Management Strategies and Their Evaluation for Carbon Sequestration in Cropland

In order to deal with the global change and to reduce emission of greenhouse gas, a number of countries have strengthened studies on carbon sequestration in cropland. Carbon sequestration in cropland is not only an important component for the global carbon stock, but also is the most active part to sequestrate the carbon in soil from atmosphere. In this sense, it is of necessity and significance to strengthen the study on management of carbon sequestration in cropland. Based on the main factors affecting carbon cycle in agro-ecosystems, this paper summarizes the relevant management measures to strengthen the capacity of reducing emission of carbon and increasing the carbon sequestration in cropland, and evaluates the effects of these measures after being implemented at a regional extent.

Carbon emission risk of construction industry in Hebei Province of China based on carbon sink thresholds

In order to assess the environmental risks caused by carbon emissions from the construction industry in Hebei Province of China,an environmental risk assessment model based on forest carbon sink threshold was constructed to evaluate the carbon emission risks of the construction industry in Hebei Province,China from 2005 to 2020.The results are shown as follows:(1)The overall carbon emissions of the construction industry in Hebei Province of China showed an inverted"V"-shaped evolution trend during the past 16 years.Tangshan and Shijiazhuang maintained high carbon emissions,while Langfang,Hengshui and Baoding saw rapid increases in carbon emissions.(2)The environmental safety threshold of carbon emission from the construction industry in Hebei Province,China,has been continuously improved,and the provincial environmental safety threshold is between 9475080-23144760 tons;The environmental safety threshold was the highest in Baoding and Langfang,and the lowest in Xingtai.(3)In the past 16 years,the carbon emission risk of the construction industry in Hebei Province of China has been in a state of extremely serious risk,and the risk index generally presents an inverted"V"type trend.(4)The carbon emission risk of Hebei city in China presents a spatial pattern of"high in the south and low in the north",which goes through two stages:risk increase period and risk reduction period.

Research on the Carbon Peak and Carbon Neutralization Model in Colleges and Universities:Taking China University of Geosciences(Beijing)as an Example

The“3060”goal demonstrates China’s responsibility in actively responding to global climate,enhances China’s voice and influence in climate governance,and sets an example of energy conservation and emission reduction for developing countries.As the main institutions that educate people for the Party and the country,colleges and universities have the responsibility to explore the realization path of carbon peak and carbon neutralization against the new problems encountered in the practice of energy conservation and emission reduction in colleges and universities.In response to the national strategy and the action plan of the Ministry of Education,taking the carbon practice of China University of Geosciences(Beijing)as the starting point,this paper conducts benchmarking research on the path of carbon peak and carbon neutralization in universities through the ecological factor method,campus carbon footprint,and questionnaire analysis.

Effects of Land Use Change on Carbon Emission:A Case Study of Yuheng Mining Area

Land use is the main factor affecting the carbon emission. Taking Yuheng Mining Area as the research object,this paper chose two periods of remote sensing data of 1999 and 2006,and adopted the remote sensing image interpretation and supervised classification to study the changes in land use types and carbon sink in different periods in the mining area. The results showed that the area of arable land was reduced from 166. 96 km2 to 81. 10 km2,the area of woodland was increased from 46.79 km2 to 134. 53 km2,and arable land decreased by 51%,but carbon sink in the mining area still showed a rising trend; the carbon sink value increased by 16. 4 million yuan in 2006 compared to 1999,an increase of 40%,indicating that the reasonable land use pattern can improve the ecological environment,and promote the sustainable development of environment and economy in the mining area.

A hefty target of reducing the intensity of carbon dioxide emissions

At the end of January, China formally handed over the report on pollution reduction targets to the United Nations.

Floristic Inventory and Evaluation of Carbon Sequestration Potential of the Misomuni Forest Massif,Kikwit City (Democratic Republic of the Congo)

The aim of this study was to inventory plant biodiversity and to evaluate the carbon sequestration potential of the Misomuni forest massif.An inventory of all trees with diameter at breast height(dbh)≥10 cm measured at 1.30 m height was performed.The aerial biomass(AGB)was used for estimating the stored CO2 and its carbon equivalent.88 plant species belonging to 71 genera and 32 families were inventoried.Fabaceae family displayed the highest number of species and genera.The highest basal area values were displayed by Scorodophloeus zenkeri(7.34±2.45 m2/ha),Brachystegia laurentii(5.82±1.94 m2/ha),Entandrophragma utile(5.28±1.94 m2/ha),Pentadesma butyracea(4.53±1.51 m2/ha).The highest values of stored carbon and their carbon equivalent were observed in Pentadesma butyracea(15.13±5.00 and 50.55±16.85 t/ha),Picralima nitida(7.02±2.34 and 23.66±7.88 t/ha),Strombosia tetandra(6.56±2.18 and 22.10±7.36 t/ha).The Misomuni forest massif is thus much floristically diversified and plays a significant role in the sequestration of CO2.The total AGB of the inventoried trees is 183.78±61.26 t/ha corresponding to stored carbon and carbon equivalent of 96.63±32.21 t/ha and 289.92±96.64 t/ha respectively.The protection of this ecosystem is highly needed for combatting climatic changes at local,national and regional scales and for the conservation biodiversity habitat.

Effect of Photovoltaic Power Generation on Carbon Dioxide Emission Reduction under Double Carbon Background

Increasing the efficiency and proportion of photovoltaic power generation installations is one of the best ways to reduce both CO_(2) emissions and reliance on fossil-fuel-based power supplies.Solar energy is a clean and renewable power source with excellent potential for further development and utilization.In 2021,the global solar installed capacity was about 749.7 GW.Establishing correlations between solar power generation,standard coal equivalent,carbon sinks,and green sinks is crucial.However,there have been few reports about correlations between the efficiency of tracking solar photovoltaic panels and the above parameters.This paper calculates the increased power generation achievable through the use of tracking photovoltaic panels compared with traditional fixed panels and establishes relationships between power generation,standard coal equivalent,and carbon sinks,providing a basis for attempts to reduce reliance on carbon-based fuels.The calculations show that power generation efficiency can be improved by about 26.12%by enabling solar panels to track the sun's rays during the day and from season to season.Through the use of this improved technology,global CO_(2) emissions can be reduced by 183.63 Mt,and the standard coal equivalent can be reduced by 73.67 Mt yearly.Carbon capture is worth approximately EUR 15.48 billion,and carbon accounting analysis plays a vital role in carbon trading.

Carbon emissions and sinks in agro-ecosystems of China

Besides ruminant animals and their wastes, soil is an important regula ting medium in carbon cycling. The soil can be both a contributor to climate cha nge and a recipient of impacts. In the past, land cultivation has generally resu lted in considerable depletion of soil organic matter and the release of greenho use gases (GHGs) into the atmosphere. The observation in the North-South Transec t of Eastern China showed that climate change and land use strongly impact all s oil processes and GHG exchanges between the soil and the atmosphere. Soil manage ment can restore organic carbon by enhancing soil structure and fertility and by doing so mitigating the negative impacts of atmospheric greenhouses on climate. A wide estimation carried out in China shows that carbon sequestration potentia l is about 77.2 MMt C/a (ranging from 26.1—128.3 MMt C/a) using proposed IPCC a ctivities during the next fifty years.

Land use effects on terrestrial carbon sources and sinks

Current and past land use practices are critical in determining the distribution and size of global terrestrial carbon (C) sources and sinks. Althoughfossil fuel emissions dominate the anthropogenic perturbation of the global C cycle, land use still drives the largest portion of anthropogenic emissions in a number of tropical regions of Asia. The size of the emission flux owing to land use change is still the biggest uncertainty in the global C budget. The Intergovernmental Panel on Climate Change (IPCC) reported a flux term of 1.7 PgC@a-1 for 1990-1995 but more recent estimates suggest the magnitude of this source may be only of 0.96 PgC@a-1 for the 1990s. In addition, current and past land use practices are now thought to contribute to a large degree to the northern hemisphere terrestrial sink, and are the dominant driver for some regional sinks. However, mechanisms other than land use change need to be invoked in order to explain the inferred C sink in the tropics. Potential candidates are the carbon dioxide (CO2) fertilization and climate change; fertilization due to nitrogen (N) deposition is believed to be small or nil. Although the potential for managing C sinks is limited, improved land use management and new land uses such as reforestation and biomass fuel cropping, can further enhance current terrestrial C sinks. Best management practices in agriculture alone could sequester 0.4-0.8 PgC per year in soils if implemented globally. New methodologies to ensure verification and permanency of C sequestration need to be developed.

水土保持碳汇项目开发与交易的机制与途径构建

水土保持碳汇具备负碳技术的特性,受到政府和交易主体广泛关注和青睐,未来将在我国碳排放权交易市场中得到广泛应用。从建立碳汇项目开发团队、实施碳汇监测与核算、协调撮合交易和宣传示范等4个方面,总结全国首单水土保持碳汇项目开发与交易的实践探索,提出水土保持碳汇项目开发与交易的机制与途径,包括加强水土保持碳汇基础研究和技术攻关、完善水土保持碳汇监测和核算体系、开展碳汇项目开发和探索碳汇交易途径与机制、建立水土保持碳汇纳入温室气体自愿减排交易机制、建设碳汇项目开发队伍与机构、提升项目开发信息管理水平等6个方面。

基于碳汇潜力的碳排放空间关联网络结构特征及影响因素——以长江中游城市群为例

考虑碳汇潜力的碳排放空间关联是促进城市群协同减排的重要基础,更是实现碳中和的有力抓手。以长江中游城市群为研究区,对传统引力模型进行修正,构建兼具碳汇潜力的碳排放空间关联网络,采用社会网络分析(SNA)和二次指派程序方法(QAP)探究长江中游城市群碳排放空间关联网络的时空特征与影响因素。结果表明:①研究期间长江中游城市群碳排放网络关联关系数、网络密度和网络关联度呈增长趋势,网络效率和网络等级度不断下降,且网络等级度在2010年后始终为0,表明碳排放空间关联网络日益稠密、网络通达性较强,存在多重叠加的溢出渠道,但等级结构并不森严。基于碳汇潜力的长江中游城市群碳排放空间关联网络从“双核化”向“多极化、多线程”网络形态发展,核心城市的扩散作用不断增强。此外,以抚州、宜昌、鹰潭、上饶和吉安等为代表的高碳生态承载力地区,在碳排放空间关联网络中的受益关联性大于溢出关联性。②2020年,长江中游城市群碳排放空间关联网络形成四大板块,相较于板块内部成员间的碳排放空间关联效应,板块间的碳排放空间关联效应更为明显,即板块间的“碳排放转移”效应较为普遍。净溢出板块主要分布在武汉都市圈、宜荆荆都市圈和长株潭城市群外围城市,处于网络核心圈层位置;净受益板块主要分布在环鄱阳湖城市群东部,“碳排放避难所”效应显著。经纪人板块集中在环鄱阳湖城市群西部,板块间表现出“净溢出板块→经纪人板块→净受益板块”的碳排放传递路径,呈现出明显的“梯度转移”特征。双向溢出板块主要位于长江中游城市群西部,对净溢出和净受益板块都存在碳排放的空间溢出。研究期内,净溢出板块的成员虽然有所变化但总数保持不变,经纪人板块的成员有所增加,而净受益和双向溢出板块的成员均减少,环鄱阳湖城市群的“碳排放避难所”效应有所弱化。③地理邻近关系能够促进城市间碳排放关联关系的建立,而城市间的经济集聚程度、土地利用强度和经济发展水平上的互补性,促使碳排放空间关联网络随着城市间分工与协作的加强而呈现出千里“碳缘”一线牵的特点。

Kenya Airways Launches New Project to Reduce Carbon Emissions

Kenya Airways announced its new carbon offset project in May,aiming to have guests directly take part in a carbon emissions reduction plan for environmental protection.Titus Naikuni,Managing Director

广西甘蔗碳汇测算方法研究及时空格局分析

为了实现广西全区植被减源增汇目标,对广西主要经济作物甘蔗的碳吸收和碳排放量进行科学的测算,并开展甘蔗碳汇时空格局的研究分析;利用广西全区14个地级市2010—2020年甘蔗产量、农资投入等相关统计数据测算广西全区甘蔗净碳汇量,并运用空间自相关分析法分析2005—2020年间广西各市时空分布格局。结果表明:2010—2020年,广西全区甘蔗净碳汇量逐步上升;2005—2020年,广西全区甘蔗碳汇量在地级市尺度下不存在明显的全局空间自相关关系;广西全区甘蔗碳汇量逐步形成以南宁市为核心的局部溢出格局,充分利用南宁市的技术、产业优势扩大甘蔗碳汇的空间溢出效应,对提高广西全区的甘蔗碳汇水平至关重要。

水土保持碳汇生态产品价值实现机制及试点设想

水土保持碳汇生态产品价值的实现是“两山”转化的重要途径,也是践行“双碳”目标的重要内容。在界定水土保持碳汇生态产品内涵基础上,论述了基于“主体—要素—运行”多层次框架,构建“多主体协同—多要素投入—全周期运行”的水土保持碳汇生态产品价值实现机制,并以福建省龙岩市为试点示范区,系统梳理其试点基础及必要性,并提出相关的试点策略,以期为龙岩市及类似地区实践提供一定的决策参考。

“双碳”目标下的农业碳问题研究进展及未来展望

减少农业碳排放,提高农业碳汇能力,是我国实现“双碳”目标的重要举措,也是潜力所在,故厘清农业碳问题的研究现状及其特征具有重要意义。为助力我国“双碳”目标早日实现,本文基于农业碳排放、农业碳汇以及农业低碳发展驱动因素3个维度对已有相关研究进行全面梳理:首先,明确了农业碳排放的基本概念并介绍了常见的测算方法,同时基于时序演变、空间分布、效率特征、减排路径等视角对其研究现状进行了回顾;其次,界定农业碳汇的基本概念,进而引申出森林碳汇、土壤碳汇和海洋碳汇并介绍各自的测算方法,而后则围绕农业净碳汇与碳汇市场化展开重点阐述;最后,从宏观和微观2个层面探讨影响农业低碳发展的主要因素,其中前者着眼于政策、经济、社会等方面,而后者则侧重于户主的内在因素和农户面临的外部环境。针对未来农业碳问题的研究方向,本文认为可重点围绕以下4个方面,即农业碳达峰的科学预测与差异化减排路径设计、农业减碳固碳潜力的科学评估与实现路径探讨、农业碳市场的构建与碳汇价值变现的思路探索以及农户低碳生产技术供需匹配探究与其制度优化。

水土保持碳汇若干关键问题研究

水土保持是生态文明建设的重要内容,也是水利行业助力实现“双碳”目标的重要举措。从理论研究和实践探索入手,着重阐述水土保持碳汇内涵与机理、碳汇能力评估与核算、碳中和潜力与碳交易实践、碳汇能力提升路径等问题。水土保持碳汇通过林草、工程和耕作措施实现,具有碳增汇、保土固碳和减蚀减排作用。基于全国尺度碳汇核算,2021年以水利部门为主实施的水土保持措施碳汇量(不包括水土保持林草措施碳汇)为1395万~1699万tC,约占我国陆地生态系统碳汇总量的4%~6%,这一部分尚未纳入国家碳汇核算体系。为提升水土保持碳汇能力和贡献度,应持续开展山水林田湖草沙系统治理,统筹水土保持拦沙减淤、净化过滤、调节反补、开源引流、减排增汇等生态多功能协调,推进水土保持提质增效,并优化生产建设项目水土保持技术,充分挖掘水土保持固碳增汇潜力。

中国粮食种植业碳效应时空演化及碳排放公平性

农业低碳转型背景下,准确把握粮食种植业碳效应时空演化及碳排放公平性特征对实现地区生态正义具有重要意义。基于2000—2021年省域面板数据,采用碳排放因子法测算中国30个省区的粮食种植业碳效应,利用核密度估计方法探析时空演化,运用Dagum基尼系数法刻画并解构全国粮食种植业碳排放公平性。研究表明:(1)从时空特征看,粮食种植业碳效应呈现波动上升的净碳汇特征,具体表现为“东强西弱,北高南低”的空间格局,且伴随明显的“马太效应”。在碳效应结构上,秸秆燃烧与玉米种植分别是粮食种植业最主要的碳源与碳汇。(2)从演化趋势来看,全国粮食种植业碳效应的非均衡性呈扩大趋势;在三大主粮中,水稻碳效应非均衡性有所减弱,小麦与玉米碳效应非均衡性均持续上升。(3)从碳排放公平性来看,区域间碳排放差异已成为影响公平性的最主要因素,基尼系数呈“快速上升-波动震荡-缓慢回落”特征,全国粮食种植业碳排放始终处于较公平区间,整体公平性呈改善态势;在三大主粮中,水稻碳排放公平性最低,玉米碳排放公平性最高。最后,提出了采取差异化固碳减排策略、构建低碳发展跨区协作机制、完善碳排放责任分摊机制、探索粮食碳汇交易试点等建议,以期推动我国粮食种植业实现低碳转型发展。

中国设施农业的减碳增汇效应分析——基于1828个县域面板数据的实证研究

设施农业作为中国现代农业的重要标志,揭示其时空格局演变及减碳增汇效应对实现“双碳”目标、促进绿色转型发展具有重要意义。本文应用空间经济计量方法,采用2013—2017年中国1828个县域面板数据,分析中国县域碳排放、固碳量及设施农业的时空演变特征,在此基础上实证分析了设施农业的减碳增汇效应,并从区域和粮食产区角度进行了异质性分析。结果表明:1)中国县域碳排放总体呈东高西低的空间格局,固碳量则显示出西高东低的特点,设施农业面积空间格局也为东高西低,三者均具有显著的空间正相关性及高-高空间集聚特征。2)设施农业面积对碳排放的直接和间接效应都呈“U”型,存在显著减碳效应,但设施农业面积对固碳量的直接和间接效应都显著为负,增汇效应不明显。3)设施农业面积对于减碳增汇的作用存在显著的异质性。就区域层面而言,设施农业面积显著促进东部和东北部地区碳减排,显著抑制中部和西部地区碳汇;就粮食产区而言,设施农业面积对粮食主产区和主销区存在显著的减碳效应,对三大粮食产区的增汇效应均不明显。研究认为,各县应当加快推进设施农业绿色发展,因地制宜发展低碳农业,加强区域间减碳增汇合作交流,以此有力地推进设施农业绿色可持续发展,实现减碳增汇的愿景。

森林碳汇的碳资产价值评估方法

森林碳汇是实现碳中和的重要途径之一,如何评价其经济价值是重要的理论与现实问题。文章将碳资产价值理论引入森林碳汇领域,提出一种评估森林碳汇碳资产价值及分析其影响因素敏感性的方法,继而通过实例估计某森林碳汇项目碳资产价值的合理值,并对该项目碳资产价值的影响因素进行敏感性分析。研究表明:(1)森林碳汇具有较高的、可度量的碳资产价值;(2)碳资产理论能够为森林碳汇经济价值的评估和计量提供一种新的方法;(3)森林碳汇的经济价值主要取决于项目碳汇量和碳汇价格,与碳汇价格变动相比,项目碳汇量变动对森林碳汇碳资产价值具有更大的影响。

林业碳汇权的法律属性及规范完善

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