中国工业碳排放强度变化的结构因素解析

以1986-2016年为研究时段,将41个工业部门归类为16个部门,在运用CKC模型分析各部门产值与其CO₂排放量关系的基础上,建立以碳排放部门结构、碳排放系数、能源消费强度以及产值部门结构为因素的工业碳排放强度kaya分解模型,运用LMDI法分析不同因素对中国工业碳排放强度变化的贡献。研究发现:工业不同部门产值与其CO₂排放量的关系不同。只有木材加工及家具制造业、造纸印刷及文教用品制造业和非金属矿物制品业呈现倒U型关系,机械交通电气电子设备制造业呈现倒N型关系,其余部门都呈现线性递增或单调递增关系。从工业碳排放强度变化的贡献因素看,非金属矿物制品、化学工业、医药工业、机械交通电气电子设备制造业和木材加工及家具制造业等资金和技术密集型行业的技术性CO₂减排效应显著。其他制造业、石油和天然气开采业、纺织服饰业和化纤及橡塑工业等以初级产品加工为主的行业的结构性CO₂减排效应显著,而石油加工炼焦和核燃料加工业、金属冶炼及制品业、电力煤气及水生产和供应业在产值与CO₂排放量的同步递增关系以及结构增长的共同作用下,CO₂减排效应不明显,需要在能源结构调整和利用效率提升方面密切关注。     

人类可持续发展指数的改进及国际比较

对人类发展指数进行绿色及公平修正是可持续发展的必然要求。基于28个国家1990-2014年的面板数据,采用生态足迹改进人类可持续发展指数,并对其分解探讨变迁原因,在此基础上进行公平校正构建综合可持续发展指数。结果表明：生物质盈余发达国家排名靠前,影响其可持续发展的主要因素是高碳排放,生物质赤字国家通过转移别国资产维持发展,不平衡导致美国的综合可持续性下降;发展中国家的收入与教育快速提升,但生态消耗及不公平度持续上升,抑制作用逐渐扩大,阿联酋排名末位,发展方式最不可持续;最不发达国家的发展主要来自健康、教育及低生态消耗的贡献。分项维度间高度相关,可持续发展需在社会、经济、生态、公平间进行更好的权衡。     

大气环境监测结果空间代表性的一个分析实例

通过计算石家庄西北郊大气环境监测站2014年的逐时浓度印痕,系统分析影响当地空气质量的潜在污染来源区域.使用实际气象观测资料和CALMET风场诊断模式获得当地区域边界层风场;使用反向拉格朗日粒子扩散模式计算印痕,分析其平均分布和日变化,以及与主要污染物(PM_(10))浓度变化的关系.结果表明,(1)石家庄地区山地-平原局地环流对风场有重要影响.(2)西北郊站监测结果代表的污染源区域有明显的日变化,午后主要为偏南和东南方向的污染来源,夜间至次日上午主要为西北山前和山地区域的来源.(3)PM_(10)浓度与污染来源区域具有同步的日变化关系,午后浓度下降,夜间浓度升高并维持到次日早上和正午.从夜间至次日上午时段西北方向的污染来源决定了该站的空气质量.(4)监测结果代表的主要污染物来源区域远超出其行政属地范围,外部来源的贡献率超过60%,当地影响不足40%.(5)造成西北郊站监测浓度整体偏高的主要原因是地形和位置因素,及测站以西的实际污染排放源.     

城市化进程中的土地自然资本利用动态分析

论文聚焦城市化进程中的土地自然资本利用演变,从生产性视角定义了土地足迹和土地承载力的核算方法,在此基础上运用一个区分自然资本流量与存量、可以进行“产品—地类—区域”尺度转换的三维足迹模型,对2000—2014年贵阳市的土地自然资本利用状况进行了系统分析。结果表明：过去15 a贵阳市的土地自然资本流动性提高了39.4%,存量消耗强度降低了15.7%。耕地自然资本的流量占用规模和存量消耗强度均为最大,农业生产结构逐渐由粮食主导型向蔬果主导型转变;林地取代草地成为自然资本利用第二大地类,其生态盈余是区域自然资本流量增加的主要来源;草地自然资本的存量-流量利用比虽有大幅回落,但仍存在较大的反弹风险;建设地对自然资本流量的占用规模超越草地仅次于林地,并与城市化率在1%的水平上显著正相关;水域的自然资本利用占比最小,且由以存量消耗为主过渡到以流量占用为主。论文从区域和地类两个层面揭示了城乡土地利用变化与自然资本流量占用和存量消耗之间的关系,为提升足迹核算与分析方法的科学性和标准化提供了参考依据。     

要素与效率耦合视角下中国人均灰水足迹驱动效应研究

论文系统测度了中国大陆31省区2000—2014年间的人均灰水足迹,首次将生产要素中最关键的资本和劳动力要素引入到人均灰水足迹的驱动效应研究中,同时耦合了传统的环境效率与技术效率因素。应用扩展的Kaya恒等式和LMDI模型,综合分析了上述因素对人均灰水足迹的驱动效应。结果表明：1）从全国范围来看,技术效率效应的减量作用最大,资本产出效应的减量作用近年有所提高,资本深化效应的增量作用最大。2）技术效率效应、资本产出效应和资本深化效应都呈现西北高、东南低的分布格局;河北、北京、天津和山东的环境效率效应和技术效率效应对人均灰水足迹的减量作用较大,其他省区技术效率效应和资本产出效应更有利于人均灰水足迹的降低;资本深化效应在各地都会造成人均灰水足迹的显著提升。     

城市食物代谢的动态过程及其水-碳足迹响应——以北京市为例

食物代谢是城市物质能量代谢的基础性过程之一。论文系统分析了1978—2015年北京市城市食物代谢通量、结构和效率的动态变化过程,并核算其水-碳足迹,提出优化城市食物代谢的有效途径。结果表明： 1）2015年北京市食物代谢通量为881.4万t,比1978年增加了3.3倍,其中植物源食物增加了2.5倍,动物源食物增加了12.0倍,由此引发的水-碳足迹分别增加了6.1倍和4.4倍; 2）北京市食物代谢的通量结构和水-碳足迹结构均呈现出主食为主转向主副食替代、植物源食物为主转向动植物源食物并重的演变特征; 3）“过度饮食”特别是高比例肉类消费,不但影响了城市居民健康水平,也显著扩大了城市人均环境足迹,导致食物代谢的生态效率指标从1.27降低至0.32; 4）降低城市食物代谢的足迹影响需要优化产业链供应,倡导绿色健康消费模式。     

Effect of water chemistry on the aggregation and photoluminescence behavior of carbon dots

Carbon dots are rapidly emerging carbon-based nanomaterials that, due to their growing applications, will inevitable find their way to natural waters; however, their environmental fate is mostly unknown. Carbon dots with different surface functionality were fabricated and characterized by TEM and FT-IR. Their surface charge, given by the zeta potential, and their hydrodynamic diameter in suspension were investigated under a variety of environmentally relevant conditions. The effect of ionic strength was studied in the presence of monovalent (NaCl) and divalent (CaCl₂) cations, for pH levels from 3 to 11; humic acid was used as a model for dissolved natural organic matter. Total potential energies of interactions were modeled by classical DLVO theory. The experimental results showed that water chemistry altered the surface charge of the nanomaterials, but their hydrodynamic size could not be correlated to those changes. Evidence of specific interactions was found for the amino functionalized particles in most cases, as well as the plain carbon dots in the presence of Ca^2 + and humic acid. Nanoparticles remained largely stable in suspension, with some exception at the highest ionic strength considered. DLVO theory did not adequately capture the aggregation behavior of the system. Moreover, cation and/or humic acid adsorption negatively affected the emission intensity of the particles, suggesting limitations to their use in natural water sensing applications. The particular stability shown by the carbon dots results in exposure to organisms in the water column and the possibility of contamination transported to significant distances from their source.     

煤炭生产的水足迹评价研究

水足迹是水资源占用的综合评价指标,能够量化人类活动对水资源和水环境的影响,为水资源的高效利用与可持续管理提供科学参考.本文在WFN水足迹评价方法和国际标准水足迹评价方法的基础上,提出了基于生命周期的包含蓝水足迹、灰水足迹和间接水足迹的能源系统水足迹评价模型.将此模型应用到煤炭生产,计算了我国单位煤炭生产的水足迹.研究结果表明,我国1 GJ煤炭生产的水足迹为0.19 m~3,水足迹的80%来源于采掘过程,从水足迹类型来看,灰水足迹占到了87%的比例.本研究为能源系统水足迹评价提供了方法理论,并可为以煤炭为原料或燃料的下游产品水足迹评价提供数据支撑.     

Risk assessment in a hypothetical network pipeline in UK transporting carbon dioxide

With the advent of Carbon Capture and Storage technology (CCS) the scale and extent of its handling is set to increase. Carbon dioxide (CO₂) capture plants are expected to be situated near to power plants and other large industrial sources. Afterward CO₂ is to be transported to storage site using one or a combination of transport media: truck, train, ship or pipeline. Transport by pipeline is considered the preferred option for large quantities of CO₂ over long distances. The hazard connected with this kind of transportation can be considered an emerging risk and is the subject of this paper.The paper describes the Quantitative Risk Assessment of a hypothetical network pipeline located in UK, in particular the study of consequences due to a CO₂ release from pipeline.The risk analysis highlighted that some sections of pipeline network cross densely populated areas. For this reason, some changes in the original path of the network have been proposed in order to achieve a significant reduction in the societal risk.     

Modeling the impacts of temperature and precipitation changes on soil CO2 fluxes from a Switchgrass stand recently converted from cropland

Switchgrass(Panicum virgatum L.) is a perennial C_4 grass native to North America and successfully adapted to diverse environmental conditions. It offers the potential to reduce soil surface carbon dioxide(CO_2) fluxes and mitigate climate change. However, information on how these CO_2 fluxes respond to changing climate is still lacking. In this study, CO_2 fluxes were monitored continuously from 2011 through 2014 using high frequency measurements from Switchgrass land seeded in 2008 on an experimental site that has been previously used for soybean(Glycine max L.) in South Dakota, USA. DAYCENT, a process-based model, was used to simulate CO_2 fluxes. An improved methodology CPTE[Combining Parameter estimation(PEST) with "Trial and Error" method] was used to calibrate DAYCENT. The calibrated DAYCENT model was used for simulating future CO_2 emissions based on different climate change scenarios. This study showed that:(i) the measured soil CO_2 fluxes from Switchgrass land were higher for 2012 which was a drought year, and these fluxes when simulated using DAYCENT for long-term(2015–2070) provided a pattern of polynomial curve;(ii) the simulated CO_2 fluxes provided different patterns with temperature and precipitation changes in a long-term,(iii) the future CO_2 fluxes from Switchgrass land under different changing climate scenarios were not significantly different, therefore, it can be concluded that Switchgrass grown for longer durations could reduce changes in CO_2 fluxes from soil as a result of temperature and precipitation changes to some extent.