Quantifying 21st-century France climate change and related uncertainties

We tackle here the question of past and future climate change at sub-regional or country scale with the example of France. We assess France climate evolution during the 20th and 21st century as simulated by an exhaustive range of global climate simulations. We first show that the large observed warming of the last 30 years can be simulated only if anthropogenic forcings are taken into account. We also suggest that human influence could have made a substantial contribution to the observed 20th century multi-decadal temperature fluctuations. We then show that France averaged annual mean temperature at the end of the 21st century is projected to be on the order of 4.5 K warmer than in the early 20th century under the radiative concentration pathways 8.5 (RCP8.5) scenario. Summer changes are greater than their winter counterpart (6 K versus 3.7 K). Near-future (2020–2049) changes are on the order of 2.1 K (with 2.6 K in summer and 1.8 K in winter). Model projections also suggest a substantial summer precipitation decrease (−0.6 mm/day), in particular over southern France, and a moderate winter increase, (0.3 mm/day), mostly over the northernmost part of France. Uncertainties about the amplitude of these precipitation changes remain large. We then quantify the various sources of uncertainty and study how their ranking varies with time. We also propose a physically-based metric approach to reduce model uncertainty and illustrate it with the case of summer temperature changes. Finally, timing and amplitude of France climate change in case of a global average 2-K warming are investigated. Aggressive mitigation pathways (such as RCP2.6) are absolutely required to avoid crossing or barely exceeding the 2-K global threshold. However, France climate change requiring adaptation measures is still to be expected even if we achieve to remain below the 2-K global target.     

The case for intensity targets

Abstract

While most of the world has pursued absolute emission limits for greenhouse gases, the Bush administration has proposed an alternative policy formulation based, among other things, on reducing emissions intensity—that is, emissions per dollar of real gross domestic product (GDP). Critics of this formulation have denounced the general idea of an intensity-based emission target, along with its voluntary nature and modest targets. This raises the question of whether intensity-based emission limits, distinct from the other features of the Bush initiative, offer a useful alternative to absolute emission limits. This essay makes the case that they do, based on how emission targets are framed. The argument draws on four key observations: greenhouse gas emissions will continue to rise over the near term; absolute targets emphasize zero or declining emissions growth while intensity targets do not; developing countries' economic development is integrally tied to emissions growth for the foreseeable future; and intensity targets need not be any more complicated to administer than absolute targets.     

A Review of “An Everyday Geography of the Global South”

Human interactions with the marine environment and pollution hold broad lessons for understanding environmental change. Expanding geographical inquiry beyond its traditional, land-based foci and delving deeper into marine environment and risk issues offers fruitful avenues by which to elaborate and refine our understanding of nature-society relationships. I present a case study of marine petroleum transportation risks in the Straits of Malacca to illustrate the complex history of political and economic processes across a range of scales and shaping the risks in the Straits. The inescapable tension between generalizing global social and environmental processes and recognizing the array of local differences drives ongoing policy debates in the Straits, as it does increasingly for many global environmental problems.     

Technical characteristics of a solar geoengineering deployment and implications for governance

ABSTRACT

Consideration of solar geoengineering as a potential response to climate change will demand complex decisions. These include not only the choice of whether to deploy solar engineering, but decisions regarding how to deploy, and ongoing decision-making throughout deployment. Research on the governance of solar geoengineering to date has primarily engaged only with the question of whether to deploy. We examine the science of solar geoengineering in order to clarify the technical dimensions of decisions about deployment – both strategic and operational – and how these might influence governance considerations, while consciously refraining from making specific recommendations. The focus here is on a hypothetical deployment rather than governance of the research itself. We first consider the complexity surrounding the design of a deployment scheme, in particular the complicated and difficult decision of what its objective(s) would be, given that different choices for how to deploy will lead to different climate outcomes. Next, we discuss the on-going decisions across multiple timescales, from the sub-annual to the multi-decadal. For example, feedback approaches might effectively manage some uncertainties, but would require frequent adjustments to the solar geoengineering deployment in response to observations. Other decisions would be tied to the inherently slow process of detection and attribution of climate effects in the presence of natural variability. Both of these present challenges to decision-making. These considerations point toward particular governance requirements, including an important role for technical experts – with all the challenges that entails.

Key policy insights

• Decisions about solar geoengineering deployment will be informed not only by political choices, but also by climate science and engineering.

• Design decisions will pertain to the spatial and temporal goals of a climate intervention and strategies for achieving those goals.

• Some uncertainty can be managed through feedback, but this would require frequent operational decisions.

• Some strategic decisions will depend on the detection and attribution of climatic effects from solar geoengineering, which may take decades.

• Governance for solar geoengineering deployment will likely need to incorporate technical expertise for making short-term adjustments to the deployment and conducting attribution analysis, while also slowing down decisions made in response to attribution analysis to avoid hasty choices.

     

中国大陆动力学研究进展——纪念中国地球物理学会成立60周年

本文简要地回顾了中国大陆动力学研究发展的历史、特点和主要成果,存在的主要问题,提出相应的改进建议.(1)我国大陆动力学研究是从1926年李四光发表《地球表面形象变化之主因》一文开始的,他肯定大陆漂移说的革命意义和不足之处,提倡和坚持了用力学原理研究地壳运动和变形,主张用多学科方法,构造体系的观点对构造运动和变形进行概括,强调要从原理上探究地质作用的发生是否可行等等,这是中国的光荣传统之一.(2)当代大陆动力学的研究是以深部调查为基础,以岩石圈为研究对象,进行三维演化的探讨.提出它是以地质学、地球物理学,地球化学,大地测量学,地质力学和高温高压实验地质学理论知识为基础的综合性学科.是研究地球成矿作用、地震火山地质灾害发生机制的基础.这是当代地球科学发展的主要趋向,且日趋深入和扩大.(3)我国深部调查工作是1958~1962曾融生在柴达木盆地所作地震测深试验开始的.从上世纪80年代扩大了工作规模,并随着国际地学的发展而不断深入和扩大,先后工作在青藏高原,大别山变质岩带,秦岭造山,华南花岗岩区,以及南海新生边缘海盆等地区,现在又转向天山造山带和华北大陆地区（研究大陆减薄与裂解问题.此外,还结合全国地震带,成矿带进行工作.已获得了丰富的科学成果,引起国际地学界的重视.(4)工作的主要体会是：如,深部研究要以地壳上地幔为对象,并力求结合实际资源、环境科学问题的探讨,以利于深化认识;要坚持多学科综合应用,特别是加强构造动力学的分析,提高深部探测技术,处理方法和软件水平,重视深源包体采集和研究;大陆深钻应与综合调查紧密结合;要以我为主积极与外国合作,与国际接轨,不能盲目跟“风”.(5)提出我国大陆动力学研究存在“一少”、“二乱”、“三假”、“四霸”的现象,及其产生的根源作了分析,并提出改进的对策建议.当前更需要我们有 “志气”走出一条自己的路,创造一个好的学术“环境”.     

A simplified urban-extent algorithm to characterize surface urban heat islands on a global scale and examine vegetation control on their spatiotemporal variability

We develop a new algorithm, the simplified urban-extent (SUE) algorithm, to estimate the surface urban heat island (UHI) intensity at a global scale. We implement the SUE algorithm on the Google Earth Engine platform using Moderate Resolution Imaging Spectroradiometer (MODIS) images to calculate the UHI intensity for over 9500 urban clusters using over 15 years of data, making this one of the most comprehensive characterizations of the surface UHI to date. The results from this algorithm are validated against previous multi-city studies to demonstrate the suitability of the method. The dataset created is then filtered for elevation differentials and percentage of urban area and used to estimate the diurnal, monthly, and long-term variability in the surface UHI in different climate zones. The global mean surface UHI intensity is 0.85 °C during daytime and 0.55 °C at night. Cities in arid climate show distinct diurnal and seasonal patterns, with higher surface UHI during nighttime (compared to daytime) and two peaks throughout the year. The diurnal variability in surface UHI is highest for equatorial climate zone (0.88 °C) and lowest for arid zone (0.53 °C). The seasonality is highest in the snow climate zone and lowest for equatorial climate zone. While investigating the change in the surface UHI over a decade and a half, we find a consistent increase in the daytime surface UHI in the urban clusters of the warm temperate climate zone (0.04 °C/decade) and snow climate zone (0.05 °C/decade). Only arid climate zones show a statistically significant increase in the nighttime surface UHI intensity (0.03 °C/decade). Globally, the change is mainly seen during the daytime (0.03 °C/decade). Finally, the importance of vegetation differential between urban and rural areas on the spatiotemporal variability is examined. Vegetation has a strong control on the seasonal variability of the surface UHI and may also partly control the long-term variability. The complete UHI data are available through this website (https://yceo.yale.edu/research/global-surface-uhi-explorer) and allows the user to query the UHI of urban clusters using a simple interface.     

融合GOCE和GRACE卫星数据的无约束重力场模型Tongji-GOGR2019S

本文在法方程层面融合GOCE卫星的V_xx、V_yy、V_zz和V_xz重力梯度分量观测数据和GRACE卫星观测数据,采用直接法解算了220阶次的重力场模型Tongji-GOGR2019S.首先利用ⅡR带通滤波器在5~41 mHz的重力梯度带宽范围内对约24个月的GOCE重力梯度观测方程进行无相移滤波处理,并组成解算220阶次重力场模型的法方程,各梯度分量根据相对于参考模型统计精度进行定权;然后与13.5 a GRACE数据建立的180阶次Tongji-Grace02s重力场模型的法方程进行叠加,解算了220阶次的无约束纯卫星重力场模型Tongji-GOGR2019S.利用EIGEN-6C4重力场模型、GNSS/水准数据、DTU15重力异常数据以及欧洲区域似大地水准面模型EGG2015等数据对Tongji-GOGR2019S模型精度进行全面的检核评定,结果表明：引入GOCE卫星梯度数据后,高于72阶的位系数精度优于Tongji-Grace02s模型,Tongji-GOGR2019S模型的整体精度接近同阶次的DIR-R6等GOCE卫星第6代模型.     

论南海海洋治理——基于墨家哲学在新型国际关系上的嵌入

立足于中国哲学与地缘政治相融合的视角,通过解构地缘政治视角下的南海海洋治理问题,对比分析百家争鸣中墨家哲学对南海治理的价值作用,针对南海海洋治理提取墨家哲学的理念要点,尝试构建墨家哲学在南海海洋治理上的实践指导体系,研究表明：1）域内治理目标的不清晰和治理保障的不落地,以及域外大国的介入和国际组织发挥的作用有限,共同造成南海海洋治理的困境。2）南海海洋治理以自然海洋与人文海洋的统一为治理客体,以主权国家为最主要的行为主体,需要国家主体间的协同治理。3）从墨家哲学中提取1个核心要点、3个指导要义和4个关键要素,应用于南海海洋治理。在战略功能上以“兼爱非攻”和“义利一体”为价值取向,打破现实主义国际关系局限,以“功利主义”和“志功合一”为行为标准,促进新型国际关系合作;在实操路径上,要嵌入墨家哲学的“法”要素,以规范和标准为牵引,并嵌入墨家哲学的“求”“节”“巧”要素,以科技创新为驱动。     

地方性知识与空间治理——以苏州东山内圩治理为例

太湖流域水环境综合治理既是一项环境治理任务,也是一项空间治理工程,它涉及太湖沿岸土地利用方式的改变。以人类学家吉尔兹关于局外人对局内人地方性知识的语义理解为学术对话观点,以苏州东山内圩地区为研究区域,采用访谈法、资料分析法、对比法,寻找规划专家的科学知识与当地养殖户地方性知识的语义“原型”。研究发现：① “长度”是“合理规划养殖水塘”的语义“原型”。语义“原型”的发掘使专家在设计空间治理指标时,可采纳养殖户的地方性知识,也为养殖户理解空间治理指标、更新其地方性知识提供可能性。② 地方性知识不单由当地人创造,还在内外两类人群的互动中不断更新。在该过程中,准局外人发挥着知识对接的桥梁作用。当地人的地方性知识没有考虑宏观区域的可持续发展,而专家的全局视野会帮助当地人改进地方性知识。     

Global aquaculture growth and institutional quality

The global aquaculture sector has grown continuously over the past 40 years, though unevenly among countries. Differences in factors such as inputs, climate, management, technology, markets, social environment, and institutions might be reasons for the disparities in growth. This study focuses on institutions, by analyzing the relationship between annual growth in the production of the major aquaculture countries and the quality of their institutions over three decades (1984–2013). Based on an ex-ante set of criteria, seventy-four aquaculture countries from five different regions - Africa, the Americas, Asia, Europe and Oceania - were selected. Annual percentage change in total aquaculture production, in terms of quantity and value, was used as a proxy for sector development. Three indices - governance, corruption, and competitiveness - were used as institutional quality proxies. Empirical results suggest that the aquaculture growth did not significantly correlate with the quality of institutions. By region, Africa had the fastest growth in the aquaculture sector, though from a low base, with 7.35% and 9.28% higher annual percentage change in aquaculture quantity and value respectively, than the Asian region. While, the European region experienced significantly lower annual percentage change in aquaculture quantity, a difference of 3.78% compared to the Asian region. Furthermore, the study found that total aquaculture production was not positively correlated with eco-label certification. The study is concluded by discussing the “aquaculture paradox.”