生命周期视角下食品碳足迹的评估及案例分析

“减排降碳”“碳达峰”“碳中和”已经成为全球气候治理的焦点,作为衡量气候变暖的重要工具,碳足迹可以对食品生命周期内的温室气体排放量进行量化评估,帮助人们提出碳减排的措施。本文从国内外的研究现状出发,以生命周期评价理论为基础,系统阐述碳足迹分析模型和食品产业链排放源,对国内外研究趋势进行可视化分析,并进一步对该领域内面临的挑战、政策环境、消费者购买行为进行讨论,以期为完善我国食品碳足迹标签制度提供借鉴。     

生命周期理论视角下的食品碳足迹分析及其应用研究进展——以国外主要肉类食品为例

随着全球肉类食品需求的增加,在此类食品生产各环节涉及能源和物质投入的同时,也伴随着大量温室气体的排放,基于生命周期理论对肉类食品生产的碳足迹进行分析对于碳标签在中国的应用及食品碳排放具有重要的约束意义。发达国家在此方面已经进行了前沿的理论研究和实践探索,而我国仍处于起步阶段。本文旨在衡量三种主要肉类食品即牛肉、猪肉、鸡肉在世界主要出口大国如澳大利亚、巴西、日本等国的温室气体(GHG)排放数据(也称碳足迹),以生命周期理论为基础,利用这些国家的研究方法,计算肉类食品系统链的GHG排放数据、探索生命周期理论在计算碳排放的优点和限制,发掘此种方法应用在碳标签上的前景,使消费者增强产品生产对环境影响的意识,以期实现碳减排目标方面产生实质性的作用,同时探索碳标签在引导食品消费上的应用前景,这也成为我国探寻碳标签制度进一步发展的驱动力。      

基于产品生命周期评价方法的燃气热水器碳足迹研究

随着全球变暖问题的日益突出，碳足迹概念被引入到产品的全生命周期评价中。碳足迹是指产品在生产、使用和废弃的整个生命周期中，对环境造成影响的温室气体排放总量。以燃气热水器为例，以产品的碳足迹为研究对象，将产品分为原材料阶段、生产阶段和使用阶段3个阶段，并对其进行详细的分析。结合IPCC排放因子，通过计算，得出产品生命周期各阶段的碳足迹。通过与其他热水器的碳足迹进行比较，分析了燃气热水器生命周期各阶段的碳足迹情况。结果表明：燃气热水器在使用阶段产生的碳排放较多。     

国内外啤酒足迹研究现状及探讨研究

1前言 2011年初雪花啤酒研发团队对啤酒碳足迹计算进行了资料收集、整理,依据PAS2050：2008,商品和服务在生命周期内的温室气体排放评价规范及PCC 2006,国家温室气体清单指南等标准,采用生命周期评价（LCA）理论,完成了产品碳足迹通用方法及啤酒碳足迹计算方法的总结报告。     

100%OCC生产的箱纸板碳足迹评价

依据PAS 2050商品和服务全生命周期的温室气体(GHG)排放评价规范及欧洲造纸工业联合会(CEPI)纸和纸板碳足迹评价框架文件,以"摇篮-到-大门"的方法对100%OCC生产的箱纸板碳足迹进行了评价。结果表明,生产1000 kg箱纸板排放的温室气体为1798.2 kg CO2e,产品碳存储为-41.4 kg CO2e,其中抄纸过程是主要排放过程,占GHG排放量的61.7%,排放源主要来自电力和蒸汽的消耗。因此造纸工业提高能源利用效率、降低单位产品能耗是推行低碳造纸的必由之路。     

香云纱面料碳足迹评价

介绍了传统纺织面料香云纱全生命周期内的碳足迹评价方法,包括各生产阶段温室气体的排放计算方法和依据。结果表明,1米黑色桑蚕丝香云纱面料的碳足迹为1.88 kg CO₂e,温室气体排放主要集中在蚕茧养殖到缫丝的原材料阶段。     

我国食品行业建立食品碳标签标识探析

低碳经济号召下,发展以低能耗、低污染、低排放为基础的低碳食品已成为越来越多人的共识。食品碳足迹分析有助于了解食品生产温室气体碳排放和寻找碳减排策略。本文对食品碳足迹与碳标签相关概念进行了介绍,分析了国内外实施食品碳标签的现状,对我国建立食品碳标签体系的意义进行了阐述,为促进我国食品碳标签体系的发展提供借鉴与参考。     

英国食品标“碳足迹”标签

英国政府计划给超市食品标上“碳足迹”标签，让消费者在选购食品的同时清楚地了解它们的二氧化碳排放量，采取绿色购物行为。 产品的碳足迹是指产品从原料取得、制造、包装、运输、废弃到回收，直接或间接的温室气体排放，碳标签是将产品的碳足迹以标签标示于商品。     

服装废弃阶段的碳足迹评价

碳足迹评价包括国家、企业（组织）、产品或服务及个人等4个层面。目前产品碳足迹国际评估标准主要包括国际标准化组织管理环境生命周期评估ISO14040/14044（2006）、英国PAS2050：2008商品和服务生命周期温室气体排放评估规范、日本产品碳足迹评估与标签之一般原则TSQ0010（2009）、产品碳足迹评估的国际标准ISO14067（2012）等。本文主要以英国PAS 2050的评价方法,对一件纯棉衬衫的废弃阶段,进行过程图绘制、系统边界的确定、收集数据和计算碳足迹。文中的评价数据则主要依据英国Defra机构已发布的研究结果。     

纺织服装产品碳足迹核算中常用能源排放系数

合理的常用能源排放系数是纺织服装产品碳足迹核算中数据一致性的基础。参照PAS 2050,应用生命周期分析法(LCA)探讨了用于产品碳足迹的能源排放系数计算方法,通过实例计算、分析并评价了纺织服装产品碳足迹核算中常用能源的排放系数。结果表明,煤电排放系数适用于纺织服装产品碳足迹的核算;化石能源排放系数的间接温室气体排放均占总温室气体排放的5%以上。研究结论对完善产品碳足迹核算体系的构建具有理论和现实意义。     

Symposium review: Defining a pathway to climate neutrality for US dairy cattle production

The US dairy industry has made substantial gains in reducing the greenhouse gas emission intensity of a gallon of milk. At the same time, consumer and investor interest for improved environmental benefits or reduced environmental impact of food production continues to grow. Following a trend of increasing greenhouse gas emission commitments for businesses across sectors of the economy, the US dairy industry has committed to a goal of net zero greenhouse gas emissions by 2050. The Paris Climate Accord's goal is to reduce warming of the atmosphere to less than 1.5 to 2°C based on preindustrial levels, which is different from emission goals of historic climate agreements that focus on emission reduction targets. Most of the emissions that account for the greenhouse gas footprint of a gallon of milk are from the short-lived climate pollutant CH₄, which has a half-life of approximately 10 yr. The relatively new accounting system Global Warming Potential Star and the unit CO₂ warming equivalents gives the industry the appropriate metrics to quantify their current and projected warming impact on future emissions. Incorporating this metric into potential future emissions pathways can allow the industry to understand the magnitude of emissions reductions needed to no longer contribute additional warming. Deterministic modeling was performed across the dairy industry's emission areas of enteric fermentation, manure management, feed production, and other upstream emissions necessary for dairy production. By reducing farm-level absolute emissions by 23% based on current levels, there is the opportunity for the US dairy industry to realize climate neutrality within the next few decades.     

Characterization factors for water consumption and greenhouse gas emissions based on freshwater fish species extinction

Human-induced changes in water consumption and global warming are likely to reduce the species richness of freshwater ecosystems. So far, these impacts have not been addressed in the context of life cycle assessment (LCA). Here, we derived characterization factors for water consumption and global warming based on freshwater fish species loss. Calculation of characterization factors for potential freshwater fish losses from water consumption were estimated using a generic species-river discharge curve for 214 global river basins. We also derived characterization factors for potential freshwater fish species losses per unit of greenhouse gas emission. Based on five global climate scenarios, characterization factors for 63 greenhouse gas emissions were calculated. Depending on the river considered, characterization factors for water consumption can differ up to 3 orders of magnitude. Characterization factors for greenhouse gas emissions can vary up to 5 orders of magnitude, depending on the atmospheric residence time and radiative forcing efficiency of greenhouse gas emissions. An emission of 1 ton of CO? is expected to cause the same impact on potential fish species disappearance as the water consumption of 10-1000 m3, depending on the river basin considered. Our results make it possible to compare the impact of water consumption with greenhouse gas emissions.     

Life cycle carbon footprint of shale gas: review of evidence and implications

The recent increase in the production of natural gas from shale deposits has significantly changed energy outlooks in both the US and world. Shale gas may have important climate benefits if it displaces more carbon-intensive oil or coal, but recent attention has discussed the potential for upstream methane emissions to counteract this reduced combustion greenhouse gas emissions. We examine six recent studies to produce a Monte Carlo uncertainty analysis of the carbon footprint of both shale and conventional natural gas production. The results show that the most likely upstream carbon footprints of these types of natural gas production are largely similar, with overlapping 95% uncertainty ranges of 11.0-21.0 g CO(2)e/MJ(LHV) for shale gas and 12.4-19.5 g CO(2)e/MJ(LHV) for conventional gas. However, because this upstream footprint represents less than 25% of the total carbon footprint of gas, the efficiency of producing heat, electricity, transportation services, or other function is of equal or greater importance when identifying emission reduction opportunities. Better data are needed to reduce the uncertainty in natural gas's carbon footprint, but understanding system-level climate impacts of shale gas, through shifts in national and global energy markets, may be more important and requires more detailed energy and economic systems assessments.     

Meat Production and Consumption: Environmental Consequences

Meat production is projected to double by 2020 due to increased, per capita global consumption of meat and population growth. The livestock sector is one of the most significant contributors to urgent environmental problems. In Europe, food consumption is responsible for approximately 30% of total greenhouse gas (GHG) emissions. Meat generally has a considerably higher carbon footprint than plant-based food. This is especially true for beef, due to the emissions of methane (CH₄) from enteric fermentation in ruminants.     

食物系统的温室气体排放及其减排策略研究进展

食物系统是一个由食物生产、加工、分配、制备和消费相关的所有要素和活动组成的复杂巨系统,其贡献了全球34%的温室气体排放,成为全球气候变化最大的驱动力之一。本文采用文献分析法,从评价方法、系统评价、减排策略和不确定性分析4 个层面综述食物系统温室气体排放研究进展,提出在未来研究中亟需从准确评价各国居民膳食消费量、完善碳足迹核算系统边界、使用区域本地化碳足迹参数3 个方面提高评价结果的准确性,以期为实现食物系统低碳可持续转型提供理论依据。     

Can reducing black carbon emissions counteract global warming?

Field measurements and model results have recently shown that aerosols may have important climatic impacts. One line of inquiry has investigated whether reducing climate-warming soot or black carbon aerosol emissions can form a viable component of mitigating global warming. We review and acknowledge scientific arguments against considering aerosols and greenhouse gases in a common framework, including the differences in the physical mechanisms of climate change and relevant time scales. We argue that such a joint consideration is consistent with the language of the United Nations Framework Convention on Climate Change. We synthesize results from published climate-modeling studies to obtain a global warming potential for black carbon relative to that of CO2 (680 on a 100 year basis). This calculation enables a discussion of cost-effectiveness for mitigating the largest sources of black carbon. We find that many emission reductions are either expensive or difficult to enact when compared with greenhouse gases, particularly in Annex I countries. Finally, we propose a role for black carbon in climate mitigation strategies that is consistent with the apparently conflicting arguments raised during our discussion. Addressing these emissions is a promising way to reduce climatic interference primarily for nations that have not yet agreed to address greenhouse gas emissions and provides the potential for a parallel climate agreement.     

A consumption-based GHG inventory for the U.S. state of Oregon

Many U.S. states conduct greenhouse gas (GHG) inventories to inform their climate change planning efforts. These inventories usually follow a production-based method adapted from the Intergovernmental Panel on Climate Change. States could also take a consumption-based perspective, however, and estimate all emissions released to support consumption in their state, regardless of where the emissions occur. In what may be the first such comprehensive inventory conducted for a U.S. state, we find that consumption-based emissions for Oregon are 47% higher than those released in-state. This finding implies that Oregon's contribution to global greenhouse gas emissions (carbon footprint) is considerably higher than traditional production-based methods would suggest. Furthermore, the consumption-based inventory helps highlight the role of goods and services (and associated purchasing behaviors) more so than do production-based methods. Accordingly, a consumption-based perspective opens new opportunities for many states and their local government partners to reduce GHG emissions, such as initiatives to advance lower-carbon public sector or household consumption, that are well within their sphere of influence. State and local governments should consider conducting consumption-based GHG inventories and adopting consumption-based emission reductions targets in order to broaden the reach and effectiveness of state and local actions in reducing global GHG emissions. Consumption-based frameworks should be viewed as a complement to, but not a substitute for, production-based (in-state) GHG emissions inventories and targets.     

纺织服装行业碳足迹研究现状分析

温室气体的大量排放加剧了全球气候变暖,使之成为目前国际社会面临的严峻挑战,为此大力倡导低碳经济,"碳足迹"这一概念应运而生。整理了国际上的碳足迹概念及相关标准,介绍了国内外纺织服装行业碳足迹研究和应用现状。     

碳捕集、封存与利用技术研究进展

二氧化碳(CO2)是一种温室气体,被认为是导致全球温度升高(也称为全球变暖)的主要因素.到2040年,全球能源需求预计将比2019年增长30％,而化石燃料仍将是满足这些需求的主要能源(预计占比74％),其直接燃烧所排放的CO2量也将持续增长.目前全球CO2总利用量低于2亿吨/年,与每年320亿吨以上的CO2排放量相比,...