The social cost of carbon revisited

An estimate of the social cost of carbon (SCC) is crucial to climate policy. But how should we estimate the SCC? A common approach uses an integrated assessment model (IAM) to simulate time paths for the atmospheric CO₂ concentration, its impact on temperature, and resulting reductions in GDP. I have argued that IAMs have deficiencies that make them poorly suited for this job, but what is the alternative? I present an approach to estimating an average SCC, which I argue can be a useful guide for policy. I rely on a survey of experts to elicit opinions regarding (1) probabilities of alternative economic outcomes of climate change, but not the causes of those outcomes; and (2) the reduction in emissions required to avert an extreme outcome, i.e., a large climate-induced reduction in GDP. The average SCC is the ratio of the present value of lost GDP from an extreme outcome to the total emission reduction needed to avert that outcome. I discuss the survey instrument, explain how experts were identified, and present results. I obtain SCC estimates of $200/mt or higher, but the variation across experts is large. Trimming outliers and focusing on experts who expressed a high degree of confidence in their answers yields lower SCCs, $80 to $100/mt, but still well above the IAM-based estimates used by the U.S. government.     

碳中和目标下的北京城市道路移动源CO2和大气污染物协同减排效应研究

为实现2060年碳中和目标,研究北京城市道路移动源CO_2和大气污染物(CO、NO_x、PM_(2.5))的协同减排效应。本文以2016年为基准年,建立CO_2和大气污染物排放量的LEAP模型,设计三种政策情景,预测到2060年各类污染物排放量,并通过减排效应坐标系分析和减排弹性系数法研究不同措施下CO_2和大气污染物的协同减排效应。结果显示,综合政策情景的减排作用最好,且协同减排效应最显著,但在2060年无法实现碳中和目标;单一措施情景下,严格排放标准措施的协同减排效果有限,但对各污染物的减排协同性最优,推广公共交通减排协同性次之,发展新能源车辆措施具有较好的协同减排效果,但对CO_2—CO和CO_2—PM_(2.5)的减排协同度较差。对此,本文提出应加快推动交通能源结构转型,在新能源车取代燃油类机动车的同时,要不断减少天然气类车型的比例,尽可能实现"电能+新能源汽车"的零排放能源结构;还要加严机动车排放标准限值以加强CO_2和大气污染物的减排协同度;制定相应的机动车CO_2和大气污染物协同排放限值标准目标,构建CO_2与大气污染物排放协同管理体系等建议。     

“大气十条”实施后大气污染协同治理政策的量化研究

针对大气污染问题,2013年国务院颁布了《大气污染防治行动计划》,从更高层次上实施国家及区域层面的大气污染协同治理战略。区域联合防控及协同治理是当前情况下治理好大气污染的必然选择,但是尚未形成完整的体系。收集整理了100篇大气污染协同治理相关政策文件,构建了政策工具量化的二维分析框架,探讨了当前对大气污染协同治理的政策工具使用情况,并针对性地提出了强化命令型政策工具、弥补能力型建设工具、完善奖惩福利机制、完善监督监测预警系统等一系列政策建议。     

山东省产业政策战略环境评价

战略环境影响评价(StrategicEnvironmentalAssessment,简称SEA)是环境影响评价在战略决策层次上的应用,是实现可持续发展战略的重要手段。首先阐述了产业政策SEA的内涵,分析论述了产业政策对环境的影响和山东省产业政策SEA的必要性,建立了山东省产业政策SEA的理论基础,最后提出了山东省产业政策SEA的初步研究框架。     

Focus and social contagion of environmental organization advocacy on Twitter

Agriculture, overexploitation, and urbanization remain the major threats to biodiversity in the Anthropocene. The attention these threats garner among leading environmental nongovernmental organizations (eNGOs) and the wider public is critical in fostering the political will necessary to reverse biodiversity declines worldwide. I analyzed the advocacy of leading eNGOs on Twitter by scraping account timelines, screening content for advocacy relating to biodiversity threats and, for prevalent threats, further screening content for positive and negative emotional language with a sentiment lexicon. Twitter advocacy was dominated by the major threats of climate change and overexploitation and the minor threat of plastic pollution. The major threats of agriculture, urbanization, invasions, and pollution were rarely addressed. Content relating to overexploitation and plastic pollution was more socially contagious than other content. Increasing emotional negativity further increased social contagion, whereas increasing emotional positivity did not. Scientists, policy makers, and eNGOs should consider how narrowly focused advocacy on platforms like Twitter will contribute to effective global biodiversity conservation.     

Addressing behavior in pollinator conservation policies to combat the implementation gap

Solutions for conserving biodiversity lie in changing people's behavior. Ambitious international and national conservation policies frequently fail to effectively mitigate biodiversity loss because they rarely apply behavior-change theories. We conducted a gap analysis of conservation behavior-change interventions advocated in national conservation strategies with the Behavior Change Wheel (BCW), a comprehensive framework for systematically characterizing and designing behavior-change interventions. Using pollinator conservation as a case study, we classified the conservation actions listed in national pollinator initiatives in relation to intervention functions and policy categories of the BCW. We included all national-level policy documents from the European Union available in March 2019 that focused on conservation of pollinators (n = 8). A total of 610 pollinator conservation actions were coded using in-depth directed content analysis, resulting in the identification of 787 intervention function and 766 policy category codes. Overall, these initiatives did not employ the entire breadth of behavioral interventions. Intervention functions most frequently identified were education (23%) and environmental restructuring (19%). Least frequently identified intervention functions were incentivization (3%), and restriction (2%) and coercion were completely absent (0%). Importantly, 41% of all pollinator conservation actions failed to identify whose behavior was to be changed. Building on these analyses, we suggest that reasons for the serious implementation gap in national and international conservation policies is founded in insufficient understanding of which behavioral interventions to employ for most beneficial impacts on biodiversity and how to clearly specify the intervention targets. We recommend that policy advisors engage with behavior-change theory to design effective behavior-change interventions that underpin successful conservation policies.     

我国农村能源政策以及收入水平对农户生活能源需求的影响研究

针对传统能源使用过程中产生的环境、气候问题,由中央政府制定并实施的农村能源政策倡导农户使用多种清洁能源及技术。同时,商品能源逐步成为当下农户生活能源的重要组成部分。“并举式”的能源政策是否造成甚至扩大不同能源、技术的需求差异,这一结果是否符合政策的初衷和目标?基于此,论文研究并分析2005—2014年农村能源政策以及收入水平对农户生活能源需求的影响。结果表明：政策的实施加剧了存在替代关系的能源、技术需求间的此消彼长;政策的溢出效应促进了部分商品能源需求;收入的提高对部分能源需求产生了正向作用。建议制定兼顾清洁能源以及商品能源的农村能源发展战略和政策,实现政策的精准发力,同时加强能源基础设施的建设和管理。     

Internal cycle modeling and environmental assessment of multiple cycle consumer products

Dynamic annual flow models incorporating consumer discard and usage loss and featuring deterministic and stochastic end-of-cycle (EOC) return by the consumer are developed for reused or remanufactured products (multiple cycle products, MCPs), including fast and slow cycling, short and long-lived products. It is shown that internal flows (reuse and overall consumption) increase proportionally to the dimensionless internal cycle factor (ICF) which is related to environmental impact reduction factors. The combined reuse/recycle (or cycle) rate is shown capable for shortcut, albeit effective, monitoring of environmental performance in terms of waste production, virgin material extraction and manufacturing impacts of all MCPs, a task, which physical variables (lifetime, cycling frequency, mean or total number of return trips) and conventional rates, via which environmental policy has been officially implemented (e.g. recycling rate) cannot accomplish. The cycle rate is shown to be an increasing (hyperbolic) function of ICF. The impact of the stochastic EOC return characteristics on total reuse and consumption flows, as well as on eco-performance, is assessed: symmetric EOC return has a small, positive effect on performance compared to deterministic, while early shifted EOC return is more beneficial. In order to be efficient, environmental policy should set higher minimum reuse targets for higher trippage MCPs. The results may serve for monitoring, flow accounting and comparative eco-assessment of MCPs. They may be useful in identifying reachable and efficient reuse/recycle targets for consumer products and in planning return via appropriate labelling and digital coding for enhancing environmental performance, while satisfying consumer demand.     

中国再生资源产业管理政策体系分析

中国再生资源产业发展离不开国家政策的支持。归类梳理和分析相关政策有利于把握现有政策体系的内在联系,实现整体的政策改进。提出中国现有关于再生资源产业的管理政策可以归纳为5个方面:再生资源回收和利用综合性管理、再生资源回收体系专门管理、环境保护领域固体废弃物管理、资源综合利用和废物进口管理。在此基础上,揭示相关政策间的层次关系和内在联系,并加以综合评价。     

农业可持续发展状态评价指标(体系)框架及其分析

通过对农业活动、农业政策与农业环境变化关系的研究,提出了反映农业可持续发展状态的指标结构以及面向农业决策的状态指标分析框架,建议采用“离差法”来评价农业系统的可持续发展状态,其评价结果可以用来判断和制定正确的农业政策;同时还论述了状态评价的具体方法、步骤及评价标准