二氧化碳动态边际减排成本及其影响机制北大核心CSCDCSSCI

二氧化碳边际减排成本可以反映环境质量与经济增长的关系,既是气候政策制定的科学基础,也是实现碳达峰、碳中和目标的关键因素。该研究基于三种方向性距离函数的行为模式构建三种二氧化碳边际减排成本的计算方法,测度中国30个省份(未涉及西藏和港澳台地区)1998—2019年间三种二氧化碳边际减排成本,并从全国、区域和省份三个层面进行分析。在进一步分析中,从减排空间和技术进步两个视角构建二氧化碳边际减排成本影响机制的理论框架,同时进行实证检验。测算结果表明:①经济主体从“传统-弱”模式时边际减排成本为负,从“传统-强”模式时边际减排成本趋近于零,从“弱-强”模式时边际减排成本均为正。②三种测量方法下边际减排成本均呈现上升、下降、上升的“N”型;区域规律一致,均为中部较高,东、西部较低;不同区域和省份间同一种边际减排成本的差别较大。影响机制的进一步分析显示:①减排空间和技术进步是影响二氧化碳边际减排成本的最为重要的两个因素,先后起主导作用。②只有当减排空间足够大,经济行为主体处于粗放型发展阶段和节能减排政策处在初始时期这两个条件同时满足时,节能减排政策才能起到降低边际减排成本的效果。③技术进步具有周期性。现阶段中国绿色技术处于快速发展的初步成长期,对技术的投入处于沉没成本阶段。虽然削减减排空间能够倒逼技术进步,但是技术进步并不能够起到显著降低减排成本的效果。因此,在减排政策的制定中要注重阶段性和区域差异,持续推进和完善碳排放权交易市场,考虑技术进步前期“沉默发酵”的特性,在中西部地区承接产业时要协调推进可持续发展。     

碳交易政策的协同减排效应北大核心CSCDCSSCI

碳减排和大气污染物减排工作是中国可持续发展的双重战略任务。碳交易政策是气候变化政策的核心议题,其关键在于通过设定排放总量控制目标,倒逼排放主体实现减排。作为调节经济发展和环境压力的市场型政策工具,碳交易政策能否对碳排放强度以及PM_(2.5)和SO_(2)等大气污染具有协同减排效应值得深入研究。该研究以2006—2018年中国276个地级市面板数据为基础,以碳交易试点政策实施作为准自然实验,运用双重差分模型进行实证研究;进一步将样本城市划分为东、中、西3个子样本,探究区域异质性,并将中介模型纳入分析框架,探究技术创新对碳交易影响温室气体和大气污染物排放的传导机制。结果表明:①碳交易政策在降低碳排放强度的同时,也能有效实现PM_(2.5)与SO_(2)协同减排;②异质性分析结果表明,碳交易政策对大气污染物和二氧化碳的减排作用大小表现为西部地区最大,中部地区其次,东部地区最小;③碳交易政策对地区降污减排的中间作用机制表现为技术创新对碳交易和碳强度、SO_(2)、PM_(2.5)的显著中介效应。这些结论表明:在城市大气环境治理中应充分发挥市场机制作用,扩大碳排放权交易制度的市场与主体范围;在全国范围内推广碳交易政策,要将区域异质性考虑在内,增强对大气污染的区域协作治理。另外,城市规划建设要以促进技术进步和提高能源利用效率为立足点,获取环境经济综合效益。研究结果为完善中国碳交易制度,优化污染物协同减排路径,实现绿色发展提供理论借鉴。     

小农发展气候智慧型农业的效率与成本改进:倡导农地流转还是发展社会服务?

气候智慧型农业是联合国粮农组织所提出的积极响应气候变化、有效保障作物生产安全的新型农业发展模式。碳减排是发展气候智慧型农业的核心要义,而中国大量且长期存在的小农是发展气候智慧型农业不可背离的重要主体。基于湖北省水稻主产区气候智慧型农业发展的调研,继而利用方向性距离函数对小农发展气候智慧型农业,即低碳生产效率与碳边际减排成本进行测算,并进一步考察小农通过土地流转或农业社会化服务衔接现代农业,对低碳生产效率和碳边际减排成本的影响。结果表明:(1)基于小农发展气候智慧型农业仍处于"低效率—高成本"阶段,水稻低碳生产效率仍存在平均56%的提升空间;碳边际减排成本均值为34.13元/kgCE;(2)土地转入虽未能提升水稻低碳生产效率,但却具有碳边际减排成本优势;(3)生产雇工和农机服务对水稻低碳生产效率和碳边际减排成本均具有显著的正向影响,可见通过农业社会化服务实现低碳生产效率的提升仍面临分工与交易费用的两难之困。基于上述结论,提出促进小农发展气候智慧型农业,实现低碳生产相关政策启示。     

碳交易的减排及绿色发展效应研究

面临来自全球气候变化加剧及国内环境污染恶化的双重压力,中国逐步明确了采用市场化手段来提高气候、环境治理水平,碳交易便为其典型代表,然而目前统筹考虑碳交易的碳减排及绿色协同发展效应的研究却相对欠缺。为此,本文以碳交易试点政策为例,区分碳交易的减排及区域绿色发展效应,分别构建碳排放强度和非期望产出包含全域排放物及区域污染物的曼奎斯特—卢恩伯格指数,基于2008—2015年30个省级行政区面板数据,采用双重差分法实证检验,并进一步检验了协同路径和作用机制。结果发现:①中国碳交易政策在促进了试点地区碳排放强度下降的同时,还促进了试点地区整体绿色发展;②中国碳交易政策的区域污染物协同减排效果主要通过协同减排SO_2实现;③中国碳交易政策实现碳减排及区域绿色发展的主要作用机制为技术升级。这些结论说明:应继续扎实推进全国碳交易市场建设,在实现全球碳减排的目标框架下同时促进区域环境改善;充分考虑碳交易与排污权交易的协同作用,在进行温室气体和区域污染物的"协同减排控制"中,综合考虑协同效应和减排成本,以达到用最低成本实现碳减排和区域污染物减排的双重目标;多手段并行推动绿色发展,除积极吸取碳交易试点阶段经验教训外,还应联合其他多项环境保护政策共同协作、相互补充,充分发挥"看不见的手"的市场调节作用和政府的总体把控能力,共同促进区域全面绿色高质量发展。     

碳排放市场一体化对异质性企业空间分布的影响

随着全国碳排放交易体系的启动,碳市场一体化对企业区位选择、产业转移以及中国空间经济格局的影响是一个值得关注的问题。本文以碳市场一体化为背景,整合"新"新经济地理学(NNEG)和基于agent的计算经济学(ACE)的理论和方法,直接从异质性企业生产决策、碳交易和区位选择行为出发,建立了一个基于agent的两区域空间经济学模型和计算实验平台,并通过设置不同的政策情景,探讨了碳市场一体化背景下碳减排、碳交易、区域政策倾斜及碳配额分配方式等多种因素对企业的区位选择、产业集聚、东西部区域差异、效率与福利、碳交易活跃度等方面的动态影响。研究表明:(1)在没有东西部地区间碳减排政策差异和碳市场交易的情形下,碳减排政策并不必然改变企业的区位选择,这种环境管制能够加剧企业间竞争,从而提升各地区企业的生产效率。(2)在没有碳市场交易的情形下,对西部地区的碳政策倾斜将影响企业区位选择,改变经济的空间格局,缩小地区之间的差异,但缩小区域差距的效果随着碳约束的收紧而减弱。(3)在同时存在区域碳政策倾斜和碳市场交易的情形下,碳市场交易有利于企业向东部发达地区集聚,企业边际成本降低,两地区企业总数量增多,社会总体福利增加。(4)碳配额的分配方式直接决定碳交易的生命力。分配规则尽可能地纳入企业异质性因素不仅能提升碳交易活跃度和持久度,还能优化资源配置,提升全局经济效率。本文还就整合空间经济学和基于agent的计算经济学的研究方法和技术路线进行了讨论。     

碳强度的双重红利:环境质量改善与经济持续增长

本文构建了一个由代表性家庭、政府和八个不同行业组成的一般均衡模型,同时在模型中嵌入了碳强度、碳交易两种不同的环境政策工具,并基于2007年我国投入产出表数据进行校准。本文通过数值分析指出我国约束全行业的碳减排政策对福利损失的边际影响最小,约束重点行业的碳减排政策对实际GDP的影响存在倒"U"型关系,在碳强度目标约束不高于17%时,碳强度政策对社会福利的损失影响要低于碳交易政策;在碳强度目标约束不高于21%时,约束重点行业的碳减排政策对实际GDP的边际损失影响要低于约束全行业的政策。我国的碳减排政策在当前碳强度约束目标下实现了环境质量改善和经济持续增长的双重红利,该结论支持了环境Porter假说。双重红利产生的原因是由于碳减排政策使得资源要素使用成本上升,进而提高了劳动等低碳要素需求,使得行业之间生产要素重新配置,在一定情况下实现了经济增长和环境改善。进一步,本文给出了环境规制政策的设计方案,根据边际减排相等以实现总减排成本最小化的原理,给出了约束全行业减排的环境政策下各行业碳强度的任务分解,通过模拟计算各行业的边际减排成本,可以为政府根据行业维度制定更为科学、合理的减排方案提供理论和实践支持。此外,本文还估计了产业需求变动、行业最终消费结构变动、行业全要素生产率变动、行业需求中间投入品替代弹性技术变动等各种经济发展方式的变化对碳排放量和碳强度的边际影响,深入分析和理解经济发展方式与碳强度变化之间的内在联系,有利于识别经济系统中相互关联的各种因素如何对碳强度的政策目标产生影响。本文的研究指出我国应大力提高各项中间投入品的单位碳排放节能技术水平,这是降低碳排放强度最直接的、最有力的政策措施。政府应进一步加大投入,通过引进、消化和吸收国际先进技术、国际合作开发和自主创新等方式,鼓励企业使用清洁能源,提高工业废气、尾气的处理技术水平,鼓励低碳部门的技术研发,鼓励企业提高资本、劳动的生产技术水平,提高中间投入品的使用效率,这些对于实现我国总体的减排目标具有十分重要的意义。     

不同碳减排政策对内外资企业竞争力的影响比较

一方面,由于我国内外资企业的生产效率和碳排放效率差距较大,不同的碳减排政策势必会对内外资企业的市场竞争力带来不同的影响;另一方面,已有文献大多在完全竞争的框架下对不同减排政策的实施效应进行分析,而事实上我国碳减排政策所覆盖的产业大多是不完全竞争甚至是寡头垄断。由此,我们基于内外资企业存在低碳技术差距这一新的研究视角,通过构建两阶段博弈模型来比较分析相同碳强度减排目标下强制减排、碳税与碳交易等三种减排政策对内外资企业产量、市场份额及其社会总产量的影响,从而有利于我国从妥善处理内外资关系的角度制定更有针对性的减排政策。结果表明:(1)三种减排政策都降低了内资企业的产量和市场份额,且内外资企业低碳技术差距越大时内资企业的市场份额下降越多。(2)强制减排降低了社会总产量,碳税和碳交易同等幅度地减少了社会总产量。(3)最优税率仅仅是减排目标的增函数。(4)市场出清的碳交易价格和碳税税率相等,且其数值仅与减排目标正相关,而与碳排放权的分配无关。(5)碳交易比碳税更有利于"保护"内资企业的市场竞争力。相关政策启示如下:(1)尽快确定普适的碳排放核算标准,核算出各行业内外资企业的低碳技术差距;(2)尽快在全国范围内启动碳交易机制,建立促进缩小内外资企业低碳技术的机制;(3)在碳交易市场条件不成熟的行业可以率先推出碳税政策;(4)政府应该根据内外资企业低碳技术差距来对不同行业采取最适宜的减排政策,而非"一刀切"。     

基于“双碳”目标的碳排放控制政策设计

该研究采用环境政策分析的一般模式,对"双碳"目标下碳排放控制政策进行了初步设计。在完成碳达峰目标过程中,已有的碳排放源主要通过采用较先进的技术,用提高能源使用效率的方式控制碳排放;新排放源则需要采用最先进的减少碳排放的技术才能被准许进入市场。在实现碳中和目标过程中,可再生能源产业逐渐成熟,开始规模化地替代化石能源;但只要使用化石能源的碳排放源的减碳成本仍然低于使用可再生能源的成本,碳排放源就需要继续减排。空气污染物排放控制的基础政策主要是固定源基于技术的排放标准、排污许可证制度等。分行业制定碳排放绩效标准是可行的,但仅依靠单独的政策手段实现碳减排目标是有局限的,将碳排放纳入排污许可证则是有必要的。二氧化碳等温室气体的管理可完全忽略传统空气污染物的时空分异性。碳减排是国家尺度的政策,不需要将国家尺度的目标分解为区域目标,具体减排目标是分行业制定的。碳排放源本身的减排贡献可能并不是最主要的,在边际减碳的同时为国家能源转型提供动力和资金应当是主要目标,碳税具有实现上述目标的天然优势;碳排放权交易政策,由于其具有更好地刺激先进企业加快技术进步和减少碳排放的特点,也有其应用的必要性。建议两项政策并行实施,对于选择碳交易政策的企业,可以豁免碳税政策。     

公平和效率维度下中国省际碳权分配原则分析

区域碳权分配原则决定了中国省际碳减排的压力,也是激励各地区转向清洁能源及减排技术创新的基础。本文运用非径向方向性距离函数(NDDF)测算了2011-2014年中国省际全要素碳排放效率(TFC)与技术差距比(CTGR),以分析各地区基于效率最优的碳减排潜力(CRC),进而确定中国区域碳权分配原则。结果表明,各地区减排潜力呈现出与经济发展水平相似的空间分布特征;"十二五"期间海南与安徽两地已处于减排的前沿面,但单一的公平原则挫伤了其持续减排的积极性,而其它低效率省市短时间内无法通过技术效率提升减排能力;无论是单一的公平原则还是单一的效率原则均无法保证各地区碳减排的合理性、稳定性与持久性;而兼顾公平与效率的原则在增加绝对碳排放效率的同时,减少了地区差异。公平与效率原则的动态混合机制更符合中国省际碳减排现状,初期应遵循"公平优先,兼顾效率",随着经济企稳,应转向"效率优先,兼顾公平"。     

中国“减缓气候变化”研究进展——中国《第四次气候变化国家评估报告·第三部分》解读

2022年10月,中国发布了《第四次气候变化国家评估报告》,其中减缓气候变化部分首先阐述了国际气候治理新机制给中国带来的挑战和机遇、中国现阶段碳减排成效以及经济转型对碳减排的影响,然后对能源部门碳减排、能源需求部门（工业、建筑、交通）碳减排、碳汇和非二氧化碳减排、CCUS和地球工程进行了评估,最后分析了2030年前二氧化碳排放达峰路径和2060年碳中和目标愿景。这些评估分析结论为中国更好地开展碳达峰、碳中和工作提供了重要支撑。     

WSSD 2002, Latin America and Brazil: Biodiversity and Indigenous People

Latin America comprehends notable variations in terms of natural environment, availability of natural resources, living standards, and demographic patterns. Latin America is a mosaic of cultures, post- and pre-Columbian. The rich variety of life forms discovered and described by chroniclers and traveling naturalists in the Neotropics contributed to the proposal, in mid-XVIIIth century, of a new system of classification and a scientific code of nomenclature for all organisms. Biodiversity was, for many centuries, a source of resources to be exploited in natura. In scientific circles, its inventory became the domain of taxonomists. But modern technology showed how important the miriad of life forms really are as sources of chemical molecules to be engineered as drugs and reassembled as novel manufactured products. We are on the brink of a new agricultural and medical revolution, thanks to the techniques of genetic engineering, which will lead eventually to the elimination of hunger and malnutrition.In this essay, the Brazilian environmental and social heterogeneity will serve as an example to illustrate some key points, which have influenced sustainability policies. The Amazon deforestation and indigenous knowledge (IK), subjects often associated with areas of high biodiversity, are usually the focus of environmental debates. The importance of IK in integrating development, reducing poverty and sustainability are considered together with the intellectual property rights of native populations.In the World Summit on Sustainable Development (WSSD) Implementation Plan, a few paragraphs were dedicated to Latin America, because of the pre-existing Action Platform on the Road to Johannesburg 2002, approved in Rio de Janeiro in October 2001. This paper calls attention to the need to draw up specific environmental policies for a region which shows an extremely high cultural and biological diversity, associated with a high availability of forests and water, among other resources.     

Ethnosciences––A step towards the integration of scientific and indigenous forms of knowledge in the management of natural resources for the future

Integration of indigenous knowledge and ethnoscientific approaches into contemporary frameworks for conservation and sustainable management of natural resources will become increasingly important in policies on an international and national level, both in countries that are industrialised and those that have a developing status. We set the scene on how this can be done by exploring the key conditions and dimensions of a dialogue between ȁ8ontologiesȁ9 and the roles, which ethnosciences could play in this process. First, the roles of ethnosciences in the context of sustainable development were analysed, placing emphasis on the implications arising when western sciences aspire to relate to indigenous forms of␣knowledge. Secondly, the contributions of ethnosciences to such an ȁ8inter- ontological dialogueȁ9 were explored, based on an ethnoecological study of the encounter of sciences and indigenous knowledge in the Andes of Bolivia, and reviewed experiences from mangrove systems in Kenya, India and Sri Lanka, and from case-studies in other ecosystems world-wide, incl. Australia, Burkina Faso, Ecuador, Ethiopia, Guatemala, Indonesia, Nepal, Niger, Philippines, Senegal, South-Africa and Tanzania.     

Paradoxical ozone associations could be due to methyl nitrite from combustion of methyl ethers or esters in engine fuels

We review studies of the effects of low ambient ozone concentrations on morbidity that found a negative coefficient for ozone concentration. We call this a Paradoxical Ozone Association (POA). All studies were in regions with methyl ether in gasoline. All but one study carefully controlled for the effects of other criterion pollutants, so the phenomenon cannot be attributed to them. One was in southern California in mid-summer when ozone levels are highest. Because ozone is created by sunlight, the most plausible explanation for a POA would be an ambient pollutant that is rapidly destroyed by sunlight, such as methyl nitrite (MN). A previously published model of engine exhaust chemistry suggested methyl ether in the fuel will create MN in the exhaust. MN is known to be highly toxic, and closely related alkyl nitrites are known to induce respiratory sensitivity in humans. Support for the interpretation comes from many studies, including three linking asthma symptoms to methyl tertiary butyl ether (MTBE) and the observation that a POA has not been seen in regions without ether in gasoline. We also note that studies in southern California show a historical trend from more significant to less significant ozone-health associations. The timing of those changes is consistent with the known timing of the introduction of gasoline oxygenated with MTBE in that region.     

湘鄂赣农业资源与专业化区域化方向

湘鄂赣地理位置优越,农业资源丰富,稻谷、茶叶、麻类、棉花、油料、柑桔和淡水产品、禽蛋、肉类等在我国居有重要的地位,因此,大力发展三省农业生产,对我国人民实现小康生活具有战略意义。今后,要加速专业化区域化进程。我们找出生产潜力所在:改造低产田、低产园、低产水面;开发“三高”技术;开垦荒地、荒山、荒水;适当提高复种指数。通过建设,三省主要农产品将自给有余,还可满足国内外市场的需要。努力方向:高效农业开发——综合农业开发,吨粮田开发,玉米带开发,饲料稻开发,山区开发;合理布局农业生产;深化农业商品基地建设,发展综合利用,搞活商品流通;全面提高农业现代化水平,加强农业社会服务体系。     

Prognosis of the spatiotemporal dynamics of ecosystems by means of universal kriging

The use of quantitative data for constructing prognostic maps of the dynamics of ecosystem degradation and restoration by nonlinear simulation methods is a topical field of landscape ecology. This method of dynamic cartography is based on fiberwise comparison of data on the state of Chernye Zemli (the Kalmyk Republic, Russia) in different years and the detailed analysis of the period on which the prognosis was based. For this purpose, materials of repeated aerial and satellite photography obtained during a long period (1954–1993) were used. Comparison of maps characterizing the dynamics of Chernye Zemli between 1958 and 1993 allows prognostic electronic maps for the next 10–15 years (with a five-year interval) to be drawn and land prognosis for the next 20–30 years (1998–2023) to be obtained. Deceased     

Household water in rural asia: a case study of the construction of a piped water system in Bangui,Ilocos Norte,Philippines

In early 1980 an extension agent was assigned to the rural municipality of Bangui, Ilocos Norte, Philippines to work on development projects – in particular the improvement of the supply of safe water for drinking and sanitation. After many months of visiting spring sites and meeting with community leaders, a small part of the municipality was selected to build a gravity fed piped water system. Although the system took many months to plan, identify funding and construct, the 600 community members were ultimately rewarded with house to house connections that enabled them to achieve per capita water consumption levels above the minimum levels recommended by the World Health Organization. Of course, money was critical to ensure the project’s success, but many other factors played an equally critical role. For instance, without the active participation of the community and the unwavering support of the community leadership the project would not have survived the initial planning stage. Also, the extension agent played a critical role by acting as a conduit between funding agencies, the Bureau of Public Works and the community. The primary lesson to be learned from this experience is that the success of rural development projects is largely driven by the synergy between the community, technical support, financial support, and agents of change such as extension agents. If any of these ingredients had been lacking, the project result would likely have been far different.     

Distributions of personal VOC exposures: a population-based analysis

Information regarding the distribution of volatile organic compound (VOC) concentrations and exposures is scarce, and there have been few, if any, studies using population-based samples from which representative estimates can be derived. This study characterizes distributions of personal exposures to ten different VOCs in the U.S. measured in the 1999-2000 National Health and Nutrition Examination Survey (NHANES). Personal VOC exposures were collected for 669 individuals over 2-3 days, and measurements were weighted to derive national-level statistics. Four common exposure sources were identified using factor analyses: gasoline vapor and vehicle exhaust, methyl tert-butyl ether (MBTE) as a gasoline additive, tap water disinfection products, and household cleaning products. Benzene, toluene, ethyl benzene, xylenes chloroform, and tetrachloroethene were fit to log-normal distributions with reasonably good agreement to observations. 1,4-Dichlorobenzene and trichloroethene were fit to Pareto distributions, and MTBE to Weibull distribution, but agreement was poor. However, distributions that attempt to match all of the VOC exposure data can lead to incorrect conclusions regarding the level and frequency of the higher exposures. Maximum Gumbel distributions gave generally good fits to extrema, however, they could not fully represent the highest exposures of the NHANES measurements. The analysis suggests that complete models for the distribution of VOC exposures require an approach that combines standard and extreme value distributions, and that carefully identifies outliers. This is the first study to provide national-level and representative statistics regarding the VOC exposures, and its results have important implications for risk assessment and probabilistic analyses.     

Geographic Variation in the Seasonal Reproductive Strategy of the Mite Varroa jacobsoni in the Honeybee Nest

Variation in the reproduction of Varroa jacobsoni mite was studied in relation to the expansion of the range of its parasitism on the honeybee. Geographic differences in the seasonal dynamics of mite reproduction in the nests of bee families were revealed. Variation in the sex ratio of mites and the factors inhibiting their reproduction at the northern boundary of the honeybee range are considered. The forms of parthenogenetic reproduction in V. jacobsoni are discussed.     

Long-term increase in climatic dryness in the East-Mediterranean as evidenced for the island of Samos

The Eastern Mediterranean region is among the regions which were predicted to become drier under IPCC climate scenarios. Here, we document a gradual reduction of rainfall and tree growth and the loss of rural springs during the last decades of the twentieth century. Years with severe drought are associated with very low tree growth (dendrochronology) and dry falling of springs as evidenced by interviews with local stakeholders. The paper discusses the consequences of accelerating drought on natural vegetation and agriculture and points at the interaction with fire dynamics and economy, both likely to enhance the drought effect.