Abstract: The Working Group III of the IPCC announced the summary for policy makers and the underlying fourth assessment report Climate Change 2007: Mitigation of Climate Change, on 4 May 2007 in Bangkok. This report provides a comprehensive review and state-of-the-art assessment of the scientific, technical, environmental, economic, and social aspects of the mitigation of climate change by updated developments in the literature during the last five years. In the report, examination is made into the greenhouse gas (GHG) emission scenarios in the short and medium term (till 2030) and in the long term (beyond 2030), mitigation potential, cost ranges, and possible choices for stabilization of GHG concentration in the atmosphere. In general, a conclusion is drawn in the report that future GHG emissions are highly dependent on development pathways. Many currently available technologies and those that would be commercially viable technologies by 2030 can reduce emissions in a cost effective manner. Stabilization of GHG concentrations in the atmosphere after 2030 can be kept at relatively low level with comparatively lost cost with respect to their impact on GDP growth. However, greater cooperative efforts are required for effective emissions reduction. Sustainable development and climate change mitigation can be mutually reinforced and synergies are required.

Abstract: Projections of change in precipitation extremes under global warming have drawn much attention abroad. In this paper, recent progresses in studies on precipitation extremes at home and abroad are summarized through the various aspects of observation, theory, simulations and projections. The projected changes in precipitation extremes derived from the five GCMs contributing to the IPCC AR4 over China in the 21st century are also discussed.

Abstract: Based on the daily observational precipitation data of 147 stations in the Yangtze River Basin during 1960-2005 and the simulated daily data of 79 grids from ECHAM5/ MPI-OM in the 20th century, time series of precipitation extremes which contain AM (annual maximum) and MI (Munger index) were constructed. The distributive feature of precipitation extremes was analyzed based on the two index series. Research results show that 1) the intensity and probability of extremely heavy precipitation are higher in the mid-Mintuo River Basin, Dongting Lake area, mid-lower main stream section of the Yangtze River, southeastern Poyang Lake Basin; whereas, intensity and probability of drought events are higher in the mid-lower Jinsha River Basin and the Jialing River Basin; 2) compared with observational data, averaged AM of modeled precipitation is higher but the discrete coefficient of the AM is lower; 3) in spite of certain differences of the spatial distributions between observed and simulated precipitation extremes by applying general extreme value (GEV) and Wakeby (WAK) functions with the method of L-moment estimator (LME) to the precipitation extremes, WAK can fit the probability distribution of precipitation extremes calculated both from observed and simulated data quite well. The WAK could be an important function for estimating the precipitation extreme events under future climatic scenarios.

Abstract: The implementation of the Kyoto Protocol would exert great influences on international trade and economy, and carbon leakage is one of the most important conceptions that describe these influences. Researching on this issue will help us to understand the future influences of the Kyoto Protocol better, especially for the interests of China. The issue of carbon leakage not only embodies the conflicts between environment and trade, but also reflects the important political economic nexus involved in international climate system negotiations. This paper introduces the definition of carbon leakage at first, summarizes literatures on the magnitude of leakage rates, regional contribution and important determinants, analyzes empirically the role of climate policies in the relocation trends of energy intensive industries, and finally discusses both benefits and challenges that the carbon leakage would possibly bring for China and gives some suggestions.

Abstract: The negative accumulated temperature, the first heating date, the last heating date, heating duration, collective heating area and energy consumption for winter heating in Xi'an during 1986-2002 were comprehensively analyzed. The results show that under the global warming, winter in Xi'an became warmer and warmer and heating duration shorter and shorter. With the development of economy, the area and energy consumption for collective heating increased continuously; and in the meantime, the energy consumption per unit area for winter heating decreased year by year, but it didn't match the winter temperature well because the energy was not proportionally consumed according to the change of temperature. In order to conserve energy effectively, heating in winter should be timely adjusted according to actual temperature change.

Abstract: Study on the geographical distribution, seasonal changes and interdecadal changes of the first-landfall and last-landfall tropical cyclones (TCs) in China were done. Results show that the first-landfall TCs generally occured between April and August, with the maximum frequency in June, while the last-landfall TCs generally appeared between August and December, with the maximum frequency in September. As for geographical distribution, the first-landfall and last-landfall TCs made landfall frequently in coasts of Guangdong, Hainan and Taiwan of China, especially in the southeast coast of Hainan. The date of first-landfall showed obvious interdecadal change and a long-term delaying trend, while the date of last-landfall displayed no long-term trend.

Abstract: This paper, using the data from "China Rural Statistical Yearbook" 1984-2003 of National Bureau of Statistics and the observation data of average temperature in the same term, has analyzed the impacts of temperature change、the agricultural input and the sown area changes in different regions of China during the last 20 years. The results show that, the climate change with the main character of getting warmer has obviously promoted the crop production increase in the Northeast of China, but restrain which in the North、Northwest and Southwest of China, and has not obvious effects on it in the East and Central South of China. The increase of agricultural input enhances the production obviously in the various regions in the early stages, but the speed of production increase become slowness in the later period. The sown area change has not obvious effects on the production in the various regions, but the continuous decreased sown area has restrained the production in the East and Central South of China.

Based on the precipitation data from four meteorological stations in Bole Prefecture during 1958-2005, precipitation changes in the growing season of crops were analyzed. The results show that there was a remarkable rise trend for the precipitation in the growing season of crops, with flood years slightly more than drought years since 1990s; the periods of 5-7 years, 16 years, and 30 years were dominant for the mean regional precipitation; the spring-summer drought was very prominent in the Bole River valley since 1990s, which was mainly caused by the precipitation reduction in the upstream of Bole River in May, the delay of the first soaking rain and the decrease of the soaking rain frequency in the midstream of the Bole River. The flood in mountainous area was easily induced by the significant increase in rainfall amount and the frequency of heavy rain from June to August in the upstream of Bole River. The increase in autumn precipitation was unfavorable for crop picking and airing, but it was advantageous for being stored and used in the next spring.

By using the data of thunderstorm of Shandong Province from 1966 to 2005 and applying EOF method and other mathematical statistical methods, the characteristics of spatial-temporal variations of thunderstorms were studied. The main results are as follows: the distribution of annual mean of thunderstorm days shows that thunderstorms in the mountainous areas of Mt. Taishan and Mts. Yimeng are more than ones in the western plain area of Shandong Province and coastal region of Shandong peninsula. Thunderstorms mainly occur in summer with obvious diurnal variation. Analyses indicate that the general trend of Shandong thunderstorms has wavily reduced during the last 40 years .The interannual and decadal variabilities of thunderstorms are obvious in Shandong Province.