Carbon Dioxide Emission Reduction Scenarios in Mexico for Year 2005: Industrial Cogeneration and Efficient Lighting

An analysis of the impacts on Mexican energy demand and associated carbon dioxide (CO₂) emissions in the year 2005 due to efficient lighting in the commercial and residential sectors and cogeneration in the industrial sector is presented. Estimation of CO₂ abatement costs and an incremental cost curve for CO₂ mitigation options are considered. These technologies are cost effective opportunities, and together are projected to reduce CO₂ emissions in 2005 by nearly 13 percent. Implementation of efficient lighting is already part of the demand side management (DSM) programs of the Mexican state-owned utility. However, there are important barriers that may hinder the implementation of large scale cogeneration plants.     

Applicability of CDM to civil engineering projects case study on reduction of CO2 emission by port extension

This paper investigates the applicability of CDM to civil engineering projects through a case study on the project to extend Port Samainda in Indonesia. The goal of this project is to improve the physical distribution system of the port so that it can accommodate increasing future demand for the cargo transportation. Based on the project report by JICA (2002), we first outline the predicted demand for the cargo transportation and select possible three options in which a cargo vessel with different capabilities and respective port facilities are assigned. For each option, CO₂ emissions from both cargo and dredging vessels are predicted and compared. It is found that the total CO₂ emission may be reduced significantly by introducing a large-draft vessel and deep navigation channels. This feature becomes more prominent if a traveling distance of the cargo vessels is long enough so that CO₂ emissions from cargo vessels dominates those of dredging vessels. This observation supports the applicability of CDM to civil engineering projects because reduction of the CO₂emission is attained by improving distribution systems through civil engineering works such as extension of the port and the maintenance dredging. Finally, we discuss future problems to be investigated for the practical application of CDM to a civil engineering project. This revised version was published online in August 2006 with corrections to the Cover Date.     

考虑能源结构和气候因素的电动汽车温室气体影响

电动汽车因在使用过程中近似零排放而被认为是节约能源和减少碳排量的有力工具.但我国的电力结构是以火力发电为主,这会使电力在生产阶段排放大量的二氧化碳.为进一步研究电动汽车的环境友好性,本文构建了一种改进的电动汽车排放指数模型,使用2017年的电网统计数据及气候统计数据,就能源结构和气候这两个关键因素对我国31个省市分区域展开实证研究.结果表明,电动汽车对温室气体产生的影响存在明显的空间变化,且其与能源结构中火力发电占比密切相关.另外,对于全年温度变化范围较宽的省市,气候因素可能是使电动汽车和燃油车的碳排量达到排放平衡点的关键因素.基于此,扩大电力结构中清洁能源使用比例、改善电池性能、完善相关政策体制是促进今后我国电动汽车清洁、低碳发展的重要途径.     

中国服务业能源消费CO2排放及其因素分解

基于IPCC温室气体排放清单指南中的CO₂排放因子与核算方法,估算了1995—2010年中国服务业能源消费与CO₂排放量,并对其总体变化趋势进行时间序列分析;以LMDI(对数平均迪氏指数)法辨识与分解3个时段(1995—2000年、2000—2005年和2005—2010年)中影响中国服务业CO₂排放量变动的关键因素及其对CO₂排放量的贡献值. 结果表明:1995—2010年中国服务业能源消费CO₂排放量增长态势明显,累计排放总量为853197.55×104t;服务业能源消费主要依赖于高碳化能源燃料,各年度油品和煤品分别占能源消费总量的67%~74%和5%~27%;LMDI分析结果显示,1995—2010年产业规模和人口效应引起CO₂排放增加量分别为133357.10×104和7691.25×104t,能源效率和能源结构引起CO₂排放减少量分别为59034.50×104和23898.60×104t. 提出CO₂减排对策:①以经济、政策和监管手段促进服务业节能减排;②依托科技创新提高能源综合利用效率,降低服务业CO₂排放量.      

中国氢燃料电池车燃料生命周期的化石能源消耗和CO2排放

氢燃料电池车(FCV)具有运行阶段高能效和零排放的优点,近年来得到快速的商业化发展.氢能生产具有多种技术路径,不同路径的能源和环境效益存在显著差异.本研究采用生命周期评价方法,运用GREET模型对不同氢燃料路径下的FCV燃料周期(WTW)的化石能源消耗和CO_2排放进行了全面评价.选取了多种制氢路径作为评价对象,建立了中国本地化的FCV燃料生命周期数据库,在此基础上分析了FCV相对传统汽油车的WTW节能减排效益,并和混合动力车和纯电动车进行比较.结果表明,使用可再生电力和生物质等绿色能源制氢供应FCV能取得显著的WTW节能减排效益,可削减约90%的化石能耗和CO_2排放.在发展相对成熟的传统能源制氢路径中,以焦炉煤气制得氢气为原料的FCV,能产生显著的节能减排效益,其化石能耗低于混合动力车,CO_2排放低于混合动力车和纯电动车.结合对资源储备和技术成熟度的考虑,我国在发展氢能及FCV过程中,近期可考虑利用焦炉煤气等工业副产物制氢,并且规划中远期的绿色制氢技术发展.     

典型城市碳达峰能源政策下空气质量协同改善效益评估

碳达峰能源政策可同时实现减污降碳,带来明显的空气质量改善及人群健康效益.本研究综合利用LEAP模型、WRF-CMAQ模型和BenMAP-CE模型,量化评估了惠州市能源政策和大气污染控制措施对二氧化碳和大气污染物排放、空气质量和人群健康的影响.结果表明, 不实施碳达峰的基准情景下惠州市CO₂排放将持续增长,而能源转型能使惠州市在2030年实现碳达峰值6906万t目标,碳减排贡献最大是 电力部门;大气污染末端控制措施叠加能源政策可从源头进一步减少SO₂、VOCs、NO_x、PM_2.5的排放,较基准年2019分别减排4695、44142、38422、12493 t.能源转型情景下惠州市2035年PM_2.5年均浓度可以从基准情景的18.25 μg·m^-3下降至14.95 μg·m^-3,小于世界卫生组织过渡期 第3阶段目标（15 μg·m^-3）,O₃年均浓度也可大幅降低至133.68 μg·m^-3;进而得到归因于PM_2.5和O₃的可避免早逝人数分别为448例（95% CI：143~737）和36例（95% CI：11~61）,相对于基准情景获得的人群健康效益为37.88亿元（95% CI：12.37~61.56）.     

Uncertainty analysis of emission estimates in the RAINS integrated assessment model

Uncertainty is a critical issue for all models that attempt to quantify the necessary emission reductions that are required to meet environmental quality targets. This paper discusses a methodology specifically developed to analyse the uncertainties in the emission estimates with the regional air pollution information and simulation (RAINS) integrated assessment model, considering the uncertainties in the model parameters themselves. Overall, it was found that a typical range of uncertainties for modeled national emissions of sulfur dioxide, nitrogen oxides and ammonia in Europe lies between 10 and 30%. In general, the uncertainties are strongly dependent on the potential for error compensation. This compensation potential is larger (and uncertainties are smaller) if calculated emissions are composed of a larger number of equal-sized source categories, where the errors in input parameters are not correlated with each other. Thus, estimates of the national total emissions are generally more certain than estimates of sectoral emissions. A sensitivity analysis with respect to the uncertainty in input parameters showed that the actual uncertainties are critically influenced by the specific situation (pollutant, year, country). However, the emission factor is an important contributor to the uncertainty in estimates of historical emissions, while uncertainty in the activity data dominates the future estimates.     

Quantitative analysis of CO2 embodiment in international trade: An overview of emerging literatures

The increasing volume of CO₂ embodiment in international trade adds a layer of complexity to environmental policies and has raised arguments on the traditional production based responsibility for CO₂ emissions. In order to help understand the quantity of CO₂ embodiment in trade and its policy implications, this paper gives observations to recently emerging literatures that quantitatively discuss CO₂ embodiment in trade. The analytical approaches share the principle of using input and output modeling but vary dramatically in study boundary and estimation accuracy. The calculations can be roughly categorized into three types: direct quantification of CO₂ embodiments in multiregional trade, direct quantification of CO₂ embodiment in bilateral trade, and indirect analysis by comparing the scenarios with or without trade. The practical estimations strongly rely on trade partner selection and data availability. An obvious imbalance of net CO₂ embodiment in the commodity trade between major developed countries and developing economies as a whole was confirmed by these literatures. Carbon taxes and other possible limitations on CO₂ emissions have been addressed. The consistency across the calculations could be enhanced by systematic analyses in more detail to convince the international community to take binding commitments for the reduction of global CO₂ emissions.     

Effects of elevated CO2 concentration and nitrogen supply on biomass and active carbon of freshwater marsh after two growing seasons in Sanjiang Plain, Northeast China

An experiments were carried out with treatments differing in nitrogen supply (0, 5 and 15 g N/m²) and CO₂ levels (350 and 700 μmol/mol) using OTC (open top chamber) equipment to investigate the biomass of Calamagrostis angustifolia and soil active carbon contents after two years. The results showed that elevated CO₂ concentration increased the biomass of C. angustifolia and the magnitude of response varied with each growth period. Elevated CO₂ concentration has increased aboveground biomass by 16.7% and 17.6% during the jointing and heading periods and only 3.5% and 9.4% during dough and maturity periods. The increases in belowground biomass due to CO₂ elevation was 26.5%, 34.0% and 28.7% during the heading, dough and maturity periods, respectively. The responses of biomass to enhanced CO₂ concentrations are differed in N levels. Both the increase of aboveground biomass and belowground biomass were greater under high level of N supply (15 g N/m²). Elevated CO₂ concentration also increased the allocation of biomass and carbon in root. Under elevated CO₂ concentration, the average values of active carbon tended to increase. The increases of soil active soil contents followed the sequence of microbial biomass carbon (10.6%) > dissolved organic carbon (7.5%) > labile oxidable carbon (6.6%) > carbohydrate carbon (4.1%). Stepwise regressions indicated there were significant correlations between the soil active carbon contents and plant biomass. Particularly, microbial biomass carbon, labile oxidable carbon and carbohydrate carbon were found to be correlated with belowground biomass, while dissolved organic carbon has correlation with aboveground biomass. Therefore, increased biomass was regarded as the main driving force for the increase in soil active organic carbon under elevated CO₂ concentration.     

Impact of Climate Change on Maize Yield in Central and Northern Greece: A Simulation Study with Ceres-Maize

The potential impacts of climate change on the phenology and yield of two maize varieties in Greece were studied. Three sites representing the central and northern agricultural regions were selected: Karditsa, Naoussa and Xanthi. The CERES-Maize model, embedded in the Decision Support System for Agrotechnology Transfer (DSSAT 3.0), was used for the crop simulations, with current and possible future management practices. Equilibrium doubled CO₂ climate change scenarios were derived from the GISS, GFDL, and UKMO general circulation models (GCMs); a transient scenario was developed from the GISS GCM transient run A. These scenarios predict consistent increases in air temperature, small increases in solar radiation and precipitation changes that vary considerably over the study regions in Greece. Physiological effects of CO₂ on crop growth and yield were simulated. Under present management practices, the climate change scenarios generally resulted in decreases in maize yield due to reduced duration of the growing period at all sites. Adaptation analyses showed that mitigation of climate change effects may be achieved through earlier sowing dates and the use of new maize varieties. Varieties with higher kernel-filling rates, currently restricted to the central regions, could be extended to the northern regions of Greece. In the central regions, new maize varieties with longer grain-filling periods might be needed.     

Carbon dioxide emissions from spring ploughing of grassland in Ireland

Grassland re-seeding or land-use change requires ploughing, which may enhance carbon dioxide (CO₂) emissions from soil. This study observed the short to intermediate-term (37 days) effects of ploughing on CO₂ emissions from poorly drained grassland using automated soil respiration chambers. Immediately after ploughing, a brief peak in CO₂ emissions from soil occurred with a maximum observed flux of 6.91 g CO₂ m⁻² h⁻¹. Contradictory to other reported results, ecosystem respiration after ploughing was lower on the ploughed than on the grass site. After including estimates of photosynthesis in the analysis, ploughing led to significantly higher net CO₂ emissions than from grassland. The main mechanism of C loss during ploughing was most likely due to a reduction in gross primary production rather than enhanced soil respiration.     

Urease inhibitor reduces N losses and improves plant-bioavailability of urea applied in fine particle and granular forms under field conditions

A field lysimeter/mini plot experiment was established in a silt loam soil near Lincoln, New Zealand, to investigate the effectiveness of urea fertilizer in fine particle application (FPA), with or without the urease inhibitor N-(n-butyl) thiophosphoric triamide (NBPT - “Agrotain”), in decreasing nitrogen (N) losses and improving N uptake efficiency. The five treatments were: control (no N) and ¹⁵N-labelled urea, with or without NBPT, applied to lysimeters or mini plots (unlabelled urea), either in granular form to the soil surface or in FPA form (through a spray) at a rate equivalent to 100 kg N ha⁻¹. Gaseous emissions of ammonia (NH₃) and nitrous oxide (N₂O), nitrate (NO₃⁻) leaching, herbage dry-matter (DM) production, N-response efficiency, total N uptake and total recovery of applied ¹⁵N in the plant and soil varied with urea application method and with addition of NBPT. Urea with NBPT, applied in granular or FPA form, was more effective than in application without NBPT: N₂O emissions were reduced by 7-12%, NH₃ emissions by 65-69% and NO₃⁻ leaching losses by 36-55% compared with granular urea. Urea alone and with NBPT, applied in FPA form increased herbage DM production by 27% and 38%, respectively. The N response efficiency increased from 10 kg DM kg⁻¹ of applied N with granular urea to 19 kg DM kg⁻¹ with FPA urea and to 23 kg DM kg⁻¹ with FPA urea plus NBPT. Urea applied in FPA form resulted in significantly (P < 0.05) higher ¹⁵N recovery in the shoots compared with granular treatments and this was improved further when urea in FPA form was applied with NBPT. These results suggest that applying urea with NBPT in FPA form has potential as a management tool in mitigating N losses, improving N-response efficiency and increasing herbage DM production in intensive grassland systems.     

Low-carbon transition of iron and steel industry in China: Carbon intensity,economic growth and policy intervention

As the biggest iron and steel producer in the world and one of the highest CO₂ emission sectors, China's iron and steel industry is undergoing a low-carbon transition accompanied by remarkable technological progress and investment adjustment, in response to the macroeconomic climate and policy intervention. Many drivers of the CO₂ emissions of the iron and steel industry have been explored, but the relationships between CO₂ abatement, investment and technological expenditure, and their connections with the economic growth and governmental policies in China, have not been conjointly and empirically examined. We proposed a concise conceptual model and an econometric model to investigate this crucial question. The results of regression, Granger causality test and impulse response analysis indicated that technological expenditure can significantly reduce CO₂ emissions, and that investment expansion showed a negative impact on CO₂ emission reduction. It was also argued with empirical evidence that a good economic situation favored CO₂ abatement in China's iron and steel industry, while achieving CO₂ emission reduction in this industrial sector did not necessarily threaten economic growth. This shed light on the dispute over balancing emission cutting and economic growth. Regarding the policy aspects, the year 2000 was found to be an important turning point for policy evolution and the development of the iron and steel industry in China. The subsequent command and control policies had a significant, positive effect on CO₂ abatement.     

Effect of elevated tropospheric ozone on methane and nitrous oxide emission from rice soil in north India

Physiological changes in crop plants in response to the elevated tropospheric ozone (O₃) may alter N and C cycles in soil. This may also affect the atmosphere-biosphere exchange of radiatively important greenhouse gases (GHGs), e.g. methane (CH₄) and nitrous oxide (N₂O) from soil. A study was carried out during July to November of 2007 and 2008 in the experimental farm of Indian Agricultural Research Institute, New Delhi to assess the effects of elevated tropospheric ozone on methane and nitrous oxide emissions from rice (Oryza sativa L.) soil. Rice crop was grown in open top chambers (OTC) under elevated ozone (EO), non-filtered air (NF), charcoal filtered air (CF) and ambient air (AA). Seasonal mean concentrations of O₃ were 4.3 ± 0.9, 26.2 ± 1.9, 59.1 ± 4.2 and 27.5 ± 2.3 ppb during year 2007 and 5.9 ± 1.1, 37.2 ± 2.5, 69.7 ± 3.9 and 39.2 ± 1.8 ppb during year 2008 for treatments CF, NF, EO and AA, respectively. Cumulative seasonal CH₄ emission reduced by 29.7% and 40.4% under the elevated ozone (EO) compared to the non-filtered air (NF), whereas the emission increased by 21.5% and 16.7% in the charcoal filtered air (CF) in 2007 and 2008, respectively. Cumulative seasonal emission of N₂O ranged from 47.8 mg m⁻² in elevated ozone to 54.6 mg m⁻² in charcoal filtered air in 2007 and from 46.4 to 62.1 mg m⁻² in 2008. Elevated ozone reduced grain yield by 11.3% and 12.4% in 2007 and 2008, respectively. Global warming potential (GWP) per unit of rice yield was the least under elevated ozone levels. Dissolved organic C content of soil was lowest under the elevated ozone treatment. Decrease in availability of substrate i.e., dissolved organic C under elevated ozone resulted in a decline in GHG emissions. Filtration of ozone from ambient air increased grain yield and growth parameters of rice and emission of GHGs.