Based on 47 global climate models within World Climate Research Program’s Coupled Model Intercomparison Project Phase 5 (CMIP5) and the VIC (variable infiltration capacity) model, possible risk of using the Mengwa flood detention area for flood control in Huaihe River basin under the Intergovernmental Panel on Climate Change (IPCC) representative concentration pathway (RCP) scenarios for the period of 2021-2050 was assessed in this study. The results show that, relative to 1971-2000, multiple models consistently project the mean annual temperature increase by 0.2-1.7℃. Although there is considerable uncertainty in projected precipitation, the projected changes in mean annual precipitation by more than 70% models have positive trends and range from 3.4% to 4.1%. The projected 20-year return flood at the Wangjiaba station is likely increased by 19%. More frequent floods due to future climate change may increase the times of using the Mengwa flood detention area for flood control.

Based on the assessment model established on the basis of the sensitivity, adaptability of the water resources system, exposure and droughts risk, from the supply-demand balance view, the water resources vulnerability were evaluated in the eastern China monsoon region. The results show that under current conditions in 2000, nearly 90% of the research region faces moderate or serious vulnerability of water resources, where 75% is moderately or highly vulnerable and 15% is extremely vulnerable. Huanghe, Huaihe, Haihe and Liaohe River basins have the high water resources vulnerability. The future climate change will aggravate the risk of water resources vulnerability. Under different RCP emission scenarios in 2030s, moderately vulnerable areas will significantly expand in the eastern China monsoon region. Extremely vulnerable areas will account for 20% to 25%. Due to the increasing water demand, the water resources vulnerability pattern will not change in North China. And the southeastern river basins will also face possible water crisis in the future.

The spatial distribution rules of 9 extreme precipitation indices are analyzed based on the daily precipitation data from 15 meteorological stations and the daily runoff data from 3 hydrological stations in the Hanjiang River basin from 1960 to 2012. The generalized extreme value (GEV) model and the Gamma model are selected for the fitting of each station’s extremum samples of maximum 1-day precipitation and maximum 3-day precipitation to single out the best statistical model, and then the precipitation design value with the given recurrence interval is calculated and its spatial distribution rules are analyzed. A joint distribution model of precipitation and flood volume is built based on three Copula functions including the Gumbel, the Clayton and the Frank, and the most appropriate Copula function model is chosen to calculate the design value of the flood volume with the given recurrence interval. The result shows that the GEV model can better simulate the extreme precipitation sequence, and the extreme precipitation in the recurrence interval presents a feature that it is high in the east and low in the west. In comparison with other Copula functions, the Frank Copula function is better to simulate the correlation relationship between the precipitation and the flood volume, and the design value of the flood volume obtained by this function is greater than the design value derived from the fitting of univariate distribution.

In order to investigate the non-stationarity and prediction method of hydrological extremes under the climate change impact, statistical prediction models for the non-stationary generalized extreme value (GEV) distributions of hydrological extremes were developed. Annual mean North Hemisphere polar vortex intensity was selected as the predictor of distribution parameters. Observational hydrological data from the upper reaches of the Huaihe River basin (HRB) and 500 hPa circulation monitoring data during 1952-2010 and 17 CMIP5 GCM simulations for historical, RCP2.6, RCP4.5 and RCP8.5 greenhouse gas emission scenarios were used for the model fitting. Responses of hydrological extremes to climate change during 2006-2050 under the 3 future scenarios were analyzed by using the fitted models. The results show that hydrological extremes with less- and longer-than-10-year return periods from non-stationary GEV distributions may have decreasing and increasing trends, respectively. However, ensemble means of multi-model predictions for different return periods under the 3 future emission scenarios all show increasing trends. The higher the emission, or the longer the return period, the faster the increase of the trend. Compared with the averages of extremes, extremes of extremes (tails of GEV distributions) are more liable to change under these scenarios.

Based on five global climate models, one regional climate model and the VIC (Variable Infiltration Capacity) model, daily discharge from Bengbu station was estimated under the Representative Concentration Pathways (RCPs) for 2021-2050. A probability model based on Copula function was established to analyze future coincidence probability changes of urban rainstorm in Bengbu and flood in the upper reaches of the Huaihe River under the RCP2.6, RCP4.5 and RCP8.5 scenarios. Relative to the baseline period (1971-2000), the coincidence probabilities of different combinations of rainfall and flood estimated by multi-model ensembles will increase with a range of 46%-79% in the future (2021-2050), which is likely to increase the pressure on urban flood control in Bengbu.

By using CROPWAT model, the wheat water requirement in 1961-2010 and 2020s (2020-2029) under IPCC RCPs scenarios were simulated. Defining the change rate of wheat water requirement as a sensitive factor, the sensitivity of wheat water requirement in China under RCP4.5 and RCP8.5 emission scenarios were discussed. The results showed that the mean annual wheat water requirement in China was 105.64 billion m³ and the highest value was located in Huang-Huai-Hai regions. Wheat water requirement in most areas of China tends to be sensitive to climate change. The highly and extremely sensitive regions in terms of wheat water requirement will be distributed in North and Northwest China. And the lightly sensitive areas will be distributed in Northeast China and Yungui Plateau, while in the middle and south of China, the wheat water requirement will not be sensitive to climate change. Moreover, the sensitivity spatial distribution of wheat water requirement is different under various RCP emission scenarios, while the lightly and moderately sensitive areas in terms of wheat water requirement under RCP8.5 scenario become larger significantly than under the RCP4.5 scenario.

The Precambrian extends over about 4 billion years from the formation of Earth to the beginning of the Cambrian (4.6 billion years ago to 0.54 billion years ago). Studying climate evolution over such a long period is really challenging, but fundamental and intriguing. It is difficult to comprehensively review progress of studies in Precambrian climate evolution. Three important issues are chosen and discussed, which are atmospheric evolution, two extremely cold periods with global-scale glaciations, and the faint young Sun paradox. For atmospheric evolution, tendencies of atmospheric evolution are briefly reviewed, and three important processes involved in atmospheric evolution are introduced, which are atmospheric escape, two rapid increases of atmospheric oxygen, and the carbonate-silicate cycle and its negative feedback to climate. Two global-scale glaciations intervals happened at the Paleoproterozoic (2.4 billion years ago to 2.1 billion years ago) and the Neoproterozoic (0.8 billion years ago to 0.58 billion years ago). Mechanisms of formation and deglaciation of the two global glaciations are reviewed. The faint young Sun paradox is a classical topic in Earth’s early climate studies. Here, most recent results are summarized.

Based on input-output model and latest data from GTAP8 database (Global Trade Analysis Project), the changes of embodied carbon emissions in North group and South group countries were analyzed in 2007 relative to 2004 resulted from international trade changes and corresponding influence on global carbon emissions. The results show that with the expending scale of imports and exports from developing countries, the shares of global embodied emissions in imports and exports of developing countries were both increasing. From 2004 to 2007, the exporting structures were enhancing: the developed focused on exports of high-end equipment manufacturing and service, and the developing focused on resource products and energy intensive goods as well as low-to-medium level manufacturing. This resulted in the increase of global CO2 emissions of 415 Mt, which accounted for 63% of embodied emissions growth during this period. The share of embodied carbon emissions from developing countries?exports is expected to further increase in the future. The changes in embodied carbon emissions flows within North-South group caused by international trade changes will have an increasingly important impact on global climate change actions.

Using a dynamic two-region computable general equilibrium model, this study conducted a quantitative assessment of the impacts of carbon emission trading on the economy of Guangdong Province, the participating sectors and the carbon trading prices. The results show that, in accordance with the energy conservation scenario to be completed by 2015 (19.5% decline in carbon intensity), GDP will lose 0.7% compared with the baseline scenario; according to a low-carbon scenario to be completed by 2015 (20.5% decline in carbon intensity), GDP will lose 0.9% compared with the baseline scenario; if carbon trading policy is implemented in the low-carbon scenario, GDP will lose 0.8% relative to the baseline scenario. The results show that the carbon trading policy can save about 9 billion yuan RMB. This analysis supports Guangdong Province to achieve both economic development and carbon emission reduction target.

A framework on the Chinese civil aviation participation in the national carbon market is proposed based on the industry’s characters and the development stage of the Chinese civil aviation. It focuses on the establishment of the CO₂ emissions Cap for the Chinese civil aviation and the design on the distribution of the Cap among Chinese aviation operators. With an assessment on the fairness and cost-efficiency, the framework would not cause tangible competition distortion among Chinese aviation operators and would increase the sector’s operation cost by USD 170 million-USD 1.43 billion under different scenarios. However, the framework would not severely impact the growth of Chinese civil aviation if it is taken into account that the industry has the capacity to transfer over 60% of the cost.