晚三叠世中卡尼期极端气候事件:研究进展及存在问题

作为三叠纪最显著的气候变化事件,全球性的卡尼期气候事件以幕次降雨量增多为特征,在西北特提斯洋地区表现较为明显,主要反映了从碳酸盐岩到黑色页岩的岩性变化,近年来这一地质事件在美国、中国、日本等地的卡尼阶地层中也有识别.其成因一直是学者研究的重点,有人认为是板块构造运动促使大气或大洋循环发生了变化,或是超级大陆聚合碰撞而触发大火成岩省喷发致使全球气候发生了紊乱,也有人认为是地球系统综合因素相互作用的结果.联系到中国西南部地区卡尼阶现状,认为超级季风、构造运动和卡尼期气候变化的关系值得深入研究,此外卡尼期气候事件过程中碳酸盐补偿深度上升问题、卡尼期黑色页岩事件反映的大洋生产力以及多幕卡尼期气候事件反映的气候波动事件等科学问题也是今后的研究中值得重视的.     

Analysis of extreme low-temperature events during the warm season in Northeast China

The trends of global warming are increasingly significant, especially in the middle and high latitude regions of the northern hemisphere, where the impact of climate change on extreme events is becoming more noticeable. Northeast China is located in a high latitude region and is sensitive to climate change. Extreme minimum temperatures causing cold damage during the warm season is a major type of agro-meteorological disaster in Northeast China, which causes serious reductions in crop yield. In this paper, we analyzed the temporal and spatial trends in the frequency of extreme minimum temperatures during the warm season (from May to September) during 1956–2005 in Northeast China. Abrupt climatic changes were identified using the Mann–Kendall test. The results show that the frequency of extreme minimum temperature days during the warm season in Northeast China decreases significantly from 1956 to 2005 with a background of climate warming. The highest number of extreme minimum temperature days occurred in the 1970s and 1980s, and there was an abrupt climatic change in 1993. The spatial analysis identified that the north and southeast of the region experienced a larger decrease in the number of extreme low temperature days than the west and south of the region. Rice, sorghum, corn, and soybeans are most vulnerable to cold damage. In severe low temperature years, the average crop yield was reduced by 15.2% in Northeast China.     

Early Cretaceous Paleoclimate Characteristics of China: Clues from Continental Climate-indicative Sediments

The Cretaceous was one of the most remarkable ‘greenhouse' climate periods in geological history. Most of the reported studies of the Cretaceous paleoclimate are based upon marine sedimentary records. Large spatial scale paleoclimatic reconstruction, which has a higher time resolution based upon continental sediments in China, is rarely found. This study presents paleoclimate reconstruction for the six time periods of the Early Cretaceous in China by employing continental climate-indicative sediments, including calcareous deposits, coal, oil shale, gypsum, halite, desert sedimentary systems, ferruginous deposits and laterite, copper-bearing deposits, limestone and dolomite. Based on the distribution of the association of climate-indicative sediments and the influences of paleotopography and orogenic belts(or important structural belts) on climate, seven climatic zones have been identified: 1) a warm and humid zone; 2) a warm and humid-warm and arid zone; 3) a warm and arid zone; 4) an arid and hot zone; 5) the Tibet hot and humid zone; 6) a hot and arid-semiarid zone; and 7) a hot and humid-hot and arid one. It is found that the Early Cretaceous climatic zones of China were nearly latitudinally distributed from northwest to southeast. The aridhot climatic zone expanded in the Aptian, suggesting that a hotter and drier climate prevailed in later period of the Early Cretaceous. Conversely, the humid climatic zone expanded in the Albian, indicating that a wetter climate appeared at the end of the Early Cretaceous. The overall distribution pattern of the seven climatic zones indicates that a hot-warm and arid climate was predominant in China; this coincides with a global ‘greenhouse climate' background. However, palaeogeographic features and specific geologic events, such as the existence and disappearance of the eastern high plateau, and the uplift and denudation of Yinshan, Yanshan, Tianshan, Qinling and Dabie Mountains, led to distinctive regional climatic features of the Cretaceous in China.     

我国沿海不同气候带山溪性河流沉积物输运特征

近年来许多研究发现山溪性小河流具有瞬时大通量、受极端气候事件控制、沉积物快速输运等特性,但是由于缺乏充足的监测数据和系统总结,其对全球沉积物输运的影响被低估,导致对于这个不同于大河流域的河海交互和风化传输系统的研究是不充分的.揭示不同气候带山溪性河流在自然变化与人类活动共同影响下的沉积物输运特征有助于深入理解地球表生过...     

黄河上游末次冰盛期古洪水事件的初步研究

洪水的发生规律是洪灾预报的前提，已有的人类洪水记录时间尺度，不足以认识和把握洪水的出现规律。因此，利用地质记录延长洪水序列，探讨地球特征气候期的洪水特点，就显得非常重要的必要。黄河上游兰州－银川段的洪水地质记录表明，在末次冰盛期的20－18ka，该区共发生了106次大洪水漫滩事件，其中有18次为多次洪峰叠加的复合型大洪水，洪水的发生频率达53次/ka。发生于末次冰盛期的大洪水可能属冰凌洪水，与末次冰盛期强烈的气候波动和不稳定有关。这些大洪水的频发与中国西部的末次冰盛期出现的高湖面相对应，既不符合一般的季风气候理论，也不同于我国东部广大地区末次冰盛期以冷干为主的气候特点，表明中国西部气候的独特性和复杂性。     

1929—1930年中国极端冷冬事件的重建*

气候变暖背景下,极端寒冷事件仍有发生且常伴随严重的经济、社会影响,需要更为深入的研究。1929—1930年极端冷冬事件作为增暖背景下的极端冷事件,对其研究相对缺乏。通过收集并分析民国时期的气象器测资料和报刊资料,对1929—1930年中国极端冷冬事件进行探讨。结果表明: (1)本次冷冬的空间范围包括华北地区、长江流域(重庆至入海口段)和北疆地区,西北地区可能存在冷冬;寒冷的核心时段为1929年12月到次年1月。(2)本次冷冬时空范围内的地区月平均气温极端性强,华北、长江流域的12月份均温都超过十年一遇的冷事件水平,长江流域、北疆地区的1月份均温均超过五十年一遇水平;但月最低气温的极端性较弱,大部分站点月的最低温达到五年一遇水平,部分站点月超过十年一遇水平。(3)本次冷冬至少经历了7次区域性或全国性的降温事件,其中有3次降温事件达到全国性寒潮事件标准,时段分别为12月1—5日、12月16—20日和1月1—5日;其中第1次和第3次是影响中国的典型中路寒潮路径,第2次降温过程的时空特征不显著。(4)综合本次冷冬前旱后涝气候特点、该时段内ENSO(厄尔尼诺-南方涛动)指数的变化以及前人对ENSO和中国气候变异的关系研究,推测1920s末到1930s初期的气象灾害很大程度受影响于ENSO事件。     

Increasing fiscal resilience to disasters in the Pacific

Pacific Island countries are among the list of countries that face the highest disaster risk globally—in per capita terms. In recent years, governments in the region have been confronted by a rise in damages from extreme catastrophic events, many increasingly linked to climate change. These events pose significant challenges to Pacific governments in terms of maintaining fiscal stability and the operation of their limited and under-diversified economies and shallow financial sectors. Governments in the region generally play a leading role in domestic economies and are responsible for leading disaster prevention, mitigation, and recovery efforts. Accordingly, measures to improve financial sustainability and the public sector’s ability to provide public services in the aftermath of major disasters must be prioritized. This paper examines the literature on fiscal resilience to disasters, the estimated impacts of major events in the Pacific, and analyses the applicability of available financial instruments to facilitate both ex ante and ex post disaster fiscal risk management in the region. The paper also discusses policies that can improve resilience against fiscal risks.

     

Climate (in)justice,vulnerability and livelihoods in the Caribbean: The case of the indigenous Caribs in northeastern St. Vincent

This paper examines climate justice from the perspective of three remote indigenous Carib communities located in northeastern St. Vincent, amidst their vulnerability to climatic hazards. The study contributes to the growing body of literature that explores the impacts climate-induced changes are having on Indigenous peoples through its explicit focus on this distinctive social group. The paper entails a detail case study of the particular ways the recent onset of two consecutive extreme weather events have impacted livelihood activities in these traditional farming villages. Primary data were collected in the aftermath of a severe drought that was followed by Hurricane Tomas in 2010, using a mixed method approach involving a questionnaire survey of 311 households, 70 unstructured interviews and 2 focus group sessions held in each of the three communities. The combined impact of these extreme weather events not only brought to light how exposed and sensitive these communities are to climatic hazards, but also illustrated some of the underlying issues driving vulnerability at the local scale that must be dealt with if climate justice is to be achieved. We argue that the factors driving vulnerability within these communities are partly a function of centuries of economic neglect and political marginalization and are also strongly related to the communities’ characteristically lower-socio economic status, geographic location, heavy reliance on land-based resources, coupled with a range of cognitive barriers that affect residents’ capacity to adapt to a changing and variable regional climate regime.     

中国西部晚中新世以来气候演化初探──以甘肃临夏红色盆地中Cl-含量变化为例

Cl-是封闭湖盆中反映气候变化的敏感指标。临夏盆地晚新生代地层Cl-含量变化表明,气候的长期演化呈现明显的阶段性与周期性,在约6.3Ma气候突然产生显著的由湿变干,并于5.3～4.5Ma达到极端干旱,其干旱程度是第四纪早期的33倍,低频上,气候呈现出约400万年的干湿波动,在晚中新世与早上新世,与同周期的全球热冷（凉）波动相对,而在第四纪早期,则与冷暖相对,可能反映亚洲季风系统于晚上新世才开始逐步形成,并于第四纪初建立,3.4Ma开始强烈隆升的青藏高原可能与此密切相关。     

SCL与中国东部气候年代际变化

据宇地磁耦合原理,利用太阳黑子周期长度(SCL)的变化及其与地磁场(文中主要考虑地热)的关系,模拟计算并重建了中国东部历史时期的气温序列变化,除了个别时段外,模拟曲线与修正后的竺可桢曲线十分相似;分析了2500a来中国东部气候的年代际变化.结果表明,该曲线能较好地再现2500a来中国东部气候的冷暖变化.对竺氏曲线中有争议的几个冷暖时段,如公元150—350年的温暖期、1050—1150年的小气候适宜期等,模拟结果与后来研究者分析的结果相合.中唐至五代的气候冷暖交替变化不稳定.该曲线也能清晰地反映出小冰期中国东部气候各个时段的变化以及现代气候的变化趋势。     

21世纪前中期三江源地区极端气候事件变化趋势分析

利用国家气候中心发布的IPCC SRES A1B温室气体排放情景下水平分辨率为25 km的连续气候变化模拟试验数据, 分析了三江源地区极端气候事件变化趋势.结果显示: 2001-2050年冷暖等级呈显著增高趋势, 其中以夏季变化最为明显, 冬季变化最小; 极端高温事件发生频次呈显著增多趋势, 而极端低温事件总体呈显著减少趋势; 干湿等级呈不显著增高趋势, 四季中只有冬季干湿等级呈减小趋势, 其余三季均呈升高趋势; 干燥和暴雨事件发生频次均呈显著增多趋势.地形尤其是经、 纬度和海拔对极端气候事件的变化趋势有明显的影响.     

我国末次冰消期古气候时空演化特征初探

为探讨我国末次冰消期古气候时空演化特征,从北到南、从西到东分别选取8个和6个已发表的持续时间较长和分辨率相对较高的古气候记录,对比分析了我国末次冰消期气候演化(以Younger Dryas和Bφlling/Allerφd 事件为主)随纬度和海拔高度变化所表现出的趋势和规律.结果显示,末次冰消期的主要事件在我国基本均有显...     

北京地区强降水极端气候事件阈值

根据北京地区1951～2008年逐日降水量资料,采用排序法、插值法、正态变换法、平方根变换法和立方根变换法等5种计算阈值的方法,对强降水极端气候事件阈值的确定问题进行研究。研究结果表明,确定日降水量百分位阈值的方法,在5种计算阈值的方法中,平方根变换方法得到最好的效果。在阈值确定的样本中,可以使用30年滑动气候阶段的样本得到的阈值平均值,作为极端气候事件阈值。     

Changes of Extreme Indices over China in Response to 1.5 ℃ Global Warming Projected by a Regional Climate Model

The possible changes of extreme climates over China under 1.5 ℃ global warming scenario were investigated by using the output of CORDEX (COordinated Regional Downscaling Experiment) experiments with a regional air-sea coupled model FROALS over East Asia domain. Results indicated that compared to the baseline period of 1986-2005, warm events would significantly increase while cold events would significantly decrease over China in a 1.5 ℃ warmer world. The risks of extreme and moderate warm events would be 2.14 and 1.93 times of that in the baseline period, respectively. The risks of extreme and moderate cold events would be 0.58 and 0.63 times of that in the baseline period, respectively. Compared to other sub-regions, the increasing amplitude of extreme warm events would be higher in North China, while the decreasing amplitude of extreme cold events would be higher in Northeast China. Risks of extreme dry events would increase in Northwest China, Tibetan Plateau and Northeast China (1.13, 1.02 and 1.22 times of that in baseline period). Precipitation intensity and extreme wet events would increase significantly over most parts of China, and the increasing amplitudes extreme wet events will be higher in North China and South China (1.88 and 1.85 times of that in the baseline period). Days when people may feel uncomfortable would increase significantly in eastern China, and compared to simple extreme warm events, the increasing amplitude of extreme uncomfortable days would be larger. The absolute changes of heating degree-days would be larger than that of cooling degree-days (-258℃·d and 72℃·d, respectively) in eastern China, but the relative change of heating degree-days would be smaller than cooling degree-days (-10% and 82%, respectively).     

南华北早二叠世泥岩沉积与深时陆地古温度重建

地球在地质历史时期经历过多次冰室与温室气候状态间的相互转换,也发生了以雪球地球为特征的极冷和以快速升温为特征的极热气候事件.二叠纪是晚古生代冰期到中生代温室气候转换的关键时期.为深入认识二叠纪的重大气候演变,急需解决的一个科学问题是如何获取高精年代地层约束的陆地古气候信息.通过总结近年来报道的华北南部石炭—二叠纪含煤岩...     

全球气候变化及其影响

全球气候变化及其对社会与自然系统产生的影响已日益受到全世界各国政府与广大民众的关注。与天气和气候有关的灾害给人类生命财产造成的损失日益增大,社会与生态系统似乎变得日趋脆弱。人们关心刚刚过去的20世纪的天气与气候发生了什么变化,更希望了解未来的21世纪,人类居住的地球会出现什么样的气候情景。根据一些国家和地区的观测记录、研究成果以及科学家们对气候变化的评估与预测展望,对全球气候变化问题进行概括。首先阐明20世纪地区性气候变化的事实;并根据政府间气候变化委员会(IPCC)科学技术报告中关于20世纪全球气候变化进行的总结性评估以及对21世纪全球气候变化的预测,作为阐述过去与未来全球气候变化的主要依据。同时,还介绍了一些科学家对IPCC关于全球气候变化的结论所持的不同观点或质疑。还就气候变化对社会与自然系统可能产生的影响略作论述。     

青藏高原东北部泥炭沉积粒度与元素记录的全新世千年尺度的气候变化

通过对青藏高原东北部共和盆地泥炭沉积的粒度与地球化学元素分析, 重建了区域全新世千年尺度的气候变化过程. 结果显示: 10.0~8.6 cal ka BP区域暖湿程度逐渐增加, 但在8.6~7.1 cal ka BP气候相对寒冷干燥, 7.1~3.8 cal ka BP 暖湿程度总体上为全新世最佳, 但也出现明显的气候波动, 3.8~0.5 cal ka BP气候向冷干方向发展, 0.5 cal ka BP以来气候又逐渐转向暖湿. 这一特征与中国东部季风区的气候变化有很好的一致性. 此外, 区域全新世气候变化过程中存在10次千年尺度的寒冷事件, 并与高原冰芯、 湖泊、 泥炭和风成沉积记录的古气候变化, 甚至与北半球高低纬度的气候变化都具有良好的可比性. 因此, 认为区域全新世气候变化具有"季风模式"与"千年尺度震荡"的双重特点.     

Spatial variability of climatic hazards in Bangladesh

Natural Hazards - Climate change is evident with the extreme climatic indices changing all over the world. Bangladesh is one of the most vulnerable countries to climate change. The patterns of...     

Climate change risks for severe storms in developing countries in the context of poverty and inequality in Cambodia

Least developed countries are generally regarded as particularly sensitive to climate change due to among other vulnerable locations and low adaptation capabilities. In the present study, we address climate change hazards in least developed countries by presenting a methodological framework, which is suitable for the estimation damage costs as a function of risk aversion, equality, income distribution and climate scenario using state-of-the-art climate model projections. As a case study, the methodology is applied to study severe storms in Cambodia based on two future climate scenarios and data on historical damages from storm events, which are used as a proxy in performing a sensitivity analysis on all input parameters. For the assumptions and parameter ranges used here, the study shows a high sensitivity to the income distribution (reflected by discount rates) and risk aversion and smaller effects from equality measures and extreme wind climate scenario. We emphasize that the assumptions on risk aversion reflecting consumption smoothing possibilities of low-income households clearly depicts that climate risks can be particularly high as a consequence of poverty and therefore recommend that context-specific vulnerabilities and equity concerns in climate risk studies should be included when making assessments for least developed countries.     

An overview of climate change impacts on the society in China

Society could sustain the impact of climate change by adapting to the change and mitigating risks from adverse effects of increasing changes, so that it can continue maintaining its prospect and improving wellbeing. Nevertheless, climate change is more or less affecting society's functions at different scales, including both individuals and communities. In this review, we discuss the relationship between society and climate change in China from the aspects of the needs at different socioeconomic developing stages. The relationship as well as the current spatial pattern and future risks of the climate change impacts on societies are summarized. The complexity of social and climatic systems leads to the spatial heterogeneity of climate impacts and risks in China. To more effectively leverage increasing knowledge about the past, we advocate greater cross-disciplinary collaboration between climate adaption, poverty alleviation and Nature-based Solutions (Nbs). That could provide decision makers with more comprehensive train of thoughts for climate policy making.