共查询到20条相似文献，搜索用时 46 毫秒
1.
典型气候/环境因子变化对九段沙湿地碳固定潜力的影响 总被引：1，自引：0，他引：1
《农业环境科学学报》2013,32(4)
利用人工气候室模拟长江口区域几种典型气候/环境因子的变化特征（全球变暖、CO2增加和海水无机氮污染加剧等）,并从植物生长量和土壤呼吸角度综合分析了这些气候/环境因素的变化对九段沙湿地土壤有机碳汇聚能力的影响。初步结果表明,在实验范围内,与对照相比,单方面的温度升高、无机氮污染加剧和CO2浓度升高会提高九段沙土壤的有机碳汇聚能力。无机氮污染加剧协同升温对土壤呼吸有一定的消减作用,从而提高了土壤有机碳汇聚能力;无机氮污染加剧协同CO2浓度升高会促使土壤有机碳的排放,使其碳汇聚能力下降;CO2浓度升高和全球升温的共同作用不会显著降低有机碳汇聚能力;无机氮污染加剧和CO2浓度升高的基础上加入升温的三因素交互作用会促进土壤有机碳的排放,使其碳汇聚能力下降。因此,要尽力避免海水中无机氮污染加剧和CO2浓度升高两个因素,以及在此基础上升温情况的同时发生。 相似文献
2.
3.
气候变暖影响区域水循环与粮食安全的研究进展 总被引：1，自引：0，他引：1
综述了气候变暖对水循环、粮食作物生产和粮食安全影响的研究进展。未来气候变暖造成的热浪以及作物生长季节温度的不确定变化导致的农业减产,将严重威胁世界的粮食安全。近些年许多地区热浪增强、强降水事件增多、干旱持续时间延长,表明了全球应对气候变暖采取减排和适应对策的紧迫性和复杂性。减缓温室气体的排放是全世界的共同责任,而适应气候变暖所采取的相应对策则是区域行为,因而难度很大。世界各国应该共同合作,集合世界的力量应对全球变暖的挑战。 相似文献
4.
The large burden of sulfate aerosols injected into the stratosphere by the eruption of Mount Pinatubo in 1991 cooled Earth and enhanced the destruction of polar ozone in the subsequent few years. The continuous injection of sulfur into the stratosphere has been suggested as a "geoengineering" scheme to counteract global warming. We use an empirical relationship between ozone depletion and chlorine activation to estimate how this approach might influence polar ozone. An injection of sulfur large enough to compensate for surface warming caused by the doubling of atmospheric CO2 would strongly increase the extent of Arctic ozone depletion during the present century for cold winters and would cause a considerable delay, between 30 and 70 years, in the expected recovery of the Antarctic ozone hole. 相似文献
5.
稻田温室气体减排成本收益分析 总被引：1，自引：0，他引：1
应用政府间气候变化专门委员会（intergovernmental panel on climate change, IPCC）推荐方法计算稻田不同技术组合温室气体排放量和单项技术减排潜力,运用边际减排成本曲线确定区域内由基准模式向最（次）优减排模式转化的相应成本,对稻田温室气体减排不同技术组合的成本 收益进行评估,确定成本有效性减排技术组合和区域内不同减排技术组合转化的边际减排成本。研究表明：（1）稻田土壤是最大排放源,其次是氮肥直接和间接排放。优化灌溉技术、氮素来源、轮作方式以及开展秸秆还田可降低水稻种植周期温室气体排放1.52%～40.17%,最大减排潜力来自于灌溉技术与模式选择差异;（2）以浙江省台州市黄岩区为例,以“淹水灌溉+化肥+秸秆燃烧”作为基准技术组合,由基准技术组合模式转向4种“低排放”技术组合模式的影子价格为1.63～9.79元·kg-1 CO2当量,“淹水灌溉+化肥+秸秆移走（作建筑材料）”技术组合模式最具成本有效性。 相似文献
6.
Reconstructions of ancient atmospheric carbon dioxide (CO2) variations help us better understand how the global carbon cycle and climate are linked. We compared CO2 variations on millennial time scales between 20,000 and 90,000 years ago with an Antarctic temperature proxy and records of abrupt climate change in the Northern Hemisphere. CO2 concentration and Antarctic temperature were positively correlated over millennial-scale climate cycles, implying a strong connection to Southern Ocean processes. Evidence from marine sediment proxies indicates that CO2 concentration rose most rapidly when North Atlantic Deep Water shoaled and stratification in the Southern Ocean was reduced. These increases in CO2 concentration occurred during stadial (cold) periods in the Northern Hemisphere, several thousand years before abrupt warming events in Greenland. 相似文献
7.
全球气候变化是现代农业生态系统目前面临的主要威胁之一。一方面,气候变化正在重塑植物与微生物的互作,诱导某些共生微生物转变为病原微生物,提升植物真菌病害发生的频率和程度;另一方面,气候变化降低植物的免疫力和抗病性,导致植物更严重的真菌病害。本文将重点讨论气候变化如何影响共生真菌与作物的互作,如何驱动植物真菌病害的发生和传播,以及采取何种调控措施从源头上预防病原真菌的危害。 相似文献
8.
Role of land-surface changes in arctic summer warming 总被引：2，自引：0，他引：2
Chapin FS Sturm M Serreze MC McFadden JP Key JR Lloyd AH McGuire AD Rupp TS Lynch AH Schimel JP Beringer J Chapman WL Epstein HE Euskirchen ES Hinzman LD Jia G Ping CL Tape KD Thompson CD Walker DA Welker JM 《Science (New York, N.Y.)》2005,310(5748):657-660
A major challenge in predicting Earth's future climate state is to understand feedbacks that alter greenhouse-gas forcing. Here we synthesize field data from arctic Alaska, showing that terrestrial changes in summer albedo contribute substantially to recent high-latitude warming trends. Pronounced terrestrial summer warming in arctic Alaska correlates with a lengthening of the snow-free season that has increased atmospheric heating locally by about 3 watts per square meter per decade (similar in magnitude to the regional heating expected over multiple decades from a doubling of atmospheric CO2). The continuation of current trends in shrub and tree expansion could further amplify this atmospheric heating by two to seven times. 相似文献
9.
10.
Radiative absorption enhancements due to the mixing state of atmospheric black carbon 总被引：3，自引：0，他引：3
CD Cappa TB Onasch P Massoli DR Worsnop TS Bates ES Cross P Davidovits J Hakala KL Hayden BT Jobson KR Kolesar DA Lack BM Lerner SM Li D Mellon I Nuaaman JS Olfert T Petäjä PK Quinn C Song R Subramanian EJ Williams RA Zaveri 《Science (New York, N.Y.)》2012,337(6098):1078-1081
Atmospheric black carbon (BC) warms Earth's climate, and its reduction has been targeted for near-term climate change mitigation. Models that include forcing by BC assume internal mixing with non-BC aerosol components that enhance BC absorption, often by a factor of ~2; such model estimates have yet to be clearly validated through atmospheric observations. Here, direct in situ measurements of BC absorption enhancements (E(abs)) and mixing state are reported for two California regions. The observed E(abs) is small-6% on average at 532 nm-and increases weakly with photochemical aging. The E(abs) is less than predicted from observationally constrained theoretical calculations, suggesting that many climate models may overestimate warming by BC. These ambient observations stand in contrast to laboratory measurements that show substantial E(abs) for BC are possible. 相似文献
11.
KR Arrigo DH Robinson DL Worthen RB Dunbar GR DiTullio M VanWoert MP Lizotte 《Science (New York, N.Y.)》1999,283(5400):365-367
Data from recent oceanographic cruises show that phytoplankton community structure in the Ross Sea is related to mixed layer depth. Diatoms dominate in highly stratified waters, whereas Phaeocystis antarctica assemblages dominate where waters are more deeply mixed. The drawdown of both carbon dioxide (CO2) and nitrate per mole of phosphate and the rate of new production by diatoms are much lower than that measured for P. antarctica. Consequently, the capacity of the biological community to draw down atmospheric CO2 and transport it to the deep ocean could diminish dramatically if predicted increases in upper ocean stratification due to climate warming should occur. 相似文献
12.
农业生态系统中的碳库是全球碳库中最活跃的部分,土壤可以通过团聚体-有机物的固碳作用降低大气中CO2浓度,从而缓解气候变暖。有机农业因其只施用有机肥、对土壤的保护性开发利用,不仅能够改善土壤形成和结构,增加养分和能量循环,而且与常规农业相比土壤的固碳能力有所增强,对缓解气候变化起到积极的作用,保护生态环境,维持农业的可持续发展。因此,发展有机农业能够实现结构优化、产业产品升级,是新时期农业和农村经济发展的方向,能够真正实现环境、经济和社会效益的完美结合。但同时,我国现阶段发展有机农业还存在很多难题,需要加大研发和宣传力度,更好地发展有机农业。 相似文献
13.
The UN Framework Convention on Climate Change calls for "stabilization of greenhouse gas concentrations at a level that would prevent dangerous anthropogenic interference with the climate system." Even if we could determine a "safe" level of interference in the climate system, the sensitivity of global mean temperature to increasing atmospheric CO2 is known perhaps only to a factor of three or less. Here we show how a factor of three uncertainty in climate sensitivity introduces even greater uncertainty in allowable increases in atmospheric CO2 concentration and allowable CO2 emissions. Nevertheless, unless climate sensitivity is low and acceptable amounts of climate change are high, climate stabilization will require a massive transition to CO2 emission-free energy technologies. 相似文献
14.
基于GIS的新乡市春季气候变化特征分析 总被引：1，自引：0，他引：1
基于新乡市1971—2014 年8 个气象站点3—5 月逐日温度、降水量和日照时数观测数据,采用线性倾向估计法、累积距平法和Mann-Kendall 检验法,结合GIS 技术,探讨和分析新乡市春季气候的变化趋势和时空分布特征,以期为当地防灾减灾和气候变化研究工作提供科学参考。结果表明：新乡市春季气温呈上升趋势,平均增幅为0.035℃/a,并且在1998 年发生显著增温突变,北部地区增温幅度高于南部地区;春季降水呈现微弱增多趋势,平均增幅为0.220 mm/a,变化不明显且年际间波动性较大,降水增幅整体上呈“北多南少”趋势;春季日照时数以平均1.216 h/a 的速率呈减少趋势,并且在1984 年发生显著递减突变,北部地区日照时数的减幅明显高于其他地区。全球变暖已造成本地区气候变异性明显增大。 相似文献
15.
气候变暖,伴随的CO2浓度升高,对植物等产生一系列的影响,文章综述了高CO2浓度对植物光合作用、生物量、土壤微生物生物量、土壤微生物多样性、土壤呼吸影响的研究进展,为相关的研究提供参考,并对今后的研究方向进行了展望。 相似文献
16.
17.
Establishing what caused Earth's largest climatic changes in the past requires a precise knowledge of both the forcing and the regional responses. We determined the chronology of high- and low-latitude climate change at the last glacial termination by radiocarbon dating benthic and planktonic foraminiferal stable isotope and magnesium/calcium records from a marine core collected in the western tropical Pacific. Deep-sea temperatures warmed by approximately 2 degrees C between 19 and 17 thousand years before the present (ky B.P.), leading the rise in atmospheric CO2 and tropical-surface-ocean warming by approximately 1000 years. The cause of this deglacial deep-water warming does not lie within the tropics, nor can its early onset between 19 and 17 ky B.P. be attributed to CO2 forcing. Increasing austral-spring insolation combined with sea-ice albedo feedbacks appear to be the key factors responsible for this warming. 相似文献
18.
SHI Bao-kun HUANG Jian-li HU Chao-xing HOU Mao-lin 《中国农业科学(英文版)》2014,(7):1520-1529
It is predicted that the current atmospheric CO2 concentration will be doubled and global mean temperature will increase by 1.5-6＆#176;C by the end of this century. Although a number of studies have addressed the separate effects of CO2 and temperature on plant-insect interactions, few have concerned with their combined impacts. In the current study, a factorial experiment was carried out to examine the effect of a doubling CO2 concentration and a 3℃ temperature increase on a complete generation of the brown planthopper （Nilaparvata lugens） on rice （Oryza sativa）. Both elevated CO2 and temperature increased rice stem height and biomass of stem parts. Leaf chlorophyll content increased under elevated CO2, but only in ambient temperature treatment. Water content of stem parts was reduced under elevated temperature, but only when coupled with elevated CO2. Elevated CO2 alone increased biomass of root and elevated temperature alone enhanced leaf area and reduced ratio of root to stem parts. Brown planthopper （BPH） nymphal development was accelerated, and weight of and honeydew excretion by the F1 adults was reduced under elevated temperature only. Longevity of brachypterous females was affected by a signiifcant interaction between CO2 and temperature. At elevated temperature, CO2 had no effect on female longevity, but at ambient temperature, the females lived shorter under elevated CO2. Female fecundity was higher at elevated than at ambient temperature and higher at elevated CO2 than at ambient CO2. These results indicate that the combined effects of elevated temperature and CO2 may enhance the brown planthopper population size. 相似文献
19.
Secord R Bloch JI Chester SG Boyer DM Wood AR Wing SL Kraus MJ McInerney FA Krigbaum J 《Science (New York, N.Y.)》2012,335(6071):959-962
Body size plays a critical role in mammalian ecology and physiology. Previous research has shown that many mammals became smaller during the Paleocene-Eocene Thermal Maximum (PETM), but the timing and magnitude of that change relative to climate change have been unclear. A high-resolution record of continental climate and equid body size change shows a directional size decrease of ~30% over the first ~130,000 years of the PETM, followed by a ~76% increase in the recovery phase of the PETM. These size changes are negatively correlated with temperature inferred from oxygen isotopes in mammal teeth and were probably driven by shifts in temperature and possibly high atmospheric CO(2) concentrations. These findings could be important for understanding mammalian evolutionary responses to future global warming. 相似文献
20.
Ramanathan V 《Science (New York, N.Y.)》1988,240(4850):293-299
Since the dawn of the industrial era, the atmospheric concentrations of several radiatively active gases have been increasing as a result of human activities. The radiative heating from this inadvertent experiment has driven the climate system out of equilibrium with the incoming solar energy. According to the greenhouse theory of climate change, the climate system will be restored to equilibrium by a warming of the surfacetroposphere system and a cooling of the stratosphere. The predicted changes, during the next few decades, could far exceed natural climate variations in historical times. Hence, the greenhouse theory of climate change has reached the crucial stage of verification. Surface warming as large as that predicted by models would be unprecedented during an interglacial period such as the present. The theory, its scope for verification, and the emerging complexities of the climate feedback mechanisms are discussed. 相似文献