温室气体排放(net greenhouse gas emission,NGHGE),并比较蔬菜种类间、省域间净温室气体排放差异和分析减排措施.结果表明:我国典型露地蔬菜生产系统温室气体排放量远高于其带来的碳固定量,是净温室气体排放系统,生产单位面积露地番茄、黄瓜、大白菜和萝卜净温室气体排放(以CO_2-eq计)分别为4 149、 3 718、 3 780和2 427 kg·hm~(-2),不同种类露地蔬菜净温室气体排放差异大;我国典型露地蔬菜净温室气体排放空间差异大,其中,海南、云南、陕西和山东等省份番茄、黄瓜、大白菜和萝卜净温室气体排放高;肥料生产运输和施用是露地蔬菜温室气体排放的主要贡献因子,贡献率为86.8%～90.8%,因此改善肥料生产工艺降低肥料生产运输过程中的温室气体排放和根据露地蔬菜种类及种植地区优化肥料施用量是实现我国露地蔬菜可持续发展的重要措施.     

华北高产粮区夏玉米生命周期环境影响评价

以山东省桓台县夏玉米生产体系为例,应用生命周期评价方法,以单位产量为评价功能单元,把夏玉米生命周期分为原料开采与运输、农资生产与运输、作物种植3个生产阶段,对不同施氮水平下夏玉米生命周期的资源消耗与污染物排放进行了清单分析和影响评价.结果表明,随着施氮量的增加,夏玉米生命周期环境影响呈指数上升趋势,其中,主要影响类型为水资源耗竭,这与农作物需水量较大、水分生产率较低有关.在低氮量条件下,主要污染影响类型是全球变暖,随着施氮量的增加,富营养化上升为主要污染影响类型.提高作物种植阶段水肥利用效率是控制夏玉米生命周期环境影响的关键,它可减少夏玉米对水资源和氮肥的需求,从而直接减少农田氮素损失污染影响,也间接降低了上游生产环节的资源消耗与污染物排放影响,进而有助于降低夏玉米生命周期环境影响总潜力.     

光伏行业生命周期碳排放清单分析

本研究建立了光伏行业生命周期碳排放清单,并在处置阶段对不同处置情景的碳排放进行比较.通过现场、资料调研和工艺研发应用的方式,获得光伏行业生产、使用、处置阶段及三个情景的资源、能源的输入/输出和污染物排放数据.结果表明：光伏行业碳排放集中在生产阶段,其中又以高纯多晶硅生产过程的碳排放最高;使用阶段碳排放较小,仅为生产阶段的3%;电耗是最主要的碳排放因素,占生产和使用阶段碳排放的64.98%.处置阶段的3种情景的碳排放由大到小依次是填埋 > 拆解 > 热解,除了填埋略微增加碳排放外,拆解和热解都能显著降低行业碳排放,可分别降低6.03%和33.59%.研究显示采用热解回收技术的光伏组件生命周期单位发电量碳排放强度,不仅低于同类研究,还远低于我国当前电力结构的碳排放水平,发展光伏行业可实现环境与能源双赢.     

Biogenic greenhouse gas emissions linked to the life cycles of biodiesel derived from European rapeseed and Brazilian soybeans

Biogenic emissions of carbonaceous greenhouse gases and N₂O turn out to be important determinants of life cycle emissions of greenhouse gases linked to the life cycle of biodiesel from European rapeseed and Brazilian soybeans. For biodiesel from European rapeseed and for biodiesel from Brazilian soybeans grown for up to 25 years with no tillage on arable soil for which tropical rainforest or Cerrado (savannah) have been cleared, the life cycle emissions of greenhouse gases are estimated to be worse than for conventional diesel. Improving agricultural practices should be an important focus for cleaner production of biodiesel. These may include increasing soil carbon stocks by, e.g., conservation tillage and return of harvest residues and improving N-efficiency by precision agriculture and/or improved irrigation practices.     

Life cycle assessment of ACQ-treated lumber with comparison to wood plastic composite decking

A cradle-to-grave life cycle assessment was done to identify the environmental impacts related to alkaline copper quaternary (ACQ)-treated lumber used for decking and to determine how the impacts compare to the primary alternative product, wood plastic composite (WPC) decking. A model of ACQ-treated lumber life cycle stages was created and used to calculate inputs and outputs during the lumber production, treating, use, and disposal stages. Lumber production data are based on published sources. Primary wood preservative treatment data were obtained by surveying wood treatment facilities in the United States. Product use and disposal inventory data are based on published data and professional judgment. Life cycle inventory inputs, outputs, and impact indicators for ACQ-treated lumber were quantified using functional units of 1000 board feet and per representative deck (assumed to be 320 square feet (30 square meters) of surface decking material) per year of use. In a similar manner, an inventory model was developed for the manufacture, use, and disposal of the primary alternative product, WPC. Impact indicator values, including greenhouse gas (GHG) emissions, fossil fuel use, water use, acidification, smog forming potential, ecological toxicity, and eutrophication were quantified for each of the two decking products. National normalization was done to compare the significance of a representative deck surface per year of use to a family’s total annual impact footprint.If an average U.S. family adds or replaces a deck surfaced with ACQ-treated lumber, their impact “footprint” for GHG emissions, fossil fuel use, acidification, smog forming potential, ecological toxicity, and eutrophication releases each is less than one-tenth of a percent of the family’s annual impact. ACQ-treated lumber impacts were fourteen times less for fossil fuel use, almost three times less for GHG emissions, potential smog emissions, and water use, four times less for acidification, and almost half for ecological toxicity than those for WPC decking. Impacts were approximately equal for eutrophication.     

轻型纯电动汽车生产和运行能耗及温室气体排放研究

基于中国本地化的环境负荷数据,建立了电动汽车全生命周期模型,深入分析和评估了电动汽车生产和运行两个阶段的能耗及温室气体排放(Greenhouse gases,GHGs).结果表明:电动汽车生产和运行过程的总能耗为474 GJ;GHGs为40500 kg(以CO2当量计),电动汽车生产和运行过程的GHGs分别占总排放量的23.5%和76.5%.对于电动汽车生产过程能耗和GHGs而言,原材料生产均为主要贡献者,GHGs占到车辆生产过程的74.6%,占生命周期的17.5%.另外,情景分析表明,再生材料应用、单位电力GHGs和百公里电耗能够在很大程度上影响电动汽车的碳排放.再生金属替代原生金属后,从情景1到情景5,车辆生产的GHGs下降了约22.2%,车辆生产和运行过程的总GHGs下降了约4.7%;单位电力GHGs每下降1%,电动汽车运行GHGs下降0.9%;电动汽车百公里电耗每下降1.0%,车辆生产和运行过程总GHGs下降约1.0%.因此,发展清洁能源、降低火力发电比例、优化原材料生产工艺、提高再生原材料用量等,是有效降低电动汽车全生命周期过程总能耗和GHGs的重要途径.     

面向2035的节能与新能源汽车全生命周期碳排放预测评价

发展节能与新能源汽车是降低交通运输行业碳排放的重要技术路径.为量化预测节能与新能源汽车的全生命周期碳排放,利用全生命周期评价方法,以汽车相关技术路线和政策为参考,选取燃油经济性、整车轻量化水平、电力结构碳排放因子和氢能碳排放因子为关键参数,构建传统燃油汽车(ICEV)、轻度混合动力汽车(MHEV)、重度混合动力汽车(HEV)、纯电动汽车(BEV)和燃料电池汽车(FCV)的数据清单并对其全生命周期碳排放进行量化预测评价,对电力结构碳排放因子和不同制氢方式碳排放因子进行了敏感性分析和讨论.结果发现,2022年ICEV、 MHEV、 HEV、 BEV和FCV的全生命周期碳排放量(以CO₂-eq计)分别为208.0、 195.5、 150.0、 113.5和205.0 g·km^-1.到2035年,BEV和FCV相比于ICEV具有较为显著的减碳效益,分别降低69.1%和49.3%.电力结构的碳排放因子对BEV的全生命周期碳排放的影响最显著.关于燃料电池汽车的不同制氢方式,短期应以工业副产氢提纯为主供应FCV氢能需求,长期以可再生能源电解水制氢和化石能源...     

Future Trends of Land-Use Emissions of Major Greenhouse Gases

Land-use emissions of greenhouse gases make up over one-third of current total anthropogenic emissions of greenhouse gases and about three-quarters of the total anthropogenic emissions of CH4 and N2O. Considering their contribution to global emissions, it is important to understand their future trends in order to anticipate and mitigate climate change. This paper reviews published scenarios of major categories of these emissions with the aim to provide background information for the development of new scenarios. These categories include CO2 from deforestation, CH4 from rice cultivation, CH4 from enteric fermentation of cattle, and N2O from fertilizer application. Base year estimates of all these categories varied greatly from reference to reference, and hence emissions of all scenarios were normalized relative to their 1990 value before being compared to one another. The range of published scenarios of CO2 emissions from deforestation is widest around the middle of the 21st century and then all scenarios converge to low values towards 2100. By contrast, the different scenarios of CH4 and N2O diverge with time, showing their widest range in 2100. Global emissions of CH4 from rice cultivation vary by a factor of three in 2100 and N2O from fertilized soils by a factor of 2.3. Emissions of CH4 from enteric fermentation of animals have the smallest range (factor of 2.0). The typical long-range trends of land-use emission scenarios vary greatly from region to region - they stabilize in industrialized regions after a few decades, but tend to stabilize later in developing regions or continue to grow throughout the 21st century. To improve the realism of the estimates of future trends of land-use emissions, it is especially important to improve the estimation of the future extent of agricultural land and the rate of deforestation, while taking into account significant driving forces such as the demand for agricultural commodities and crop yields.     

长江经济带农业源非二氧化碳温室气体排放的时空特征

利用清单方法核算了1980~2016年长江经济带农业源非二氧化碳（CO₂）温室气体的排放总量和排放强度,分析了不同经济发展情景和农业-环境脱钩状态下长江经济带2030年和2050年的排放情景.研究表明：时间维度上,1980~2016年长江经济带农业源非CO₂温室气体排放总量呈上升趋势,从0.26Gt CO₂-eq上升到0.32Gt CO₂-eq;2030年和2050年在高情景和中情景2种情景下,长江经济带农业源非CO₂温室气体排放量不会达峰,江苏、湖南、重庆、云南、湖北和安徽等六省（市）的单位农地面积排放强度将增加;3种情景下,四川始终为单位农地面积排放强度较低的地区.     

Managing the nitrogen cycle to reduce greenhouse gas emissions from crop production and biofuel expansion

Public policies are promoting biofuels as an alternative to fossil fuel consumption in order to mitigate greenhouse gas (GHG) emissions. However, the mitigation benefit can be at least partially compromised by emissions occurring during feedstock production. One of the key sources of GHG emissions from biofuel feedstock production, as well as conventional crops, is soil nitrous oxide (N₂O), which is largely driven by nitrogen (N) management. Our objective was to determine how much GHG emissions could be reduced by encouraging alternative N management practices through application of nitrification inhibitors and a cap on N fertilization. We used the US Renewable Fuel Standards (RFS2) as the basis for a case study to evaluate technical and economic drivers influencing the N management mitigation strategies. We estimated soil N₂O emissions using the DayCent ecosystem model and applied the US Forest and Agricultural Sector Optimization Model with Greenhouse Gases (FASOMGHG) to project GHG emissions for the agricultural sector, as influenced by biofuel scenarios and N management options. Relative to the current RSF2 policy with no N management interventions, results show decreases in N₂O emissions ranging from 3 to 4 % for the agricultural sector (5.5–6.5 million metric tonnes CO₂?eq.?year^?1; 1 million metric tonnes is equivalent to a Teragram) in response to a cap that reduces N fertilizer application and even larger reductions with application of nitrification inhibitors, ranging from 9 to 10 % (15.5–16.6 million tonnes CO₂?eq.?year^?1). The results demonstrate that climate and energy policies promoting biofuel production could consider options to manage the N cycle with alternative fertilization practices for the agricultural sector and likely enhance the mitigation of GHG emissions associated with biofuels.     

电动重卡替代柴油重卡的全生命周期碳减排效益分析

为精准预测电动重卡替代柴油重卡的全生命周期碳减排效益,以单辆重卡为对象,通过预测2023~2050年的电力和柴油碳排放因子变化特性,耦合两类重卡寿命及生命周期行驶里程,分阶段构建了重卡动态碳排放模型,深入分析了“2050年净零排放（NZE）情景”、“承诺目标（APS）情景”和“既定政策（STEPS）情景”下两类重卡的碳排放足迹,并计算碳减排量和碳减排率.结果表明,电池生产和电池回收是分别导致电动重卡生产阶段和拆解回收阶段碳减排效益不佳的重要因素.电力碳排放因子（以CO₂计）每降低1 g·（kW·h）^-1,电动重卡全生命周期碳排放可减少1.74 t.3种情景下,两类重卡运行阶段碳排放均占全生命周期碳排放总量的90%以上.碳减排效益由高到低的情景依次为NZE、APS和STEPS,其对应的全生命周期碳减排量分别为1 054.68、1 021.78和1 007.97 t,碳减排率分别为54.38%、52.68%和51.97%.     

Life cycle assessment of borate-treated lumber with comparison to galvanized steel framing

A cradle-to-grave life cycle assessment was done to identify the environmental impacts related to borate-treated lumber used as structural framing and to determine how the impacts compare to the primary alternative product, galvanized steel framing members. Borate-treated lumber may be used for framing buildings in locations of high decay or termite hazard. A model of borate-treated lumber life cycle stages was created and used to calculate inputs and outputs during the lumber production, treating, use, and disposal stages. Lumber production data are based on published sources. Primary wood preservative treatment data were obtained by surveying wood treatment facilities in the United States. Product use and disposal inventory data are based on published data and professional judgment. Life cycle inputs, outputs, and impact indicators for borate-treated lumber were quantified using life cycle assessment LCA methodologies at functional units of 1000 board feet, 100 linear feet (30.5 linear meters) of structural perimeter wall framing, and framing required for the perimeter walls of one representative home. In a similar manner, a life cycle inventory model was developed for the manufacture, use, and disposal of the primary alternative product, galvanized steel framing, and comparisons were done using an equivalent measure of 100 linear feet of structural perimeter wall framing. Impact indicator values such as greenhouse gas (GHG) emissions, fossil fuel use, water use, acidification, ecological toxicity, smog forming potential, and eutrophication were quantified for each of the two framing products.National normalization was done to compare the significance of the framing in a representative U.S. family home to the family’s total annual impact footprint.If a U.S. family of three builds a 2225 square feet (207 square meters) home using borate-treated lumber for structural perimeter wall framing, the framing impact “footprint” (normalized over the use life of the structure) for GHG emissions, fossil fuel use, acidification, ecological toxicity, smog forming potential, and eutrophication each is less than one-tenth of a percent of the family’s annual overall impact. The cradle-to-grave life cycle impacts of borate-treated lumber framing were approximately four times less for fossil fuel use, 1.8 times less for GHGs, 83 times less for water use, 3.5 times less for acidification, 2.5 times less for ecological impact, 2.8 times less for smog formation, and 3.3 times less for eutrophication than those for galvanized steel framing.     

瓦楞纸箱全生命周期环境影响评价研究

分析了瓦楞纸箱从原材料生产、产品加工到使用后的废物处置整个全生命周期的物耗、能耗及向环境中的排放;根据ISO14040系列标准制定的技术框架,建立了全生命周期评价(Life Cycle Assessment,LCA)模型,采用Eco-indicator 99方法,对瓦楞纸箱进行了整体和基于流程的全生命周期环境影响分析,得出其全生命周期和原料生产、产品加工、废物管理3个流程的主要环境影响类型和对应指标值,以及造成各流程主要环境影响类型的原因.为改善瓦楞纸箱的环境性能,针对其设计、生产加工、使用、废物处理等方面提出了改进建议;并对全生命周期环境影响评价研究中存在的不足进行了总结.      

Life cycle assessment of mobile phone housing

The life cycle assessment of the mobile phone housing in Motorola(China) Electronics Ltd. was carried out, in which materials flows and environmental emissions based on a basic production scheme were analyzed and assessed. In the manufacturing stage, such primary processes as polycarbonate molding and surface painting are included, whereas different surface finishing technologies like normal painting, electroplate, IMD and VDM etc. were assessed. The results showed that housing decoration plays a significant role within the housing life cycle. The most significant environmental impact from housing production is the photochemical ozone formation potential.Environmental impacts of different decoration techniques varied widely, for example, the electroplating technique is more environmentally frieodly than VDM. VDM consumes much more energy and raw material. In addition, the results of two alternative scenarios of dematerialization showed that material flow analysis and assessment is very important and valuable in selecting an environmentally friendly process.     

The potential benefits of on-farm mitigation scenarios for reducing multiple pollutant loadings in prioritised agri-environment areas across England

Mitigation of diffuse water pollution from agriculture is a key national environmental policy objective in England. With the recent introduction of the new agri-environment scheme, Countryside Stewardship, there is an increased emphasis on the macro-spatial targeting of on-farm mitigation measures to reduce pollutant pressures, and a concomitant need to forecast the technically feasible impacts of on-farm measures detailed in current policy and their associated costs and benefits. This paper reports the results of a modelling application to test these limits in the context of the associated costs and benefits for the reduction of diffuse water pollution from agriculture for each Water Framework Directive (WFD) water management catchment (WMC) and nationally. Four mitigation scenarios were modelled, including pollutant source control measures only (SC), mobilisation control measures only (MC), delivery control measures only (DC) and measures for source, mobilisation and delivery control (SMDC) combined. Projected impacts on nitrate, phosphorus and sediment export to water, ammonia, methane and nitrous oxide emissions to the atmosphere, together with the associated costs to the agricultural sector were estimated for each WFD WMC and nationally. Median WMC-scale reductions (with uncertainty ranges represented by 5th–95th percentiles) in current agricultural emissions, were predicted to be highest for the SMDC scenario; nitrate (18%, 11–23%), phosphorus (28%, 22–37%), sediment (25%, 18–43%), ammonia (26%, 17–32%), methane (13%, 7–18%) and nitrous oxide (18%, 16–20%). The median benefit-to-cost ratios (with uncertainty ranges represented by 5th–95th percentiles) were predicted to be in the following order; DC (0.15, 0.09–0.65), MC (0.19, 0.09–0.95), SMDC (0.31, 0.20–1.39) and SC (0.44, 0.19–2.48). Of the four scenarios simulated, the SC and SMDC suites of measures have the greatest potential to deliver reductions in BAU emissions from agriculture, and the best benefit:cost ratio.     

Life cycle greenhouse gas emissions, fossil fuel demand and solar energy conversion efficiency in European bioethanol production for automotive purposes

Crop derived biofuels such as (bio)ethanol are increasingly applied for automotive purposes. They have, however, a relatively low efficiency in converting solar energy into automotive power. The outcome of life cycle studies concerning ethanol as to fossil fuel inputs and greenhouse gas emissions associated with such inputs depend strongly on the assumptions made regarding e.g. allocation, inclusion of upstream processes and estimates of environmentally relevant in- and outputs. Peer reviewed studies suggest that CO₂ emissions linked to life cycle fossil fuel input are typically about 2.1–3.0 kg CO₂ kg⁻¹ starch-derived ethanol. When biofuel production involves agricultural practices that are common in Europe there are net losses of carbon from soil and emissions of the greenhouse gas N₂O. Dependent on choices regarding allocation, they may, for wheat (starch) be in the order of 0.6–2.5 kg CO₂ equivalent kg⁻¹ of ethanol. This makes ethanol derived from starch, or sugar crops, in Europe still less attractive for mitigating climate change. In case of wheat, changes in agricultural practice may reduce or reverse carbon loss from soils. When biofuel production from crops leads to expansion of cropland while reducing forested areas or grassland, added impetus will be given to climate change.     

东北地区农业源一次颗粒物排放清单研究

采用自下而上的清单编制方法,搜集各农业环节(秸秆燃烧、整地、收割、谷物处理、化肥施用、农机排放、风蚀)排放因子、作物面积和耕作方式等信息,编制了2010年东北地区县级尺度的农业一次颗粒物(PM₁₀和PM_2.5)排放清单,并分析了农业源颗粒物排放的时空分布特征.结果表明:1)2010年东北地区农业源一次颗粒物PM₁₀总排放量54.6万t,PM_2.5总排放量35.6万t;2)东北地区农业源一次颗粒物PM₁₀排放量最大的农业活动环节是秸秆燃烧,占农业源总排放量的比例为60%,秸秆燃烧排放PM_2.5占PM_2.5农业源排放量的87%,整地环节是一次颗粒物排放的第2大农业排放源,对农业源排放PM₁₀和PM_2.5总量的贡献率分别是27%和6%; 3)PM₁₀和PM_2.5的排放强度空间分布表明,东北地区农业源颗粒物排放区域集中在黑龙江省东北部和中部地区,吉林省中部和辽宁省中部地区; 4)PM₁₀和PM_2.5排放的时间变化特征显示,PM₁₀农业源排放年变化曲线中,5月份和9、10月份是农业源排放一次颗粒物PM₁₀较多的月份,PM_2.5排放集中在9、10月份;5)本研究估算的污染物排放清单的不确定性为184.3%.未来的工作将侧重于典型农业区本土排放因子测定,从而有效减小排放清单的不确定性.     

The energy consumption and environmental impacts of a color TV set in China

The present study analyses the different processes followed during color TV set production along with the energy consumption and the environment emissions in each stage. The purpose is to identify “hot-spots”, i.e. parts of the life cycle important to the total environmental impact. The analysis is performed using life cycle assessment (LCA) methodology, which is a method used to identify and quantify in the environmental performance of a process or a product from “cradle to grave”. LCA methodology provides a quantitative basis for assessing potential improvements in the environmental performance of a system throughout the life cycle. The system investigated includes the production of manufacturing materials, transport of manufacturing materials, color TV set manufacturing, transport of color TV sets, use of color TV sets, discarding color TV sets and partial plastic waste energy utilization. The environmental burdens that arise from color TV sets are mainly due to air emissions derived from fossil fuel utilization.