Based on the output of CMIP5 coupling models under RCP2.6, RCP4.5 and RCP8.5 scenarios, the time with a 2℃ global warming was detected, taking 1890-1900 as a baseline climatology. The mean climate change and extreme climate events over the Qinghai-Tibetan Plateau at that time were compared with the baseline climatology. The results show that 2℃ global warming will appear respectively in 2063, 2040 and 2036 under the RCP2.6, RCP4.5, RCP8.5 scenarios, and the temperature of the Qinghai-Tibetan Plateau will increase 2.99℃, 3.22℃ and 3.28℃ respectively, which are higher than 2℃ of global warming level. The annual precipitation will also increase, and the anomaly percentage is 8.35%, 7.16% and 7.63% respectively. Affected by the temperature and precipitation increasing, the frost days and frozen days will reduce; the days of warm night and warm day will increase; the moderate rain days, strong precipitation, and precipitation intensity will increase; the days of continuous drought will decrease under RCP4.5 scenario. Chaidam Basin is a sensitive area to climate change in the Qinghai-Tibetan Plateau according to the change results of mean climate and extreme climate events.

Based on the 1961-2013 daily maximum/mean/minimum temperature at 25 meteorological observation stations across Dongting Lake ecological economic zone, the change characteristics for heat resources were systematically analyzed by using the relevant statistical methods. Moreover, the impacts of maximum/minimum temperature on the variations of mean temperature were also analyzed by caculating the contribution ratio. Results show that different temperature elements show different spatial distribution patterns. The spatial distribution of steady temperature above 0/5/10/15/20℃ accumulated temperature are consistent, which are high in west and low in east. The largest difference between the beginning and ending dates of steady temperature above 0/5/10/15/20℃ is 10 days at different stations. But most of the difference is within 5 days. Significant increasing or extremely significant increasing trends are identified in the maximum/mean/minimum temperature. But in terms of the warming, there is inhomogeneity in different meteorological elements and seasons. The main feature of climate warming is the increase of minimum temperature. The maximum temperature increasing plays a role in acceleration of warming in spring, which leads to the biggest seasonal temperature rising rate. Extremely significant increasing trends are identified in steady temperature above 0/5/10/15/20℃ accumulated temperature for the climate warming. The variations of beginning and ending dates of steady temperature, abrupt change time are directly affected by inhomogeneous temperature increase. The beginning date of steady above 5/15℃ is earlier than before significantly. The abrupt change time of the steady above 0/5/10℃ accumulated temperature is similar to that of minimum temperature, and the abrupt change time of the steady above 15/20℃ accumulated temperature is similar to that of maximum temperature. Spring cold damage will happen more likely under the background of climate warming.

Based on climate data, geographic information data and economic data, the risk and vulnerability of maize cold damage in Heilongjiang Province were analyzed by using natural disaster risk theory, formation mechanism of cold damage, and GIS technology. The assessment and regionalization were also analyzed. The risk of maize cold damage from 2015 to 2044 was projected with CMIP5 MRI-CGCM3 model. During 1961-2014, there were 24 cold damage years, including 12 severe cold damage years. The most part of Songnen Plain, Sanjiang Plain and south of Heihe are frequency-occurring area of general cold damage, with higher exposure. If the cold damage occurs, impact on the grain production is serious. The probability of cold damage in Heilongjiang Province will decrease in the next 30 years. East and south of Songnen Plain are the high risk areas of general cold damage, and west of Sanjiang Plain is a high risk area of severe cold damage.

In this paper, the relationship between ecological quality for land vegetation and the precipitation & temperature changes during 1978-2013 in the northern part of China (North China, Northeast and Northwest China, Shelterbelt Construction Program region) was analyzed, and so was grassland productivity and precipitation & temperature changes during 1961-2013 in main grassland in China. The ecological quality for land vegetation increased due to the precipitation increase in the northern part of China, and the ecological degradation in grassland slowed down, resulting from the precipitation increase and the grassland ecological protection. The temporal and spacial distribution of precipitation and temperature in China and the extreme events are the main constraints on the achievements of Shelterbelt Construction Program in the northern part of China and Grassland Ecological Protection Project. According to the future climate change in China under RCPs greenhouse gas emission scenarios, the climate will get warmer and wetter in the northern part of China in the next 30-60 year, which will be beneficial to the Shelterbelt Construction Program and Grassland Ecological Protection Project, and the time for ecological restoration will be shorten. But the warmer temperature will increase the risk of wild fire, pest and disease. In coping with these, speeding up the schedule of the shelterbelt construction and grassland ecological restoration is preferable, meantime the scientific research on adaption to climate changes as well as disaster prevention and mitigation should be carried out as soon as possible.

This study was conducted by using the UVic Earth System Model to simulate the change of seawater chemistry and analyze the chemical habitat surrounding shallow- and cold-water coral reefs from the year 1800 to 2300 under RCP2.6, RCP4.5, RCP6.0, and RCP8.5 scenarios. The results show that the global ocean will continue to absorb atmospheric CO₂. Global mean surface ocean temperature will rise 1.1-2.8 K at the end of the 21st century across RCP scenarios. Meanwhile, the global mean surface ocean pH will drop 0.14 to 0.42 and the ocean surface mean concentration of carbonate will decrease 20% to 51%. The saturation state of sea water with respect to calcite carbonate minerals (W) will decrease rapidly. During the pre-industrial period, 99% of the shallow-water coral reefs were surrounded by seawater with W >3.5, and 87% of the deep-sea coral reefs were surrounded by seawater with aragonite supersaturation. Within the 21st century, except for the high mitigation scenario of RCP2.6, almost none shallow-water coral reefs will be surrounded by seawater with W >3.5. Under the intensive emission scenario of RCP8.5, the aragonite saturation horizon will rise to 308 m under water by 2100 from 1138 m at the pre-industrial period, thus 73% of the cold-water coral reefs will be surrounded by seawater with aragonite undersaturation. By the year 2300, only 5% of the cold-water coral reefs will be surrounded by seawater with aragonite supersaturation.

This paper adopted the adaptive control model to simulate the climate system, and simultaneously projected the global admissible emission paths under 2℃ warming targets relative to various base-years. It further proposed three viable warming targets based on the feasibility assessment of the aforementioned targets. Finally, we analyzed the corresponding admissible emissions and emission gaps for China under various principles of allocation. It indicated that it is hard to fulfill the 2℃ warming target relative to the pre-industrial level; while the likelihood to limit the warming within the 2℃ target relative to 1850-1900 or 1861-1880 is high. Moreover, we proposed the light-, mid- and heavy-abatement targets, which are to limit the warming within 2.5℃ relative to pre-industrial level, within 1.0℃ relative to 1986-2005 and within 1.5℃ relative to 1850-1900. China will acquire about one fifth of global emissions under the sovereignty, egalitarianism and ability-to-pay principles. But with all these principles, China’s admissible emissions will shrink gradually under the three warming targets and the emission gap between demand and supply will enlarge accordingly.

In 2012, China owns 357 million units of room air conditioners. Based on capacity of total air conditioner units from survey results and working hours when provincial average temperature in summer exceeds 26℃, annual electric power consumption was 3.28×1011 kW?h, equivalent to 318 Mt CO₂-eq of carbon emission. Domestic demand for room air conditioners is expected to grow further and may fold 4-5 times of the current number of units by 2030. If the power structure remains the same but the energy efficiency of room air conditioners doubles, greenhouse gas emissions generated from electric power consumption of room air conditioners will be 603 Mt CO₂-eq in 2030. If the overall energy efficiency of room air conditioners doubles, the consumption percentage of the room air conditioners with high energy efficiency inereases, and China’s energy percentages of hydro, nuclear, solar and other low-carbon energy continue to grow, under the assumption that China’s demand for room air conditioners is satisfied in 2030, it is possible to maintain the greenhouse gas emissions produced by room air conditioners from electric power consumption at the current level.

Based on the GTAP8 database, the global multi-regional input-output (MRIO) tables for the year of 2004 and 2007 were established. The production-based and consumption-based CO₂ emissions of China, the United States, EU and Japan were calculated and the carbon embodied in foreign trade of China, the United States, EU and Japan were analyzed. The features of carbon embodied in bilateral trade of China-USA, China-EU and China-Japan were also compared. In 2004 and 2007, the production-based CO₂ emission is 15% higher than the consumption-based CO₂ emission for China, but the production-based CO₂ emission is 5% lower than the consumption-based CO₂ emission for the United States, EU and Japan. China is a net exporter of embodied carbon whereas the other three are net importers of embodied carbon. The top three industries with highest carbon emission embodied in export of China are equipment manufacturing industry, textiles and apparel industry, and other manufacturing industry, but the top three industries with highest carbon emission embodied in exports of the United States and EU are equipment manufacturing industry, transportation, and petrochemical. The carbon emission embodied in export of Japan is highly concentrated on equipment manufacturing industry.

Based on the practice of EU ETS and domestic carbon market development status, the carbon cost pass-through principle are analyzed. Power sector is taken as an instance to emphatically study the effect factors of pass-through rates. Result shows that the pass-through rate (RPT) depends mainly on two factors: the method of allocating CO₂ emission allowances, and the structure of the power market. The method of allocating CO₂ emission allowances includes several factors: auctioning versus perfect free allocation, updating free allocation to incumbents or not, contingent allocation to plant closures or not, and free allocation to new entrants or not. The structure of the power market also includes several factors: the level of market concentration or market competitiveness, the shape of the demand curve, and the shape of the supply (or marginal cost) curve. The influence of the structure of the power market on the RPT is mainly reflected in the degree of market competition, market demand and supply conditions. Finally, based on the current domestic carbon market pilot, the article gives some suggestions: changing the initial allocation of carbon emission allowance step by step, reducing one-time payment of free allowance for long period, and allocating allowance based on electricity production instead of capacity.