城市餐饮业食物浪费碳足迹——以北京市为例

食物浪费及其造成的环境影响已成为全球广泛关注的热点。无论从生命周期还是碳足迹的视角来看,食物浪费意味着生产、运输、加工与储存这些被浪费掉的食物过程中所投入的各种资源的浪费以及不必要的温室气体排放。以北京市餐饮食物浪费问题为切入点,在通过问卷调查和称重方法对餐饮食物浪费状况进行调查的基础上,将整个食物生命周期各供应链环节相应的温室气体排放纳入考量,估算了北京市餐饮食物浪费的碳排放量。研究结果表明:北京市餐饮食物浪费总量为39.86×10~4t/a。其中,蔬菜类浪费量最高,约占浪费总量的43.16%,其次为肉类和主食类,分别占食物浪费总量的20.59%和16.66%。北京市餐饮食物浪费所产生的总碳足迹为192.51×10~4—208.52×10~4t CO_2eq。其中,农业生产阶段的碳排放量最大为99.34×10~4t CO2eq,占食物浪费总碳足迹的47.64%。其次是消费阶段的碳足迹77.96×10~4t CO_2eq,占食物浪费总碳足迹的37.39%,再次是餐厨垃圾处理阶段的碳足迹28.54×104tCO2eq,占食物浪费总碳足迹的13.68%。这些不同供应链环节的碳排放比例,为透视食物浪费所带来的环境影响提供了新的认知,也为遏制食物浪费提供了科学的理论依据。     

厦门市城市能源代谢综合分析方法及应用

城市代谢理论目前被认为是系统解析城市病症结的重要切入点。能源是人类活动和城市发展的物质基础, 研究其代谢规律可以揭示城市能源利用过程中存在的问题及其代谢污染物的生态环境效应, 从而为城市能源规划与管理提供科学依据。文章在部门调研数据、统计年鉴数据和文献资料分析的基础上, 提出了一种基于能量流的城市能源代谢综合分析方法。该方法系统分析能源在城市内部的流动过程, 全面核算5 种主要代谢污染物的排放量, 并使用7 个指标对能源代谢进行评价, 进一步使用该方法系统研究了厦门市2009 年能源代谢情况, 结果表明: (1)厦门本地能源稀缺, 对外依存度高, 并且结构较为单一, 主要依赖煤炭和燃油, 分别占能源总量的61%和23%。(2)代谢污染物CO₂、NO₂ 和废热首要来自能源加工转化, SO₂ 和PM2.5 首要来自工业。(3)2009 年能源代谢总效率为0.43 tce·t^-1, 在各部门中服务业及其他的效率最高, 加工转化的效率最低, 代谢效率与能源结构关系密切。(4)文章提出的方法可为城市能源代谢研究提供方法参考。     

食物源CNP的城市代谢特征——以厦门市为例

基于元素流分析原理,将食物源碳氮磷3种元素在城市系统中的代谢特征进行耦合分析,追踪以\"食物消费\"、\"废物处置\"、\"人体代谢\"为主要环节的食物碳氮磷代谢过程,发掘其中共同的代谢环节,明晰3种元素代谢路径、代谢通量及其影响因素的差异,并对厦门市1991—2010年食物源碳氮磷城市代谢进行案例分析。结果表明,食物源碳氮磷城市代谢中通量最大的代谢路径是\"食物—食物摄入—人体粪尿—未还田粪尿—污水处理—污泥—污泥填埋—土壤\";食物源碳氮磷城市代谢主要引起土壤和水体的环境负荷加重;厨余垃圾中碳氮磷占食物源的比例分别为13.7%、32.2%、70.3%,在整个代谢过程中具有最大的减量管理潜力。提出优化代谢过程、减少碳氮磷环境负荷的若干对策建议,包括增大食物的有效食用比例、资源化利用污泥和厨余垃圾等。     

农田生态系统碳足迹时空变化——以河南省为例

农田生态系统是陆地生态系统的重要组成部分,起着碳源和碳汇的双重作用,对维持整个生态系统碳平衡具有重要意义.本文基于ArcGIS 10.1、SPSS 20.0、Sigmaplot 12.5等分析平台,以农田生态系统为研究对象,构建农田生态系统碳足迹模型,分析2005—2014年河南省农田生态系统碳排放、碳吸收和碳足迹及三者之间的关系.结果表明: 2005—2014年,研究区碳排放年平均增长率为2.7%,其中因化肥施用引起的碳排放量占总碳排放量的比例最高,占66.2%,且化肥的使用强度为890.38 kg·hm^-2,远高于发达国家公认的安全警戒线225 kg·hm^-2.河南省农田生态系统的碳总储量整体呈逐年上升趋势,其中,小麦的碳吸收比例最高,占总吸收量的60%,水稻的碳吸收增速最快,为7.9%.河南省农田生态系统存在碳生态盈余,且农田生态系统碳足迹总体呈现不断增加趋势,农田生态系统碳足迹占同期生产性土地面积(耕地)的平均比例为5.7%.研究区碳排放、碳吸收、碳足迹的空间变化较为一致,均呈现东南多、西北少的空间分布规律,且地区差异及变化幅度差异较大是三者的最主要外部特征.     

基于土地利用变化的四川省碳排放与碳足迹效应及时空格局

土地利用变化的碳排放与碳足迹研究对了解人类活动对生态环境的扰动程度及其机理、制定有效的碳排放政策具有重要意义。采用1990—2010年四川省能源消费数据和土地利用数据,通过构建碳排放模型、碳足迹及其压力指数模型,对研究区20年来土地利用的碳排放及碳足迹进行了定量分析。结果表明:(1)土地利用变化的碳排放和能源消费碳的足迹呈显著增加趋势。碳排放增加5407.839×10~4t,增长率达143%;能源消费的碳足迹增加1566.622×10~4hm~2,四川全省的生态赤字达1563.598×10~4hm~2。(2)建设用地和林地分别为四川省最大的碳源与碳汇。20年间建设用地的碳排放增加5407.072×10~4t,增长率达126.27%,占碳排放总量的88%以上;林地的碳汇减少10.351×10~4t,但仍占四川省碳汇的96%以上。(3)土地利用碳排放、碳足迹和生态赤字存在明显区域差异。成都平原区碳排放、碳足迹压力最大,生态赤字严重,西部高山高原区和盆周山区碳排放、碳足迹最小,未出现生态赤字;成都、德阳、资阳和内江等地的碳排放、碳足迹压力最大,生态赤字最严重,甘孜、阿坝等地的碳排放、碳足迹最小,未出现生态赤字。(4)土地利用结构与碳排放、碳足迹存在一定的相互关系,趋高的碳源、碳汇比导致土地利用的碳源效应远大于碳汇效应。因此,四川省减排的重点应该在保持或增加现有的林地的同时,主要以降低建设用地的碳排放、碳足迹为主。     

生态设计家具的碳足迹核算与减排效果分析——以木质家具为例

我国的木质家具不仅产量大,而且碳排放强度也相对较高,利用生态设计理念可以降低木质家具的碳足迹。为了定量化生态设计所带来的减排效果,按照减少资源消耗和环境污染、节省住宅空间等木质家具生态设计原则,通过在一款多功能家具的框架内安装不同面板,形成了4种不同材质和结构的设计方案,利用生命周期分析方法核算了4种方案的碳足迹,并进一步量化了改进方案的减排效果。结果表明:4种家具设计的碳足迹从小到大为三聚氰胺板家具、木皮板家具、拼板家具、嵌条板家具,其中,实木类家具原材料碳排放较低,人造板类家具加工过程电力碳排放较低(主要来源于喷涂工段,占电力排放的83%—92%);通过各种减排方案的减排效果分析,发现采用\"可拆卸无胶连接方式\"改进方案减排效果显为明显;同时发现,合理的\"低碳设计\"(采用以实木板为基板,以三聚氰胺纸为贴面制作面板),可以避免中纤板喷涂过程的碳排放,从而减少产品整体碳足迹。     

海湾型城市半城市化地区空间扩展演化——以厦门市为例

选择海湾型城市--厦门市半城市化地区为研究对象,基于研究区1987、1992、1997、2002和2007年5个时相的TM/ETM+遥感影像数据,在遥感与GIS技术支持下获取了近20a 来各期土地利用信息数据,采用景观格局转移矩阵、景观格局指数和分形理论等方法研究了厦门市半城市化地区城市化过程中的景观格局空间演变特征,详细分析了城市形态演变、城市围填海特征及政策影响.结果表明:20 a 年来厦门近郊建设用地从18.4 km2增加到108.4 km2,远郊则从35.7 km2增加到114.9 km2,分别增长为原来5.9倍和3.2倍;城市空间扩展过程通过不断侵蚀耕地、林地和大规模填海造地完成,其中耕地景观变化最大,城市扩展最高峰(2002～2007年)近郊与远郊被建设用地\"蚕食\"的耕地多达19.74 km2和33.11 km2;在城市空间不断扩展的过程中,近郊城市城市由不稳定形态逐步向稳定形态(填充增长)演化,但远郊形态格局尚处于以中心城市扩展为主体的时期;填海造地面积及其时空分布与政策因素密切相关,20 a来厦门半城市化地区海岸线缩短了14.3%,近郊与远郊海岸分维数分别从1.236和1.267降到1.191和1.262,岸线复杂性明显降低,逐步趋于平直;海湾型城市战略的提出对填海造地影响最为明显,2002～2007年期间填海进程明显加快,近郊与远郊分别填海13.32和9.15 km2,超越了前15 a 填海总面积.     

基于碳足迹研究的中国地区工业低碳转型——以山东省为例

行业的低碳发展是工业低碳转型的目标,以工业部门为对象,应用脱钩效应和面板模型分析行业能源消费的碳足迹,对深入研究地区工业低碳转型具有重要现实意义。以山东省为例,分析工业能源消费碳足迹的1997年至2012年样本数据,将工业部门分为高耗能行业、其他行业、战略性新兴行业,展开研究,结果表明:(1)自20世纪90年末代开始节能降耗,山东省工业呈现强负\"脱钩\"、强\"脱钩\"、扩张负\"脱钩\"和弱\"脱钩\"交替发生,表明对工业节能降耗调控波动大,不利于工业部门均衡有序发展;(2)高耗能行业是能耗大户,高耗能行业与工业在绝大部分年份的脱钩状态相同,表明高耗能行业主导工业总体脱钩状态,是节能减排的主要对象;随着节能降耗的深入,相关政策趋紧,碳足迹边际成本不断升高,应关注锁定效应大的火电行业和碳足迹边际成本高的化学工业;(3)其他行业包含行业多,但总体能耗水平不高,随着节能减排的开展和行业持续发展,能耗将增加,必将承担更多的节能减排,需要关注锁定效应强的金属制品业发展,推动碳生产力系数高的食品饮料业发展;(4)战略性新兴行业碳锁定效应最弱、碳足迹边际成本最低和碳生产力系数最高,是国家大力倡导发展的行业;由于基数低,对工业碳排放态势影响极其有限,应大力推动碳锁定效应弱的新一代信息技术产业、碳足迹边际成本低的新材料行业、碳生产力系数高的节能环保业和新材料行业。     

快速城市化生态系统服务格局分析与空间管控——以厦门市为例

快速城市化对生态系统服务产生消极影响,科学识别二者的空间规律并进行管控对国土空间资源可持续开发意义重大。基于土地利用、遥感影像、POI等多源数据,借助ArcGIS、InVEST平台分析厦门市六类生态系统服务的空间分布及权衡协同格局,并引入人工神经网络算法与土地利用程度指数模型定量识别城市化空间格局,通过决策矩阵提出空间管控策略。结果表明：①厦门生态系统服务分布在\"陆-海\"方向上分异显著,岛外地区综合生态系统服务指数总量占全域的91.78%,其中同安区的总量和均值都处于首位;②生态系统服务之间以协同作用为主,在全局关系中生境质量与雨涝调蓄以及与温度调节的协同水平最高,在局部空间关系中水源涵养与雨涝调蓄的协同水平最高,休闲游憩服务与其他服务的权衡效应最强;③翔安区开发潜力最大,同安区过度城市化问题突出,市域未开发单元中生境质量、水源涵养和雨涝调蓄服务较强,建成单元仅在休闲游憩服务具有优势;④叠加空间细分单元的城市化与生态系统服务特征,得到厦门市生态管控分区和决策矩阵,提出四类单元八种情景的具体管控策略。     

旅游风景区旅游交通系统碳足迹评估——以南岳衡山为例

随着全国各地旅游业的蓬勃发展,旅游风景区内碳排放总量不断攀升,严重影响了旅游业的可持续发展。选择南岳衡山旅游风景区为典型案例区,运用生命周期评价理论,构建了南岳风景区旅游交通系统碳足迹计算模型。结果表明:①从总量来看,不同类型交通方式的碳足迹情况相差甚远。公路旅游交通对旅游景区的环境威胁最大,碳足迹总量是索道旅游交通的2.6倍,人行道旅游交通的46.1倍;②从阶段构成来看,公路和索道旅游交通系统运营使用阶段碳足迹占整个生命周期的大部分,所占比率分别为79%和96%.而人行道旅游交通系统中建造施工和运营后期阶段能源消耗比较大;③从来源构成来看,在使用期内公路旅游交通的碳足迹比重最大,约占碳足迹总量的71%,其次是索道旅游交通占27%,人行道旅游交通仅占2%。研究结果有利于实现旅游风景区低碳旅游发展目标,为旅游风景区节能减排提供理论支撑。     

Reply to the first systematic response by the Global Footprint Network to criticism: A real debate finally?

We respond to a reaction of the Global Footprint Network/GFN on our 8-point criticism of the ecological footprint. We also refer to, and comment on, an associated debate in this journal between Giampietro and Saltelli, 2014a, Giampietro and Saltelli, 2014b, on the one hand, and Goldfinger et al. (2014), on the other. We conclude that criticism on the footprint is accumulating and coherent across the various studies and disciplines and among the different authors. This was the first time that Wackernagel/GFN systematically responded to our criticisms. Hence, our response contains several original elements and the resulting exchange can be seen to add value to the existing literature. It ultimately allows readers to better make up their mind about the different viewpoints on the ecological footprint.     

Carbon footprints of rice production in five typical rice districts in China

Five provinces located in the five main rice-growing regions in China were selected as study areas, which were Jiangsu, Heilongjiang, Sichuan, Guangdong and Hunan province respectively in the middle and lower reaches of the Yangtze River, northern, southwest, southern and central rice districts. Carbon footprints of rice production in these five provinces were calculated through the life cycle assessment method using governmental statistical data, industrial standards and relevant technical data separately. Material and energy consumptions were estimated, key stages of energy consumptions and carbon emissions were identified as well. Moreover, improving measurements had been suggested correspondingly. The results indicated that: the energy consumptions of rice production in these five provinces ranked as following (high to low): Guangdong, Heilongjiang, Hunan, Sichuan and Jiangsu. The carbon footprints of rice production were 2504.20 kg carbon dioxide equation per ton rice (kgCO₂-eq./t) (Guangdong province), 2326.47 kgCO₂-eq./t (Hunan province), 1889.97 kgCO₂-eq./t (Heilongjiang province), 1538.90 kgCO₂-eq./t (Sichuan province) and 1344.92 kgCO₂-eq./t (Jiangsu province) respectively. Reducing the quantities of urea and using the intermittent irrigation method could decrease energy consumption as well as carbon footprint.     

Quantification of the water,energy and carbon footprints of wastewater treatment plants in China considering a water–energy nexus perspective

Water and energy are closely connected and both are very important for human development. Wastewater treatment plants (WWTPs) are central to water–energy interactions as they consume energy to remove pollutants and thus reduce the human gray water footprint on the natural water environment. In this work, we quantified energy consumption in 9 different WWTPs in south China, with different treatment processes, objects, and capacities. The energy intensity in most of these WWTPs is in the range of 0.4–0.5 kWh/m³ in 2014. Footprint methodologies were used in this paper to provide insight into the environmental changes that result from WWTPs. A new indicator “gray water footprint reduction” is proposed based on the notion of gray water footprint to better assess the role of WWTPs in reducing human impacts on water resources. We find that higher capacity and appropriate technology of the WWTPs will result in higher gray water footprint reduction. On average, 6.78 m³ gray water footprint is reduced when 1 m³ domestic sewage is treated in WWTPs in China. 13.38 L freshwater are required to produce the 0.4 kWh electrical input needed for treating 1 m³ domestic wastewater, and 0.23 kg CO₂ is emitted during this process. The wastewater characteristics, treatment technologies as well as management systems have a major impact on the efficiency of energy utilization in reducing gray water footprint via these WWTPs. The additional climate impact associated with wastewater treatment should be considered in China due to the enormous annual wastewater discharge. Policy suggestions are provided based on results in this work and the features of China's energy and water distribution.     

Footprints of carbon and nitrogen: Revisiting the paradigm and exploring their nexus for decision making

Paradigms used for developing footprint metrics define the efficacy of these metrics for guiding decisions in the correct direction. Several metrics in use are developed from a narrow viewpoint of only looking at the output side impact of human activities on natural systems. This underestimates or overlooks other impacts on natural systems that occur due to input side interaction of human systems with natural systems. We revisit the paradigms used for development of footprint metrics and analyze the carbon and nitrogen footprints from these perspectives. Based on our analysis, utilizing both input and output side footprint measures is suggested such that heterogeneity of the nature of impact on both sides is not ignored. Utilizing these viewpoints, updated carbon and nitrogen footprints are proposed. Eco-LCA data for 2002 US economy is used to study the effect on decisions if these updated metrics are used. We also highlight the importance of understanding the multidimensional nature of environmental impacts that does not get captured by a single footprint, thus necessitating attention to the nexus of various footprints in decision making. Thus, the nexus between the updated carbon and nitrogen metrics is studied to show the shift in decisions resulting from looking at multidimensional impacts. Results for the US economy show that revisiting the paradigm for development of footprint metrics is a crucial step to avoid pushing decisions in incorrect directions due to use of narrowly focused footprint measures.     

A comprehensive evaluation on industrial & urban symbiosis by combining MFA,carbon footprint and emergy methods—Case of Kawasaki,Japan

One proposed strategy to solve current environmental challenges is industrial and urban symbiosis (I/UrS); however, appropriate evaluation methods are needed so that the potential benefits of I/UrS can be quantified. Several evaluation methods have been applied separately to study I/UrS, but no integrated studies have been conducted by applying different methods in the same case study area. Therefore, this study aimed to establish a comprehensive framework to evaluate I/UrS by combining the material flow analysis (MFA), carbon footprint (CF) and emergy methods. First, we developed a unified database and step-by-step process to clarify the waste distribution and recycling processes in an industrial city. Then a baseline scenario and an I/UrS scenario were set up to define the baselines and effects of I/UrS and compare the results. Finally, the three methods were applied to identify physical features in the I/UrS system. The MFA-based results showed that the use of I/UrS led to a 6.4% reduction in the physical value of material use. The CF-based results indicated that reduction of waste and by-products results in a 13.8% reduction in CO₂e emissions. The emergy-based results showed that, with the implementation of I/UrS, the value of the emergy sustainability index (excluding labor and services) improved greatly (a 49.2% emergy reduction) as compared with the baseline case (a 14.3% reduction). In addition, the effects of implementing I/UrS by waste and by-product exchanges for blast furnace slag, scrap steel, waste paper, and waste plastic were evaluated. Whereas the CF reductions of unit ton of blast furnace slag is relatively low, emergy reductions of that is comparatively high. If policymakers only consider CF results when addressing the issue of climate change, the effects on emergy will be underestimated in this case. We conclude that the main actors in this area release huge emissions, but they also have a high potential to reduce their environmental loads. In addition, with appropriate designs, waste paper and plastics recycling could be highly efficient. Finally, the integration of the three evaluation methods should contribute to creating a low carbon and more resource independent society.     

厦门地区观赏藤本植物资源及其在园林绿化中的应用

本文报道厦门地区观赏藤本植物资源58科127属201种,并探讨它们在城市园林绿化中的应用。