GDP and employment effects of policies to close the 2020 emissions gap

Four policies might close the gap between the global GHG emissions expected for 2020 on the basis of current (2013) policies and the reduced emissions that will be needed if the long-term global temperature increase can be kept below the 2 °C internationally agreed limit. The four policies are (1) specific energy efficiency measures, (2) closure of the least-efficient coal-fired power plants, (3) minimizing methane emissions from upstream oil and gas production, and (4) accelerating the (partial) phase-out of subsidies to fossil-fuel consumption. In this article we test the hypothesis of the International Energy Agency (IEA) that these policies will not result in a loss of gross domestic product (GDP) and we estimate their employment effects using the E3MG global macro-econometric model. Using a set of scenarios we assess each policy individually and then consider the outcomes if all four policies were implemented simultaneously. We find that the policies are insufficient to close the emissions gap, with an overall emission reduction that is 30% less than that found by the IEA. World GDP is 0.5% higher in 2020, with about 6 million net jobs created by 2020 and unemployment reduced.

Policy relevance

The gap between GHG emissions expected under the Copenhagen and Cancun Agreements and that needed for emissions trajectories to have a reasonable chance of reaching the 2 °C target requires additional policies if it is to be closed. This article uses a global simulation model E3MG to analyse a set of policies proposed by the IEA to close the gap and assesses their macroeconomic effects as well as their feasibility in closing the gap. It complements the IEA assessment by estimating the GDP and employment implications separately by the different policies year by year to 2020, by major industries, and by 21 world regions.     

Petrogenesis of Two Types of Archean TTGs in the North China Craton: A Case Study of Intercalated TTGs in Lushan and Non-intercalated TTGs in Hengshan

TTG(Tonalite-Trondhjemite-Granodiorite) gneisses,a major component of Precambrian continental crust,play a significant role in understanding the process and mechanism of the crustal evolution in the early periods of the Earth. In terms of field occurrence,there are two kinds of Archean TTGs in the NCC(North China Craton): intercalated and non-intercalated TTGs. In this contribution,we make a comprehensive comparison of these two types of TTGs from the typical areas(Lushan and Hengshan) in the NCC with an aim to constrain their petrogenesis. The results suggest that they have similar mineral assemblages of Pl + Qtz + Bt ± Amp ± Kfs but different field appearances and geochemical compositions,thus probably reflecting different source materials and tectonic settings. Differences in the contents of characteristic elements,such as Sr,REE and HFSE,suggest that the nonintercalated TTGs in Hengshan were generated at deeper levels than those of intercalated TTGs in Lushan. Constraints from element contents and geochemical modeling results are consistent with derivation from dual sources involving both garnet amphibolite and rutile-bearing eclogite residues for the non-intercalated TTGs in Hengshan,whereas the compositions of intercalated TTGs in Lushan indicate that they were formed by partial melting with amphibolite to garnet-amphibolite residues. Moreover,accumulation of plagioclase is also required in the petrogenesis of intercalated TTGs in Lushan,at least for part of them. In addition,the non-intercalated TTGs in Hengshan display distinctly higher Mg O,Mg#,Cr and Ni values and lower SiO_2 average contents compared to the intercalated TTGs in Lushan. These features suggest that the former magma,at least a part,might have interacted with the mantle wedge during ascent. Considering all the above factors and in combination with the whole-rock Nd and zircon Hf isotopic data,it is suggested that the non-intercalated TTGs in Hengshan were produced by partial melting of subducted slab contaminated by the overlying mantle wedge at deeper levels and high pressures,whereas the intercalated TTGs in Lushan were generated by melting of the thickened lower crust at lower pressures and shallower depths. The tectonic settings of the two types of TTGs shed new light on the growth of the NCC.     

Enhalus acoroides responses to experimental shoot density reductions in Haad Chao Mai National Park,Trang Province,Thailand

The effect of self‐shading and competition for light in the seagrass Enhalus acoroides were investigated with a density reduction experiment in Haad Chao Mai National Park, Trang Province, Thailand. The study was carried out in a monospecific meadow with a natural density of 141.0 ± 8.7 shoots·m^?2. The intent was to determine the response of E. acoroides beds to loss of shoots and thinning, which often occur during typhoons and severe storm activity. Permanent quadrats were manipulated by clipping the seagrass shoots to 140, 72, 36 and 16 shoots·m^?2, to yield natural, 50%, 25% and 10% densities, respectively. Reducing shoot density in E. acoroides increased underwater light intensity below the canopy, generating increased leaf surface area and shoot weight. Seagrass leaf width, growth rate, and number of leaves per shoot also increased with greater light. The extent of flowering varied among treatments with no consistent trend. Our results demonstrate that increasing the available light to E. acoroides produces an increasing leaf size response as self‐shading in the bed is reduced.     

温度、盐度和光照对浒苔生长和光合作用的影响

Intensive Pyropia aquaculture in the coast of southwestern Yellow Sea and its subsequent waste, including disposed Ulva prolifera, was speculated to be one of the major sources for the large-scale green tide proceeding in the Yellow Sea since 2007. It was, however, unclear how the detached U. prolifera responded and resumed growing after they detached from its original habitat. In this study, we investigated the growth and photosynthetic response of the detached U. prolifera to various temperature, salinity and irradiance in the laboratory. The photosynthetic rate of the detached U. prolifera was significantly higher at moderate temperature levels(14–27°C)and high salinity(26–32), with optimum at 23°C and 32. Both low(14°C) and highest temperature(40°C), as well as low salinity(8) had adverse effects on the photosynthesis. Compared with the other Ulva species, U. prolifera showed higher saturated irradiance and no significant photoinhibition at high irradiance, indicating the great tolerance of U. prolifera to the high irradiance. The dense branch and complex structure of floating mats could help protect the thalli and reduce photoinhibition in field. Furthermore, temperature exerted a stronger influence on the growth rate of the detached U. prolifera compared to salinity. Overall, the high growth rate of this detached U. prolifera(10.6%–16.7% d~(–1)) at a wide range of temperature(5–32°C) and salinity(14–32) implied its blooming tendency with fluctuated salinity and temperature during floating. The environmental parameters in the southwestern Yellow Sea at the beginning of green tide were coincident with the optimal conditions for the detached U. prolifera.     

放养密度对大杂交鲟生长性能的影响及生理应答机制

为探讨放养密度对鱼类生长及生理应答机制的影响规律和作用,作者以大规格大杂交鲟(达氏鳇(Huso dauricus)♀×施氏鲟(Acipenser schrenckii)♂)为实验材料,研究了平均初始体质量约为243 g/尾,放养密度分别为6(SD1组)、9(SD2组)、12(SD3组)、15 kg/m3(SD4组)条件下,不同放养密度处理70 d后的实验鱼生长性能变化及生理应答机制。结果显示,放养密度对大杂交鲟肥满度影响不显著,SD2组鱼类具有最大的特定生长率和生长效率,随着放养密度增加,日增质量显著降低(P0.05),特定生长率和生长效率下降。测定了血液甲状腺素(T4)、三碘甲腺原氨酸(T3)和皮质醇水平变化,发现放养密度能引起大杂交鲟3个血液生理指标发生显著改变;随着养殖时间推移,T3和皮质醇浓度显著升高,T4浓度显著下降(P0.05)。这些结果说明神经内分泌活动的变化引起大杂交鲟血液生理指标变化,进而影响实验鱼生长性能。因此,在该养殖条件下推荐的养殖密度为9 kg/m3。     

文蛤早期发育阶段生长性状遗传参数的估计

采用部分因子设计构建了23个全同胞家系,应用单性状及两性状动物模型对文蛤(Meretrix meretrix)早期不同生长发育时期的生长性状进行遗传力和相关性估计。结果表明,文蛤附着变态期以及稚贝期生长性状的遗传力并无显著差别,在0.11~0.41范围内变化,属于中等遗传力。非遗传的共同环境效应随着年龄的增长而呈现上升趋势,由附着变态期的0.02逐渐增加到稚贝期的0.38,且稚贝期的共同环境效应显著大于其附着变态期(P0.01)。壳长与壳高表型相关和遗传相关的分析结果显示,从附着变态期到稚贝期,壳长与壳高之间的表型相关及遗传相关都存在极显著的正相关性,相关系数的范围分别为0.84~0.95、0.93~0.99。早期发育连续时间段生长性状之间的遗传相关均为正相关,但并不显著,且不同时期的遗传相关也不尽相同(0.34~0.71)。     

Ecosystem services assessment and compensation costs for installing seaweed farms

In a global context of promotion and expansion of blue growth initiatives, the development of activities such as aquaculture calls for the assessment of the potential impacts on biodiversity at different levels and associated services. This paper presents an assessment of the potential impact of the installation of seaweed farms on ecosystem services and the induced compensation costs. Biophysical and socioeconomic indicators have been developed for helping decision makers to select the most suitable locations. The approach considers a multi-criteria approach based on Geographical Information Systems (GIS) and Habitat Equivalency Analysis (HEA). The former is used to obtain biophysical ecosystem services and socioeconomic indicators and the latter to evaluate the costs required to compensate the loss of cultural and provisioning ecosystem services. A case-study in the Normand-Breton (Saint Malo) Gulf, France, illustrates this method through the analysis of hypothetical locations of seaweed farms. Results highlight the differences between alternative locations regarding biophysical constraints (in terms of distance and depth), potential risks of conflicts with existing uses, impacts on habitats and the ecosystem services delivered, and compensation costs. This case-study illustrates the flexibility of this approach which can be further adapted to include other indicators in order to deliver integrated information to coastal planners.     

上海中心城就业中心体系测度————基于手机信令数据的研究

利用手机信令数据识别上海市域内手机用户的工作地和居住地,获取就业者的通勤数据,测度上海中心城的就业中心体系.首先用就业者工作地数据生成就业密度分布图,基于中心城的就业密度识别就业中心.随后,用就业者工作地和居住地数据分别从就业密度和通勤联系两方面测度各中心的能级,分析各中心的腹地和势力范围.研究发现:① 上海中心城的就业中心呈主中心强大的弱多中心体系;② 就业密度越高的中心与其他地区的通勤联系一般也越强,但通勤联系在各中心间的差异更显著;③ 能级越高的中心腹地面积越大,但势力范围不一定越大;④ 相比于能级,职住功能混合度对职住平衡的影响更大;⑤缺少就业中心的地区势力范围呈交替状.本研究一定程度上能有助于解决既往就业中心体系研究因空间单元较大,缺少通勤数据在中心识别,通勤联系测度等方面受到的局限,希望能为构建上海中心城就业多中心体系提供帮助.     

Age and growth of Cape stumpnose Rhabdosargus holubi (Pisces: Sparidae) in the Eastern Cape,South Africa

Rhabdosargus holubi is a small (maximum weight=2.4?kg) yet important fishery species in the estuaries of the south-east coast of South Africa. Little is known of its biology and specifically its growth rate, which is essential for sustainable management of the fishery. We examined and counted the opaque zones in the sectioned otoliths of 134 R. holubi to determine its age and growth parameters. The otoliths from two recaptured fish marked with oxytetracycline confirmed that one opaque zone was deposited annually. The species reached a maximum age of 18 years and growth was adequately described by a von Bertalanffy growth function of the form: L_t = 358.1 (1 – e^{?0.24(t+0.77)}) mm fork length. There were no significant differences between any of the male and female growth parameters (likelihood ratio test: p = 0.3). The growth was slow (omega index: ω = 86.56); however, despite this, the unique life history of R. holubi may provide a degree of resilience to heavy fishing pressure in estuaries.     

藏北羌塘中部日湾茶卡地区晚三叠世安山岩与闪长质包体岩石成因及地质意义

龙木错-双湖-澜沧江缝合带将羌塘板块划分为南、北2个次级板块,在缝合带两侧大规模发育晚三叠世岩浆作用,并伴随大量的高压超高压变质岩。在缝合带以南的日湾茶卡地区识别出一套安山岩,其中发育大量的暗色闪长质捕虏体,锆石U-Pb测年结果在安山岩中获得了364.7±1.9Ma和223.9±1.3Ma两组年龄信息,锆石原位Hf同位素测试结果εHf(t)分别为+7.22~+8.69和-5.94~-4.14。结合羌塘中部已有的研究成果,认为闪长质捕虏体形成于晚泥盆世洋壳俯冲背景,是地幔楔部分熔融底侵至地壳的产物;而安山岩形成于晚三叠世碰撞后伸展背景,是深部板片断离机制下深俯冲陆壳边缘一侧熔体混染晚泥盆世新生地壳的产物。安山岩中闪长质捕虏体的发现支持了俯冲带作为大陆生长的重要场所的观点。