The characteristics of haze days and the climatic background were analyzed by using daily observations of haze, precipitation, mean wind speed and maximum wind speed of 664 meteorological stations from 1961 to 2012. The results show that haze days are significantly more in eastern China than in western China. The annual haze days are 5-30 d in most central-eastern China, more than 30 d in some areas, but less than 5 d in western China. Haze days are mainly concentrated in winter half year, the most in winter, followed by autumn and spring, and the least in summer. Haze days are the most in December, nearly 20% of annual haze days. The haze days in winter half year averaged in central-eastern China have a significant increasing trend of 1.7 d per decade during 1961-2012. There were great increases in haze days in the 1960s, 1970s and the beginning of the 21st century. There was a significant abrupt change of haze days in the early 1970s and the beginning of the 21st century. Haze days of winter half year increased in South China, the middle-lower reaches of the Yangtze River and North China, but decreased in Northeast China, eastern Northwest China and eastern Southwest China from 1961 to 2012. The consecutive haze process is becoming more and more. The longer the process, the more significant the process’s increasing trend. Unfavourable climate conditions exacerbated the occurrence of haze. The correlation coefficient is mainly negative in central-eastern China between haze days and precipitation days in winter half year, and the precipitation days showed decreasing trends in most China, with the rate of around -4 d per decade in central-eastern China, which reduces the sedimentation capacity of atmospheric pollutants. During 1961-2012, the correlation coefficient is mainly negative in central-eastern China between haze days and mean wind speed and strong wind days, but positive between haze days and breeze days in winter half year. The mean wind speed and strong wind days reduced, while the breeze days increased in most China, which leads to the reduction of pollutants diffusion capacity. As a result, haze occurs more easily.

Based on the daily surface wind speed data during 1971-2010 in China, a comparative analysis of changes of mean wind speed in four subset networks with different station densities relative to the full-size national network (standard network) was conducted. The results show that China-wide mean wind speed varied in the four networks, but the absolute value of the relative difference of mean wind speed is below 10%. The spatial distribution of the wind speed in the basic baseline stations and basic stations come closest to that in the standard network. All networks can detect the downtrend of annual wind speed during 1971-2010, the basic baseline stations and basic stations witness smaller differences. In the case of spatial distribution of wind speed, the monitoring results of these networks are unsatisfactory.

Based on monthly observational data sets of 61 meteorological stations from 1961 to 2010, the pan evaporation trend and abrupt change in the Yellow River basin were analyzed by using Mann-Kendall test method, and then the influence factors were detected and analyzed by using multiple regression method and SVD (Singular Value Decomposition). The results show a significant decreasing trend in annual evaporation in 1961-2010, and the most significant decreasing trend occurs in summer. The abrupt changes of annual, spring and summer evaporation occurred in 1979. In the upper, middle and lower reaches of the Yellow River, the annual evaporation decreased at the rates of 2.38 mm/a, 2.35 mm/a and 8.35 mm/a, respectively with the most significant decreasing trend in the lower reaches. As to the spatial distribution, annual, spring and summer evaporation decreased significantly in the river source region, the west and north parts of Hetao region and the north part of Henan Province, while increased significantly in the east part of Hetao region. By using the method of SVD, it is found that there is a correlation between the spatial change of evaporation and different factors. Based on the multiple regression results, it is concluded that in the region with increasing evaporation, the main influence factor is temperature, whereas in the region with decreasing evaporation, the main influence factor is wind speed.

Based on researches of municipal greenhouse gas (GHG) inventories in China, the paper discussed four key issues: allocation of GHG emissions, inventory framework, inventory border, and inventory scope. This paper comes to four conclusions: according to the characteristics of vertical administration in China, municipal GHG inventory should be consistent with provincial GHG inventory in methodology and comparable with foreign cities; in the light of the characteristics of urban GHG emissions, the framework of inventory method and process of three types (city, central city area, and town) should be established; the inventory border should be defined in accordance with the administrative jurisdiction, which is conducive both to the local government’s overall effective control and jurisdiction of GHG emissions, and to the target decomposition and assessment; the inventory should cover direct emissions and indirect emissions, helping to highlight urban GHG emissions characteristics and to achieve comparison between Chinese and international cities.

Three future cement output trends in 2010-2030 were developed based on international comparisons and macroeconomic drivers, and the potential energy saving and CO² emission reduction were evaluated based on bottom-up calculation by process in China’s cement industry. The results reveal that, relative to current technology scenario, there exist energy-saving potential of 13.4%-14.6% and CO² emission reduction potential of 15.3%-16.3% in China’s cement industry, which could bring cumulative final energy savings of average 420 million tons of standard coal and 3.72 billion tons of cumulative emission reduction under the best technology scenario. On the whole, effects of energy saving and carbon reduction from fuel and clinker substitution are higher than those from energy efficiency measures. Among three kinds of CO² emission sources, process-related emission reduction accounts for about 42% of the total emission reductions, followed by fuel-related emission reduction (36%) and electricity-related reduction (22%).

Consensus and disagreements between China and the US are the key factors influencing the direction that global climate negotiation is heading for. By taking into account the uncertainties of temperature increment and its impact on GDP growth, together with the positive, negative and spillover effects of climate change investment on utility, a strategic simulation model including China and the US is developed based on utility and game theory, and sensitivity analyses are also carried out. The results show that first-mover disadvantage exists in the game, and the scale of each country’s climate change investment under non-cooperate scenario is too tiny to reach the 2℃increment target. To ensure the stability and win-win basis for global cooperation, the simulation results also indicate that it makes sense to pay attention to the assistance and compensation of technology and funding to China.

The issues of loss and damage became one of the key points during the Doha conference of UNFCCC in 2012. This paper analyzed the positions and key problems of main negotiation groups, by reviewing the background and process of negotiation, and revealed the fundamental reasons for slow progress on loss and damage talk are that developed countries hold a negative attitude for their historical responsibility and even attempt to transfer responsibility to developing countries. If developing countries want to succeed in loss and damage talk during COP19, they should enhance their unity and ensure that international loss and damage mechanism possesses some key functions such as finance, concrete actions, assessment and report.

This paper reviewed methods applied by 38 Annex I parties based on their submission of the forest management reference level (FMRL) and technical assessment reports, including in-depth analysis on three key factors influencing FMRL: area of forest management, parameters and harvest rate. Most Annex I parties applied country-specific method or European common method, and a few used historical level or its extrapolation. Methods and parameters applied mostly came from and/or were consistent with national greenhouse gas inventories and national forest inventories. Age-class structure and projected harvest rate are key factors influencing FMRL. In the determination of FMRL, most Annex I parties took a strategy that could result in a lower FMRL based on forest characteristics and the projection of macro-economy, aiming to use credits from forest management as much as possible.

The potential problem of excessive carbon price fluctuation in the carbon emission trading schemes is proposed based on the experience of the EU emission trading scheme (EU ETS). Then possible factors leading to excessive carbon price fluctuations and the negative effect of the excessive price fluctuation are analyzed, and the necessity of using carbon price stabilization mechanism is clarified. Several kinds of carbon price stabilization mechanism and the means of implementing them are summarized, and the potential problem of the mechanisms is analyzed. Based on the analysis above, it is proposed that a systematic, flexible, easy-to-operate and low cost carbon price stabilization scheme should be designed at the initial development stage of the China’s carbon market, incorporating mechanisms to prevent the possible carbon price spurt or collapse and mechanisms to minimize price volatility among years over the entire pilot phase, so that the carbon abatement target could be realized at a low cost.