Based on the outputs of CMIP5 models, 1.5℃ and 2℃ global warming threshold-crossing time above pre-industrial levels are evaluated under different Representative Concentration Pathways (RCPs) scenarios. The results of multi-model ensemble showed that relative to the pre-industrial levels, the global warming would exceed 1.5℃ threshold in 2029, 2028 and 2025 in the RCP2.6,RCP4.5 and RCP8.5 scenarios, respectively. Under RCP2.6 scenario, the global warming would be kept below 2℃ until the end of the 21st century while the 2℃ global warming would occur around 2048 and 2040 in the RCP4.5 and RCP8.5 scenarios. The time required from 1.5℃ to 2℃ global warming threshold is cut down in RCP8.5 compared with RCP4.5. On the regional scales, the threshold-crossing times over the land are earlier than those over the ocean and show little difference among scenarios whereas the time can be advanced in stronger emission for the ocean. Regarding global warming, the times crossing 1.5℃ and 2℃ warming threshold in China are both earlier, especially for Northeast China and Northwest China.
Based on the daily maximum and minimum temperature from 23 climate models from Coupled Model Intercomparsion Project Phase 5 (CMIP5) under RCP4.5 scenario, five temperature extreme indices including average maximum temperature (TXAV), average minimum temperature (TNAV), heat wave duration index (HWDI), frost days (FD) and warm nights (TNF90) were calculated, and the probability projection of extreme temperature indices were analyzed after evaluating the performance of models in simulating the extreme indices. The results show that there has a high probability (more than 66% chance) of increasing by 2.0℃for TNAV and TXAV during mid of the 21st century. The increasing maximum regions are located over south of Tibetan Plateau region. TNF90 increases by 15% across the whole region, with the largest values over 20% in southwestern China and south coastal region. FD is projected to decrease with the largest negative magnitude over 20 d regions over the Tibetan Plateau. HWDI increase by 10 d occurs across the whole China region, with maximum value by 30 d located over southern Tibetan Plateau. The uncertainties results show that temperature indices change have large reliabilities except HWDI. For the end of the 21st century, the increase magnitude of indices is more remarkable than the former period, and both TNAV and TXAV have very high probabilities (larger than 90%) by 2.0℃. Increasing magnitudes of TNF90 over southwestern China and south coastal regions are larger than 25% while TNF90 in most regions decreases by 15%. FD decreases by 20 d in most regions and by 40 d around the Tibetan Plateau. HWDI increases by 20 d throughout the whole region, maxima increase region is located over southeastern of TP. The credibility is the same as that during the mid-21st century except FD.
The Chaobai River Basin, which provides majority freshwater for Beijing City, is an important guarantee to water safety in Beijing. So it is of vital importance to assess the future change in discharge in the Chaobai River Basin under 1.5℃ and 2.0℃ global warming. In this study, the hydrological responses to climate forcing under 1.5℃ and 2.0℃ global warming in the Chaobai River Basin were studied using hydrological model SWAT driven by five general circulation models (GCMs) under three Representative Concentration Pathways (RCPs). The uncertainties of projected impacts from GCMs structure and RCPs scenarios were estimated and compared quantitatively further. The results indicated that: (1) The simulation results of SWAT model have good agreement with discharge observations in both calibration and validation period, it is feasible to apply the SWAT model to estimate the impacts of climate change. (2) The mean annual temperature and precipitation of the Chaobai River Basin will increase under 1.5℃ and 2.0℃ global warming. The mean annual discharge will increase slightly under 1.5℃ global warming and be more concentrated in summer and early autumn. When under 2.0℃ global warming, the mean annual runoff will rise by more than 30%. However projected mean proportion of monthly to annual discharge will decrease in the peak season (July and August) of water usage, which will have impact on water resource management and control. (3) Extreme monthly and annual discharge will increase dramatically under global warming, especially in 2.0℃warming. As a result, the risk of flooding will grow and lead to more pressure on flood mitigation. (4) It is proved that there are more uncertainties in above results under 2.0℃ global warming than under 1.5℃ global warming. Uncertainties in projections of discharge are greater compared with those in precipitation projections. Under both 1.5℃ and 2.0℃ global warming, uncertainties in the projections of all indicators from GCMs structure are larger than those from RCPs scenarios.
In this paper, the changes in structure of summertime precipitation over South China (SC) were comprehensively analyzed using the concentration index (Q), based on 1961-2010 daily precipitation data collected at 64 rain gauge stations. The results indicate that the regions with smaller (larger) Q values were mostly located in the north (south) of SC, where daily precipitation events tended to become temporally dispersed (concentrated) during the study period. Variations of the Q and the total summertime rainfall amount during the period 1961-2010 in SC both exhibited an upward trend. The precipitation showed a more increase trend in north of SC than it in south of SC. However, the Q index showed a more increase trend in south of SC than it in north of SC. In SC, when the daily precipitation is greater than 1 mm, 25 mm and 50 mm, 1 d precipitation showed negative trends. In contrast, the precipitation events related to long wet spells increased. Over most parts of SC, the rainy days with precipitation amount greater than 1 mm tended to decrease whereas the wet spells with daily precipitation greater than 25 mm and 50 mm tended to increase.
Considering the premise of consistency hypothesis is no longer satisfied for the traditional runoff frequency analysis methods, so the Generalized Additive Model of Location, Scale and Shape (GAMLSS) was employed to detect the non-stationarity of the annual runoff series (1956-2014) in Manas River and correlation analysis method was used to build time varying moment models based on time and climatic factors as covariate variables respectively, whose effects were compared with the traditional model (P-III). The results show that: NAO index could be as one of the climatic factors because of its best relativity with annual runoff serials and the correlation coefficient is -0.322; the optimal distribution model which is based on the accumulated temperature deficit, precipitation index and NAO as covariate variables effectively describes dynamic characteristics of annual runoff in Manas River under climate change. Under different design guarantee rates, annual design runoff by the LOGNO model is larger than the traditional model (P-III Model0) by 3.08%-16.10%. Particularly, the monthly runoff design value is rather different from Model0. The research results provide reference for the efficient use of resources and scientific management of Manas River.
In this paper the impacts of climate change on vegetation net primary productivity (NPP) were estimated in the near term (2018-2030), mid-term (2031-2050), and long term (2051-2099) of the 21st century using a NPP model driven by 5 general circulation models under 3 Representative Concentration Pathways (RCPs). The results indicated that the simulation effect of multi-model ensemble is better than that of single model, and the model of MIROC-ESM-CHEM has better simulation ability for precipitation through the assessment of climate patterns. The climate of Anhui province will continue to warm in the 21st century, with the northern warming rate will be higher than the south, especially in the RCP8.5 scenario. Precipitation will be increasing, with the southern increasing more than the northern. As the climate tends to be warm and humid, vegetation NPP will increase in the 21st century, and the trend of NPP increase will be not obvious in the near term, but will be significant in the mid-term and long period as compared with baseline, and vegetation NPP could be generally higher in the south region than in the north region. From the perspective of climate change response, there is a significant correlation between NPP and precipitation and mean temperature in Anhui province, and the response to precipitation is more significant.
Four typical international carbon databases International Energy Agency (IEA), Carbon Dioxide Information Analysis Center (CDIAC), The Emissions Database for Global Atmospheric Research (EDGAR) and Energy Information Administration (EIA) have been selected to carry out a comparison analysis of their carbon emissions accounting for China’s fossil fuels and cement production. The results show that: 1) the accounting by IEA and EDGAR is more detailed; 2) there is a large difference in activity data classification for the four carbon databases, which is 8, 4, 8, 5 for coal-based fuels, 15, 10, 14, 13 for oil-based fuels, and 4, 1, 4, 2 for gaseous fuels; 3) the carbon emission factors are selected in different way, some use the institute’s own China-specific parameter, some use the default value from IPCC.
Construction of carbon emission management standards system is an important step of standardization. On the basis of current progress on carbon emission management standards in China, a 3D-frame of carbon emission management standards was built up with three sorting techniques as dimensions, namely, property, application object and life cycle. For a full carbon emission management standards framework, many standards are missing at present. According to the framework, 44 items of standards were identified to be established next stage related to prophase work on climate change. To complete the framework, three principles should be followed, which are choosing standards based on the characters of carbon emission, subdivision consideration of relationships with international standards, and carrying out standardization in steps. Relevant suggestions were also proposed on construction of carbon emission management standards system.
To strengthen the research of forest carbon storage and carbon sequestration potential, which is an important basis for the development of China’s policy of increasing carbon sequestration, plays an important role in climate change negotiations and comprehensive understanding of carbon sequestration potential in China. Based on the 7th (2004-2008) and 8th (2009-2013) national forest inventory data of China, IPCC volume-biomass method was used to estimate the carbon storage and carbon density of China’s provinces. The variations and age group characteristics of the carbon storage and carbon density were analyzed in the natural forest and artificial forest in China. The accumulation of per unit area-age groups logistic growth equation model was established different regions and different dominant species. Combined with the growth target of the forest area and accumulation in 2020 and 2030 in China, the future carbon sequestration potential was predicted. The main conclusions are as follows: The total carbon storage of forests in China is 6135.68 Tg, and the carbon density is 37.28 Mg/hm 2; The carbon storage of natural forest and plantation is 5246.07 Tg and 889.61 Tg, which account for 85.50% and 14.50% of total carbon storage, respectively. By 2050, carbon storage and carbon density of forest in China will reach 11125.76 Tg and 52.52 Mg/hm 2, increasing by 81% and 41%, respectively compared with 2010. The results show that China’s forest has a great carbon sequestration potential, and will play an important role in combating and mitigating global climate change.
The Nationally Determined Contribution (NDC) mechanism was established at the Paris Climate Change Conference in 2015, requiring Parties to take a “bottom-up” approach to set climate change targets with reference to national circumstances. This paper summarizes the 164 submitted Intended Nationally Determined Contributions (INDCs) as the former version of NDCs, generalizes a common framework of the documents, and delivers the statistical analysis focusing on the four characteristics of national mitigation and adaptation goals, conditions and fairness. Results show significant differences in the text of INDCs of each Party. Although a common text framework is developed, different choices are made in specific demonstration of target, coverage of economic sectors and gases, implementation conditions and fairness. In addition, the climate change negotiation position has a significant impact on the choices of content and form of commitment made by Parties.
Based on the time sequence data of carbon emissions and GDP of the world’s top 20 emitters between 1990-2015, this paper conducts a cointegration analysis and Granger Causality Test to empirically analyze the relationship between carbon emissions and economic growth in the world’s major emitters. According to the cointegration analysis, there remains a long-term balanced relationship between carbon emissions and economic growth in most countries; furthermore, in the light of the results deduced from the Granger Causality Test concerning carbon emissions and GDP, there exists a one-way relationship of causality between carbon emissions and economic growth in most of the major emitters. In developed countries, the relationship is mainly manifested in the economic growth as a Granger cause of carbon emissions; whereas for developing nations, the opposite is true. Research findings have reflected the stage characteristics of developed and developing countries in terms of CO2 emissions reduction, suggesting that emission reduction obviously exerts a more negative influence on the economic growth of developing nations than their developed counterparts. On the ground of the conclusion drawn from Granger Causality analysis, this paper holds that at the current stage, demand for developing countries to set forth a substantial emission reduction target in the process of international climate governance is not in accordance with the characteristics of their development stages, which may probably affects the normal order and rules of economic development in developing countries. Developed countries, based on their historical emission responsibility, development stage and capability, should take a lead in undertaking emission reduction actions, assist developing countries with transition and upgrading, in order to reduce their dependence of economic growth on carbon emissions. International climate governance needs to base on and take into account the development demand and features of various countries to establish institutional arrangements of international cooperation, so as to push for a concerted and coordinated relationship between socio-economic development and global climate governance.
There are many factors that can influence the demand and supply of allowances in carbon emission trading system. To avoid a severe unbalance between demand and supply of allowances or an excessive fluctuation of carbon price, the Hubei ETS pilot set up a systematic carbon price stabilization mechanism, including classified allowance management, automatic cancellation, ex-post adjustment, allowance reserve and price limit, which has been exerting positive effects. In conclusion, attention should be paid on carbon price stabilization mechanism in the establishment of the national carbon trading system.
The national meteorological service survey in China in 2015 showed that the perception level of climate change and satisfaction degree of meteorological disaster warning of Chinese men are higher than those of Chinese women. To cope with climate change, the ratio of urban women to choose environmentally friendly products, green travel and willing to change ways of living or working is higher than that of urban men, but the ratio of urban men to choose adjusting planting or breeding methods, planting or breeding new varieties and transforming the way of living is higher than those of women. The percentage of men to choose buying meteorological insurance and taking part in climate related training is higher than that of women, while more women are willing to learn professional knowledge of meteorological disasters and climate change. The scale of female to obtain meteorological service information is higher than that of male. To enhance Chinese women’s awareness and ability of coping with meteorological disasters and climate change, it is necessary to develop meteorological service products for women, and to broaden the channels for the dissemination of meteorological knowledge for women.