Antarctica and global change

The Antarctic region of the globe is of special importance for a wide range of studies of global change. The IGBP research activities needing special focus for global change should be multidisciplinary, should involve both the geosphere and the biosphere, and should be of global as well as local interest. There are a number of important Antarctic research topics which fit these criteria.A decrease of Antarctic sea ice has a positive feedback on global warming. Reduction in the sea ice also impacts on deep ocean circulation and can give a positive feedback to the increase of atmospheric carbon dioxide by the reduction of a deep ocean sink. Changes in the mass balance of the Antarctic ice sheet impact on global sea level. A unique historic record of past climate and global environmental changes is being obtained from deep core drilling in the Antarctic ice sheet. Decreases of stratospheric ozone are most pronounced over the Antarctic in spring. The impact of increases in ultraviolet radiation on the biosphere can be studied in the Antarctic as a precurser to possible changes developing elsewhere around the globe. Changes in the atmosphere and ocean circulations resulting from the decrease in Antarctic sea ice cover can have important effects on ocean surface temperatures which impact on the climates of the continents.These topics are discussed briefly and a number of Antarctic research areas are highlighted which build on existing or planned international programmes and which can make critical contributions to multidisciplinary studies of global change.     

A Review of Decadal／Interdecadal Climate Variation Studies in China

Decadal/interdecadal climate variability is an important element in the CLIVAR (Climate Variability and Predictability) and has received much attention in the world. Many studies in relation to interdecadal variation have also been completed by Chinese scientists in recent years. In this paper, an introduction in outline for interdecadal climate variation research in China is presented. The content includes the features of interdecadal climate variability in China, global warming and interdecadal temperature variability,the NAO (the North Atlantic Oscillation)/NPO (the North Pacific Oscillation) and interdecadal climate variation in China, the interdecadal variation of the East Asian monsoon, the interdecadal mode of SSTA(Sea Surface Temperature Anomaly) in the North Pacific and its climate impact, and abrupt change feature of the climate.     

Lightning and climate: A review

Research on regional and global lightning activity and the global electrical circuit is summarized. This area of activity has greatly expanded through observations of lightning by satellite and through increased use of the natural (Schumann) resonances of the Earth–ionosphere cavity. The global electrical circuit provides a natural framework for monitoring global change on many time scales. Lightning is responsive to temperature on many time scales, but the sensitivity to temperature appears to diminish at the longer time scales.     

“Reporting on climate change: A computational analysis of U.S. newspapers and sources of bias, 1997–2017”

News organizations constitute key sites of science communication between experts and lay audiences, giving many individuals their basic worldview of complex topics like climate change. Previous researchers have studied climate change news coverage to assess accuracy in reporting and potential sources of bias. These studies typically rely on manually coding articles from a handful of prestigious outlets, not allowing comparisons with smaller newspapers or providing enough diversity to assess the influence of partisan orientation or localized climate vulnerability on content production. Making these comparisons, this study indicates that partisan orientation, scale of circulation, and vulnerability to climate change correlate with several topics present in U.S. newspaper coverage of climate change. After assembling a corpus of over 78,000 articles covering two decades from 52 U.S. newspapers that are diverse in terms of geography, partisan orientation, scale of circulation, and objectively measured climate risk, a coherent set of latent topics were identified via an automated content analysis of climate change news coverage. Topic model results indicate that while outlet bias does not appear to impact the prevalence of coverage for most topics surrounding climate change, differences were evident for some topics based on partisan orientation, scale, or vulnerability status, particularly those relating to climate change denial, impacts, mitigation, or resource use. Overall, this paper provides a comprehensive study of U.S. newspaper coverage of climate change and identifies specific topics where outlet bias constitutes an important contextual factor.     

海冰在大气环流模式中的重要作用

文章简要综述了次网格尺度海冰非均匀性对大气环流模式性能的影响；南极冰在全球环流和短期气候变化中的作用；以及模式中不同的海冰反照率参数化对地表温度和辐射的影响等研究结果．说明海冰对极地海洋和大气的能量收支及短期气候变化有重要作用，不同的海冰参数化方案对气候模拟结果有重要影响．     

土地利用和土地覆盖变化对气候系统影响的研究进展

土地利用和土地覆盖变化（LUCC或LULCC）不仅对人类赖以生存的地球环境有重要影响,同时与人类福祉密切联系。人类活动对气候的强迫不仅包括温室气体排放导致的气候变暖,还通过直接改变地表物理性状以及间接改变其他生物地球物理过程和生物地球化学过程等对气候系统产生深刻影响。作者在此认识的基础上回顾了LUCC对气候系统影响的研究历史,结合新近的研究结果归纳了诸如森林砍伐、城市化、修坝等LUCC活动在区域和全球尺度的气候效应。LUCC具有高度的空间异质性,因此气候系统对它的反馈也具有明显的空间差异。由于全球平均后变化幅度相对区域上的小,LUCC对区域气候影响显著,而对全球气候影响不明显。它对区域气候的影响取决于反照率、蒸散发效率和地表粗糙率等变化的综合效应：在热带地区LUCC主要引起温度升高,在高纬度地区使温度下降。在全球尺度上LUCC导致气候的变暖主要通过减少蒸散发和潜热通量引起陆表水循环的改变,其次通过改变地表反照率导致辐射强迫改变。最后指出目前LUCC在气候变化学科中的研究所存在的问题。在此基础上提出了未来的研究首先需要评估的3个气候指标,并提倡多学科间的相互合作。     

Understanding variations and seasonal characteristics of net primary production under two types of climate change scenarios in China using the LPJ model

The approach of conditional nonlinear optimal perturbation related to parameter (CNOP-P) is employed to provide a possible climate scenario and to study the impact of climate change on the simulated net primary production (NPP) in China within a state-of-the-art Lund-Potsdam-Jena dynamic global vegetation model (LPJ DGVM). The CNOP-P, as a type of climate perturbation to bring variation in climatology and climate variability of the reference climate condition, causes the maximal impact on the simulated NPP in China. A linear climate perturbation that induces variation in climatology, as another possible climate scenario, is also applied to explore the role of variation in climate variability in the simulated NPP. It is shown that NPP decreases in northern China and increases in northeastern and southern China when the temperature changes as a result of a CNOP-P-type temperature change scenario. A similar magnitude of change in the spatial pattern variations of NPP is caused by the CNOP-P-type and the linear temperature change scenarios in northern and northeastern China, but not in southern China. The impact of the CNOP-P-type temperature change scenario on magnitude of change of NPP is more intense than that of the linear temperature change scenario. The numerical results also show that in southern China, the change in NPP caused by the CNOP-P-type temperature change scenario compared with the reference simulated NPP is sensitive. However, this sensitivity is not observed under the linear temperature change scenario. The seasonal simulations indicate that the differences between the variations in NPP due to the two types of temperature change scenarios principally stem from the variations in summer and autumn in southern China under the LPJ model. These numerical results imply that NPP is sensitive to the variation in temperature variability. The results influenced by the CNOP-P-type precipitation change scenario are similar to those under the linear precipitation change scenario, which cause the increasing NPP in arid and semi-arid regions of the northern China. The above findings indicate that the CNOP-P approach is a useful tool for exploring the nonlinear response of NPP to climate variability.     

利用CloudSat资料分析青藏高原、高原南坡及南亚季风区云高度的统计特征量

云与辐射的相互作用对全球的天气和气候变化过程有着重要的影响,不同高度的云有着不同的辐射强迫,获得云体高度及其在时空上的变化对研究全球气候的变化有着重要意义。本文利用云卫星上的云廓线雷达(CloudSat/CPR)2006年6月—2007年12月期间的资料,对比分析了青藏高原、高原南坡和南亚季风区域不同云类的云顶、云底高度和云厚统计量。结果表明,在所研究区域单位面积上的云顶和云底高度变化具有一定的时空连续性,不同云类的云顶和云底高度存在不同的变化范围,且随着季节的改变均有明显的变化;同时各区域不同云类的云体厚度在夏季较大,冬季较小;各区域不同云类所占的比例(云量)也具有一定的季节变化规律。     

Uncertainties in projected impacts of climate change on European agriculture and terrestrial ecosystems based on scenarios from regional climate models

The uncertainties and sources of variation in projected impacts of climate change on agriculture and terrestrial ecosystems depend not only on the emission scenarios and climate models used for projecting future climates, but also on the impact models used, and the local soil and climatic conditions of the managed or unmanaged ecosystems under study. We addressed these uncertainties by applying different impact models at site, regional and continental scales, and by separating the variation in simulated relative changes in ecosystem performance into the different sources of uncertainty and variation using analyses of variance. The crop and ecosystem models used output from a range of global and regional climate models (GCMs and RCMs) projecting climate change over Europe between 1961–1990 and 2071–2100 under the IPCC SRES scenarios. The projected impacts on productivity of crops and ecosystems included the direct effects of increased CO₂ concentration on photosynthesis. The variation in simulated results attributed to differences between the climate models were, in all cases, smaller than the variation attributed to either emission scenarios or local conditions. The methods used for applying the climate model outputs played a larger role than the choice of the GCM or RCM. The thermal suitability for grain maize cultivation in Europe was estimated to expand by 30–50% across all SRES emissions scenarios. Strong increases in net primary productivity (NPP) (35–54%) were projected in northern European ecosystems as a result of a longer growing season and higher CO₂ concentrations. Changing water balance dominated the projected responses of southern European ecosystems, with NPP declining or increasing only slightly relative to present-day conditions. Both site and continental scale models showed large increases in yield of rain-fed winter wheat for northern Europe, with smaller increases or even decreases in southern Europe. Site-based, regional and continental scale models showed large spatial variations in the response of nitrate leaching from winter wheat cultivation to projected climate change due to strong interactions with soils and climate. The variation in simulated impacts was smaller between scenarios based on RCMs nested within the same GCM than between scenarios based on different GCMs or between emission scenarios.     

Impact of Climate Change and Variability on Irrigation Requirements: A Global Perspective

Anthropogenic climate change does not only affect water resources but also water demand. Future water and food security will depend, among other factors, on the impact of climate change on water demand for irrigation. Using a recently developed global irrigation model, with a spatial resolution of 0.5° by 0.5°, we present the first global analysis of the impact of climate change and climate variability on irrigation water requirements. We compute how long-term average irrigation requirements might change under the climatic conditions of the 2020s and the 2070s, as provided by two climate models, and relate these changes to the variations in irrigation requirements caused by long-term and interannual climate variability in the 20th century. Two-thirds of the global area equipped for irrigation in 1995 will possibly suffer from increased water requirements, and on up to half of the total area (depending on the measure of variability), the negative impact of climate change is more significant than that of climate variability.     

From MONEX to the global monsoon: A review of monsoon system research

Substantial progress has been made over the past three decades since the Monsoon Experiments(MONEX) of 1978–79. Here, we review these achievements by highlighting four breakthroughs in monsoon research:(1) The identification of the coupled ocean–land–atmosphere nature of the monsoon in the process of the annual cycle of solar heating;(2) new understanding of the changes in the driving forces of monsoon systems, with anthropogenic factors(climate effects of increased greenhouse gas and aerosol emissions) playing an important role in the regulation of monsoons;(3) detection of the interdecadal- and centennial-scale variability of monsoon systems, and its attribution to the combined impact of global warming and natural(especially oceanic) effects; and(4) the emerging concept of the global monsoon and its long-term variation under the impact of global climate change. All the observational and model-derived evidence demonstrates that the monsoon system, as an important component of the global climate system, has already changed and will continue to change in the future. This picture of an evolving monsoon system poses great challenges for near-term prediction and long-term projection.     

Multi-scale analysis of global temperature changes and trend of a drop in temperature in the next 20 years

Summary A novel multi-timescale analysis method, Empirical Mode Decomposition (EMD), is used to diagnose the variation of the annual mean temperature data of the global, Northern Hemisphere (NH) and China from 1881 to 2002. The results show that: (1) Temperature can be completely decomposed into four timescales quasi-periodic oscillations including an ENSO-like mode, a 6–8-year signal, a 20-year signal and a 60-year signal, as well as a trend. With each contributing ration of the quasi-periodicity discussed, the trend and the 60-year timescale oscillation of temperature variation are the most prominent. (2) It has been noticed that whether on century-scale or 60-year scales, the global temperature tends to descend in the coming 20 years. (3) On quasi 60-year timescale, temperature abrupt changes in China precede those in the global and NH, which provides a denotation for global climate changes. Signs also show a drop in temperature in China on century scale in the next 20 years. (4) The dominant contribution of CO₂ concentration to global temperature variation is the trend. However, its influence weight on global temperature variation accounts for no more than 40.19%, smaller than those of the natural climate changes on the rest four timescales. Despite the increasing trend in atmospheric CO₂ concentration, the patterns of 20-year and 60-year oscillation of global temperature are all in falling. Therefore, if CO₂ concentration remains constant at present, the CO₂ greenhouse effect will be deficient in counterchecking the natural cooling of global climate in the following 20 years. Even though the CO₂ greenhouse effect on global climate change is unsuspicious, it could have been excessively exaggerated. It is high time to re-consider the trend of global climate changes.     

气候变化对重庆农业的影响及对策研究

本文分析了重庆市气候特点及其对重庆农业的影响;并在全球气候变暖的大气候背景下,分析了重庆气候的变化趋势,并就气候变化对重庆农业可能造成的影响进行了初步的探讨;提出了重庆农业应对气候变化的适应性战略和技术措施。     

全球闪电活动与气候变化

全球闪电活动与气候变化关系的研究正受到越来越多的重视,该文从卫星上观测到的全球闪电活动、闪电活动和全球电路对温度的响应,闪电和对流层上部水汽的联系,闪电和N0,等几方面进行了阐述,指出了闪电活动在气候变化研究中的重要性。同时,文中还对影响闪电活动和起电过程的热力动力作用以及气溶胶的作用等进行了分析。     

An Introduction to the Integrated Climate Model of the Center for Monsoon System Research and its simulated influence of El Niño on East Asian-western North Pacific climate

This study introduces a new global climate model--the Integrated Climate Model （ICM）--developed for the seasonal prediction of East Asian-western North Pacific （EA-WNP） climate by the Center for Monsoon System Research at the Institute of Atmospheric Physics （CMSR, IAP）, Chinese Academy of Sciences. ICM integrates ECHAM5 and NEMO2.3 as its atmospheric and oceanic components, respectively, using OASIS3 as the coupler. The simulation skill of ICM is evaluated here, including the simulated climatology, interannual variation, and the influence of E1 Nifio as one of the most important factors on EA-WNP climate. ICM successfully reproduces the distribution of sea surface temperature （SST） and precipitation without climate shift, the seasonal cycle of equatorial Pacific SST, and the precipitation and circulation of East Asian summer monsoon. The most prominent biases of ICM are the excessive cold tongue and unrealistic westward phase propagation of equatorial Pacific SST. The main interannual variation of the tropical Pacific SST and EA-WNP climate E1 Nifio and the East Asia-Pacific Pattern--are also well simulated in ICM, with realistic spatial pattern and period. The simulated E1 Nifio has significant impact on EA-WNP climate, as in other models. The assessment shows ICM should be a reliable model for the seasonal prediction of EA-WNP climate.     

ENSO动力学与预测

发生在热带太平洋地区的ENSO现象是海气相互作用的集中表现,是年际气候变化中的最强信号.由于它的发生会在全球许多地区引起严重的气候异常,极大地影响着这些地区的工农业生产和人民生活,因此,对ENSO的机理及其预测的研究一直是大气海洋界的一个热点研究课题.中国科学院大气物理研究所在ENSO的机理及其预测等方面进行了大量的研究,取得了许多研究成果.作者将对中国科学院大气物理研究所在这方面的一些研究成果进行回顾和介绍.     

全球气候治理对中国中长期发展的影响分析及未来建议

全球气候变暖毋庸质疑。政府间气候变化专门委员会(IPCC)第五次评估报告(AR5)再次证实,全球气候持续变暖,由此引发风险越来越明确,而人类活动对全球气候变化影响的证据也越来越确凿。如何应对气候变化带来的不利影响是全人类共同的任务。中国作为人类命运共同体的一员,一直非常重视气候变化。2007年,国务院成立国家应对气候变化及节能减排工作领导小组,作为国家应对气候变化和节能减排工作的议事协调机构。自此,国家应对气候变化领导小组统一领导、国家发展和改革委员会归口管理、有关部门和地方分工负责、智库机构有力支撑、全社会广泛参与的应对气候变化管理体制和工作机制已经初步形成,并逐步将应对气候变化工作放入中国中长期发展战略中。随着对全球气候变化认知的深入,气候变化对中国中长期发展及战略部署的影响也越来越大,应对气候变化工作也将成为中国中长期发展必须考虑的一部分。应对气候变化是生态文明建设的重要一环,力推绿色低碳安全发展应是未来发展的必然之路。同时,对外需积极参与全球气候治理,对内更需加强科普宣传,提高全民意识。     

A summary of the PRUDENCE model projections of changes in European climate by the end of this century

An overview of the PRUDENCE fine resolution climate model experiments for Europe is presented in terms of their climate change signals, in particular 2-meter temperature and precipitation. A comparison is made with regard to the seasonal variation in climate change response of the different models participating in the project. In particular, it will be possible to check how representative a particular PRUDENCE regional experiment is of the overall set in terms of seasonal values of temperature and precipitation. This is of relevance for such further studies and impact models that for practical reasons cannot use all the PRUDENCE regional experiments. This paper also provides some guidelines for how to select subsets of the PRUDENCE regional experiments according to such main sources of uncertainty in regional climate simulations as the choice of the emission scenario and of the driving global climate model.     

Climate governance,justice, and transnational civil society

Justice dilemmas associated with climate change and the regulatory responses to it pose challenges for global governance, arguably hampering progress and raising concerns over efficacy and relevance. Scholarly literature suggests that transnational civil society groups can help address problems of governance and injustice that cross borders and pit states against each other. Findings of a comparative, qualitative study of climate justice advocacy suggest, however, that civil society groups' work in the US and EU is significantly shaped by institutional factors specific to those regimes, limiting advocates' broader impact. Moreover, political opportunities for the pursuit of climate action, and justice particularly, have diminished in those settings. By contrast, the United Nations Framework Convention on Climate Change (UNFCCC) provides greater opportunities for discussions of justice, although civil society actors are significantly constrained within it. It is argued that greater roles for civil society in the UNFCCC could prove constructive in the face of current challenges connected with justice issues. Three themes in civil society advocacy linking principles of global justice with current climate policy debates are summarized. Finally, it is suggested that the first iteration of the UNFCCC Periodic Review provides timely opportunities to more fully draw upon civil society's potential contributions toward a fair and effective global climate regime.

Policy relevance

The roles of civil society organizations in climate governance were examined in three policy contexts: the UNFCCC, the US, and the EU, with special attention to advocacy addressing issues of equity and justice, identified as key challenges for a post-2012 global agreement. Findings suggest that (1) civil society roles are significantly constrained in each context, and (2) political opportunities for climate advocacy have diminished since 2009 in the US and EU, underlining (3) the continued salience of the UNFCCC as a forum for engagement and the construction of effective and equitable climate policy. Potential exists for increased civil society involvement at the UNFCCC to help resolve obstacles based in divergent national priorities. Three areas of justice-focused civil society activity are reviewed for current negotiation topics and the governance structure of the institution. The current UNFCCC Periodic Review is identified as an opportunity to increase civil society involvement.     

我国近海和邻近海的海洋环境对最近全球气候变化的响应

鉴于全球气候变暖对海洋环境和海洋生态及对经济和社会可持续发展影响的严重性,作者首先利用ERA-40再分析的风场资料以及HadISST 和SODA等海洋高分辨率再分析资料,分析了近50年来全球气候变化对中国近海(包括渤海、黄海、东海和南海)和邻近海(主要是热带和副热带西太平洋)海面附近的风力、海表纬向和经向风应力和海表温度的影响.分析结果表明: 由于受全球气候变暖的影响,1976年之后中国近海和邻近海上空的冬、夏季风变弱,从而引起中国近海冬、夏季海表风应力减弱(尤其是经向风应力),而海表水温明显上升; 并且,冬、夏季海表风应力的减弱和海水温度的上升在中国东海反映尤其明显,这些为中国近海赤潮的频繁发生提供了有利的海洋环境.此外,从中国近海上空环流散度分布的变化可见,中国近海上空从1976年之后大气环流辐散增强,这不利于中国近海上升流的形成,从而会对沿岸水域营养盐的输送产生影响.