Using the PMTred (penalized maximum T test) and PMFT (penalized maximum F test) developed by theEnvironment Canada, inhomogeneity test of monthly surface relative humidity of national station in China during 1951-2014 has been launched. The homogenous nearby stations with high correlation coefficients with the area averaged annual relative humidity are chosen to construct reference series by correlation coefficient weighted average method. Combined with the detailed metadata of each station, the main reasons causing the homogenization problem of the surface relative humidity in China have been analyzed. The result shows that the surface relative humidity data have serious problems of inhomogeneity, 68% stations existing break points. Automation, relocation and change of observe times are the main causes of the data discontinuity. For the whole dataset, the negative correction values have the high proportion, mainly between -5% and 0, which is linked tightly to the humidity decreasing after automation. The averaged surface humidity is decreasing in 1951-2014 before adjustment, and there is no obvious trend after adjustment.
This research uses the mean wind speed observation data in China, adopts linear fitting method. Aims to quantitatively recognize the change of wind speed using wind speed trend and trend of wind speed variability from 1961 to 2012 and regionalize the wind speed change in China on a county-level basis. The findings suggest that level-I regionalization include six zones according to different change rate of wind speed trend value in different regions. Northeast-North China substantial declining zone, East-Central China declining zone, Southeast China slightly declining zone, Southwest China very slightly declining zone, Northwest China declining zone, Qinghai-Tibetan Plateau slightly declining zone. Level-II regionalization divides China into twelve regions based on trend of wind speed variability and the results from level-I regionalization.
In this study, 347 wetland areas in Xinjiang, investigated in two earlier studies, were examined in detail. Using 3S technology, CBERS-CCD, SPOT5, and LandsatTM remote sensing data, which were verified in the field, were used to compare the spatio-temporal variation of the wetland resources in Xinjiang in 2000 and in 2011. The reasons behind the changes were then analyzed. The results showed that the total wetland area in Xinjiang declined during the period. River wetland and marsh wetland areas increased to 29162 and 17130 hm2, respectively, while lake wetland and artificial wetland areas reduced to 126618 and 19391 hm2, respectively. In the different wetland types, the areas of permanent rivers, marshes, forests-swamps, and seasonal brackish marshes increased, while the areas of flood plains, inland salt marshes, permanent freshwater lakes, seasonal freshwater lakes, seasonal saltwater lakes, and reservoirs decreased. The total change rate of wetlands in Xinjiang was -7%. Among the 4 principal types of wetland, the change rate of lake wetland was the largest (-18%) and the change rate of marsh wetland was the smallest (5%). The main reasons for the changes in wetland areas were climate change and human activities.
Huaihe River basin is located in central-eastern China, and it stands between the south-north climatic transitional zone. Varied kinds of weather systems mutually interlock and mutually effect, which forms a typical ecologically fragile area, and Huaihe River is also a sensitive area of climate change. In order to fully understand the impact of climate change to runoff in the upper-middle reach of Huaihe River basin, the paper applied the data of monthly runoff from 1971 to 1990 for the calibration and the data from 1991 to 2014 for verification by using automatic adjusting and parameters adjusting of SWAT model. The evaluation results showed that the Nash-Sutcliffe efficiency coefficient and linear determination coefficient were more than 0.8, and the relative error of simulation (Re) was less than 1%, indicating that the model could effectively reproduce the rainfall-runoff process of monthly scale. The annual runoff depth didn’t show obvious linear trend in general, while the upstream and the southern part of the runoff depth of the sub-basin were linear decreasing, and other areas were increasing. The annual evaporation and water percolation past bottom of soil profile in watershed for the year contributed more to the change of annual water balance elements. The average temperature, precipitation and evaporation were the critical factors of the changes of hydrological elements in the upper-middle reach of Huaihe River basin using principal component analysis. Eliminating the influence of human factors, the annual water resources were slightly decreased in the upper-middle reach of Huaihe River basin in 1971-2014, which might be the result of significantly increase of the annual average temperature, slightly decrease of annual precipitation, and notably decrease of annual evaporation. This study could provide a scientific basis for the management of water resources and policy-making in the upper-middle reach of Huaihe River basin.
Through analyzing the implementation status and related problems of global carbon tax, it finds that the carbon tax is levied mainly in developed countries and now the public voice for establishing carbon tax is growing all over the world. Relevant research and scientific views on carbon tax implementation in China were evaluated, the result shows that current research on basic elements of carbon tax is not thorough. Based on above analysis, it is concluded that current carbon tax environment is not yet mature in China and more effort is needed to strengthen carbon tax research and establish a perfect system for carbon tax in the future.
By collecting, processing and combining the Community Independent Transaction Log (CITL) data, the market micro structure of the trial phase European Union Emission Trading Scheme (EU ETS) was built. On this basis, the market setup, the trading behaviour of emitting companies, and the evolution of the market demand supply situation of the EU ETS were conducted. From a general perspective, the main motivation of emitting companies’trading behaviour was for compliance. Consequently, their trading behaviour was found inactive, seasonal and inclined to resort only one type of behavior either buying or selling. The companies who had massive amounts of allowances therefore dominated the allowances trading by using their advantages of allowance stock, financial condition and information asymmetry. This paper also regarding the impacts of the participation of the financial companies, it was observed that the oversupply situation was eased when the allowances were absorbed by financial companies in the initial two years and became deteriorated, when the allowances were flowed out of them in the last year. Under the background of China preparing its unified national ETS, analyzing the trading behaviour of market participants and the potential risk of their behaviour can provide several enlightenments to design market mechanism.
Focused on the main allocation schemes in the international community at present, China’s emission allowances during 2011-2050 under the 2℃ target are studied in this paper. The sensitivity of parameter settings are further analyzed by controlling key variables. The results indicate that to follow the RCP2.6 pathway consistent with the 2℃ target, China would receive allowances around 150-440 Gt CO2 until 2050. However, the schemes purely based on equal per capita emission have already been the most unfavorable to China. To preserve reasonable emission rights, China should insist on the full coverage of historical responsibilities in climate negotiations. The choice of global emission pathways will significantly affect China’s allowances. If the global budget is reduced by 40%-50% compared with the 2010 level, the range of China’s CO2 allowances is 151-474 Gt CO2. If the reduction increases to 50%-60%, the range changes to 138-478 Gt CO2. It shows that the floor of China’s fair range will be relied on the global pathway more greatly.