首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献，搜索用时 750 毫秒
1.
SUN Guodong  MU Mu 《大气科学进展》2011,28(6):1266-1278
The response of a grassland ecosystem to climate change is discussed within the context of a theoretical model.An optimization approach,a conditional nonlinear optimal perturbation related to parameter(CNOP-P) approach,was employed in this study.The CNOP-P,a perturbation of moisture index in the theoretical model,represents a nonlinear climate perturbation.Two kinds of linear climate perturbations were also used to study the response of the grassland ecosystem to different types of climate changes.The results show that the extent of grassland ecosystem variation caused by the CNOP-P-type climate change is greater than that caused by the two linear types of climate change.In addition,the grassland ecosystem affected by the CNOP-P-type climate change evolved into a desert ecosystem,and the two linear types of climate changes failed within a specific amplitude range when the moisture index recovered to its reference state.Therefore,the grassland ecosystem response to climate change was nonlinear.This study yielded similar results for a desert ecosystem seeded with both living and wilted biomass litter.The quantitative analysis performed in this study also accounted for the role of soil moisture in the root zone and the shading effect of wilted biomass on the grassland ecosystem through nonlinear interactions between soil and vegetation.The results of this study imply that the CNOP-P approach is a potentially effective tool for assessing the impact of nonlinear climate change on grassland ecosystems.  相似文献   

2.
One of the key issues in international climate negotiations is the formulation of targets for emissions reduction for all countries based on the principle of "common but differentiated responsibilities". This formulation depends primarily on the quantitative attribution of the responsibilities of developed and developing countries for historical climate change. Using the Commuity Earth System Model(CESM), we estimate the responsibilities of developed countries and developing countries for climatic change from 1850 to 2005 using their carbon dioxide, methane and nitrous oxide emissions. The results indicate that developed countries contribute approximately 53%–61%, and developing countries approximately 39%–47%, to the increase in global air temperature, upper oceanic warming, sea-ice reduction in the NH, and permafrost degradation. In addition, the spatial heterogeneity of these changes from 1850 to 2005 is primarily attributed to the emissions of greenhouse gases(GHGs)in developed countries. Although uncertainties remain in the climate model and the external forcings used, GHG emissions in developed countries are the major contributor to the observed climate system changes in the 20 th century.  相似文献   

3.
In terms of nine-layer global spectral model involving fuller parameterization of physical process,with arhomboidal truncation at wavenumber 15,experiments are conducted by virtue of two numerical schemes,one withlong-range mean coverage of Arctic ice,and the other with supercooled water at the same temperature as the ice,fol-lowed by an analysis of the difference field simulated by the two schemes.Results show that(1)the impact of Arctic iceon the northern short-range climate is realized through the change in polar ice coverage to cause local temperaturechange in the polar region to set up gradient difference in temperature from north to south,thus affecting the atmospher-ic circulations and,on the other hand,two trains of two-dimensional Rossby waves excited by the atmospheric heatsource anomaly have impacts on the Northern Hemisphere(NH)extratropical region,one of which is similar to the JPteleconnection pattern first presented by Nitta(1987);(2)The significant impact of Arctic ice anomaly on the southernshort-range climate change is accomplished with the aid of the anomaly of the equatorial heat source that excites a two-dimensional Rossby wavetrain propagating along a great circle route into the Southern Hemisphere(SH)extratropics,and the cross-equatorial propagation of the NH wavetrain also has effects on the SH atmosphere.Simulation indicatesthat with the 15-day integration the Arctic ice exerts an influence mainly on the NH and when the model atmosphere isgetting stabilized,the effect is dominantly on the SH short-range climate change.  相似文献   

4.
Evaluating the projection capability of climate models is an important task in climate model development and climate change studies. The projection capability of the Beijing Climate Center (BCC) Climate System Model BCC CSM1.0 is analyzed in this study. We focus on evaluating the projected annual mean air temperature and precipitation during the 21st century under three emission scenarios (Special Report on Emission Scenarios (SRES) B1, A1B, and A2) of the BCC CSM1.0 model, along with comparisons with 22 CMIP3 (Coupled Model Intercomparison Project Phase 3) climate models. Air temperature averaged both globally and within China is projected to increase continuously throughout the 21st century, while precipitation increases intermittently under each of the three emission scenarios, with some specific temporal and spatial characteristics. The changes in globally-averaged and China-averaged air temperature and precipitation simulated by the BCC CSM1.0 model are within the range of CMIP3 model results. On average, the changes of precipitation and temperature are more pronounced over China than over the globe, which is also in agreement with the CMIP3 models. The projection capability of the BCC CSM1.0 model is comparable to that of other climate system models. Furthermore, the results reveal that the climate change response to greenhouse gas emissions is stronger over China than in the global mean, which implies that China may be particularly sensitive to climate change in the 21st century.  相似文献   

5.
Numerical Simulation of Long-Term Climate Change in East Asia   总被引：1，自引：0，他引：1       下载免费PDF全文
A 10-yr regional climate simulation was performed using the fifth-generation PSU/NCAR Mesoscale Model Version 3 (MM5V3) driven by large-scale NCEP/NCAR reanalyses. Simulations of winter and summer mean regional climate features were examined against observations. The results showed that the model could well simulate the 10-yr winter and summer mean circulation, temperature, and moisture transport at middle and low levels. The simulated winter and summer mean sea level pressure agreed with the NCAR/NCEP reanalysis data. The model could well simulate the distribution and intensity of winter mean precipitation rates as well as the distribution of summer mean precipitation rates, but it overestimated the summer mean precipitation over North China. The model's ability to simulate the regional climate change in winter was superior to that in summer. In addition, the model could simulate the inter-annual variation of seasonal precipitation and surface air temperature. Geopotential heights and temperature at middle and high levels between simulations and observations exhibited high anomaly correlation coefficients. The model also showed large variability to simulate the regional climate change associated with the El Nino events. The MM5V3 well simulated the anomalies of summer mean precipitation in 1992 and 1995, while it demonstrated much less ability to simulate that in 1998. Generally speaking, the MM5V3 is capable of simulating the regional climate change, and could be used for long-term regional climate simulation.  相似文献   

6.
The Response of First Flowering Dates to Abrupt Climate Change in Beijing   总被引：1，自引：0，他引：1  
Phenological data on the First Flowering Date(FFD) of woody plants in Beijing from 1963-2007 are analyzed.The correlation between each species’ yearly FFD and the mean monthly temperatures for every year over a 45-year period is used to identify the month in which temperature has the most effect on FFD. Through further analysis,the FFDs of 48 woody plant species are shown to have advanced an average of 5.4 days from 1990-2007 compared to 1963-1989.The results indicate that 70.8%of species flowered significantly earlier(7 days on average) during the period 1990-2007,while only one species(2.1%) flowered significantly later.Moreover,the responses of FFD to climate change are shown to be different in two climatic stages, defined by an abrupt climate change point.Thirty-three species which first flower in March and April are sensitive to temperature are examined.The correlation coefficients between FFD and temperature for 20 species during the latter period(1990-2007) are shown to be larger than during the former period(1963- 1989),with a difference of around -0.87 days per 1℃on average.The paper concludes that with the warming of climate,the linear trend of FFD variation,as well as its responsiveness to temperature,became more prominent during 1990-2007 than 1963-1989.The data analyzed in this study present a strong biological indicator of climate change in Beijing,and provide further confirmation of previous results from regional and local studies across the Northern Hemisphere.Phenophase variations indicate that the climate is changing rapidly.  相似文献   

7.
The Intergovernmental Panel on Climate Change (IPCC) released the report of Working Group III of the Sixth Assessment Report "climate change 2022: mitigating climate change". The report accessed and summarized the latest research progress on climate change mitigation since the release of the Fifth Assessment Report, which will provide an important reference for the international community to further understand climate change mitigation actions, system transformation, and the pursuit of sustainable development. The report pointed out that human activities had cumulatively emitted about 2.4 trillion tons of CO2 from 1850 to 2019, of which 58% was emitted before 1990. In order to control the level of global temperature rise in the future, deep and immediate mitigation actions are required. In both low and minimum emission scenarios, fossil energy needs to be greatly reduced; renewable energy will be the mainstay of future energy supply; achieving carbon neutrality requires relying on negative emission technologies and increasing carbon sinks. Technological progress is one of the key conditions for helping the world combat climate change. Accelerated and equitable climate action is critical to sustainable development. The report's conclusions once again show that China's carbon neutrality target is in line with the mitigation path of the Paris Agreement's temperature rise target of less than 2 °C and striving to achieve 1.5°C. In the future, China should strengthen special research programs on the national concerns and key contents covered in the report. While strengthening scientific interpretation and effective use of the report's conclusions, it is also necessary to actively participate in the IPCC scientific assessment process, actively contribute Chinese wisdom, and contribute to the international dissemination of Chinese climate governance concepts. © 2022 Chinese Journal of Digestive Endoscopy All rights reserved.  相似文献   

8.
The climate change in China shows a considerable similarity to the global change, though there still exist some significant differences between them. In the context of the global warming, the annual mean surface air temperature in the country as a whole has significantly increased for the past 50 years and 100 years, with the range of temperature increase slightly greater than that in the globe. The change in precipitation trends for the last 50 and 100 years was not significant, but since 1956 it has assumed a weak increasing trend. The frequency and intensity of main extreme weather and climate events have also undergone a significant change. The researches show that the atmospheric CO2 concentration in China has continuously increased and the sum of positive radiative forcings produced by greenhouse gases is probably responsible for the country-wide climate warming for the past 100 years, especially for the past 50 years. The projections of climate change for the 21st century using global and regional climate models indicate that, in the future 20-100 years, the surface air temperature will continue to increase and the annual precipitation also has an increasing trend for most parts of the country.  相似文献   

9.
Regional climate change in China under the IPCC A2 Scenario, was simulated for continuous 10-yr period by the MM5V3, using the output of an IPCC A2 run from CISRO Mark 3 climate system model as lateral and surface boundary conditions. The regional climate change of surface air temperature, precipitation, and circulation were analyzed. The results showed that （1） the distribution of mean circulation, surface air temperature, and precipitation was reproduced by the MM5V3. The regional climate model was capable to improve the regional climate simulation driven by GCM. （2） The climate change simulation under the IPCC A2 Scenario indicated that the surface air temperature in China would increase in the future, with a stronger trend in winter and the increasing magnitude from the south to the north. The precipitation distribution would appear a distinct change as well. Annual mean precipitation would remarkably increase in Northeast China, Yangtze and Huaihe River Valley, and the south area of the valley. Meanwhile, rainfall would show a decreasing trend in partial areas of North China, and many regions of Southwest and Northwest China.  相似文献   

10.
This paper uses Dobson spectrometer total ozone data,Total Ozone Mapping Spectrometer(TOMS) data and radiosonde reports from Kunming,which is located in southwest China,from 1980 to 2008 to analyze the total ozone-climate relationship.The total ozone decadal long-term trend and abrupt change were studied using enhanced Dobson data whose missing data were amended by the TOMS data.Stepwise linear regression was used for the selection of the key factors that influence total ozone,including temperatures,geopotential heights,depressions of the dew point,wind velocities,and total solar radiation.The relationship between the selected factors and total ozone was analyzed using the methods of stepwise regression and partial least squares regression(PLSR).Results showed that although the PLSR method was slightly better and more reasonable to study the relationship than stepwise regression,while the two regression results were only slightly different.It was also suggested that local climate,especially local circulation and temperature,were important for the variations in total ozone,and the local climate could almost linearly explain 80% of the variance of total ozone.The relationship also indicated that the abrupt change of total ozone in the year 1994 may be related to abrupt local climate change.  相似文献   

11.
Post-Kyoto greenhouse gas inventories: production versus consumption   总被引：8，自引：0，他引：8  
For the long-term stabilization of greenhouse gas (GHG) concentrations it is important that post-Kyoto policy has broad participation to ensure environmental integrity. Many post-Kyoto frameworks have been debated, but surprisingly approaches that focus on consumption have received little attention in the climate change literature despite broader interest in other areas. In this article we extend the argument for constructing GHG inventories using a country’s consumption rather than production. First, we argue that constructing GHG inventories using a country’s economic activity instead of geographic territory solves allocation issues for international activities such as international transportation and carbon capture and storage. Second, we argue that consumption-based GHG inventories have many advantages over production-based inventories. The main advantages are to address carbon leakage, reduce the importance of emission commitments for developing countries, increase options for mitigation, encourage environmental comparative advantage, address competitiveness concerns, and naturally encourage technology diffusion.  相似文献   

12.
气候变化科学的最新进展—IPCC第四次评估综合报告解析   总被引：69，自引：2，他引：67  
政府间气候变化专门委员会（IPCC）第四次评估报告综合报告于2007年11月17日在西班牙正式发布。综合报告将温室气体排放、大气温室气体浓度与地球表面温度直接联系起来,综合评估了气候变化科学、气候变化的影响和应对措施的最新研究进展。综合报告指出：控制温室气体排放量的行动刻不容缓;能否减小全球变暖所带来的负面影响,将在很大程度上取决于人类在今后二三十年中在削减温室气体排放方面所作的努力和投资。这对国际社会和各国政府制定经济社会发展政策,适应和减缓气候变化有一定的指导和促进作用。  相似文献   

13.
Public attitudes about climate change reveal a contradiction. Surveys show most Americans believe climate change poses serious risks but also that reductions in greenhouse gas (GHG) emissions sufficient to stabilize atmospheric GHG concentrations can be deferred until there is greater evidence that climate change is harmful. US policymakers likewise argue it is prudent to wait and see whether climate change will cause substantial economic harm before undertaking policies to reduce emissions. Such wait-and-see policies erroneously presume climate change can be reversed quickly should harm become evident, underestimating substantial delays in the climate’s response to anthropogenic forcing. We report experiments with highly educated adults – graduate students at MIT – showing widespread misunderstanding of the fundamental stock and flow relationships, including mass balance principles, that lead to long response delays. GHG emissions are now about twice the rate of GHG removal from the atmosphere. GHG concentrations will therefore continue to rise even if emissions fall, stabilizing only when emissions equal removal. In contrast, most subjects believe atmospheric GHG concentrations can be stabilized while emissions into the atmosphere continuously exceed the removal of GHGs from it. These beliefs – analogous to arguing a bathtub filled faster than it drains will never overflow – support wait-and-see policies but violate conservation of matter. Low public support for mitigation policies may arise from misconceptions of climate dynamics rather than high discount rates or uncertainty about the impact of climate change. Implications for education and communication between scientists and nonscientists (the public and policymakers) are discussed.  相似文献   

14.
Uncertainty analysis facilitates identification of the most important categories affecting greenhouse gas (GHG) inventory uncertainty and helps in prioritisation of the efforts needed for development of the inventory. This paper presents an uncertainty analysis of GHG emissions of all Kyoto sectors and gases for Finland consolidated with estimates of emissions/removals from LULUCF categories. In Finland, net GHG emissions in 2003 were around 69 Tg (±15 Tg) CO2 equivalents. The uncertainties in forest carbon sink estimates in 2003 were larger than in most other emission categories, but of the same order of magnitude as in carbon stock change estimates in other land use, land-use change and forestry (LULUCF) categories, and in N2O emissions from agricultural soils. Uncertainties in sink estimates of 1990 were lower, due to better availability of data. Results of this study indicate that inclusion of the forest carbon sink to GHG inventories reported to the UNFCCC increases uncertainties in net emissions notably. However, the decrease in precision is accompanied by an increase in the accuracy of the overall net GHG emissions due to improved completeness of the inventory. The results of this study can be utilised when planning future GHG mitigation protocols and emission trading schemes and when analysing environmental benefits of climate conventions.  相似文献   

15.
The EU allows those installations that are subject to emissions trading to use a limited volume of certified emissions reductions (CERs), generated through the Clean Development Mechanism (CDM), to cover their own GHG emissions. These CERs can be used in addition to the EU allowances (EUAs), which were primarily allocated free to installations in Phase II of the EU Emissions Trading Scheme (EU ETS) from 2008 to 2012. For the year 2008, the CER limits, which are differentiated by EU Member State, created substantial arbitrage rents (due to the CER-EUA spread) of approximately EU€250 million. Different options for the allocation of this rent are discussed and it is found that, according to economic theory, making the right to use CERs tradable or the regulator pre-committing to buying CERs at the level of the relevant limit reduces the inefficiencies connected to the current regulation. Furthermore, auctioning these CER usage rights shifts the rents created through the CER-EUA spread to the Member State itself. The improved design and implementation of CDM limits justifies EU policy makers intervening to correct previously competition-distorting choices.  相似文献   

16.
This study focusing on the climate equity debate in the context of GHG mitigation explores design of a framework that is based on the ‘common but differentiated responsibilities’ principle of the United Nations Framework Convention on Climate Change (UNFCCC). Besides incorporating the widely recognized differences among countries such as current and historic GHG emissions and capabilities, the framework also accounts for their relative vulnerabilities to climate change. The study argues that since climate change impacts are akin to global public bad, compensation, especially for the poorer nations who are also the worst victims of the climate change impacts, could be conceived in the form of greater share in the GHG emission rights. This, it is argued, would provide the much needed space to grow for the poorer countries and facilitate enhancement of their adaptive capacity to face climate and other threats. It is also argued that the framework results accord with one of the welfare principles, the Weak Equity Axiom (WEA) (Sen, A. K. (1973). On economic inequality. Delhi: Oxford University Press), and yield an equitable distribution of burden.

Policy relevance

The present study attempts to inform the equity debate in the international climate negotiations. The multi-criteria framework of the study suggests a means to incorporate various national attributes which could result in an equitable sharing of the GHG mitigation burden among countries. The study results highlight that impacts due to climate change could provide an important and equitable basis for burden sharing in the present and in future. The study also highlights the significance of scientific literature on climate change impact assessments in informing the future policy dialogue in the climate negotiations.  相似文献   

17.
An analytic solution of an energy balance model (EBM) is presented which can beused as a recursive filter for time series analysis. It is shown that the EBM can reproduce the solution of a coupled atmosphere-ocean general circulation model (AOGCM) experiment. Contrary to the AOGCM, the EBM easily allows for variations in climate sensitivity to satisfy the full range of uncertainty concerned with this parameter. The recursive filter is applied to two natural and two anthropogenic forcing mechanisms which are expressed in terms of heating rate anomaly time series: volcanism, solar activity, greenhouse gases (GHG), and anthropogenic tropospheric aerosols. Thus, we obtain modelled global mean temperature variations as a response to the different forcings and with respect to the uncertainty in the forcing approximations and climate sensitivity. In addition, it is shown that the observed (ENSO-corrected) global mean temperature time series within the period from 1866 to 1997 can be explained by the external forcings which have been considered and an additional white noise forcing. In this way we are able to separate different signals and compare them. As a result, global anthropogenic climate change due to GHG forcing can be detected at a high level of significance without considering spatial patterns of climate change but including natural forcing, which is usually not done. Furthermore, it is shown that solar forcing alone does not lead to significantclimate change, whereas solar and volcanic forcing together lead to a significant natural climate change signal. Anthropogenic climate change due to GHG forcing may partly be masked by anthropogenic aerosol cooling.  相似文献   

18.
In this article, we evaluate and compare results from three integrated assessment models (GCAM, IMAGE, and ReMIND/MAgPIE) regarding the drivers and impacts of bioenergy production on the global land system. The considered model frameworks employ linked energy, economy, climate and land use modules. By the help of these linkages the direct competition of bioenergy with other energy technology options for greenhouse gas (GHG) mitigation, based on economic costs and GHG emissions from bioenergy production, has been taken into account. Our results indicate that dedicated bioenergy crops and biomass residues form a potentially important and cost-effective input into the energy system. At the same time, however, the results differ strongly in terms of deployment rates, feedstock composition and land-use and greenhouse gas implications. The current paper adds to earlier work by specific looking into model differences with respect to the land-use component that could contribute to the noted differences in results, including land cover allocation, land use constraints, energy crop yields, and non-bioenergy land mitigation options modeled. In scenarios without climate change mitigation, bioenergy cropland represents 10–18 % of total cropland by 2100 across the different models, and boosts cropland expansion at the expense of carbon richer ecosystems. Therefore, associated emissions from land-use change and agricultural intensification as a result of bio-energy use range from 14 and 113 Gt CO2-eq cumulatively through 2100. Under climate policy, bioenergy cropland increases to 24–36 % of total cropland by 2100.  相似文献   

19.
IPCC特别报告SRCCL关于气候变化与粮食安全的新认知与启示   总被引：3，自引：0，他引：3  
气候变化对粮食安全的影响是广泛的,不但影响粮食产量和品质,还会影响到农户的生计以及农业相关的产业发展等;而粮食系统在保障粮食安全的同时,又会产生一系列的环境问题,其中农业源温室气体（GHG）的排放加剧全球变暖。IPCC在2019年8月份发布的《气候变化与土地特别报告》（SRCCL）,从粮食生产、加工、储存、运输及消费的各个环节评估气候变化对粮食安全的影响及粮食系统的温室气体排放对气候系统的影响;系统梳理粮食系统供给侧和需求侧的适应与减缓措施、适应与减缓的协同和权衡问题,以及气候变化条件下保障粮食安全的政策环境等。SRCCL评估结论认为,由于大量施用氮肥和消耗水资源,目前粮食系统GHG排放占全球总排放的21%~37%;农业和粮食系统是全球应对气候变化的重要方面,供给侧和需求侧的综合措施可以减少食物浪费、减少GHG排放、增加粮食系统的恢复力。未来工作的重点应丰富和扩展气候变化影响评估内容,量化适应效果,加深对适应、减缓及其协同和权衡的科学认知,大力加强应对气候变化能力建设。  相似文献   

20.
《Climate Policy》2002,2(2-3):197-209
Korea, straddled between developing and developed country status, is facing challenges and opportunities in energy use and climate change mitigation potential. Unlike other OECD countries, Korea’s greenhouse gas (GHG) emissions are expected to continue to grow for the next two decades. The responses Korea could take to lower emissions without hampering economic development have an important bearing on the global response to climate change. This paper summarizes and evaluates mitigation strategies and major options for Korea in the energy sector, a major contributor to GHG emissions.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号