适用于城市碳排放反演的CO2格点化排放清单编制——以杭州市为例

基于碳监测网络测算城市人为碳排放通量，需要二氧化碳（CO₂）格点化排放清单作为反演计算的先验信息。现有格点化清单大多针对全球或全国尺度编制，排放源的空间位置不确定性高，不足以支撑城市碳监测工作。以杭州市为例，构建了高空间分辨率（1 km）、分部门（工业能源、工业过程、交通等6类排放部门）的城市CO₂格点化排放清单，并对其不确定性进行了表征。该格点化清单基于中国城市温室气体工作组编制的《中国城市二氧化碳排放数据集（2020）》，依据848个点源的精确位置信息和一系列空间代理数据，对各部门的城市CO₂排放量进行格点化分配，得到杭州市高分辨率排放清单模型。与现有清单，如欧洲开发的全球大气研究排放数据库（EDGAR）、清华大学开发的中国多尺度排放清单模型（MEIC）等相比，本研究编制的格点化清单能合理地反映杭州市CO₂排放的空间格局，包括人口、路网密集的市中心，萧山区和钱塘区的工业园区，钱塘江中上游沿岸的水泥企业等高排放热点，可以作为杭州市CO₂反演的人为源先验清单。     

南京温室气体监测点位规划方法研究

以南京市为温室气体监测区域，以2021年1月和7月作为冬、夏季的代表，利用拉格朗日粒子扩散模型（LPDM）和K均值（K-Means）聚类算法对南京市已有的高塔点位进行筛选，研究温室气体监测点位布设最优位置。通过计算不同点位的城市CO₂贡献度，最终确定了冬季和夏季各8个温室气体监测建议点位。结果表明，通过聚类算法筛选出的监测站点选址能对南京市大部分城区的温室气体排放具有相对最大的覆盖范围和较高的敏感性，能够有效反映出南京市CO₂排放量的梯度变化，对南京市不同时空尺度上的温室气体排放达到相对最好的监测效果。     

南通市温室气体排放估算

以2009年南通市主要领域碳排放情况为基数,采用IPCC指南中的计算方法,选取IPCC 指南明确的领域中对南通市而言具有代表性的部分内容,对2009年南通市全市碳排放量进行估算。估算结果表明,能源活动(化石燃料燃烧)为南通市主要温室气体排放源,其比例占据了主导地位。在能源活动中,原煤燃烧排放的CO₂远高于其他化石燃料燃烧的排放量。因此,南通市可在产业结构和能源结构调整、提高能源利用效率及加强能源管理等方面进行努力,以减少南通市温室气体排放量。     

城市绿地温室气体通量监测与减排研究

采用LGR-密闭式动态通量箱法对城市绿地生态系统温室气体(CO₂、CH₄)通量的日变化、季节变化特征及其影响因子等进行了较为系统的研究。城市绿地花草CO₂通量有明显的日变化和季节变化特征,白天通量值为负,是CO₂的净吸收汇;夜晚为正值,是CO₂的净释放源;7:00左右由源转为汇,17:00左右由汇转为源,不同花卉24 h总通量有正负2种结果。冬季草坪作为源的时间延长,而作为汇的时间缩短。光强和温度是影响CO₂通量日变化和季节变化的主要因素。城市绿地CH₄通量较小,不足以对温室气体总量产生显著影响。从减少温室气体排放的角度对城市绿地花草的选择提出了建议。     

西宁市金属冶炼和压延加工业大气颗粒物排放清单

大气污染物排放清单是了解大气污染特征和控制对策的前提。根据排放因子方法,建立了2018年西宁市金属（包括黑色和有色金属）冶炼和压延加工业PM_2.5、PM₁₀大气污染物的排放清单,并对其时空分布特征和清单不确定性进行了分析。结果表明：西宁市黑色金属冶炼和压延加工业PM_2.5、PM₁₀的总排放量分别是4.88×10³、8.37×10³ t;该行业对PM_2.5、PM₁₀排放量贡献率最大的是城北区,分别为58.36%、49.61%。有色金属冶炼和压延加工业PM_2.5、PM₁₀的总排放量分别是1.85×10³、2.78×10³ t,该行业对PM_2.5、PM₁₀贡献率最大的是大通县,分别为53.51%、56.99%。黑色金属冶炼和压延加工业对PM_2.5、PM₁₀贡献率最大的产业是粗钢产业,贡献率分别是38.41%、30.28%。有色金属冶炼和压延加工业对PM_2.5、PM₁₀贡献率最大的是铝行业,贡献率分别是97.33%和98.01%。2个行业PM_2.5和PM₁₀的排放受月份影响较小,一天中09：00—18：00是排放高峰期。蒙特卡罗法模拟结果表明：黑色金属冶炼和压延加工业95%置信区间的不确定性较高,PM_2.5和PM₁₀的不确定性分别为-59.33%~58.55%和-47.51%~47.28%。     

省级高空间分辨率扬尘源排放清单研究

通过对浙江省统一开展部署和行动，现场调查收集全省7 507个施工工地、3 923个堆场以及不同等级公路和城市道路的真实活动水平数据，并基于点源地理信息和路网信息图层，采用排放系数法和ArcGIS工具构建了浙江省2015年3 km×3 km高空间分辨率扬尘源排放清单。结果表明，2015年浙江省扬尘源PM₁₀和PM_2.5的排放量分别为24.26×10⁴ t和6.00×10⁴ t，其中PM₁₀和PM_2.5排放贡献均主要为施工扬尘和道路扬尘，施工扬尘分别贡献37.7%和39.3%，道路扬尘分别贡献36.5%和39.1%。从城市空间分布来看，杭州市、宁波市、温州市、绍兴市扬尘排放总量居于全省前四，舟山市最低，而城市主城区排放量显著高于郊区。     

基于OCO-2卫星重构的中国地区高覆盖XCO2时空分布特征

卫星遥感技术是深入了解大气二氧化碳（CO₂）时空分布特征的重要手段之一，由于探测技术的限制，目前基于卫星遥感观测数据反演的CO₂产品的空间覆盖度较低，数据缺失严重，不足以反映CO₂浓度的空间分布情况。现基于轨道碳观测卫星-2 （OCO-2）、哨兵5P （Sentinel-5P）、美国CO₂同化模拟系统（Carbon Tracker）和欧洲中期天气预报中心第5代（ERA-5）气象再分析数据，结合时间序列拟合估算模型和随机森林算法，重构了2019—2022年中国地区高精度（0.05°×0.05°）大气CO₂平均干空气混合比（XCO₂），分析了中国地区CO₂时空变化特征。与OCO-2和Carbon Tracker对比结果显示，重构得到的XCO₂与OCO-2的观测结果一致性更高，均方根误差为1.05 ×10^-6，决定系数高达0.96，可以在较高空间分辨率上体现中国地区XCO₂的时空分布情况。基于重构的XCO₂数据得知，中国地区XCO₂呈现明显的季节性波动，XCO₂呈冬春高、夏秋低的特征；2019—2022年，中国地区XCO₂呈现逐年上升的趋势，增长率达到（2.41±0.01）×10^-6/a，但近年来增长速率有所降低；从空间分布来看，中国东部、北部、中部地区的XCO₂显著高于其他地区，且增长率也较高；进一步分析中国典型经济区的XCO₂发现，杭州、天津、成都的XCO₂在各经济区内的增长最为迅速。研究成果可为碳监测研究、碳排放清单验证、碳排放管理、温室气体减排等研究提供重要的数据支撑。     

基于GOSAT卫星的中国CO2浓度时空特征分析

采用温室气体观测卫星(GOSAT) 傅里叶变换光谱仪(FTS)发布的CO₂柱浓度L₃级别数据集产品,利用TCCON地基站点的CO₂柱浓度数据对卫星遥感数据进行验证,分析中国CO₂柱浓度时空变化特征及其影响因素。研究结果表明,GOSAT卫星的CO₂柱浓度产品精度较高,线性回归的r²为0.99,线性方程斜率为0.98,平均偏差为0.11 mg/L。中国CO₂柱浓度呈现逐年增长的趋势,存在12个月的周期性季节性变化。2010、2020年区域年平均CO₂柱浓度分别约为389.30、412.62 mg/L,增长了23.32 mg/L,年平均增长率大约为0.58%。中国区域大气CO₂柱浓度的月变化存在明显的时空差异,最大值和最小值分别出现在4月和8月,2020年4月和8月的区域平均值分别为415.09、409.13 mg/L。中国区域CO₂柱浓度从东部沿海向西部逐级递减,且呈现明显的季节性变化,夏季高值主要集中在东南部沿海地区,冬季高值主要集中在华北地区。     

基于OCO-3卫星观测的上海CO2柱浓度特征分析

随着卫星遥感技术的发展，城市内部的二氧化碳柱浓度（XCO₂）时空特征逐渐能够被识别。本研究基于轨道碳观测卫星（OCO-3）快拍（SAM）模式XCO₂观测数据，探讨了上海市2020—2022年XCO₂的时空分布特征以及该数据对于火电厂CO₂烟羽信号来源识别的能力。结果表明，上海市XCO₂呈现春季＞冬季＞夏季的特征，上海市XCO₂年均值为418.3×10^-6，高于华东地区的年平均值。从XCO₂空间分布差异来看，中部和东北部是上海冬季XCO₂的高值区域，这主要是由于城市中部人口密集，北部沿江区域大型电厂较为集中，在冬季盛行风西北风的作用下，CO₂被传输至东部沿江多个行政区域。此外，结合近地面风场、CO₂人为排放清单、电厂点源信息、对流层监测仪器（TROPOMI）卫星观测数据等，证实了OCO-3快拍模式具有探测到重点点源信号的能力。     

基于OCO-2卫星观测的浙江省典型城市CO2柱浓度变化特征及碳排放重点源识别应用

为有效制定城市层面的低碳发展政策，实现碳达峰的发展目标，利用碳卫星2号（OCO-2）监测的高分辨率大气CO₂柱浓度数据（XCO₂），分析浙江省杭州、宁波和嘉兴3个典型城市的XCO₂变化特征，以及人类活动和XCO₂变化的关系；识别城市碳排放热点区域，评估碳排放热点源对XCO₂的影响，并利用拉格朗日粒子扩散模型（LPDM）进行验证。结果表明：（1）2016—2021年3个城市的XCO₂年增长量分别为3.1×10^-6，2.3×10^-6和2.2×10^-6，杭州的增长量最为明显；杭州和宁波在2019—2021年XCO₂增量明显，分别为8.0×10^-6和5.7×10^-6。杭州XCO₂的变化趋势与临安大气本底站CO₂观测数据的变化趋势一致。（2）与2017年相比，3个城市的建筑用地面积都略有增加，分别增加了0.9%，2.2%和4.8%；从人口和GDP数据来看，2016—2021年3个城市也均呈持续增加的变化趋势。表明CO₂浓度升高与人类活动密切相关。（3）XCO₂正距平高值区域基本都对应了碳排放热点源（电力企业）的下风向地区，电力企业CO₂的排放会导致下风向地区的XCO₂出现局地性增长，增量为7×10^-6～9×10^-6。     

Scientific aspects of the framework convention on climate change and national greenhouse gas inventories

Though the principles of the Earth's greenhouse effect have been known for well over a century, it is only recently that advances in climate research have indicated that significant and possibly costly climate change, due to growing emissions of greenhouse gases and their precursors by human activity, is a real possibility. Current estimates of the global human-related emissions of carbon dioxide, methane and nitrous oxide are presented, though many sources remain poorly known or understood. The compilation of national greenhouse inventories as required by the United Nations Framework Convention on Climate Change is likely in the longer term to help improve such global estimates, as long as comparable methodologies are used. The development of the IPCC Guidelines for National Greenhouse Gas Inventories is described, emphasizing the strategies employed to gain wide international participation.     

The composition, trend and impact of urban solid waste in Beijing

This paper provides an overview of the trend of generation, composition, and management of municipal solid waste, and estimates the carbon emissions arising from municipal solid waste management in Beijing. The correlation analysis conducted shows that the generation of municipal solid waste in Beijing has been growing steadily, showing high correlations (r > 0.9) to the total GDP, per capita income, and the population. Food waste showed an increasing trend since 1990. Compared with the results of an investigation in 1990, ash and woodchips content in 2003 declined from 56% to 17%, while the percentage of paper and plastic increased from 10% to 29% over the same period. The calorific value of the municipal waste also increased, from 2,686 kJ/kg in 1990 to 4,667 kJ/kg in 2003, indicating that the waste is suitable for incineration. Currently, the source separation ratio of municipal waste is approximately 15%. About 94% of all the collected solid waste goes to the landfill while 4% is composted and 2% is incinerated. A moderate garbage collection fee is applied to both permanent and temporary residents in Beijing, but the willingness to pay for solid waste collection and treatment is still low. Under current treatment mode, the total amounts of carbon emission from waste disposal sites and incineration increased with the increase of municipal solid waste, from 29.8 Gg in 1990 to 84.5 Gg in 2003, including 83.3 Gg of CH₄ and 22.0 Gg of CO₂. The data availability and methodological challenges in monitoring the quantity and characteristics of municipal solid waste are discussed.     

National GHG inventories: Recent developments under the IPCC/OECD Joint Programme

This paper summarises key results of the Joint IPCC/OECD Programme, in particular the draft IPCC Guidelines for National GHG Inventories to be released in January 1994. The focus is on how these results are likely to improve the availability and the quality of national inventories of anthropogenic GHG emission sources and removals by sinks. The IPCC/OECD has already received nearly 50 inventories from 35 countries. Most of the data are for 1988, but some reports cover 1989 and 1990. In addition to CO₂, many of these inventories include CH₄, N₂O, NOx, CO, and NMVOC. Detailed analyses of these inventories have provided valuable insights about the strengths and weaknesses of the national inventories, differences in approach to estimation, reporting, available methods and data. These results in turn, have facilitated the development of the draft Guidelines, most notably the proposed reporting system, and also on estimation methods for the different anthropogenic sources and sinks of GHG. The paper previews key aspects of the draft Guidelines for non-CO₂ GHG. Experts are urged to actively participate in the IPCC/OECD Programme to continue to improve inventory methods and overall the Guidelines.The views presented in this paper are those of the authors and do not necessarily represent the views of the OECD or their Member countries.     

Modeling lifetime greenhouse gas emissions associated with materials for various end-of-life treatments

This research has developed mathematical models for computing lifetime greenhouse gas (GHG) emissions associated with materials. The models include embodied carbon (EC) emissions from the manufacture of materials, and GHG emissions from incineration, or landfill gas (LFG) production from landfill disposal of the material beyond their service lives. The models are applicable to all materials; however, their applications here are demonstrated for the lumber from a residential building with 50- and 100-year service lives, and with incineration, landfill, and deconstruction as end-of-life treatments. This paper introduces a new metric for lifetime GHG emissions associated with materials termed “Global Warming Impact of Materials (GWIM).” The GWIM is subdivided into two portions: (i) productive portion (GWIM_p) that includes the materials’ emissions until the service life of the facility and (ii) non-productive portion (GWIM_np) which includes the materials’ GHG emissions beyond the service life until they are eliminated from the atmosphere. In place of the current, static, EC measurements (kgCO₂e or MTCO₂e), this model reports the GWIMs in units of kgCO₂e-years or MTCO₂e-years, which includes the effects of “time of use” of a facility. Using the models, this paper has computed GHG reductions by deconstruction, with material recoveries of 30%, 50%, and 70% at demolition for reuse, recycle, or repurpose. A 70% material recovery, after a 50-year service life of the building, affected a savings of 47% and 52% if the remaining 30% debris was incinerated or landfilled respectively. All of the values computed using models checked out with manual calculations.     

Greenhouse gas emission inventory for Senegal, 1991

The first greenhouse gas (GHG) emission estimates for Senegal, for the year 1991, were produced according to the draft IPCC/OECD guidelines for national inventories of GHGs. Despite certain discrepancies, nonavailability of data, the quality of some of the data collected, and the methodology, the estimates provide a provisional basis for Senegal to fulfill its obligations under the UN Framework Convention on Climate Change. This inventory reveals that GHG emissions in Senegal, like those in many developing countries, can mainly be attributed to the use of biomass for energy, land-use change and forestry, and savanna burning. Taking into account the direct global warming potential of the main GHGs (CO₂, CH₄, and N₂O), Senegal's emissions are estimated at 17.6 Tg ECO₂. The major gases emitted are CO₂ (61% of GHG emissions), followed by CH₄ (35%) and N₂O (4%). Energy accounts for 45% of total emissions (12% from fossil energy and 33% from traditional biomass energy); land-use change and forests, 18%; agriculture, 24%; waste, 12%; and industry, 1%.     

Greenhouse gas emission reductions through waste management and disposal planning

The Third Conference of the Parties of the UN-FCCC (CoP-3) held in Kyoto in 1997 defined a Protocol with level of reduction of the Greenhouse Gasses (GHGs) overall emissions for Italy of 6.5% with respect to 1990 emissions. A mathematical model was created in order to evaluate the range of GHGs reduction effects obtained by upgrading waste collection, treatment and disposal system to new Italian regulation. This revised version was published online in July 2006 with corrections to the Cover Date.     

生活垃圾与危险废物焚烧二噁英类排放特征研究

对某省52家焚烧企业(21家生活垃圾和31家危险废物)排放烟气数据进行了分析,结果表明,两类焚烧企业二噁英类17种单体分布有所不同,生活垃圾焚烧烟气中浓度较高的是O8CDD和O8CDF;危险废物焚烧烟气中较大的是2,3,4,7,8-P5CDF、2,3,7,8-T4CDD和1,2,3,7,8-P5CDD;两类焚烧企业二噁英类单体对I-TEQ贡献最高的都是2,3,4,7,8-P5CDF,贡献率分别为0. 7%～45%和10%～67%;两者的17种二噁英类与I-TEQ的相关性分析表明,1,2,3,7,8-P5CDF在2类焚烧炉中与I-TEQ均存在较高的相关性,其相关系数分别0. 932和0. 927,可以作为潜在的测定指示物。     

An evaluation of alternative household solid waste treatment practices using life cycle inventory assessment mode

Waste disposal is an important part of the life cycle of a product and is associated with environmental burdens like any other life-cycle stages. In this study, an integrated assessment for solid waste treatment practices, especially household solid waste, was undertaken to evaluate the impact contribution of household solid waste treatment alternatives towards the sustainable development by using Life Cycle Inventory Assessment method. A case study has been investigated under various possible scenarios, such as (1) landfill without landfill gas recovery, (2) landfill with landfill gas recovery and flaring, (3) landfill with landfill gas recovery and electric generation, (4) composting, and (5) incineration. The evaluation utilized the Life Cycle Inventory Assessment method for multiple assessments based on various aspects, such as greenhouse gas emission/reduction, energy generation/consumption, economic benefit, investment and operating cost, and land use burden. The results showed that incineration was the most efficient alternative for greenhouse gas emission reduction, economic benefit, energy recovery, and land use reduction, although it was identified as the most expensive for investment and operating cost, while composting scenario was also an efficient alternative with quite economic benefit, low investment and operating cost, and high reduction of land use, although it was identified as existing greenhouse gas emission and no energy generation. Furthermore, the aim of this study was also to establish localized assessment methods that waste management agencies, environmental engineers, and environmental policy decision makers can use to quantify and compare the contribution to the impacts from different waste treatment options.     

Greenhouse gas emissions from Australian open-cut coal mines: contribution from spontaneous combustion and low-temperature oxidation

Spontaneous combustion and low-temperature oxidation of waste coal and other carbonaceous material at open-cut coal mines are potentially significant sources of greenhouse gas emissions. However, the magnitude of these emissions is largely unknown. In this study, emissions from spontaneous combustion and low-temperature oxidation were estimated for six Australian open-cut coal mines with annual coal production ranging from 1.7 to more than 16 Mt. Greenhouse emissions from all other sources at these mines were also estimated and compared to those from spontaneous combustion and low-temperature oxidation. In all cases, fugitive emission of methane was the largest source of greenhouse gas; however, in some mines, spontaneous combustion accounted for almost a third of all emissions. For one mine, it was estimated that emissions from spontaneous combustion were around 250,000 t CO₂-e per annum. The contribution from low-temperature oxidation was generally less than about 1% of the total for all six mines. Estimating areas of spoil affected by spontaneous combustion by ground-based surveys was prone to under-report the area. Airborne infrared imaging appears to be a more reliable method.     

Greenhouse gas emissions from two hydroelectric reservoirs in Mediterranean region

Water reservoirs are used for many purposes, such as water supply, irrigation, flood mitigation, and hydroelectric energy generation. Although hydroelectric energy is considered “green,” many studies show that the construction of a reservoir enhances greenhouse gas (GHG) emissions at the transformed area. These emissions, mainly of CO₂, CH₄, and N₂O gases, depend on the age of the reservoir, landscape and soil composition, fauna and flora remnants of the impounded area, climatic conditions, and basin runoffs. Consequently, GHG emissions significantly vary between reservoirs and depending on local specificities. Several studies have investigated GHG emissions from reservoirs around the world, focusing mainly on reservoirs located in cold regions, temperate regions, and tropical regions. Research is lacking for reservoirs in Mediterranean countries, like Greece, and similar regions. This work initially assesses the net GHG emissions of a newly created reservoir (Ilarion est. 2012) in Western Macedonia, Greece. The methodology for net GHG emission calculation was based on the use of literature data concerning pre-impoundment emission factors and local specificities of the reservoir (terrain type, canopy cover), as well as on the 2-year measurement data that were collected using a “static floating chamber.” Furthermore, in this work, the gross GHG emissions of an older, in-line reservoir (Polyfytos est. 1974) were also calculated, based on 2-year measurement data. The results show that the global warming potential (GWP) of the reservoirs is dictated by methane emissions; it minimizes during winter and spring and maximizes during summer and autumn. Hydroelectric energy production at Ilarion Reservoir results in 32 to 97 times less total CO₂ equivalent emissions in comparison to fossil fuels, while at Polyfytos Reservoir only 8 to 24 times less (based on gross emissions). It appears that the impact of a reservoir’s morphology on GHG emissions is more significant than that of a reservoir’s age.