基于投入产出方法的中国能源消费碳排放情景分析

中国目前是世界上最大的发展中国家,同时也是世界上最大的二氧化碳排放国家之一,因此节能减排不仅有利于中国的可持续发展,而且对缓和全球气候变暖具有突出贡献。本文将情景分析法与投入产出法相结合,建立了基于投入产出的能源消耗和CO2排放情景分析模型,模拟在不同的经济增长方式情景下中国2020年能源消耗及其CO2排放情况。然后,对中国节能减排影响因素进行分析。最后得到了有关结论,并提出了相应政策建议。     

2020年中国发电行业碳减排目标规划相符性分析

基于发电行业节能减排技术的现有应用规划,预测3种不同的GDP增长情景,即减速发展,基准情景和高速发展情景下,若能实现我国现有关于发电行业节能减排技术的规划目标,2020年发电行业的CO2排放量将达到35.32,39.15,43.20亿t.同时基于中国2020年碳强度减排承诺,计算得国家2020年CO2排放目标在不同发展情景下将达到97.30~127.96亿t不等.结合上述结果讨论,发电行业规划目标相符要求2020年的CO2排放比例为33.27%~36.82%.结果表明,若能实现我国现有关于发电行业节能减排技术的规划目标,则对应于不同的GDP增长速度,发电行业总碳排放量能够完成国家承诺碳强度减排的分解目标.     

基于降低温室效应的航空器运行策略

以航空器运行对环境造成温室效应的两个主要因素—CO_2和凝结尾为研究对象,通过绝对全球温变潜势(AGTP)建立科学统一的衡量标准,将CO_2和凝结尾对环境的影响转换为全球地表温度的改变,为降低温室效应提供依据。最后结合典型高空的探空资料对实际增温进行计算,对比分析25、50、100年时间水平下CO_2和凝结尾对全球地表温度造成的影响,为航空器降低温室效应提供飞行高度指导。     

基于LEAP模型的厦门交通能耗及大气污染物排放分析

交通部门能源消耗和污染物排放的比例较大,增长迅速,因此研究交通部门的节能减排措施显得尤为迫切。文章以厦门市城市交通部门为例,基于LEAP模型构建Xiamen-2008Tra交通模型,研究从基准年2008年到2030年的能源消费量以及CO2、SO2、NOx和PM10的排放量,评估各种节能减排措施的效果。模型设定了基准情景和最佳情景,前者作为参考情景假设政府没有采取任何措施来抑制交通部门能源增长,后者作为最乐观情景包括私家车控制、燃料经济性调整、新能源车推广、燃料税和生物燃料推广五个节能减排子情景。研究结果表明:2030年最佳情景要比基准情景节能36.08%,CO2、SO2、NOx和PM10的排放量分别减少40.46%、47.06%、32.07%和44.91%;在各种节能减排措施中,私家车控制措施节能减排效果最好。     

深部煤层对CO_2地质处置机制及应用前景

CO2是重要的温室气体之一,CO2的有效处置对减缓全球变暖具有重大意义。由于煤介质具有特殊的双重孔隙结构、吸附性强等物性特征,对CO2具有很强的吸附能力,且大于煤介质吸附CH4的能力,因此,可将CO2注入深部不可开采煤层储存,在长久处置CO2的同时亦可促进深部煤层气的开采。在我国,深部不可开采煤层处置CO2显示了巨大的潜力,可以处置26-46年的CO2排放量,尤其在华北煤炭能源基地具有良好的应用前景。     

Screening life cycle assessment of an office used for academic purposes

The aim of this study is to contribute to the analysis of the environmental impacts deriving from common aspects of the service sector activity and to identify auxiliary actions and hot spots in order to improve the environmental performance of offices used for educational purposes. In that aspect, a screening life cycle assessment (LCA) for a university office-workstation of Democritus University of Thrace, Greece, was performed with the application of the SimaPro LCA software, and the Impact 2002+ method with fifteen impact categories for the interpretation of results. Findings from this research indicated that energy consumption for the powering electronic appliances was the key factor affecting most of the environmental impact categories examined. The impact categories most seriously affected by the office life cycle were the emissions of respiratory inorganics (39%), global warming (31%) and non-renewable energy use (27%). The saving of the energy consumed due to standby mode could lead to a reduction of 2.4% of the total energy consumption in the office in a yearly basis with proportional positive influence in all the respective impact categories. Additionally, utilization of solar energy through photovoltaic panels could lead to a reduction close to 90% for a number of impact categories. Therefore, actions and strategies for improving the environmental performance of academic offices should focus on the reduction of energy consumption.     

现行脱硫技术存在排放温室气体的隐患

工业革命以来,由于人类活动持续大量排放温室气体,使得全球出现了持续性的气候变暖趋势,而为了治理局部的和区域的SO2污染问题,大规模的脱硫活动在我国急速增加,这势必大幅增加CO2的排放,加剧气候变暖的进程,如果我国大型火电厂的脱硫率达到80%,按照2005年全国SO2排放量已经达到0.2549Gt计算,采用现行脱硫方法将每年向大气中排放0.088Gt的CO2。将占我国CO2年排放量的10%,对人类赖以生存的地球形成严重威胁。因而,需要研究脱硫的无碳工艺,以及碳捕集、碳储存、碳利用技术,树立综合的环境意识,在控制大气污染、减排温室气体与保护臭氧层方面寻找结合点。     

全球能源消费与CO2排放量

在收集全球能源储量和流通状况的基础上，综述了世界各地区能源消费量和各国人均能源水平，汇总了全球ＣＯ２排放总量及各大洲对全球ＣＯ２排放量的贡献率，到２１００年，全球Ｃ矿量预计将从目前６０亿ｔ／ａ增加到３６０亿ｔ／ａ，同时，旨出１９９６年中世界人口１８．８％的北美、欧洲、日本、ＣＯ２排放３１．６亿ｔ（碳），占全球当年ＣＯ２排放总量的５２．４％。     

The analysis of greenhouse gas emissions/reductions in waste sector in Vietnam

The global waste sector produces, on average, 2–5 % of global anthropogenic greenhouse gas (GHG) emissions. The amount of GHG emissions has grown steadily and is predicted to increase considerable in the forthcoming decades because of the increases in population and gross domestic product (GDP). However, the GHG mitigation opportunities for the sector are still fully not exploited, in particularly in developing countries. A series of initiatives were highly successful and showed that large reductions in emissions are possible. This study aims to propose a holistic quantification model, which can be used for estimation of waste generation and evaluation of the potential reduction of GHG emissions in waste sector for developing countries with a particular application to Vietnam. The two scenarios set for the study were business as usual (BaU) which waste management is assumed to follow past and current trends and CounterMeasure (CM) which alternative waste treatment and management are assessed. Total emissions in the BaU scenario are projected to increase from 29.47 MtCO₂eq in 2010 to 85.60 MtCO₂eq by 2030 and 176.32 MtCO₂eq by 2050. The highest emissions are due to methane (CH₄) released by disposal sites, accounting for about 60 % of the GHG emissions from waste in Vietnam in 2030. This emission is projected to increase significantly (67 % in 2050), unless more of the methane is captured and used for energy generation. The CM scenario gives emission reductions from 25.7 % (2020), 40.5 % (2030) to 56.6 % (2050) compared to the BaU scenario. The highest GHG reduction is achieved through recycling, followed by methane recovery to optimize the co-benefit for climate change mitigation.     

地铁建设环境影响评估及减排效益研究:以深圳市为例

地铁大规模建设和运营消耗了大量资源能源,已逐渐成为城市交通环境影响的主要贡献源。基于生命周期评价(life cycle assessment,LCA)方法,以深圳市为研究区域,定量分析了地铁建设过程的资源与能源消耗强度,选取全球变暖潜能值(global warming potential,GWP)为度量指标,构建了地铁建设碳排放分析框架及测算方法,并基于情景分析法预估了减排潜力。结果表明:截至2020年底,深圳已开通运营的地铁线站建设造成的碳排放量约累积达到2730万t CO₂e,其中地铁车站建设碳排放量占比约为72%,地铁隧道建设碳排放量占比约为28%。建设阶段单位里程盾构隧道碳排放强度约为1.3万t CO₂e/km,单位面积车站碳排放强度约为371 t CO₂e/100 m2。通过推广绿色建造技术,如采用再生混凝土和再生钢材,地铁建设阶段最高碳减排率可达到8.5%/a,2021—2035年累积节碳可达到508万tCO₂e,可一定程度上能缓解地铁建设的碳排放压力。     

Economic structural change,renewable energy development,and carbon dioxide emissions in China

As the world’s largest emitter, China’s reduction of carbon dioxide (CO2) emissions is crucial for the achievement of global temperature rise goals. In this paper, we employed input-output structural decomposition analysis and index decomposition analysis to assess the factors driving changes in China’s CO2 emissions from 2000 to 2018, with particular attention to the role of renewable energy development. Our results indicate that the slowdown of economic growth and rapid structural change, rather than the shifting fuel mix, were the major forces driving China’s recent slowdown of CO2 emissions ever since 2011. Despite the great importance attached to renewable energy development, non-hydro renewable has played negligible role in reducing China’s CO2 emissions. This suggests that China cannot simply rely on the large-scale development of renewable energies to achieve its Paris 2015 target and must make further drastic cuts that will help keep global temperature rise well below 2 °C above pre-industrial level. Major breakthroughs in scalable low carbon energy sources and technologies will be required, especially in the developing world.

     

Simulating global soil-CO2 flux and its response to climate change

It has been argued that increased soil respiration would become a major atmospheric source of CO2 in the event of global warming. The simple statistical models were developed based on a georeferenced database with 0.5° × 0.5° longitude/latitude resolution to simulate global soil-CO2 fluxes, to investigate climatic effects on these fluxes using sensitivity experiments, and to assess possible responses of soil-CO2 fluxes to various climate change scenarios. The statistical models yield a value of 69 PgC/a of global soil CO2 fluxes for current condition. Sensitivity experiments confirm that the fluxes are responsive to changes in temperature,precipitation and actual evapotranspiration, but increases in temperature and actual evapotranspiration affect soil-CO2 fluxes more than increases in precipitation. Using climatic change projections from four global circulation models, each corresponding to an equilibrium doubling of CO2, it can be found that the largest increases in soil-CO2 fluxes were associated with the boreal and tundra regions. The globally averaged soil-CO2 fluxes were estimated to increase by about 35 ％ above current values, providing a positive feedback to the greenhouse effect.     

Optimize emission reduction commitments for international environmental agreements

In order to restrict global warming to no more than 2 ^°C, more efforts are needed. Thus, how to attract as more as possible countries to international environment agreements (IEAs) and realize the maximum reduction targets are meaningful. The motivation of this paper is exploring a set of method of designing IEA proposals. The paper built a chance-constrained two-stage cartel formation game model, which can explore whether a country signs an agreement in the first stage and discusses how the countries joining the coalition can make the best emission commitments in the second stage. Based on the model, the real emission data of 45 countries was collected for numerical experiments, which almost completely depict the current global emissions of different countries. A numerical experiment has also been carried out in the paper. Then some interesting results emerge as follows: risk averse, high cost, high emission reduction duty, and external stability impede large coalition formation; transfer scheme and high perceived benefits stimulate countries to join IEAs and make a good commitment; the most influential countries for coalition structure and commitment are those low-cost and low-emission entities. The results also demonstrate that the design of IEA proposals should not only pay attention to those economically developed and high-emission “big” countries, but also attach importance to those low-emission “small” countries.     

Structural Change of the Manufacturing Sector in Korea: Measurement of Real Energy Intensity and CO2 Emissions

In terms of energy use, it is wellknown that energy intensity in the manufacturingsector is higher than any other sector. In Korea, theenergy intensity of the manufacturing sector hasdeteriorated since the late 1980s. This phenomenonis quite unique compared with the trend of energyintensity in other countries. In this study, weclosely examine the structural composition of Korea'smanufacturing sector from 1981 to 1996, its energyintensity, and its implications for carbon dioxide(CO₂) emissions by introducing the measurement ofreal energy intensity.The conventional index of energy intensity is notappropriate for aggregate industries. Since theaggregation of industries in the manufacturing sectorincludes structural change, it would be better toseparate the effect of structural change. Hence, inthis study, we apply a decomposition methodology forenergy intensity based on the `Divisia Index'. Ateach industry level, energy intensity is a mixedmeasurement of pure energy efficiency improvement andfuel substitution. We also calculate real energyintensity at each industry level. Based on ouranalysis, we derive carbon dioxide (CO₂) intensity and analyze the factors that affect CO₂ emission in this sector.During 1988–1993, the energy intensity of themanufacturing sector in Korea deteriorated. Industrial structural change,the real energy intensity in this sector became evenworse during this period. The primary reason for thisphenomenon was that the share of energy intensiveindustries, such as steel, cement, and petro-chemicalindustries increased. Second, during the sameperiod, liquefied natural gas (LNG) rapidlypenetrated this sector, so that theCO₂ intensity improved. We find thatharmonization of economic development strategies andenvironmental consideration is crucial for sustainabledevelopment. Based on our study, we derived somepolicy implications. Integration of industrialpolicies and energy efficiency improving programs isquite important, as well as the acceleration of fuelsubstitution to less carbon (C) intensive ones. Integration of local and global environmental policiesplays an important role for mitigatingCO₂ emissions.     

植树造林缓解温室效应的再认识

植树造林已普遍作为减缓全球变暖的主要对策之一,其主导思想是利用森林的光合作用吸收大气中的CO_2。目前很少人注意到缓解全球变暖的另一种途径,即从森林生物量中获取替代矿物燃料的生物能源。     

Carbon dioxide direct air capture for effective climate change mitigation based on renewable electricity: a new type of energy system sector coupling

Pathways for achieving the 1.5–2 °C global temperature moderation target imply a massive scaling of carbon dioxide (CO₂) removal technologies, in particular in the 2040s and onwards. CO₂ direct air capture (DAC) is among the most promising negative emission technologies (NETs). The energy demands for low-temperature solid-sorbent DAC are mainly heat at around 100 °C and electricity, which lead to sustainably operated DAC systems based on low-cost renewable electricity and heat pumps for the heat supply. This analysis is carried out for the case of the Maghreb region, which enjoys abundantly available low-cost renewable energy resources. The energy transition results for the Maghreb region lead to a solar photovoltaic (PV)-dominated energy supply with some wind energy contribution. DAC systems will need the same energy supply structure. The research investigates the levelised cost of CO₂ DAC (LCOD) in high spatial resolution and is based on full hourly modelling for the Maghreb region. The key results are LCOD of about 55 €/t_CO2 in 2050 with a further cost reduction potential of up to 50%. The area demand is considered and concluded to be negligible. Major conclusions for CO₂ removal as a new energy sector are drawn. Key options for a global climate change mitigation strategy are first an energy transition towards renewable energy and second NETs for achieving the targets of the Paris Agreement.

     

转型期中国物质生产能源消费与CO2排放关联特征

论文利用计量经济模型,就近30 a来我国物质生产过程中能源消费与CO₂排放变动关联特征进行研究,结果表明:①物质生产部门能源消费的持续增长是我国能源消费总量增长与CO₂排放量增长的主要驱动因子;②物质生产部门的产业能源消费结构均衡度长期以来处于较低水平,呈现"低水平不平衡-平衡-较高水平不平衡"的变化规律;③物质生产部门能源消费-GDP脱钩弹性系数分布情况与物质生产部门CO₂排放-GDP脱钩弹性系数分布情况相似,均表明目前我国物质生产对能源消费的依赖度趋低,单位能源消费的经济产出量逐渐提高,但我国物质生产部门的经济产出与能源消费的弱脱钩关系相较于发达国家的强脱钩关系之间仍存在较大差距。最后,论文针对研究结论,从物质生产部门行业结构、能源消费结构、经济增长与能源消费间脱钩关系三个角度,提出调控未来物质生产部门能源消费的建议要点。     

国际贸易“碳中和”研究热点领域及其动向

碳中和是世界各国面临的共同问题。经济全球化与贸易自由化背景下国际贸易总量快速增长,伴随着深度国际分工与产业转移,贸易产品的生产者与消费者在陆表形成严重的空间位移。利用文献计量软件CiteSpace分析国际贸易主题下碳中和相关文献,揭示国际贸易“碳中和”研究动向。研究发现：（1）温室气体在全球范围时空演变,使跨区域、多尺度的全球碳治理变得更加复杂,发达国家将高污染与低价值链产业转移至各发展中国家,以生产者责任划分的碳核算原则不再适用于国际贸易合作。（2）进出口贸易逐渐成为新兴经济体经济发展动力,全球碳治理应转向新兴经济体与区域一体化,全球气候政策设计应遵守国际碳市场公平性底线,不断优化碳排放量核算体系,完善碳会计方法,模拟全球碳减排预期效果。重点提高产业部门碳减排意识和产业清洁技术及能源利用效率,利用多种手段改变生态系统的增汇减碳能力。新兴经济体在承接发达国家技术援助同时,应重点关注本国能源产业,发展可再生能源产业,提高能源的利用效率,并运用经济政策与金融工具促进本国的气候变化投融资产业发展。全球碳治理应更加注重公平性与国家间的经济发展、环境资源差异,利用多样的碳治理工具与协商合作方式,促使更多国家参与全球化或区域一体化的碳治理模式。（3）中国亟待通过国内多产业、多部门的增汇减排与国际碳减排、碳中和实践,健全碳市场机制,提高碳治理水平,为国际碳治理合作提供“最大公约数”。     

Simulating global soil-CO2 flux and its response to climate change

ＩｎｔｒｏｄｕｃｔｉｏｎＧｌｏｂａｌｃｌｉｍａｔｅｍｏｄｅｌｓｐｒｅｄｉｃｔｔｅｍｐｅｒａｔｕｒｅｉｎｃｒｅａｓｅｓｄｕｅｔｏｅｎｈａｎｃｅｄｇｒｅｅｎｈｏｕｓｅｗａｒｍｉｎｇｉｎｔｈｅｎｏｔ ｔｏｏ ｄｉｓｔａｎｔｆｕｔｕｒｅ (Ｈｏｕｇｈｔｏｎ ,1990 ) .Ｉｔｈａｓｂｅｅｎａｒｇｕｅｄｔｈａｔｏｎｅｏｆｔｈｅｉｍｐｏｒｔａｎｔｅｆｆｅｃｔｓｏｆｇｌｏｂａｌｗａｒｍｉｎｇｗｉｌｌｂｅｔｏａｃｃｅｌｅｒａｔｅｔｈｅｄｅｃｏｍｐｏｓｉｔｉｏｎｏｆｓｏｉｌｏｒｇａｎｉｃｍａｔｔｅｒ,ｔｈｅｒｅｂｙｒｅｌｅ…     

Accounting for time in Mitigating Global Warming through land-use change and forestry

Many proposed activities formitigating global warming in the land-use change and forestry(LUCF) sector differ from measures to avoid fossilfuel emissions because carbon (C) may be held out ofthe atmosphere only temporarily. In addition, thetiming of the effects is usually different. Many LUCFactivities alter C fluxes to and from the atmosphereseveral decades into the future, whereas fossil fuelemissions avoidance has immediate effects. Non-CO₂ greenhouse gases (GHGs), which are animportant part of emissions from deforestation inlow-latitude regions, also pose complications forcomparisons between fossil fuel and LUCF, since themechanism generally used to compare these gases(global warming potentials) assumes simultaneousemissions. A common numeraire is needed to expressglobal warming mitigation benefits of different kindsof projects, such as fossil fuel emissions reduction,C sequestration in forest plantations, avoideddeforestation by creating protected areas and throughpolicy changes to slow rates of land-use changes suchas clearing. Megagram (Mg)-year (also known as`ton-year') accounting provides a mechanism forexpressing the benefits of activities such as these ona consistent basis. One can calculate the atmosphericload of each GHG that will be present in each year,expressed as C in the form of CO₂ and itsinstantaneous impact equivalent contributed by othergases. The atmospheric load of CO₂-equivalent Cpresent over a time horizon is a possible indicator ofthe climatic impact of the emission that placed thisload in the atmosphere. Conversely, this index alsoprovides a measure of the benefit of notproducing the emission. One accounting methodcompares sequestered CO₂ in trees with theCO₂ that would be in the atmosphere had thesequestration project not been undertaken, whileanother method (used in this paper) compares theatmospheric load of C (or equivalent in non-CO₂GHGs) in both project and no-project scenarios.Time preference, expressed by means of a discount rateon C, can be applied to Mg-year equivalencecalculations to allow societal decisions regarding thevalue of time to be integrated into the system forcalculating global warming impacts and benefits. Giving a high value to time, either by raising thediscount rate or by shortening the time horizon,increases the value attributed to temporarysequestration (such as many forest plantationprojects). A high value for time also favorsmitigation measures that have rapid effects (such asslowing deforestation rates) as compared to measuresthat only affect emissions years in the future (suchas creating protected areas in countries with largeareas of remaining forest). Decisions on temporalissues will guide mitigation efforts towards optionsthat may or may not be desirable on the basis ofsocial and environmental effects in spheres other thanglobal warming. How sustainable development criteriaare incorporated into the approval and creditingsystems for activities under the Kyoto Protocol willdetermine the overall environmental and social impactsof pending decisions on temporal issues.