There are obvious progress in the evaluation methods of the recent Earth system models (ESMs), from single variable to the multi-variable, multiple process, much phenomenon quantitative assessments in five layers (spheres) of the Earth, from the climatic mean assessment to climate change (such as trend, periodic, interdecadal variability), extreme value, abnormal characters and phenomenon quantitative assessments, from a qualitative evaluation to quantitative calculation of reliability and uncertainty for model simulation. Researchers began to consider patterns between independence and similarity in multi-model use, as well as the quantitative evaluation of climate prediction and projection effect and the quantitative uncertainty contribution analysis.

The spatial and temporal characteristics and dynamic mechanism of arid and semi-arid climate change have been reviewed in this paper. Recently, most of the research on the arid and semi-arid regions’ climate change mainly focused on the specific regions. However, there are less systematic studies for the relationship of climate change on the different global arid and semi-arid regions. The understanding of the mechanism of land surface process model development is another shortage on the climate change studies because the experiments are limited to work on it. Finally, the questions in arid and semi-arid climate change studies and future research direction are proposed.

This study conducted a statistical analysis on the temporal and spatial distribution characteristics of the frequency, days and intensity of heatwaves in China in 1961-2010 based on the summer daily maximum temperature data of 753 stations over China and the heatwave indicators developed based on the significant increase in mortality. The results show that the high frequency, days and intensity of heatwaves occurred in the Jianghuai region, most of the Jiangnan region, as well as eastern Sichuan Basin, with the highest frequency in northern Jiangxi and northern Zhejiang, the largest days in northern Jiangxi and northern Zhejiang, and the highest intensity in northern Zhejiang. The frequency, days and intensity of heatwaves have temporally showed an overall increasing trend in the past 50 years, with a strong stage variation characteristic: the frequency (intensity) of summer heatwaves displayed a decreasing (weakening) trend from the 1960s to the early 1980s, followed by an increasing (strengthening) trend from the late 1980s up to now. The regional heatwave change characteristics were also distinctive, with a significant strengthening (increasing) trend in the northern and western parts of North China, central-northern part of Northwest China, the central part of South China, the Yangtze River Delta and the southern Sichuan Basin, but a remarkable decreasing trend in the local areas of the southern Huanghuai region, the northern Jianghuai region and the Hanjiang River basin. Since the 1990s, the frequency, days and intensity of heatwaves in China have significantly increased and strengthened, and its spatial range has also expanded.

Daily minimum temperature datasets of observation stations, the NCEP reanalysis data were used in this study to assess the BCC-CSM1.1 modeling data over China. Firstly, the grid data were downscaled to observational stations with the Optimal Points Regression (OPR) method, and then China’s regional low temperature events were identified from the three datasets using the Objective Identification Technique for Regional Extreme Events (OITREE). Results show that the NCEP reanalysis data show very good consistency with the observational daily minimum temperatures, while the BCC-CSM1.1 generally also shows a good ability in modeling the daily minimum temperatures, although its modeled data are not as good as the NCEP reanalysis data. For China’s regional low temperature events, the NCEP reanalysis data show very good consistency with the observations in the long-term trend and interannual variation, and the spatial distributions of accumulated intensity and frequency. Meanwhile, the BCC-CSM1.1 simulations show good consistency with the observations in the decreasing tendencies in frequency, extreme intensity, maximum impacted area, duration, accumulated impacted area and integrated index of China’s regional low temperature events during 1961-2005. In addition, the BCC-CSM1.1 model overall shows good ability in modeling the main characteristics of the spatial distributions of the accumulated intensity and frequency of China’s regional low temperature events, but relatively poor ability in modeling the locations of the high-value centers.

The maximum daily precipitation samples are constructed based on the daily observations of 9 meteorological stations from 1961 to 2008 and the multi-model ensembles of the IPCC Fourth Assessment Report in the water source area for the Middle Route Project of South-to-North Water Transfer. The generalized extreme value distribution (GEV) and the generalized Pareto distribution (GPD) are employed to fit the samples. The results show that during 1961-2008, the maximum daily precipitation conforms to both the GEV and GPD, but the simulated results of GPD model are superior to those of GEV model. Then, the corresponding values of different return periods are evaluated. Finally, the extreme precipitation of different return periods are estimated under the A2, A1B, and B1 scenarios. Extreme precipitation events will be more frequent and intense under A2 scenario than under A1B and B1 scenarios, indicating that impacts of the high emissions scenario on future extreme precipitation will be more intense than those of the medium and low emissions scenarios.

With the data of observed monthly evaporation at 44 meteorological stations in Xiangjiang River basin from 1960 to 2006. Changes in pan evaporation and their causes are analyzed. The main results are as follows: pan evaporation decreased by 21.29 mm per 10 year (90% confidence level) in Xiangjiang River basin during the recent 47 years. Significant decrease of annual pan evaporation occurred at 75% of meteorological stations. As for the seasonal pan evaporation, especially in summer, it decreased by 15.58 mm per 10 year (99% confidence level). Spatially, the pan evaporation declined from the southwest to the northeast, the significant decrease of pan evaporation occurred in the downstream. The decrease of pan evaporation is mainly attributed to the decrease of vapor pressure deficit and the significant decrease of wind speed at most of the meteorological stations in Xiangjiang River basin.

Heating and cooling degree-days have been considered to be the simplest and most reliable measures of building energy demands, but their applicability lacks comprehensive assessment. Hence, we simulated the energy consumption of different types of buildings (i.e. office buildings, department stores, and residential buildings with different energy saving levels) in Tianjin from 1961 to 2009 and analyzed its relationships with heating and cooling degree-days. The results show that the relationships between heat loads of office buildings or department stores and heating degree-days in winter reached a high significant level (P < 0.01) with a large determination coefficient (R2) of 0.99 and 0.97, respectively. However, during the hot summer period the determination coefficients (R2) for office buildings and department stores were only 0.64 and 0.55 respectively, although the cooling loads were both significantly correlated with cooling degree-days (P < 0.01). The heat loads of residential buildings with different energy saving levels were all closely correlated with heating degree-days and their determination coefficients were above 0.99. These results suggest that heating degree-days is able to reflect the characteristics of the heat loads of office buildings, department stores and residential buildings and thus can be used to study the impact of climate change on building energy consumption. By contrast, cooling degree-days is unable to entirely reflect the changes of the cooling loads of office buildings and department stores because the cooling degree-days can only explain 64% and 55% of their cooling loads, respectively. It was found from the analysis on relationships between building energy consumption and its relevant climatic factors that the energy consumption in the heating period was dominantly affected by temperature while in the hot summer period it was jointly affected by both temperature and humidity.

The global warming potential (GWP) and global temperature potential (GTP) are two common metrics to calculate the CO2 equivalence of greenhouse gases. If the country’s emissions of greenhouse gases are calculated with GTP instead of GWP, the shares of EU, USA, Japan, Canada and South Africa rise in the period 1990-2005, and those of Brazil, Australia, China, India, Mexico and Russia decrease. From 2015 to 2030, the projected shares of EU, USA, Japan and China will increase, but those of Russia, Canada, Australia, India, Mexico and Brazil will decrease. The reduced shares of Brazil and Australia and increased share of EU might be one of the important reasons that Brazil and Australia suggested to adopt GTP instead of GWP as early as possible, but the EU opposed it.

This paper analyzes and elaborates the developing course of California’s greenhouse gas inventory, the defining principles of inventory boundary, estimation methods, the sources of activity data and emission factors, inventory reporting format used in the inventory, and the latest mandatory greenhouse gas reporting system. Based on the status quo and difficulties of Chinese provincial greenhouse gas inventory, several suggestions are put forward, such as determining how to deal with the emission of imported electricity as soon as possible, improving the base of statistical data, mapping national economy sectors to IPCC codes, and studying the direct reporting system of greenhouse gases of key emission sources.