基于国际碳足迹标准的中国人造板产业碳减排路径研究

基于生命周期分析的碳足迹评估,量化产品从原材料获取到最终处理各个阶段的温室气体排放,已在多个产业和产品间得到应用和实践。碳足迹评估的标准化对碳足迹核算提出指导,减排承诺背景下林产品兼具碳储减排和替代减排的双重效益,规范和统一其碳足迹评估标准并挖掘减排潜力,对于统一中国产业间的碳足迹评估有借鉴意义。本文聚焦国际主流且关联度较高的产品碳足迹核算标准(PAS 2050和GHG Protocol),以在中国人造板产业占支柱地位的胶合板为研究对象,量化国际碳足迹标准方法学的差异性。具体涉及系统界限、取舍原则、分配方法、碳储存及其延迟排放等。为综合分析国际碳足迹标准的适用性,通过"摇篮到大门"和"摇篮到坟墓"系统模型进行评价。结果表明:①PAS 2050和GHG Protocol对中国胶合板产业的碳足迹核算,结果分别为-1 123. 46 kg CO_2e和-1 117. 63 kg CO_2e,在应对气候减排的背景下,PAS 2050标准的应用对胶合板生产企业承受的减排压力较小。②PAS 2050对评估实质的环境影响提供了具体的指导,尤其是对区别于石化产品的林产品碳储功能,PAS 2050提供了测算延迟排放的具体方法,从产品生产企业和政策制定的视角,PAS 2050对胶合板的碳足迹核算也更具普适性。国际碳足迹标准对中国人造板产业的碳减排提供了可供借鉴的改进路径:①气候减排能力发掘。产品的填埋处理相对燃烧处理可实现549. 32%的减排效果。②能源结构调整。现场生产阶段采用木质生物质能源替代化石能源可显著减少36. 99%～38. 24%的温室气体排放。③产业链优化。木质原料获取端应推进林板一体化战略,废旧产品处理端应加快产品回收利用及政策设计。④市场结构调整。林木资源稀缺,胶合板面临被定向刨花板等对木质原材料要求较低的新型木质复合材料替代的趋势,人造板产业结构的升级亟待完善。     

基于终端消费的山东省旅游碳足迹研究

旅游业在全球气候变暖中的贡献率约为5%-14%,其碳排放问题成为全球关注的焦点之一。本文以山东省为研究对象,构建了综合模型和行业模型两个模型,研究了山东省旅游碳足迹总量以及各旅游部门的碳足迹,综合模型测算出时间跨度的山东省旅游碳足迹,从2000年至2013年,旅游碳足迹总量是逐年增加的。而行业模型进一步分析了2013年山东省旅游六大部门的碳足迹,2013年山东省旅游碳足迹的总量是637.70万t,其中交通碳足迹占总量的61.40%,最后根据以上计算结论,提出山东省旅游节能减排的主要方向是减少旅游交通碳足迹,从政府、旅行社、游客三方面提出了旅游碳减排路径。     

建立中国碳标签体系研究

碳标签,作为一种将产品或服务的全生命周期中产生的温室气体排放量的标识,能直接影响厂商的生产决策和消费者的消费行为,在国外被越来越多的采用实施。中国目前还没有权威的、完整的、可实行的碳标签体系,因此建立中国碳标签体系具有紧迫性和重要的现实意义。借鉴国际标准组织已经发布的标准和英国Carbon Trust的PAS 2050标准,本文尝试搭建中国碳标签体系的框架,总结了碳足迹的计算方法,碳标签的颁发与核证以及碳标签咨询服务机构的设置与运行,探讨了建立中国碳标签完整体系。最后对我国建立碳标签体系提出了政策建议。     

林产品生物碳通量的动态生命周期评估

将时间因素和生物碳通量纳入林产品生命周期碳足迹评估,通过动态生命周期分析法(Dynamic Life Cycle Assessment,DLCA),确定林产品生产、使用和废弃阶段替代化石能源的净温室气体减排和对森林碳损失的净弥补时间。首先,建立温室气体排放和封存的动态生命周期清单,评估刨花板全生命周期的碳动态和碳足迹;其次,根据ISO 14040和PAS 2050标准提供的静态生命周期分析法分别核算包含与不包含碳储计算的碳足迹,量化时间因素和生物碳通量对于碳足迹结果差异的影响程度;最后,对比自然生长状态的森林碳汇情境,评估刨花板使用和废弃阶段替代化石燃料实现净气候减排所需的时间。研究表明:①时间因素和生物碳通量核算对碳足迹结果影响较大(223.34%),忽视时间因素会低估刨花板的减排贡献(18.98%)。②动态生命周期分析法可准确评估生物碳和温室气体排放的时间问题,但对时间范围非常敏感(75.19%和113.25%)。③生产、使用林产品以及林产品对化石能源的替代是实现长期气候减排的有效方式,在100a的时间范围能够弥补因森林砍伐造成的碳损失,从而实现碳中性。     

环境保护视角下的食物里程研究

随着全球环境问题日趋严峻,可持续发展越来越重要,食品与环境如何相互影响,食品生产和消费过程中的碳减排问题,日益受到人们的广泛关注。"食物里程"通过考察食品从生产到餐桌的距离,量化食品生产、运输、消费过程的碳排放,考察食品对环境的影响,该指标得到政府、食品加工厂、贸易商、消费者、环保主义者和学者普遍关注。本文从食物里程的内涵着手,系统阐述食物里程概念的形成与发展,介绍食物里程的两种计算方法,包括投入产出-生命周期法和供应链中的能源使用等,食物里程涉及到碳排放的三个公认的评估标准:1PAS 2050,联合国气候变化框架公约清洁发展机制,ISO/CD 14067。在此基础上,本文从食物里程的价值角度、消费者角度及国际贸易角度对国内外相关研究进行系统的归纳与总结,提出未来的研究方向主要在于合理界定食物里程的内涵,科学利用食物里程改变生产和消费方式,从而改善环境,防止食物里程成为新的国际贸易壁垒。     

畜牧业“碳排放”到“碳足迹”核算方法的研究进展

全球变暖趋势日益加剧,不仅影响农业可持续发展,而且威胁到人类生存。畜牧业碳排放因其在农业碳排放中乃至全球碳排放中占比较大而日益备受关注。准确核算畜牧业碳排放是制定切实可行的碳减排政策的前提,也为我国在气候变化下承担共同但有差别的减排责任提供话语权。本文基于研究范式的演进,对畜牧业碳排放到碳足迹核算方法的研究发展进行了系统梳理,研究表明,在学者的不断研究与质疑下,畜牧业碳排放到碳足迹的核算方法经历了从OECD核算法、IPCC系数法到生命周期法与投入-产出法的演变与完善,学术界认为区域异质性、养殖规模与管理方式均影响碳足迹;散养比规模化养殖产生更多的碳排放,舍饲比户外放牧排放更多的碳。畜牧业碳足迹核算能够更加全面地反映畜牧业全生命周期的碳排放情况,但由于研究假设、研究方法及研究样本等差异导致不同区域、不同畜产品的碳排放核算结果存在不确定性。运用生命周期法和投入-产出法对欧盟成员国畜牧业碳排放的核算结果基本一致,但运用IPCC系数法和全生命周期法对中国畜牧业碳排放核算中,牛、猪和羊的碳排放量排序结果不尽一致。鉴于核算结果的差异性,本研究对不同核算方法的起源、最早采用时间、特点、局限性等方面进行了归纳总结,并建议后续研究探讨基于生命周期评价的畜牧业碳足迹研究边界的延伸性,标准化畜牧业碳排放或碳足迹核算,避免学者重复核算畜牧业碳排放,以便深入展开畜牧业碳排放其他方面的研究。     

产品碳足迹评价方法及在服装产品的应用

在全球气候变暖的大背景下,促进碳减排是企业和社会的共同责任。要推动企业的碳减排,必须先对企业的碳排放情况有全面的认识。文章在界定产品碳足迹基本含义的基础上,从全生命周期分析的角度对产品碳足迹分析的一般方法进行了阐述,指出产品碳足迹的核查应包含生命周期各个环节的碳排放,而碳排放既包含产品生命周期中温室气体的排放,也包含产品的能源消耗。在此基础上,分析了服装产品全生命周期包含的阶段,并对各个阶段碳足迹的计算方法进行了分析,旨在对服装全生命周期的碳排放有一个全面的认识,以推进服装产品的碳减排。     

基于ISO14067的长江上游某水电项目碳足迹分析

以长江上游某大型水电站为案例,根据国际标准化组织碳足迹量化标准(ISO14067)评价流程,对该水电站全生命周期(建设阶段,运行维护阶段,退役阶段)碳足迹进行估算,并着重考虑了蓄水前后水库温室气体通量差异。研究以碳足迹系数和能源回收率作为指标进行评价,结果表明生命周期碳足迹为5 417.0万t CO_(2eq),碳足迹系数为7.0~13.1 g CO_(2eq)/kW·h,中位值为9.4 g CO_(2eq)/kW·h,该水电站项目能源回收率达236.4。与各种能源电站以及国内外同类型水电站相比较,该水电站碳足迹明显较低,且能源回收率显著较高,说明以该水电站为代表的我国西南水电具有显著的优质性,大力开发水电能有效节能减排,明确了生命周期评价方法对于水电站碳足迹评估的适用性。     

布什政府温室气体减排政策评析

美国作为世界政治经济大国和世界第一大温室气体排放国家，其温室气体减排政策备受关注。布什政府上台后不久宣布拒绝接受《京都议定书》，并于2002年2月提出“全球气候变化计划”。布什政府实际上在以各种借口推托美国应该承担的温室气体减排国际责任，这将对以UNFCCC为基础的全球气候合作产生消极影响，并对全球气候政策提出挑战。     

碳排放影子价格模型——以深圳市电力行业为例

以煤电为主的电力行业是中国最大的温室气体(Green House Gas,GHG)排放部门,该部门GHG排放量约占全国GHG排放总量的40%,因此能否有效控制电力行业GHG排放增长将直接影响国家GHG减排目标能否顺利实现。在电力行业碳排放受限情况下,GHG排放权(也称碳排放权)成为电力企业生产所必须获取的一种资源。在此基础上,本文构建了以系统发电总成本最小化为目标的电力系统数学规划模型,利用对偶原理求解GHG排放权的影子价格。以深圳电网为案例,本文计算了电力系统GHG排放权的影子价格并对其主要影响因素进行分析。研究结果显示:碳排放总量对GHG排放权影子价格的影响较大,同时各种能源资源的丰富程度也会对其产生影响;核能发电可以降低发电系统平均成本,也有助于减少发电系统对碳排放权的需求,因此可以有效抑制碳排放权资源影子价格的上升;化石能源发电碳捕集和封存(Carbon Capture and Storage,CCS)改造也可以减少发电系统对碳排放权资源的需求,也会起到降低碳排放权影子价格的效果。本文所得的GHG排放权资源影子价格可以为碳排放权定价和制定碳税税率提供科学参考。     

不同麦秸还田方式对周年稻麦轮作农田碳足迹的影响

为明确麦秸不同还田方式对稻麦轮作农田碳足迹的影响，该研究通过开展两年的大田试验，设计了3种麦秸还田方式（麦秸旋耕还田、麦秸翻耕还田和麦秸沟埋还田），并以麦秸不还田为对照，采用静态箱-气相色谱法连续两年对农田温室气体排放进行监测，并对不同麦秸还田方式的生产资料投入和生产过程碳排放及温室气体排放进行全面分析。结果表明：(1）与不还田相比，麦秸还田显著增加了稻季日均CH4排放，稻麦周年全球增温潜势95%来自稻田CH4排放；（2）在水稻季，农田CH4排放占碳足迹总量比例最大，3种麦秸还田方式中，麦秸沟埋还田处理下碳足迹最小，且能比麦秸旋耕还田处理减少4.9%；(3）在小麦季，化肥投入造成的碳足迹所占比例最大，为64.5%~77.4%，其次是土壤N2O的排放；（4）从整个稻麦周年轮作系统来看，与麦秸旋耕还田和麦秸翻耕还田处理相比，麦秸沟埋还田处理能分别减少4.6%和3.6%的周年碳足迹及8.7%和4.9%的周年单位产量的碳足迹。因此，对于稻麦轮作地区，采用麦秸沟埋还田能在一定程度上降低农业生产过程中的碳足迹。     

Component-level embodied carbon database for landscape hard works in Taiwan

Environment, Development and Sustainability - Facing the escalating crisis of global warming, life cycle assessment (LCA) for carbon footprint has recently seen rapid development in the building...     

Carbon Footprint Analysis for Baby Strollers

Abstract

The increasing awareness of climate change has led organizations to demand a standard procedure to measure and communicate greenhouse gas (GHG) emissions linked to their products or services. The publicly available specification PAS 2050 has been developed in response to broad community and industry desire for a consistent method-carbon footprint for assessing the life cycle GHG emissions of goods and services. Specifically, this paper illustrates the implementation of carbon footprint for a baby stroller in accordance with PAS 2050. A fial value of 321 kg per one stroller including package was calculated. Moreover, the study led to identify raw materials production of the stroller as the main source of GHS emissions where efforts need to focus for emission reduction opportunities. This case study is hoped to be a starting point for organizations to benefit from the increasing application of carbon footprint assessment.     

Regional carbon footprints of households: a German case study

Households are either directly or indirectly responsible for the highest share of global anthropogenic greenhouse gas emissions. Hence, programs helping to improve human consumption habits have been identified as a comparatively cost-effective way to reduce household emissions significantly. Recently, various studies have determined strong regional differences in household carbon footprints, yet a case study for Germany has not been conducted. Local information and policies directed at household consumption in Germany thus devoid of any foundation. In this paper, we analyze the impact of different criteria such as location, income and size on household carbon footprints in Germany and demonstrate how the impact of GHG mitigation opportunities varies for different population segments. We use a multi-region input output hybrid LCA approach to developing a regionalized household carbon footprint calculator for Germany that considers 16 sub-national regions, 15 different household sizes, and eight different income and age categories. The model reveals substantial regional differences in magnitude and composition of household carbon footprints, essentially influenced by two criteria: income and size. The highest income household is found to emit 4.25 times as much CO₂e than the lowest. We identify indirect emissions from consumption as the largest share of household carbon footprints, although this is subject to fluctuation based on household type. Due primarily to local differences in vehicle availability, income and nutrition, an average household in Baden-Wuerttemberg is found to have 25 % higher carbon footprint than its Mecklenburg-West Pomeranian counterpart. Based on the results of this study, we discuss policy options for household carbon mitigation in Germany.     

Brazil’s Amazonian forest carbon: the key to Southern Amazonia’s significance for global climate

Southern Amazonia is the first region of Brazil’s Amazon area to be exposed to intensive conversion to agriculture and ranching. This conversion emits greenhouse gases from the carbon stock in the biomass and soils of the previous vegetation. Quantifying these carbon stocks is the first step in quantifying the impact on global warming from this conversion. This review is limited to information on Brazilian Amazonia’s carbon stocks. It indicates large amounts of carbon at risk of emission in both biomass and soils, as well as considerable uncertainty in estimates. Reducing uncertainty is a priority for research but the existence of uncertainty must not be used as an excuse for delaying measures to contain deforestation. The magnitude of carbon stocks is proportional to greenhouse gas emissions per hectare of deforestation and consequently to impact on global climate.

     

江苏省交通运输业能源消费碳排放及脱钩效应

通过自上而下的计算方法，测算了江苏省1995～2010年交通运输行业能源消费碳排放量和人均碳排放量，并结合行业自身发展特点，扩展了Kaya恒等式，运用LMDI分解法进行分解分析。同时，在上述基础上采用Tapio模型对江苏省交通碳排放与交通运输业经济发展的脱钩关系进行了探讨。研究发现:(1)江苏省交通碳排放量与人均碳排量均呈明显上升趋势，其中石油制品类能源消费碳排放表现突出;(2)正向驱动交通碳排放量增加的因素为经济产出、人口规模和产业结构，负向驱动因素为交通能源结构和交通能源强度。其中，拉动碳排放量增长的决定性因素是经济产出规模的扩大，而促使碳排放减少的主要因素是交通能源强度的降低，相对于正向驱动因素，负向驱动因素抑制交通碳排放增加作用有限;(3)交通碳排放量变化与运输业经济发展之间的脱钩状态以扩张负连接、扩张负脱钩和弱脱钩为主，脱钩关系总体呈先恶化后改善的趋势，但要完全实现两者的绝对脱钩，依然任重道远     

Mitigating GHG Emissions in the Humid Tropics: Case Studies from the Alternatives to Slash-and-Burn Program (ASB)

Tropical forest conversion contributes as much as 25% of the net annual CO₂ emissions and up to 10% of the N_2O emissions to the atmosphere. The net effect on global warming potential (GWP) also depends on the net fluxes of greenhouse gases from land-use systems following deforestation. Efforts to mitigate these effects must take into account not only the greenhouse gas fluxes of alternative land-use systems but also the social and economic consequences that influence their widespread adoption. The global alternatives to slash-and-burn program (ASB) investigated the net greenhouse gas emissions and profitability of a range of land-use alternatives in the humid tropics. The analysis showed that many tree-based systems reduced net GWP compared to annual cropping and pasture systems. Some of these systems are also profitable in terms of returns to land and labor. The widespread adoption of these systems, however, can be limited by start-up costs, credit limitations, and number of years to positive cash flow, in addition to the higher labor requirements. Projects that offset carbon emissions through carbon sinks in land use in the tropics might be a means of overcoming these limitations. A synthesis of the findings from this program can provide guidelines for the selection and promotion of land-use practices that minimize net global warming effects of slash-and-burn.     

Certainty and uncertainty in understanding global warming

Global warming has greatly concerned the whole world. Owing to the limitation we currently have, it is still difficult to completely understand the mechanism and physical science of climate change. Now both certainty and uncertainty coexist in the understanding of climate warming. This paper aims to summarize certainties and uncertainties in climate-warming studies, which focus on seven key problems related to human activities, namely, global warming, atmospheric concentrations of greenhouse gases, relationship between greenhouse gas emissions and climate warming, climate models, future climate change, 2°C warming threshold and tipping point in the Earth’s system. We should comprehensively take into account the level of certainty and uncertainty in our understanding of climate change while adapting to and mitigating global warming and adjusting our industrial structures accordingly. This would allow us to respond to change with certainty, while avoiding the risks associated with uncertainty.