全球气候变化对我国气候安全影响的思考

依据政府间气候变化专门委员会 (IPCC) 第5次评估报告以及国内相关科学研究成果,使用最新的观测资料凝练了对全球气候变化的有关认识;从极端天气气候事件和气候承载力角度,分析了气候变化给我国带来的气候风险。研究发现:1961—2015年我国平均高温日数增加了28.4%,暴雨日数增加了8.2%。21世纪以来,登陆我国热带气旋的强度明显增加。在全球气候变暖的背景下,我国气候承载力将发生明显变化,未来面临的气候风险将加大。因此,保障我国气候安全,需要科学认识气候,提高气候风险意识; 主动适应气候,提高应对极端事件能力;努力保护气候,减缓气候变化的影响。     

全球气候变化对水文与水资源的影响

介绍了国内外全球气候变化对水文与水资源影响研究的现状与进展,简述了研究气候变化对水文与水资源影响的方法,指出了研究中存在的问题,分析了未来研究的发展趋势。     

Impacts of Climate Change on the Global Forest Sector

The path and magnitude of future anthropogenic emissions of carbon dioxide will likely influence changes in climate that may impact the global forest sector. These responses in the global forest sector may have implications for international efforts to stabilize the atmospheric concentration of carbon dioxide. This study takes a step toward including the role of global forest sector in integrated assessments of the global carbon cycle by linking global models of climate dynamics, ecosystem processes and forest economics to assess the potential responses of the global forest sector to different levels of greenhouse gas emissions. We utilize three climate scenarios and two economic scenarios to represent a range of greenhouse gas emissions and economic behavior. At the end of the analysis period (2040), the potential responses in regional forest growing stock simulated by the global ecosystem model range from decreases and increases for the low emissions climate scenario to increases in all regions for the high emissions climate scenario. The changes in vegetation are used to adjust timber supply in the softwood and hardwood sectors of the economic model. In general, the global changes in welfare are positive, but small across all scenarios. At the regional level, the changes in welfare can be large and either negative or positive. Markets and trade in forest products play important roles in whether a region realizes any gains associated with climate change. In general, regions with the lowest wood fiber production cost are able to expand harvests. Trade in forest products leads to lower prices elsewhere. The low-cost regions expand market shares and force higher-cost regions to decrease their harvests. Trade produces different economic gains and losses across the globe even though, globally, economic welfare increases. The results of this study indicate that assumptions within alternative climate scenarios and about trade in forest products are important factors that strongly influence the effects of climate change on the global forest sector.     

Chlorine initiated oxidation studies of hydrochlorofluorocarbons: Results for HCFC-123 (CF3CHCl2) and HCFC-141b (CFCl2CH3)

Oxidation reactions of the proposed CFC substitutes HCFC-123 (CF₃CHCl₂) and HCFC-141b (CFCl₂CH₃) have been studied in the laboratory using long-path Fourier transform infrared spectroscopy. The air oxidation of the HCFCs was initiated by the photolysis of Cl₂ forming Cl atoms that abstract H atoms from the HCFC. CF₃C(O)Cl was the only carbon containing compound observed in the infrared spectrum of the products of the HCFC-123/Cl₂ irradiations and its yield was approximately one. The product data are consistent with formation of CF₃C(O)Cl by Cl elimination of the intermediate halogenated alkoxy radical CF₃CCl₂O. The Cl-initiated oxidation of HCFC-141b led to the formation of CO and C(O)FCl. The product data are consistent with a 1 : 1 relationship between C(O)FCl formed and HCFC-141b reacted. Product data were compatible with both decomposition by cleavage of the C–C bond of the radical CFCl₂CH₂O leading to the prompt generation of C(O)FCl and reaction of the radical with O₂ forming the two carbon halogenated aldehyde CFCl₂CH(O), which in the presence of Cl was likely oxidized to C(O)FCl. An approximate method was developed in which the ratio was extracted from analysis of the time evolution of HCFC-141b, C(O)FCl, and CO. The data suggest that the contributions are comparable.     

Assessing the Impacts of Eurasian Snow Conditions on Climate Predictability with a Global Climate Model

On the basis of two ensemble experiments conducted by a general atmospheric circulation model (Institute of Atmospheric Physics nine-level atmospheric general circulation model coupled with land surface model, hereinafter referred to as IAP9L_CoLM), the impacts of realistic Eurasian snow conditions on summer climate predictability were investigated. The predictive skill of sea level pressures (SLP) and middle and upper tropospheric geopotential heights at mid-high latitudes of Eurasia was enhanced when improved Eurasian snow conditions were introduced into the model. Furthermore, the model skill in reproducing the interannual variation and spatial distribution of the surface air temperature (SAT) anomalies over China was improved by applying realistic (prescribed) Eurasian snow conditions. The predictive skill of the summer precipitation in China was low; however, when realistic snow conditions were employed, the predictability increased, illustrating the effectiveness of the application of realistic Eurasian snow conditions. Overall, the results of the present study suggested that Eurasian snow conditions have a significant effect on dynamical seasonal prediction in China. When Eurasian snow conditions in the global climate model (GCM) can be more realistically represented, the predictability of summer climate over China increases.     

土地利用变化对气候影响的研究进展

为满足人类对食物、纤维、水和居住地的需求,全球土地利用格局发生了巨大的变化,IPCC 第四次评估报告（IPCC,2007）指出土地利用变化是人类影响气候的重要强迫之一。土地利用变化对气候的影响分为生物地球物理作用和生物地球化学作用。分别对有关生物地球物理作用和生物地球化学作用的研究进展以及研究热点进行了综述;并从定量评估两者对气候影响的相对贡献以及两者共同效应的角度,回顾了辐射强迫计算和耦合模式数值模拟两种方法的研究进展,及其在森林恢复、人工造林以及碳封存等气候变化应对措施可行性评估中的应用。最后分析和展望了当前土地利用变化对气候影响相关研究中的不确定性以及未来发展方向。     

欧亚大陆积雪对我国春季气候可预报性的影响

利用大气环流模式IAP9L_CoLM,通过两组集合后报试验,考察了欧亚大陆积雪对我国春季气候可预报性的影响。一组试验为常规后报试验,积雪是由模式陆面过程预报得到的,另一组试验为积雪试验,模式积分过程中欧亚大陆雪水当量由微波遥感积雪资料替代,一天替换一次。通过分析两组试验后报结果的差异,来考察欧亚大陆积雪对我国春季（3~5月）气候可预报性的影响。分析表明:欧亚大陆积雪模拟水平的改善能提高春季欧亚大陆中高纬环流场（海平面气压场和中、高层位势高度场）的可预报性,模式对我国春季气温异常的年际变化和空间分布的可预报能力也有显著增强。对我国春季降水,虽然预报技巧较低,但引入较真实的欧亚积雪作用后,由于中高纬环流场预报技巧的改进导致降水的预测能力也有所改进。个例分析也表明,欧亚中高纬春季积雪异常模拟水平的改善导致了欧亚中高纬贝加尔湖及以南区域环流场可预报性的提高,最终使中国东部区域春季气候异常模拟技巧得以改善。以上结果也证实,欧亚大陆积雪是影响东亚区域春季气候的一个重要因子,要提高模式对中国春季气候的预报技巧,积雪模拟水平的改进是非常必要的。     

全球气候变化对冬季滑雪旅游的影响

旅游应对全球气候变化的挑战是当前旅游研究者面临的一项重要课题。目前有关气候变化对滑雪旅游的影响研究在国际上日趋成熟,但在我国尚属空白。通过广泛综合国外的研究,系统总结了目前国际上有关研究的基本思路、所运用的技术方法,以及获得的主要结论,分析了目前研究存在的局限性,并提出未来研究应注意的主要问题,以期为我国开展有关研究提供有益参考。     

Future Effects of Ozone on Carbon Sequestration and Climate Change Policy Using a Global Biogeochemical Model

Exposure of plants to ozone inhibits photosynthesis and therefore reduces vegetation production and carbon sequestration. The reduced carbon storage would then require further reductions in fossil fuel emissions to meet a given CO₂ concentration target, thereby increasing the cost of meeting the target. Simulations with the Terrestrial Ecosystem Model (TEM) for the historical period (1860–1995) show the largest damages occur in the Southeast and Midwestern regions of the United States, eastern Europe, and eastern China. The largest reductions in carbon storage for the period 1950–1995, 41%, occur in eastern Europe. Scenarios for the 21st century developed with the MIT Integrated Global Systems Model (IGSM) lead to even greater negative effects on carbon storage in the future. In some regions, current land carbon sinks become carbon sources, and this change leads to carbon sequestration decreases of up to 0.4 Pg C yr⁻¹ due to damage in some regional ozone hot spots. With a climate policy, failing to consider the effects of ozone damage on carbon sequestration would raise the global costs over the next century of stabilizing atmospheric concentrations of CO₂ equivalents at 550 ppm by 6 to 21%. Because stabilization at 550 ppm will reduce emission of other gases that cause ozone, these additional benefits are estimated to be between 5 and 25% of the cost of the climate policy. Tropospheric ozone effects on terrestrial ecosystems thus produce a surprisingly large feedback in estimating climate policy costs that, heretofore, has not been included in cost estimates.     

Numerical Experiment for the Impact of the Ozone Hole over Antarctica on the Global Climate

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Numerical Experiment for the Impact of the Ozone Hole over Antarctica on the Global Climate

A numerical experiment has been carried out with IAP (Institute of Atmospheric Physics) 9-layer general circulation model to investigate the influence of the Antarctic Ozone Hole on the global climate. The results show that the changes of total amount of ozone over higher latitude and polar region of the Southern Hemisphere affect not only the climate in the Southern Hemisphere, but also that in the Northern Hemisphere significantly. In the next spring, although the total amount of ozone over Antarctica has returned to the normal value, the influences of Ozone Hole still exist. Suppported by LASG and the National Key Project of Fundamental Research “Climate Dynamics and Climate Prediction Theory.≓     

Evaluating the Impacts of Cloud Microphysical and Overlap Parameters on Simulated Clouds in Global Climate Models

The improvement of the accuracy of simulated cloud-related variables, such as the cloud fraction, in global climate models (GCMs) is still a challenging problem in climate modeling. In this study, the influence of cloud microphysics schemes (one-moment versus two-moment schemes) and cloud overlap methods (observation-based versus a fixed vertical decorrelation length) on the simulated cloud fraction was assessed in the BCC_AGCM2.0_CUACE/Aero. Compared with the fixed decorrelation length method, the observation-based approach produced a significantly improved cloud fraction both globally and for four representative regions. The utilization of a two-moment cloud microphysics scheme, on the other hand, notably improved the simulated cloud fraction compared with the one-moment scheme; specifically, the relative bias in the global mean total cloud fraction decreased by 42.9%–84.8%. Furthermore, the total cloud fraction bias decreased by 6.6% in the boreal winter (DJF) and 1.64% in the boreal summer (JJA). Cloud radiative forcing globally and in the four regions improved by 0.3%?1.2% and 0.2%?2.0%, respectively. Thus, our results showed that the interaction between clouds and climate through microphysical and radiation processes is a key contributor to simulation uncertainty.     

飞机排放的NOx对中国地区NOx和臭氧的影响

根据2000年亚音速飞机排放的NO_x,利用三维全球化学输送模式(OSLOCTM2)研究亚音速飞机排放的NO_x对中国地区NO_x和臭氧的影响。模式结果表明:亚音速飞机排放的NO_x明显地影响中国北方地区,在1月份,250hPa高度NO_x的浓度增加大约50pptv,最大的相对变化为60％;在4月份,250hPa高度臭氧增加8ppbv,相对变化为5％。NO_x的增加主要是由于输送过程引起的,但臭氧的增加则是化学过程生成的结果。由于中国地区亚音速飞机排放的NO_x造成的NO_x的增加不超过10pptv,而且臭氧增加小于0.4ppbv。即使中国地区亚音速飞机排放的NO_x增加一倍,这个影响仍然比较小。     

自然气候变异与人为气候变化对径流影响研究进展

 在回顾IPCC于1990-2007年4次关于气候变化对径流影响的评估报告进展的基础上,将第一次与第二次评估报告归纳为第一代--以气候均值变化对径流影响及其适应为主要特征;第三次与第四次评估报告为第二代--突出人为气候变化与自然气候变异对径流影响及其适应问题,分析了常规的气候变化对水文水资源影响评估方法的发展过程及存在的问题。研究结果反映了年代际时间尺度的自然气候变异的影响,而未能考虑与极端事件发生频次和强度变化密切相联的日、季和年际尺度的气候变异的影响,从而低估了气候变暖对洪水、干旱以及农业灌溉需水的负面作用。在介绍国内外研究的基础上,为第五次IPCC评估报告提出了加强交叉学科综合研究的建议。     

自然气候变异与人为气候变化对径流影响研究进展

在回顾IPCC于1990-2007年4次关于气候变化对径流影响的评估报告进展的基础上,将第一次与第二次评估报告归纳为第一代--以气候均值变化对径流影响及其适应为主要特征;第三次与第四次评估报告为第二代--突出人为气候变化与自然气候变异对径流影响及其适应问题,分析了常规的气候变化对水文水资源影响评估方法的发展过程及存在的问题。研究结果反映了年代际时间尺度的自然气候变异的影响,而未能考虑与极端事件发生频次和强度变化密切相联的日、季和年际尺度的气候变异的影响,从而低估了气候变暖对洪水、干旱以及农业灌溉需水的负面作用。在介绍国内外研究的基础上,为第五次IPCC评估报告提出了加强交叉学科综合研究的建议。     

全球碳排放空间约束条件下美国退出《巴黎协定》对中欧日碳排放空间和减排成本的影响

应用全球多部门、多区域动态可计算一般均衡（CGE）模型,采用情景分析方法,评估美国退出《巴黎协定》后,由于其碳排放路径的变化对国际气候谈判中的3个重要谈判方中国、欧盟和日本实现国家自主贡献（NDC）和2℃目标情景下碳排放空间和减排成本的影响。结果表明：在全球碳排放固定且分配方式固定的条件下,美国不同程度的退约将为自身获得较大的碳排放空间,同时挤压其他地区,包括中国、欧盟和日本实现NDC和2℃目标的碳排放空间,将推高中国、欧盟和日本实现NDC和2℃目标的碳价。2030年,2℃目标下中国碳价的升幅将达4.4~14.6美元/t,欧盟为9.7~35.4美元/t,日本为16.0~53.5美元/t。同时将增加中国、欧盟和日本等其他国家和地区的GDP损失。2030年,2℃目标下中国GDP损失的升幅将达220.0亿~711.0亿美元（相当于16.4~53.1美元/人）,欧盟为93.5亿~321.4亿美元（相当于20.7~71.1美元/人）,日本为41.3亿~134.5亿美元（相当于34.3~111.7美元/人）。     

气象灾害和气候变化对国家安全的影响

概述了中国因气象灾害和气候变化引发的各种自然灾害造成的经济损失,分析了中国政府对环境问题的基本国策,引证了气候变化对国家安全造成的潜在威胁,并提出了我国应对气候变化的对策建议。     

Assessing the Impacts of Initial Snow Conditions over the Tibetan Plateau on China Precipitation Prediction Using a Global Climate Model

Two ensemble experiments were conducted using a general atmospheric circulation model. These experiments were used to investigate the impacts of initial snow anomalies over the Tibetan Plateau（TP） on China precipitation prediction. In one of the experiments, the initial snow conditions over the TP were climatological values; while in the other experiment, the initial snow anomalies were snow depth estimates derived from the passive microwave remote-sensing data. In the current study, the difference between these two experiments was assessed to evaluate the impact of initial snow anomalies over the TP on simulated precipitation. The results indicated that the model simulation for precipitation over eastern China had certain improvements while applying a more realistic initial snow anomaly, especially for spring precipitation over Northeast China and North China and for summer precipitation over North China and Southeast China. The results suggest that seasonal prediction could be enhanced by using more realistic initial snow conditions over TP, and microwave remote-sensing snow data could be used to initialize climate models and improve the simulation of eastern China precipitation during spring and summer. Further analyses showed that higher snow anomalies over TP cooled the surface, resulting in lower near- surface air temperature over the TP in spring and summer. The surface cooling over TP weakened the Asian summer monsoon and brought more precipitation in South China in spring and more precipitation to Southeast China during summer.