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1.
大气中CO_2的容积含量一般为0.03%,即320PPm。从本世纪以来浓度已有了增加并在继续增加,增加速率还有增长的趋势,大气CO_2含量的增加主要是由于矿物燃料使用量增加(研究表明,大气中CO_2含量的增加大约相当于矿物燃料燃烧时放出的CO_2的50%),人类活动的增加和更多的开发利用也增加了CO_2的释放。  相似文献   

2.
作者以怀疑的眼光回顾了有关大气中CO_2增加引起的可能气候效应的争论。对一般认为的十种谬误或未经证实的论点进行了讨论,它们是: 1.模式比数据好; 2.政府认可即等于科学证实; 3.气候变化将表现出不连续性; 4.随气候变率气候变化的增加; 5.过去100年的变暖趋势清楚证明CO_2增加引起气候变暖正在来临; 6.破记录的高温表明CO_2增加引起升温,破记录的低温表明临近一个冰期; 7.CO_2的间接的气候效应比直接效应更重要; 8.即使许多模式建立者不能预测下一年度的气候,农民制定农业生产计划时仍使用气候变暖的预测; 9.由于树的生长期很长,森林尤其易受气候变暖的危害; 10.砍伐森林相当于使土地沙漠化。  相似文献   

3.
李丽 《气象科技》1980,(1):41-41
美国海洋大气局发表了一篇关于大气中二氧化碳(CO_2)增加将会带来什么后果的综合报告.这篇报告是为美国环境科学情报中心提供的.报告指出:1850年以来,大气中CO_2的含量增加了8-27%(以工业时代以前的CO_2含量的估算为准);1958年以来增长了5%.但上述CO_2的增加对  相似文献   

4.
CO2浓度增加对植物生长和农业生产的影响   总被引:10,自引:1,他引:9  
王馥棠 《气象》1993,19(7):8-13
评述了近年来国内外有关大气中CO_2含量的增加趋势及其对植物生长和农业生产影响的研究进展。指出,无论是“直接效应”还是“间接影响”都有有利和不利两方面的影响;虽然,目前有“弊大于利”的趋向性认识,但由于科学理论上的许多不确定性,如何进行综合评估是今后要大力深入研究的重要课题。  相似文献   

5.
使用维多利亚大学的地球系统模式进行模拟,选取1800—2500年间较高的CO_2浓度情景(ROP8.5),分析由于CO_2增加引起的气候变化对海洋碳循环的影响。当气候敏感度为3.0K时,相对于无气候变化,到2100年,由于大气CO_2增加造成的气候变化导致海表面温度升高2.7 K,北大西洋深水流量减少4.5 Sv,海洋对人为碳的年吸收减少0.8 Pg C;比较人为溶解无机碳在海洋中的垂直累积分布,发现气候变化对海洋吸收大气CO_2的影响在北大西洋区域最明显。1800—2500年,相对于不考虑气候变化的情景,模式模拟的气候变化导致整个海洋对人为碳的累积吸收总量减少23.1%,其中北大西洋减少32.0%。此外,比较不同气候敏感度(0~4.5K,间隔为0.5K)的模拟结果发现,气候敏感度越高,气候变化对海洋吸收CO_2能力的抑制作用越明显。  相似文献   

6.
二氧化碳遍及整个地球系统.它不是被动地存在于地球系统中,而是作为海洋、大气和生物圈中碳循环的中介物质.从CO_2的循环特点方面可以看出,海洋和生物圈中的CO_2的交换是基本平衡的,而人类燃烧矿物燃料却使大气中CO_2含量持续增加.根据美国的两个观测记录最长的测站(在夏威夷群岛)资料可见,自1958年以来,CO_2增加了10%以上.据研究指出,在工业革命前,CO_2的含量是270-290ppm,现在达340ppm,估计到二十一世纪中期将上升到600ppm. 按CO_2变化量的估计值推断的全球性增  相似文献   

7.
利用典型半干旱区定西试验基地的开顶式气室(Open-Top Chamber,OTC)研究平台,以春小麦"定西24号"为供试品种,设置对照(370μmol·mol~(-1))和增加90μmol·mol~(-1)(460μmol·mol~(-1))、180μmol·mol~(-1)(550μmol·mol~(-1))3个CO_2浓度梯度,研究大气CO_2浓度升高对半干旱区春小麦生长发育、产量及产量构成因素的影响。结果表明:CO_2浓度升高使春小麦冠层空气温度和相对湿度增加,10 cm深处的土壤环境温度降低,春小麦根际浅层的土壤湿度增加;CO_2浓度增高,春小麦发育加快,生育期相应提前,全生育期缩短2~4 d;CO_2浓度升高对春小麦株高、叶面积指数和叶绿素含量有明显促进作用。其中,株高和叶面积指数在开花期增幅最大,叶绿素含量在灌浆后期到乳熟期增加更为显著;随着CO_2浓度升高,穗长、穗重、小穗数、穗粒数、穗粒重、千粒重、产量均呈增加趋势,而无效小穗数、不孕率以及收获指数则呈下降趋势,在460μmol·mol~(-1)和550μmol·mol~(-1)浓度下,籽粒产量分别比对照提高8.88%和19.93%。  相似文献   

8.
全球变暖与亚洲夏季风北边缘带:CO2增倍的数值模拟   总被引:1,自引:0,他引:1  
利用NCAR CAM3全球大气环流模式(包含CLM陆面模式)进行了20年(1998-2017年)CO2增倍的数值试验,并通过计算海陆热力差异,分析了环流形势、雨带分布和云量特征等物理量,研究了全球变暖对东亚夏季风北边缘带的影响。结果表明,CAM3大气环流模式能较好地描述东亚地区大尺度环流的季节变化特征,当CO2含量成倍增长后,将对亚洲经度范围内的夏季风北边缘的位置产生不同的影响,具体表现为100°~123°E地区北边缘位置偏北明显,100°E以西略偏北,123°~132°E略偏北幅度很小,132°E以东呈现出一定的偏北趋势。其原因可能是由于陆地增温有利于青藏高原低层气旋性环流的加强以及北半球纬向海陆热力差异的增加,从而导致我国西南和东南方向向北的水汽输送明显增加。研究表明,南北半球的海陆热力差异无明显变化,南北半球间的相互作用与北半球夏季风增强无明显的联系,两者的关系还有待进一步研究。  相似文献   

9.
本文研究了大气中 H_2O、CO_2和 O_3吸收带对因 CO_2增加一倍所引起的辐射收支扰动的重叠影响。这种影响与大气中的各种气体量以及吸收带的强度有关。我们用吸收带的窄谱带表达式研究了与气体含量的变化有关的这种影响。这个谱带表达式能考虑吸收带结构,从而说明吸收气体频谱特征的相关。据发现,H_2O 和 O_3的存在对 CO_2所引起的平流层中太阳辐射和热辐射扰动的影响都是比较小的。然而,在对流层和地面,这种重叠影响似乎是十分重要的,并且改变了 CO_2引起的辐射能量扰动的垂直分布。例如,在红外区,这个影响是减小了 CO_2放射辐射的效率,同时加强由于 CO_2增加所引起的从平流层来的向下热通量在对流层的吸收。各种气体的重叠吸收的净效果是使由于 CO_2增加而引起的对流层的加热变大和使引起的地面加热减小。我们也发现,由于大气中 H_2O的变化,重叠吸收影响有很强的季节和纬度变化。  相似文献   

10.
河南省气候变化对大豆生育期的影响研究   总被引:2,自引:0,他引:2  
利用河南省林州市和泛区农业气象观测站1993—2013年及正阳县农业气象观测站1993—2008年的大豆生育期观测资料和同期气象观测资料,通过数理统计、标准化处理和通径分析等方法分析河南省气候变化对大豆生长发育的影响。研究表明:河南省大豆播种期有逐渐提前的趋势,全生育期日数和各生育期间隔日数有增加的趋势;从北到南,播种期、出苗期和开花期逐渐提前,成熟期有所延长;大豆生育期日数有延长的趋势,南部的趋势比北部的明显。从北到南,各生育期同期降水量增多的趋势逐渐明显,日照时数减少的趋势逐渐减弱,平均气温增长的趋势逐渐减弱。河南省北部地区日照时数和平均气温的变化对大豆生育期有较大的影响,中部地区降水量和平均气温的变化对大豆生育期有较大的影响,南部地区平均气温是主要影响因子。  相似文献   

11.
 Based on the China Rural Statistical Yearbook of 1984-2003 published by State Statistics Bureau, and the annual temperature in the same period, impacts of temperature change, agricultural input, and planting area on grain production were analyzed for different regions of China during the last 20 years. The results show that the main characteristic of climate warming has obviously promoted the increase of grain yield in Northeast China, but to some extent suppressed it in North China, Northwest China and Southwest China, and shown no obvious effect on it in East China and Central-South China. The increase in agricultural input facilitated the grain production obviously in various regions in the early stage of the past 20 years, but showed no obvious effect in the late stage. The continuous reduction in sown area had a significant negative effect on the grain production in East China and Central-South China.  相似文献   

12.
Based on the China Rural Statistical Yearbook of 1984-2003 published by State Statistics Bureau,and the annual temperature in the same period,impacts of temperature change,agricultural input,and planting area on grin production were analyzed for different regions of China during the last 20 years.The results show that the main characteristic of climate warming has obviously promoted the increase of grain yield in Northeast China.but to some extent suppressed it in North China,Northwest China and Southwest China,and shown no obvious effect on it in East China and Central-South China.The increase in agricultural input facilitated the grain production obviously in various regions in the early stage of the past 20 years,but showed no obvious effect in the late stage.The continuous reduction in sown area had a significant negative effect on the grain production in East China and Central-South China.  相似文献   

13.
两种气候变化情景下中国未来的粮食供给   总被引:4,自引:0,他引:4  
熊伟  居辉  许吟隆  林而达 《气象》2006,32(11):36-41
全球温室气体排放导致的全球温度的上升一直是国际社会关注的重点问题之一。利用IPCC(政府间气候变化专门委员会)SRES(排放情景特别报告)的A2(中-高)和B2(中-低)温室气体排放情景,结合区域气候模式PRECIS和CERES作物模型模拟和分析了未来不同的温室气体排放情景下,中国未来2020年、2050年和2080年各个时段粮食的供需情景,并结合未来社会经济的发展分析了气候变化对未来粮食供求的影响,探讨了不同的气候变化程度对未来中国粮食供应的影响。结果表明:如果不考虑CO2的肥效作用,未来我国三种主要粮食作物(小麦、水稻和玉米)均以减产为主,灌溉可以部分地减少减产幅度,如果单考虑CO2的肥效作用,三种作物的产量变化以增产为主。若保持959/6的粮食自给率,人口按照SRESA2和B2情景增长,到2030年的技术进步可使粮食年单产递增0.79/6以上,维持目前的种植比例和种植面积,B2情景下,气候变化对我国的粮食安全问题将不会构成威胁,而A2情景下,气候变化将会对我国可持续发展的粮食安全造成威胁。  相似文献   

14.
The impact of climate change on agriculture has received wide attention by the scientific community. This paper studies how to assess the grain yield impact of climate change, according to the climate change over a long time period in the future as predicted by a climate system model. The application of the concept of a traditional "yield impact of meteorological factor (YIMF)" or "yield impact of weather factor" to the grain yield assessment of a decadal or even a longer timescale would be suffocated at the outset because the YIMF is for studying the phenomenon on an interannual timescale, and it is difficult to distinguish between the trend caused by climate change and the one resulting from changes in non-climatic factors. Therefore, the concept of the yield impact of climatic change (YICC), which is defined as the difference in the per unit area yields (PUAY) of a grain crop under a changing and an envisaged invariant climate conditions, is presented in this paper to assess the impact of global climate change on grain yields. The climatic factor has been introduced into the renowned economic Cobb-Douglas model, yielding a quantitative assessment method of YICC using real data. The method has been tested using the historical data of Northeast China, and the results show that it has an encouraging application outlook.  相似文献   

15.
Crop yields are affected by climate change and technological advancement. Objectively and quantitatively evaluating the attribution of crop yield change to climate change and technological advancement will ensure sustainable development of agriculture under climate change. In this study, daily climate variables obtained from 553 meteorological stations in China for the period 1961-2010, detailed observations of maize from 653 agricultural meteorological stations for the period 1981-2010, and results using an Agro-Ecological Zones (AEZ) model, are used to explore the attribution of maize (Zea mays L.) yield change to climate change and technological advancement. In the AEZ model, the climatic potential productivity is examined through three step-by-step levels: photosynthetic potential productivity, photosynthetic thermal potential productivity, and climatic potential productivity. The relative impacts of different climate variables on climatic potential productivity of maize from 1961 to 2010 in China are then evaluated. Combined with the observations of maize, the contributions of climate change and technological advancement to maize yield from 1981 to 2010 in China are separated. The results show that, from 1961 to 2010, climate change had a significant adverse impact on the climatic potential productivity of maize in China. Decreased radiation and increased temperature were the main factors leading to the decrease of climatic potential productivity. However, changes in precipitation had only a small effect. The maize yields of the 14 main planting provinces in China increased obviously over the past 30 years, which was opposite to the decreasing trends of climatic potential productivity. This suggests that technological advancement has offset the negative effects of climate change on maize yield. Technological advancement contributed to maize yield increases by 99.6%-141.6%, while climate change contribution was from-41.4% to 0.4%. In particular, the actual maize yields in Shandong, Henan, Jilin, and Inner Mongolia increased by 98.4, 90.4, 98.7, and 121.5 kg hm-2 yr-1 over the past 30 years, respectively. Correspondingly, the maize yields affected by technological advancement increased by 113.7, 97.9, 111.5, and 124.8 kg hm-2 yr-1, respectively. On the contrary, maize yields reduced markedly under climate change, with an average reduction of-9.0 kg hm-2 yr-1. Our findings highlight that agronomic technological advancement has contributed dominantly to maize yield increases in China in the past three decades.  相似文献   

16.
SOME ADVANCES IN CLIMATE WARMING IMPACT RESEARCH IN CHINA SINCE 1990   总被引:1,自引:0,他引:1  
Increasing the concentration of greenhouse gases in the atmosphere will strengthen the naturalgreenhouse effect,which could lead to global climate warming and more other changes.China is alargely agricultural country with a large size of population and the relative shortages of farminglands and water resources,thus increasing the importance of climate warming for national economydevelopment.Therefore,Chinese government and scientists have paid great attention to theimpact-assessment of climate warming on national economy in China,especially during the past 10years.This presentation will briefly describe some major issues of climate warming impact researchon national vegetation,agriculture,forest,water resources,energy use and regional sea level forChina,etc.As a result,all climate change scenarios derived by GCMs suggest a substantial change in thecharacteristic natural vegetation types.It is also shown that comparing with the distributionsimulated under the normal time period 1951—1980 as the present climate,by 2050 large changesin cropping systems would occur almost everywhere in China.Climate warming would lead toincrease cropping diversification and multiplication.Unfortunately,the possible net balancebetween precipitation and evapotranspiration would be negative and it would lead to reduce thegrain production in China significantly due to enhanced moisture stress in soil.The most evidentinfluence of climate warming on water resources would happen in Huanghe-Huaihe-Haihe Basin andthe water supply-demand deficit would be substantially enhanced in this area.And also,a warmerclimate for China will alter the energy requirement for domestic heating and cooling,that is,reduce energy use for heating in northern China and increase energy consumption for cooling insouthern China.  相似文献   

17.
CHANGE OF CLIMATE AND ITS INFLUENCE ON THE CROPPING SYSTEM IN CHINA   总被引:3,自引:0,他引:3       下载免费PDF全文
Tne global change of climate and its influence on the cropping system in China have been investigatedin this paper.It is found that the temperature was increased during the last decade and the precipitationdecreased in northern China and increased in southern China during the last 30 years.The sea level hasbeen rising by about 21—26 cm in the coastal areas south of 30°N in China during the last 100 years.The most of results as simulated by the general circulation models(GCMs)show that the temperature increasewould amount to about 2°—4°C in the most parts of China and precipitation and soil moisture might bedecreased in northern China and increased in sourthern China due to doubling of carbon dioxide(CO_2).The effects of doubled CO_2 on growth period and climatic yield capability in China have been estimatedroughly.It is shown that the regions of the growth period in China would be moved northward about fivedegrees latitude and the climatic yield capability might be increased by about 10% in the most parts of China.  相似文献   

18.
Net primary production (NPP) of crop represents the capacity of sequestrating atmospheric CO2 in agro-ecosystem, and it plays an important role in terrestrial carbon cycling. By linking the Crop-C model with climate change scenario projected by a coupled GCM FGOALS via geographical information system (GIS) techniques, crop NPP in China was simulated from 2000 to 2050. The national averaged surface air temperature from FGOALS is projected to increase by 1.0℃ over this period and the corresponding atmospheric CO2 concentration is 535 ppm by 2050 under the IPCC A1B scenario. With a spatial resolution of 10 ×10 km^2, model simulation indicated that an annual average increase of 0.6 Tg C yr^-1 (Tg=10^12 g) would be possible under the A1B scenario. The NPP in the late 2040s would increase by 5% (30 Tg C) within the 98×10^6 hm^2 cropland area in contrast with that in the early 2000s. A further investigation suggested that changes in the NPP would not be evenly distributed in China. A higher increase would occur in a majority of regions located in eastern and northwestern China, while a slight reduction would appear in Hebei and Tianjin in northern China. The spatial characteristics of the crop NPP change are attributed primarily to the uneven distribution of temperature change.  相似文献   

19.
The WAVES model was used to simulate the effect of global warming on soil moisture on the semi-arid Taihang Mountain in China. Parameters of the WAVES model were first adjusted according to soil moisture data from a field global warming experiment. Then, the reliability of WAVES in predicting soil moisture changes induced by climatic change was confirmed by comparing the simulated and observed soil moisture values under different climatic conditions and plant growth rates of another field treatment. Next, 10 climate change scenarios incorporating increases in temperature and changes in precipitation were designed. When a simulation was conducted using the leaf area index (LAI) growth pattern from a field experiment under the present climatic conditions, the results suggested that the combination of temperature increase and precipitation decrease would greatly decrease soil water content throughout the entire simulation period. On the other hand, only when precipitation increased by 20% and temperatureincreased by 2 °C, the effect of precipitation increase on soil moisture was obviously positive. Although soil moisture conditions in the T2P1 (temperature increase by 2 °C and precipitation increase by 10%) and T4P2 (temperature increase by 4 °C and precipitation increase by 20%) scenarios were slightly better during the rainy season and notmuch changed before the rainy season, the positive effect of 10%precipitation increase on soil moisture was totally offset by moisture decrease caused bya 4 °C temperature increase in the T4P1 scenario. At the same time, the trends of soil-moisture change were highly coincident with predicted changes in productivity. Finally, the predicted LAI values from other studies were combined with the climatic change scenarios and used in the simulation. The results showed that changes in LAI alleviated, at least to some extent, the effects of temperature and precipitation changes on soil moisture.  相似文献   

20.
近十年来我国气候变暖影响研究的若干进展   总被引:51,自引:12,他引:51       下载免费PDF全文
近年来,我国政府和科技界十分关注气候王馥棠变暖对我国经济发展可能影响的评估, 开展了许多重大项目和课题的研究。该文仅就气候变暖对我国自然植被、农业、森林、水资源、能源利用和区域海平面上升等领域影响评估研究的若干有意义的初步结果简要归纳和评述如下:取自不同GCM模型的未来气候变化情景下的影响评估模拟表明,我国的特征性自然植被类型将会发生明显的变化。同当前气候(1951~1980年)下的模拟分布相比,到2050年我国几乎所有地方的农业种植制度均将发生较大变化;气候变暖将导致复种指数增加和种植方式多样化,但降水与蒸散之间可能出现的负平衡和土壤水分胁迫的增加以及生育期的可能缩短,最终将导致我国主要作物的产量下降。气候变暖对我国水资源最明显的影响将会发生在黄淮海流域,这个区域的水资源供需短缺将大大提高。同时,气候变暖将改变我国室内取暖和降温的能源需求关系:北方冬季取暖的能源消耗将减少, 而南方夏季降温的能源消耗将会增加。海平面的上升将使我国三个主要沿海低洼脆弱区,即珠江三角洲、长江三角洲和黄河三角洲,面临部分遭受海水淹没的威胁。  相似文献   

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