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Constructing a mathematic transfer function of pollen and climatic factors is one of the most important approaches in the quantitative reconstruction of paleoclimate elements. In the function building, the key point is the response sensitivity to the climate change for different pollen families and categories. As an example in this paper, the pollen samples from the surface and stratum in Dajiuhu basin, Shennongjia are used to estimate the sensitivity of pollen factor-temperature in the transfer function by the EOF analysis, multiple regression and stepwise regression techniques. Thereafter, the selection methods of pollen factors are discussed and compared with other results from different researchers. The results show that in the pollen samples, the quantity of woody plants is larger than others, but the woody plants have relatively lower sensitivity and slow responses to the climate evolution and abrupt climate change. While the pollens from lower grade plants (herb and fern) have a relatively high sensitivity to the temperature change and fast response to the abrupt climate changes. Therefore, the pollen of herb and fern may significantly record the extreme events in the climate change. Also in different regions, the pollen samples have different sensitivity and optimum combination in the transfer functions. Final conclusion is that the stepwise regression is one of the best methods for transfer function building since it can obtain the maximum multiple correlation coefficients and optimum combination of sensitive pollen factors. [ABSTRACT FROM AUTHOR]

Sky islands are high-elevation areas in continental mountain ranges, which are geographically isolated. We adopted this concept for the mountains in southwest China, which are among the most important biodiversity hot spots on earth. We reviewed the phylogeographic studies of this area and highlighted the sky-island features. We concluded that the genetic structures of species in these islands were shaped by complex topography, climate and habitats. The global climate change, such as Pleistocene climate fluctuations and periodic uplift of the Qinghai-Tibetan Plateau, also have important effects on biodiversity and geographic patterns, when species have responded idiosyncratically by changing their distributions or through adaptation. Future research needs in sky islands include multilocus data and comparative phylogeographic studies, integrating with the methodological advances in the other fields. Using these approaches, we can examine to what degree the geographic, climate and/or biological factors, shape strong geographic patterns, promote diversification/speciation and preserve species/genetic diversity. We hope this paper will inspire future work to uncover the mechanism that has generated the endemic biodiversity and to further resolve the most essential problem: How to protect the biodiversity with limited funding during the coming drastic global climate change. [ABSTRACT FROM AUTHOR]

Understanding the seasonal behaviour of a subtropical forest and its inter-annual variation is crucial to understanding and monitoring its ecosystem function in the context of global warming. Based on the Moderate Resolution Imaging Spectroradiometer (MODIS) Enhanced Vegetation Index dataset, a wavelet transform method was used to investigate the inter-annual variations of vegetation phenology in a subtropical mountain and hill region in Fujian, China, during 2001-2010. The results show a distinct inter-annual variation of vegetation phenology related to climate variability even if most areas presented non-significant trends. The start dates significantly advanced and end dates delayed in 2003 and 2008, due to anomalously warm conditions. There was generally a gradient of increasing start dates, and earlier end dates of vegetation growing season, due to colder temperatures at higher altitudes. However, the altitudinal phenology relationship also depends on its corresponding rainfall conditions. Earlier start dates were observed at higher altitudes during rainfall deficit years such as 2008, which coincides with relatively abundant rainfall at higher altitudes. This paper reveals that vegetation phenology was coupled with altitudinal gradient, with distinct responses at different combinations of alternate temperature and precipitation conditions variability. [ABSTRACT FROM AUTHOR]

This paper presents a 457-year reconstruction of precipitation in the southeastern Qinghai-Tibet Plateau using tree-ring records. Tree-ring samples were collected from the Hengduan Mountains in the southeastern part of the Qinghai-Tibet Plateau, China. A nearly 500-year chronology was developed using tree-ring width records. Correlation analysis shows moisture is the main factor limiting tree growth in this region. Ring-widths were significantly positively correlated with the Palmer Drought Severity Index (PDSI) and precipitation in many months. The highest correlation coefficient was found between the annual growth of trees and precipitation from the previous September to the current June (0.738). Based on this relationship, we reconstructed the precipitation history from 1509 to 2006. The reconstruction explains 54.4% ( R=53.5%, N=49, F=56.12) of the actual precipitation variation during the calibration period (1958-2006). During the reliable period of the reconstruction (1549-2006), some low-frequency climate signals are included, indicating this region has been getting wetter in the last 20 years. The reconstruction documents six apparently dry and five pluvial periods and the 17th century dry period lasted longer than any other. When compared with other recent studies, this study and these earlier reconstructions show a similar trend in the variation of drought and pluvial. Further spatial correlation analysis confirms that the reconstructed precipitation adequately represents the rainfall history of the entire Hengduan Mountain area. The Multi-taper method, a type of spectral analysis, reveals that precipitation in this area had significant ( P<0.01) spectral peaks at 3-5 a, 60 a and 79-85 a. [ABSTRACT FROM AUTHOR]

This paper describes 2007/2008 inter-annual changes in runoff from the Zhadang Glacier located on the northern slope of Nyainqêntanglha Range, Tibet, and analyzes their causes. Precipitation increased by 17.9% in summer months of 2008 compared with the same period in 2007, drainage basin runoff decreased by 33.3%, and glacial meltwater decreased by 53.8%. Change in positive accumulated air temperature explained approximately half of the inter-annual difference in glacial meltwater using a degree-day model. This suggests that the glacier is extremely sensitive to changes in air temperature. Energy balance analysis showed that change in glacier surface albedo, considered to be caused by difference in precipitation form, resulted in the large inter-annual difference in glacial meltwater. It was shown statistically that precipitation form in the summer months of 2007 was mainly rainfall which comprised 71.5% of total precipitation, while during the same period in 2008 rainfall accounted for 30.7%, with the majority of precipitation falling as snow. Precipitation form should be considered an independent factor when analyzing glacier sensitivity to climate change or forecasting the runoff from certain glaciers. [ABSTRACT FROM AUTHOR]

Global warming tends to be the major characteristics of the dramatic global climate change. To deal with these changes, the impact of reducing greenhouse gas (GHG) emission on Chinese future economic and social development has to be assessed. In this paper, a Regional Integrated model of Climate and the Economy (RICE), which is well known and accepted widely, has been used for Chinese economic assessment of climate change after introduction, assimilation and verification. Based on a sensitivity analysis of technical parameters in the RICE model and constrained targets proposed for energy saving and emissions reduction technological advance programs of China from 2000 to 2050, the economic impact of the programs is examined. The results indicate that when technology advances, Chinese CO2 emission, climate loss, and the growth rate of atmospheric CO2 concentration and temperature will all decrease. It is assumed that in 2010, the CO2 emission is 20% lower than in 2005, CO2 emission in 2050 would only double the level in 2000, the accumulative CO2 emission would be decreased by 12.4 GtC, and the atmospheric CO2 concentration and temperature in 2050 would reduce by 35 GtC and 0.04°C respectively from 2000 to 2050. The accumulative climate loss from 2000 to 2050 will drop down by 4.6 billion dollar, which only accounts for 6% of the global total benefits. However, the economic benefit the developed countries will obtain is 10 times that for China under such a technological advance scenario. The decrease of the CO2 emission control rate is 1% in cooperation policy while 4.6% in non-cooperation policy, which would relieve China's burden in the control of CO2 total emission and thereby benefit China in participation of the international cooperation for CO2 emission reduction. [ABSTRACT FROM AUTHOR]

Pollen analysis is one of the best and possible approaches for the quantitative reconstruction of paleobotany and paleoclimate, and discrimination of human activities. In this paper, we reveal the characteristics of pollen assemblages in different agricultural units and their spatial distribution of major pollen taxa in the Anyang area where the human influences are serious, so as to get more information about climate change and human activities from pollen records. The pollen assemblages of total 122 surface soil samples from different agricultural units (farm lands, vegetable plots, wastelands, cape-lands, woodlands, etc.) indicate that herbaceous pollen dominates the pollen assemblages with an average of 73%, mainly from Poaceae, Artemisia, Chenopodiaceae and Cruciferae; arboreal pollen percentages reach 18%, mainly from Pinus and Ulmus; shrub pollen and fern spores have very low percentages. In general, pollen assemblages are consistent with vegetation composition, though some differences also exist in different agricultural units. In farmlands and vegetable lands, Poaceae pollen has the highest percentages (averaging 27%) compared to other agricultural units with dominant corn or wheat pollen, while in wastelands and woodlands, arboreal and Artemisia pollen percentages have higher values (averaging 20% and 19% respectively). Cruciferae has the highest pollen percentages (70%) in rape-lands. Both pollen assemblages and PCoA can generally identify the vegetable plots, farmlands, woodlands, wastelands, and rape-lands. Pinus and Artemisia pollens mainly appear in the western part of Anyang, which is consistent with the parent plants; Poaceae pollen mainly exist in the eastern part with more farmlands; Chenopodiaceae pollen mainly appear in the urban areas and near major roads where human influences are stronger, Cruciferae pollen can mainly be found in the urban area and in the northwest part of Anyang where more vegetables are planted. [ABSTRACT FROM AUTHOR]

Coral reefs worldwide are becoming increasingly and detrimentally impacted upon by a variety of factors including significant climate changes, such as global warming and increased El Niño-Southern Oscillation activity. Generally, the persistence of coral reefs, especially at low-latitudes, is governed, in part, by sea surface temperatures not exceeding the critical limit (∼30°C) at which mass mortality can occur. Thus, it is thought that corals living at high-latitudes (i.e., currently cooler sea surface temperatures) will likely respond more favourably to hypothesized future temperature increases than corals living at low-latitudes (i.e., currently warmer sea surface temperatures). Consequently, high-latitude coral communities may have the potential to act as regions of refugia for many coral species in the face of potential future global warming. The Daya Bay (22°31'-22°50'N), northern South China Sea, contains several high-latitude non-reefal coral communities and represents one of the most northerly distributions of scleractinian corals within the region. Significantly, Daya Bay has experienced dramatic warming in both air and sea surface temperatures throughout the past 50 years. In this paper, we analyze 25 years of change in the Daya Bay coral communities, based both on historic surveys and our latest 2006-2008 regional ecological surveys. Our results suggest that, contrary to predictions, there have been significant declines in coral cover within the Daya Bay during the past 25 years (i.e., 76.6% coral cover in 1983/1984 to only 15.3% coral cover by 2008). Such changes also reflect a significant shift in the most abundant coral species, from Acropora pruinosa to Favites abdita. Most of the modern coral communities became established between 15 and 30 years ago, corresponding to a period of increased winter sea surface temperature. However, very few colonies have become established within the last 15 years, despite a more intense period of warming. By taking into account additional factors, we hypothesize that direct anthropogenic impacts, rather than climatic events, have both restricted the development, and drove the decline, of Daya Bay coral communities in the last 15 years. The Daya Bay has also been subjected to occasional extreme cold events during the past 50 years, with the most recent occurring in early 2008 (13 January-13 February). During the 2008 cold event, the lowest air temperature reaches only 6.6°C, and the mean sea surface temperature for February fall to <14°C, including six continuous days at 12.3°C. Significantly, the sea surface temperatures fall below the hypothesized critical lower temperature threshold (∼13°C) that commonly leads to mass mortality in scleractinian coral communities. Surprisingly, our coral community surveys, conducted both before (August 2007) and after (late February 2008) the extreme 2008 cold event, demonstrate that the Daya Bay coral ecosystems are barely impacted upon during the cold period. Those observations suggest that the Daya Bay scleractinian coral communities have developed adaptations to low sea surface temperatures. Overall, our data support the hypothesis that high-latitude coral communities, such as Daya Bay, have the potential to act as areas of refugia for scleractinian corals in the advent of potential future global warming. [ABSTRACT FROM AUTHOR]

This paper analyzes the statistics of faults in a transmission and distribution networks in central China, unveils long-term autocorrelation and power law distribution of power system faults, which indicates that power system fault has self-organized criticality (SOC) feature. The conclusion is consistent with the power systems data in 2008 with ice storm present. Since power systems cover large areas, climate is the key factor to its safety and stability, In-depth analysis shows that the SOC of atmosphere system contributes much to that of power system faults. Extreme climate will be more intense and frequent with global warming, it will have more and more impact upon power systems. The SOC feature of power system faults is utilized to develop approaches to facilitate power systems adaptation to climate variation in an economical and efficient way. [ABSTRACT FROM AUTHOR]

Methane (CH4) is the most important greenhouse gas and reactive trace gas in the atmosphere. Recently, it has been reported that terrestrial plants can emit CH4 under aerobic conditions, which may call for reevaluation of the inventory of CH4 emissions in China. In this paper, those emissions over China and their effects on CH4 concentrations in lower troposphere were investigated. Firstly, based on the work of Keppler et al., the aerobic plant CH4 emission model (PLANTCH4) for China was established. And by using the database of normalized difference vegetation index (NDVI) derived from NOAN AVHRR, the distribution of net primary productivity (NPP) over China was simulated, and thereby, for the first time, the amount and distribution of the newly identified source in China were estimated. Secondly, with the aid of the three-dimensional atmospheric chemistry model system (MM5-CALGRID), the effects of the emissions were studied. The results show that the annual aerobic plant CH4 emissions over China amount to 11.83 Tg, i.e. nearly 24% of Chinese total CH4 emissions. And the major fraction (about 43%) comes from forests. When those emissions are considered in modeling, computed countrywide mean surface concentration of CH4 is 29.9% higher than without them, with a maximum increase of 69.61 μg · m-3 in the south of Yunnan Province. In conclusion, to study CH4 emissions from terrestrial plants over China may have important implications for correctly estimating the contribution of China to global CH4 budget, and may call for a reconsideration of the role of CH4 in global and regional environment and climate change. [ABSTRACT FROM AUTHOR]

The nitrogen isotope of soil is of emerging significance as an indicator of climatic change and blogeochemical cycle of nitrogen in nature systems. In this paper, the nitrogen content and isotopic composition of modern ecosystems from arid and semiarid Loess Plateau in northwestern China, including plant roots and surface soil, were determined to investigate trends in δ15N variation of plant roots and soil along a precipitation and temperature gradient in northwestern China under the East Asian Monsoon climate condition. The δ15N values of surface soil from the study area vary from -1.2‰ to 5.8‰, but from -5.1‰ to 1.9‰ in the plant roots. Our results indicate that (1) although the isotopic compositions of both plant roots and surface soil change with a similar trend along the climate gradient, the apparent nitrogen difference between plant roots and soil existed, with Δδ15N values ranging from 0.3‰ to 7.2‰ with average of 4.1‰ and (2) mean annual precipitation (MAP) is the dominant factor for isotopic composition of plant-soil nitrogen in the Loess Plateau, and the δ15N values are less correlated with MAT; we suggest that nitrogen isotopic composition of soil is a potential tracer for environmental changes. [ABSTRACT FROM AUTHOR]

This paper presents a multi-proxy reconstruction of the climate change in Caotanhu wetland using pollen, phytolith and charcoal records, and the data of loss of ignition (LOl), grain size analysis, and susceptibility. Results reveal that between 4550 and 2500 cal. a BP, a dry climatic condition was not favorable for the accumulation of peat. Since 2500 cal. a BP, the climate became humid and the wetland developed with abundant freshwater aquatic plants, which contributed to peat accumulation. Nevertheless, alternate periods of rain and dry climate occurred during that period. Between 2500 and 1810 cal. a BP (550 BC-140 AD), the climate was more humid than at present. A lot of emerged plants, such as Phragmites, Typha and Sparganium, and freshwater green algae grew in the wetland which was surrounded by desert-steppe vegetation composed mainly of Chenopodiaceae, Artemisia, Compositae and Thalictrum. However, from 1810 to 1160 cal. a BP (140-790 AD), the water level started to decrease and hydrophyte species reduced greatly, but some Phragmites still grew in the wetland and around it was desert vegetation with high proportion of Chenopodiaceae and Artemisia. Then from 1160 to 650 a BP (790-1300 AD), it entered a period of desert-steppe with abundant mesic and xerophytic plants. And a lot of aquatic plants prevailed in the wetland. Here, what is noticeable is that percentages of arboreal pollen, consisting mainly of Betula and Picea, increased greatly and reached a maximal value of 27.2%, in which, Betula percentages rose to 23.2%. Hence, it is reasonable to conclude that Betula grew in the highland of the wetland, or Picea timberline shifted downward resulting in the increase of percentages of Betula and Picea pollen, which were transported into the wetland by flood or wind. But since 650 cal. a BP, desert vegetation prevailed around the wetland again with dominant Chenopodiaceae and Artemisia, and the climate was similar to modern one. Despite some aquatic plants still growing in the wetland at that time, their amounts diminished greatly. [ABSTRACT FROM AUTHOR]

Nearly 200000 animal skeletons are unearthed in the Unit T0202 from Zhongba Site of Zhongxian County. According to the analysis of 129165 specimens, these skeletons may be classified into 5 kinds, namely, Mammalia, Osteichthys, Ayes, Amphibian and Reptilia, which belong to 13 orders, 28 families and 42 genera. In this paper, based on archeological dating and AMS14C data, through statistically analyzing the unearthed skeletons and studying the change of the smallest individual numbers, these research results detected the following: 1) In almost all the time of 2370-200 BC, in Zhongba region, some animals distributed widely, such as Muntiacus sp, Elaphodus cephalophus and Muntiacus sp. inhabiting in glade and grassland, Scrofa sp. and Canis famiiaris raised by the ancient people, rodentia rabbit and Rattus rattus, which suggested that a fairly good ecological environment of forest and grassland was preserved at that period and the predecessors began to raise domestic animals from 1750 to 1000 BC, which has lasted until today. 2) Rhinoceros only lived during 2000-1750 BC, 1000-700 BC and 700-500 BC, which indicates that the ecological environment of grassland and wetland might be better in these phases. 3) Macaca sp. and Ursus arctos appeared only after 1750-1000 BC, which may show that the forest condition is better for animals to live during 1750-200 BC. 4) The smallest individual numbers of Bublus sp., bos sp. and otters emerged during about 2370-1750 BC, which perhaps infers that water area during the early period was wider than that of the late period. 5) Since skeletons of rhinoceros are discovered in strata of Zhongba Site during 2000-1750 BC and 1000-500 BC, according to the climate and ecology environment which rhinoceros live in now, the average annual temperature and precipitation during 2000-1750 BC and 1000-500 BC are supposed to be probably higher than that of today. Although Zhu Kezhen considered that the first low temperature period in the past 5000 years of China was between 1100 BC and 850 BC, massive pollen of Morus, Ulmus, Fagus, Quercus, Castanea, etc. were found in Dajiuhu peat at that time, which should indicate that the climate was still moderate for living things to live at least in Dajiuhu basin and Zhongba Site. 6) Because skeletons of Gervus albirostris were unearthed during 310-200 BC at Zhongba Site, based on the climate and the ecological environment those animals live in now, the average annual temperature and the average annual precipitation in Zhongba area between 310 BC and 200 BC should be lower than those of today, which is confirmed by the TOC research of Zhongba Site strata. [ABSTRACT FROM AUTHOR]

This article presents an analysis of tree species abundance and its association with climatic variables along elevation gradient in the Gaoligong Mountains in west Yunnan, China. Data from scientific papers and books in the Gaoligong Mountains area were collected and extrapolated to elucidate a mechanistic understanding of elevation patterns and the relationship between the elevation range and elevation mid-point of tree species along the gradient by examining climatic variables. Tree species abundance showed a unimodal pattern with a peak at mid-elevation (about 2000 m) and species with a narrow elevation range occurred at higher or lower elevation, while a wider elevation range was found at the middle of the gradient. Tree species abundance was the highest where both temperature and water availability were moderate. The relationship between the climatic variables affecting species appear to be due to both direct and indirect factors, and the effect of these effects varied at different gradients. [ABSTRACT FROM AUTHOR]

Both the climate change and human activities are the major influence factors to the sediment change in mountainous rivers. Based on the over 40 years' record, suspended sediment loads (SSL) change at the Manhao gauging station in the lower reaches of Yuanjiang River (upper Red River). In this paper, the variation of the sediment and its drivers were analyzed through different methods such as synchronous data comparison, traditional correlation, linear regression, and Granger causality. The results show that (1) the general trend of the annual average sediment concentration (SSC) and SSL at Manhao station is increasing from the 1960s to the 1990s, and there is a quick change period after 1984; (2) the SSL and SSC at Manhao station, during different periods of the 1960s, 1970s, 1980s and 1990s, are 1.87, 2.49, 3.12, 3.63 kg/m3, and 28.7×106, 40.3×106, 44.1×106, 60.3×106 t/a, respectively; (3) the correlation analysis and the Granger causality test proved that the climate changes in the catchment were the main driving factors to the sediment variation in the period of 1960s and 1990s, but the influence by the mountainous human actions on the sediment change is stronger than that by the local climate changes in the 1970s and 1980s; (4) the correlation between the sediment changes and the forest coverage change is negative, which further proves that the sediment changes are strongly affected by the human activities in the basin. [ABSTRACT FROM AUTHOR]

Recent climatic changes have affected terrestrial net primary productivity (NPP). This paper presents an investigation of the impact of climatic changes on Chinese terrestrial vegetation NPP by analyzing 18 years' (1982 to 1999) climatic data and satellite observations of vegetation activity. Results indicate that climatic changes in China have eased some critical climatic constraint on plant growth. (1) From 1982 to 1999, modeled NPP increased by 1.42% · a-1 in water-limited regions of Northwest China, 1.46% · a-1 in temperature-limited regions of Northeast China and Tibet Plateau, and 0.99% · a-1 in radiation-limited regions of South China and East China. (2) NPP increased by 24.2%, i.e. 0.76 petagram of carbon (Pg C) over 18 years in China. Changes in climate (with constant vegetation) directly contributed nearly 11.5% (0.36 Pg C). Changes in vegetation (with constant climate) contributed 12.4% (0.40 Pg C), possibly as a result of climate-vegetation feedbacks, changes in land use, and growth stimulation from other mechanisms. (3) Globally, NPP declined during all three major El Niño events (1982 to 1983, 1987 to 1988, and 1997 to 1998) between 1982 and 2000, but Chinese vegetation productivity responded differently to them because of the monsoon dynamics. In the first three events (1982 to 1983, 1987 to 1988, and 1992), Chinese vegetation NPP declined, while in the later two events (1993, 1997 to 1998) increasing obviously. [ABSTRACT FROM AUTHOR]

This paper applies climate change scenarios in China based on the SRES assumptions with the help of RCMs projections by PRECIS (providing regional climates for impacts studies) system introduced to China from the Hadley Centre for Climate Prediction and Research at a high-resolution (50 km×50 km) over China. This research focuses on B2 scenario of SRES. A biogeochemical model "Atmosphere Vegetation Integrated Model (AVIM2)" was applied to simulating ecosystem status in the 21st century. Then vulnerability of ecosystems was assessed based on a set of index of mainly net primary production (NPP) of vegetation. Results show that climate change would affect ecosystem of China severely and there would be a worse trend with the lapse of time. The regions where having vulnerable ecological background would have heavier impacts while some regions with better ecological background would also receive serious impacts. Extreme climate even would bring about worse impact on the ecosystems. Open shrub and desert steppe would be the two most affected types. When the extreme events happen, vulnerable ecosystem would extend to part of defoliate broad-leaved forest, woody grassland and evergreen conifer forest. Climate change would not always be negative. It could be of some benefit to cold region during the near-term. However, in view of mid-term to long-term negative impact on ecosystem vulnerability would be enormously. [ABSTRACT FROM AUTHOR]

Climate change and hydrologic process response in the Tarim River Basin over the past 50 years are the tocus of more and more researchers' attention. In this paper, both temperature and precipitation time series were found to present a monotonic increasing trend using nonparametric tests. Noticeably, a significant step change in both temperature and precipitation time series occurred in 1986. By contrasting the trends of natural water process in headstream and mainstream, we found that it was anthropogenic activities not climate change that caused the river dried up and vegetation degenerated in the lower reaches of Tarim River. The results of gray correlation analysis show that the runoff of higher latitude distributing river is more closely associated with winter snow stocking, while that of lower latitude is more closely related to summer temperature. Runoff in the headstream is more sensitive to precipitation, while that in the mainstream is more sensitive to evaporation. The strong evaporation caused by increasing temperature weakened runoff to some extent in spite of the fact that precipitation increased over the past 50 years. [ABSTRACT FROM AUTHOR]

An article by Zhang et al. questions the interpretation of our oxygen isotope record from Wanxiang Cave and the sediment titanium record from Lake Huguang Maar, and the possible linkage between climate change and Chinese culture. In response, we explain that their approach lacks logical rigor and their major argument is broadly consistent with, rather than contradictory to our original conclusions. We also note that climate-culture relationships similar to those that we observe in China have been observed for other cultures around the world. [ABSTRACT FROM AUTHOR]

The study of the temporal and spatial variation of atmospheric water vapor has the important significance to show the response to climate change in the Taklimakan Desert. The series of monthly atmospheric water vapor from 1961 to 1998 are reconstructed using the observation data including the precipitation, ground water vapor pressure data over the period of 1961 to 2006 from 27 observation stations in its surrounding areas and meteorological data from the Tazhong station during 1999-2006. Then the relationship between atmospheric water vapor and ground vapor pressure is calculated and validated using the observation data for the period of 1976 to 2006 from 5 sounding stations (Hotan, Kuqa, Ruoqiang, Kashgar, and Minfeng). The temporal and spatial variation of atmospheric water vapor in the Taklimakan Desert and its surrounding areas is studied and then its distribution is generated. Results show that high value zone of atmospheric water vapor is mainly distributed in the northern Taklimakan Desert and the oasis-marginal belt of western desert and the value ranges from 14 to 15 mm. The low value center of atmospheric water vapor is in the hinterland of the desert and the value is only 7?8 mm. The annual variations of atmospheric water vapor show generally the increasing trend. However, the variation of atmospheric water vapor in the surrounding areas and the hinterland of the desert is insignificant during 1961?1986. The atmospheric water vapor changes abruptly after 1986 and increases clearly in the two regions. The variation trend accords with that of the precipitation's increasing significantly in southern Xinjiang for the recent 50 years. There is great error between the NCEP/NCAR reanalysis data of atmospheric water vapor and real data in the Taklimakan Desert. [ABSTRACT FROM AUTHOR]

There is considerable interest in the potential impact of climate change on wind energy in China. The climate change of near-surface wind energy potential in China under the background of global warming and its association with anthropogenic land-use changes are investigated by calculating the difference in surface wind speeds between the NCEPINCAR reanalysis data and the observations since the re- analysis dataset contains the influence of large-scale climate changes due to greenhouse gases, it is less sensitive to regional surface processes associated with land types. The surface wind data in this study consist of long-term observations from 604 Chinese Roution Meteorological Stations and the NCEPINCAR reanalysis data from 1960-1999. The results suggest that the observed mean wind speeds signif icantly weakened and the near-surface wind power trended downward due to urbanization and other land-use changes in the last 40 years. The mean wind energy weakened by -3.84 W•m-2 per decade due to the influence of anthropogenic land-use change, which is close to the observed climate change (-4.51 W•m-2/1 0 a). [ABSTRACT FROM AUTHOR]

The article reports that the Monsoon and Environment Research Group of Peking University has submitted a report regarding the China monsoon rainfall prediction. It notes that the research group has showed how the regional summer monsoon rainfall in China can be predicted through the use of signals from the sea surface temperature anomaly (SSTA) and the subsurface temperature anomaly (STA) in the central equatorial Pacific (CEP). Several of the facts been revealed are also presented.

Based on the nonlinear Lyapunov exponent and nonlinear error growth dynamics, the spatiotemporal distribution and decadal change of the monthly temperature predictability limit (MTPL) in China is quantitatively analyzed. Data used are daily temperature of 518 stations from 1960 to 2011 in China. The results are summarized as follows: (1) The spatial distribution of MTPL varies regionally. MTPL is higher in most areas of Northeast China, southwest Yunnan Province, and the eastern part of Northwest China. MTPL is lower in the middle and lower reaches of the Yangtze River and Huang-huai Basin. (2) The spatial distribution of MTPL varies distinctly with seasons. MTPL is higher in boreal summer than in boreal winter. (3) MTPL has had distinct decadal changes in China, with increase since the 1970s and decrease since 2000. Especially in the northeast part of the country, MTPL has significantly increased since 1986. Decadal change of MTPL in Northwest China, Northeast China and the Huang-huai Basin may have a close relationship with the persistence of temperature anomaly. Since the beginning of the 21st century, MTPL has decreased slowly in most of the country, except for the south. The research provides a scientific foundation to understand the mechanism of monthly temperature anomalies and an important reference for improvement of monthly temperature prediction. [ABSTRACT FROM AUTHOR]

Fossil pollen records from 45 sites across China were evaluated and synthesized to document vegetation and climate change during Marine Isotope Stage 3 (MIS 3) at 60-27 ka and to understand the large-scale controls. During MIS3, vegetation type was dominantly forest in eastern China, forest steppe/meadow in the north and Tibetan Plateau, and steppe desert in northwestern arid China. We developed a semi-quantitative vegetation index to reflect change in plant abundance (by inferring the general climate conditions), with a vegetation score from 1 to 3 based on the different vegetation types inferred from pollen data at individual sites at intervals of 2,000 years. The reconstructed vegetation index shows higher values during MIS 3, especially during the period 53-40 ka, than at the Last Glacial Maximum. Our results also suggest that climate on the basis of vegetation change was cooler and drier during MIS 3 than during the Holocene optimum; however, MIS 3 vegetation was probably similar to modern vegetation. The close relationship between vegetation change, insolation and Asian summer monsoon strength suggests that climate variations, probably in both temperature and precipitation, are the primary drivers of regional vegetation change. Additional well-dated, high-resolution palaeoclimate records from many locations across China will be needed to understand the vegetation change and climate forcings on millennial and centennial scales within MIS 3. [ABSTRACT FROM AUTHOR]

1-Chloro-1,1-difluoroethane (HCFC-142b) was both ozone depleting substance under restriction of the Montreal Protocol on Substances that Deplete the Ozone Layer ( Montreal Protocol) and potent greenhouse gas with high GWP. Controlling its emissions in China will contribute to both mitigating climate change and protecting ozone. A national emission inventory of HCFC-142b for China during 2000-2012 was established and projected to 2050 based on the 2006 IPCC Guidelines for National Greenhouse Gas Inventories and the Montreal Protocol, showing that (i) in contrast to the downward trend revealed by existing researches, HCFC-142b emissions kept increasing from 0.1 kt/y in 2000 to the peak of 14.4 kt/y in 2012, making China a crucial contributor to global HCFC-142b emissions and (ii) for future emission projections, a continuous increase from 14.9 kt/y in 2013 to 97.2 kt/y in 2050 was anticipated under the business-as-usual (BAU) scenarios, while a reduction of about 90% of the projected BAU emissions would be obtained by fulfilling the Montreal Protocol, namely an accumulative mitigation of 1578 kt HCFC-142b from 2013 to 2050, equal to 103 kt ODP and 3504 Tg CO emissions. Emissions from each province in 2012 were also estimated to identify key emission areas. Among the 31 mainland provinces in China (Hong Kong, Macao, and Taiwan were not included), Jiangsu, Zhejiang, Shandong, and Guangdong had the highest emission rates in 2012 (2.06, 1.85, 1.52, and 1.04 kt/y, respectively); Zhejiang, Jiangsu, and Shanghai exhibit the strongest emission strength (0.83, 0.59, and 0.54 t/km, respectively), much higher than the average national level of 0.33 t/km. [ABSTRACT FROM AUTHOR]

Previous studies revealed the double-peak mode (DPM) in South China precipitation, corresponding to the two stages in the rainy season, i.e. the first rainy stage (FRS) and the second rainy stage (SRS). But observations in recent two decades show that the DPM has changed to a single-peak mode (SPM). Both the precipitation amount and the heavy rainfall event frequency enhanced significantly in the gap between the FRS and the SRS in 1991–2010, compared to those in 1961-1990. This change can be linked to the effects of the global warming. During the warmer period, the July sea surface temperature over the western Pacific has greater increases than that over the central and eastern Pacific, especially west of 140°E. It may generate more tropical cyclones (TCs) in the inshore areas and then more typhoon rainfall over South China. On the other hand, the increments of the air temperature over the East Asian continent are greater than those of the SST over the western Pacific under the global warming, which enlarges the land-ocean temperature/pressure contrast and leads to a trend of the earlier onset dates of the Asian summer monsoon (ASM) in recent two decades. Then, the earlier ASM will facilitate the western Pacific subtropical high (WPSH) to retreat earlier from the South China Sea and enhance the convective precipitation in South China between the FRS and the SRS. Also, due to the warmer ocean, the WPSH locates more westward in July, and more moisture will be transported to South China from the southwest side to the WPSTH. All these influences favor a remarkably increasing precipitation in the gap in the warmer period and changes the seasonal cycle from double-peak mode to single-peak mode. [ABSTRACT FROM AUTHOR]

The Last Glacial Maximum (LGM, c. 26-16 ka) and the Holocene Optimum (HO, c. 9-5 ka) were characterized by cold-dry and warm-wet climates respectively in the recently geological Earth. How Chinese deserts and sand fields responded to these distinctive climatic changes is still not clear, however. To reconstruct environments of the deserts and sand fields during the LGM and HO is helpful to understand the forcing mechanisms of environment change in this arid region, and to test paleoclimatic modeling results. Through our long-term field and laboratory investigations, 400 optically stimulated luminescence (OSL) ages and more than 100 depositional records in the Chinese deserts and sand fields were obtained; on the basis of these data, we reconstruct spatial distributions of the deserts and sand fields during the LGM and HO. Our results show that the sand fields of Mu Us, Hunshandake, Horqin and Hulun Buir in northern and northeastern China had expanded 25%, 37%, 38% and 270%, respectively, during the LGM; the sand fields of Gonghe in the northeastern Qinghai-Tibetan Plateau had expanded 20%, and the deserts of Badain Jaran, Tengger in central northern China had expanded 39% and 29% separately during the LGM; the deserts of Taklimakan, Gurbantünggüt and Kumtag in northwestern China had expanded 10%-20% respectively, compared to their modern areas. On the other hand, all of the sand fields were nearly completely covered by vegetation during the HO; the deserts in northwestern and central northern China were reduced by around 5%-20% in area during this time. Lakes in this arid region were probably expanded during the HO but this conclusion needs more investigation. Compared with the geological distributions of deserts and sand fields, human activity has clearly changed (expanded) the area of active sand dunes at the present time. Our observations show that environmental conditions of Chinese deserts and sand fields are controlled by regional climate together with human activity. [ABSTRACT FROM AUTHOR]

Projection of future climate changes and their regional impact is critical for long-term planning at the national and regional levels aimed at adaptation and mitigation. This study assesses the future changes in precipitation in China and the associated atmospheric circulation patterns using the Couple Model Intercomparison Project 5 Phase (CMIP5) simulations under the RCP4.5 and RCP8.5 scenarios. The results consistently indicate that the annual precipitation in China is projected to significantly increase at the end of the 21st century compared to the present-day levels. The number of days and the intensity of medium rain, large rain and heavy rain are obviously increased, while the number of trace rain days is projected to decrease over the entire area of China. Further analysis indicates that the significant increase of annual precipitation in Northwest China is primarily due to the increase of light rain and the increases in North and Northeast China are primarily due to the increase of medium rain. In the region of southern China, the increases of large rain and heavy rain play an important role in the increase of annual precipitation, while light rain events play a negative role. Analysis of the changes in atmospheric circulation indicates that the East Asian summer monsoon circulation is projected to be considerably stronger, and the local atmospheric stratification is projected to be more unstable, all of which provide a background benefit for the increase of precipitation and extreme rainfall events in China under global warming scenarios. [ABSTRACT FROM AUTHOR]

This study analyses the decadal changes in winter precipitation and extreme precipitation in a warming environment in China. The results show that, together with a trend of winter warming in China, winter precipitation and extreme precipitation in the region are also increasing. In addition, concurrent with the decadal warming shift that occurred in the mid-1980s, precipitation and extreme precipitation both increased significantly. Quantitative analysis shows that precipitation and extreme precipitation increased at rates of 9.7% and 22.6% per 1°C of surface warming in China. This rate of precipitation increase is greater than the global mean, which indicates that precipitation in China is highly sensitive to climate warming and further highlights the importance of studying regional responses to climate warming. The fact that extreme precipitation is increasing at a higher rate than precipitation implies that winter precipitation in China will increasingly be of more extreme type in the context of global warming, which could partly explain why there have recently been a number of record-breaking extreme snowfall events in China. [ABSTRACT FROM AUTHOR]

Climate change is expected to cause the alteration of litter production in forests, which may result in substantial changes in soil CO efflux (FCO) process as litter represents a major pathway of carbon from vegetation to the soils. In this study, we conducted an aboveground litter manipulation experiment to examine the influence of litter addition and exclusion on soil FCO in Camphor tree, Masson pine, and mixed Camphor tree and Masson pine forests in central south China. Litter input manipulation included three treatments: non-litter input (litter exclusion), double litter input (litter addition), and natural litter input (control). On average, litter exclusion significantly reduced soil FCO rate by approximately 39%, 24% and 22% in Camphor tree forests, the Mixed forests, and Masson pine forests, respectively. On a yearly basis, double litter addition significantly increased soil CO by 12% in the Mixed forests ( P=0.02) but not in both Camphor tree and Masson pine forests ( P>0.05), when compared with their corresponding control treatments. However, litter addition increased soil FCO rates in the months of June-August in Camphor tree and Masson pine forests, coinciding with high soil temperature of summer conditions. Litter exclusion reduced soil FCO more than litter addition increased it in the study sites. Responses of soil respiration to litter input treatments varied with forest types. Litter input treatments did not alter the seasonal patterns of soil temperature and soil water content. Our results indicated that changes in aboveground litter as a result of global climate change and/or forest management have a great potential to alter soil respiration and soil carbon balance in forest ecosystems. [ABSTRACT FROM AUTHOR]

Isolated NE-SW stretching the Helan Mountain massif, separating the temperate grassland of the Ordos plateau from the Tenggeli Desert, is a key position of studying the glacier development in west China as well as the coupling conditions of climate change with tectonic uplift. The glacial landforms and deposits including cirques, peaks, knife-edge ridges, lateral moraines, and terminal moraines distribute above 2800 m a.s.l. in the middle part of the Helan Mountain. This distribution indicates that here was once glaciated during the late Quaternary. Morphology features show a clear sequence of landscape forming events took place throughout the Helan Mountain. Laboratory optically stimulated luminescence (OSL) and accelerator mass spectrometry radiocarbon dating (AMS C) results indicate a late history of glacial advance. Late Pleistocene glaciers in the middle part of the Helan Mountain advanced to near their positions at least four times, and the glacial sequences can be assigned as the middle stage of last glacial cycle (MIS3b, 43.2±4.0 ka), last glacial maximum (LGM, ∼18 ka), late glacial (12.0±1.1 ka) and neo-glacial (3.4±0.3 ka) respectively. Adopting equilibrium line altitude ∼2980 m of last glacial maximum and the modern theoretical snowline altitude ∼4724 m as the maximum amplitudes, and the standard marine isotope curve (MIS) as the glacial equilibrium line change since the Gonghe Movement (150 ka), the relationship between the mountain altitude and glacier development is discussed herein. Compared with other environmental indexes such as the loess-paleosol and ice core, conclusions are made that glacier advances in the Helan Mountain during the late Quaternary obviously depended on the coupled control of tectonic uplift of mountain with the climate condition. It is at last glaciation that the mountain reached the altitude above snowline and coupled with the glacial climate. The glacial advances occurred in the early and middle stages of last glacial cycle after the Gonghe Movement. [ABSTRACT FROM AUTHOR]

The modern atmospheric observation and literatural historical drought-flood records were used to extract the inter-decadal signals of dry-wet modes in eastern China and reveal the possible relationship of global and China temperature changes associated with the East Asian summer monsoon advances. A climate pattern of 'wet-north and dry-south' in eastern China and cool period in China and globe are associated with the strong summer monsoon that can advance further to the northernmost part in the East Asian monsoon region. On the contrary, a climate pattern of 'dry-north and wet-south' in eastern China and a warm period in China and globe are associated with the weaker summer monsoon that only reaches the southern part in the region. An interdecadal oscillation with the timescale about 60 years was found dominating in both the dry-wet mode index series of the East Asian summer monsoon and the global temperature series after the secular climate states and long-term trend over inter-centennial timescales have been removed. [ABSTRACT FROM AUTHOR]

Since Westman (1977) and Ehrlich (1982) put forward the concepts of 'the service of nature' and 'ecosystem service functions', respectively, methods for conducting value accounting for them, and their practical application have become the subjects of intense study. Based on an overview of available research findings, we discuss three scientific hypotheses. First, the terrestrial ecosystem offers both positive and negative service functions. Second, changes in terrestrial ecosystem service functions lie not only in the number of ecosystem types and the coverage area of each type, but also in their quality. Third, the value of terrestrial ecosystem service functions should be assessed both in terms of the value stocked and the value added. We collected land use data from China during the period 1999-2008, and Normalized Difference Vegetation Index data based on remote sensing images from the Global Inventory Modeling and Mapping Studies for the same period. We then calculated and analyzed spatial and temporal changes in China's terrestrial ecosystem service values over the 10-year period. Considering temporal change, the total value (stocked) of China's terrestrial ecosystem service functions decreased from 6.82 trillion Yuan RMB in 1999 to 6.57 trillion Yuan RMB in 2008. During that period, the positive value decreased by 240.17 billion Yuan RMB and the negative value increased by 8.85 billion Yuan RMB. The decrease in total value lies mainly in the humidity control, soil formation, and waste recycling functions. The total value (added) of China's terrestrial ecosystem service functions increased by 4.31 billion Yuan RMB in 2000, but decreased by 0.13 billion Yuan RMB in 2008 (based on the constant price of China in 1999). The value (added) was a negative figure. From the perspective of spatial change, we can see that the supply of China's terrestrial ecosystem service functions fell slightly over the past 10 years, mainly in Northeast and Southern China. As a result of human activities on ecosystems, the loss of ecosystem service functions' value was relatively prominent in Shanxi and Gansu provinces, compared with an increase in value in Shaanxi Province. Terrestrial ecosystem service functions' value per unit area was relatively high in mid- and East China, showing a prominent spatial change over the 10-year period, but low in Western China. Some conclusions are drawn after an in-depth analysis of the factors causing the spatial and temporal changes in China's terrestrial ecosystem service functions, in the hope that our suggestions will be helpful for the management of China's terrestrial ecosystems. [ABSTRACT FROM AUTHOR]

Climate change in the 21st century over China is simulated using the Abdus Salam International Centre for Theoretical Physics (ICTP) Regional Climate Model version 3 (RegCM3). The model is one-way nested within the global model CCSR/NIES/FRCGC MIROC3.2_hires (Center for Climate System Research/National Institute for Environmental Studies/Frontier Research Center for Global Change/Model for Interdisciplinary Research on Climate). A 150-year (1951-2100) transient simulation is conducted at 25 km grid spacing, under the Intergovernmental Panel on Climate Change Special Report on Emissions Scenarios (IPCC SRES) A1B scenario. Simulations of present climate conditions in China by RegCM3 are compared against observations to assess model performance. Results show that RegCM3 reproduces the observed spatial structure of surface air temperature and precipitation well. Changes in mean temperature and precipitation in December-January-February (DJF) and June-July-August (JJA) during the middle and end of the 21st century are analyzed. Significant future warming is simulated by RegCM3. This warming becomes greater with time, and increased warming is simulated at high latitude and high altitude (Tibetan Plateau) areas. In the middle of the 21st century in DJF, a general increase of precipitation is found in most areas, except over the Tibetan Plateau. Precipitation changes in JJA show an increase over northwest China and a decrease over the Tibetan Plateau. There is a mixture of positive and negative changes in eastern China. The change pattern at the end of the century is generally consistent with that in mid century, except in some small areas, and the magnitude of change is usually larger. In addition, the simulation is compared with a previous simulation of the RegCM3 driven by a different global model, to address uncertainties of the projected climate change in China. [ABSTRACT FROM AUTHOR]

Frequent winter snowstorms have recently caused large economic losses and attracted wide attention. These snowstorms have raised an important scientific question. Under scenarios of future global warming, will winter precipitation in China increase significantly and produce more snow in the north? Using Coupled Model Intercomparison Project phase 3 (CMIP 3) model projections under the Special Report on Emissions Scenario A1B scenario, we generated a possible future Arctic condition, the summer (September) 'ice-free Arctic' condition. We then used corresponding monthly sea surface temperature (SST) values and a set of CO concentrations to drive an atmospheric general circulation model (AGCM), for simulating East Asian climate change. The experimental results show that during the boreal winter (December-January-February; DJF), global surface air temperature would increase significantly under this scenario, producing substantial warming in Arctic regions and at high latitudes in Asia and North America. The Siberian High, Aleutian Low and East Asian winter monsoon would all weaken. However, because of increased transport of water vapor to China from the north, winter precipitation would increase from south to north. In addition, the significant increase in winter temperature might cause fewer cold surges. [ABSTRACT FROM AUTHOR]

Using historical records on first and last frost and snow, spring cultivation, David peach blossom, autumn crop harvest, grade of sea freeze and change in northern citrus boundary, we reconstructed temperature change during 601-920 AD. The mean temperature of the winter half-year (October to April) over Central East China during this period was about -0.22°C higher than that of the present (1961-2000 AD mean). During 601-820 AD, mean temperature was about -0.52°C higher than the present. During 821-920 AD, the mean temperature was 0.42°C lower than the present. The temperature fluctuations were characterized by a maximum amplitude of 1.05°C at the centennial scale, 1.38°C at the 50-year scale, 2.02°C at the 30-year scale, and 2.3°C at the 20-year scale. There were four peaks warmer than today (601-620 AD, mean of 1°C higher temperature; 641-660 AD, 1.44°C; 701-720 AD, 0.88°C; 781-800 AD, 0.65°C). Three cold periods were in 741-760, 821-840, and 881-900 AD, the mean temperature of which was 0.37-0.87°C lower than the present. [ABSTRACT FROM AUTHOR]

Stalagmite growth rates are usually considered to reflect changes in paleoclimate and paleoenvironment. However, how exactly growth rates are affected by climate and environment is still unclear. We launched a monitoring and modeling program that lasted approximately 4 years on two active drip sites in Heshang Cave, central China. We collected comprehensive quantitative data on growth rates, cave temperature, CO2 concentration, drip rate and drip-water chemistry to better understand the relationship between stalagmite growth and cave environment. By laying out glass substrates, we successfully grew stalagmite calcite crystals with rhombic characteristics, and quantified growth rates by measuring the long and short axes of calcite crystals under a microscope. Combined with coeval environmental data, we explicitly examined the roles of cave temperature, drip rate and drip-water chemistry in controlling the micro-scale growth of stalagmite calcite. Results show that growth of stalagmite calcite crystals at two drip sites exhibited similar seasonal variations -- generally faster in the summer months, at ~3 µm d-1, and slower during the late winter to early spring, at ~1.5 µm d-1. Variations in calcite growth rates were mainly determined by changes in cave temperature, with the growth rate increasing by 8.1%/°C and 6.6%/°C at the two locations. This indicates the potential use of stalagmite growth rates as a seasonal-resolution paleo-temperature proxy in some ventilated caves. On the other hand, the effect of drip rate and drip-water Ca2+ and SIC values on growth rates were not significant. [ABSTRACT FROM AUTHOR]

Potential evapotranspiration (ETo) is important to hydrological cycling and the global energy balance. Based on a modified FAO56-Penman-Monteith model, ETo was simulated for 603 meteorological stations across China in the period 1971-2008. Spatial distribution and temporal change of ETo were characterized, and the determining factors in ETo were revealed by sensitivity analysis. Results show obvious regional differences in annual average ETo and its determining factor. In general, annual average ETo decreased in the period 1971-2008, but increased since the 1990s. Wind speed and sunshine duration were determining factors in the annual ETo trend, with smaller contributions from relative humidity and temperature. Declining wind speed was the determining factor in decreasing annual ETo in northern temperate regions and the Tibetan Plateau. The spatial extent of wind speed influence contracted to northwest China in summer, and expanded to the whole country in autumn. Decreasing sunshine duration was the determining factor in decreasing annual ETo in subtropical and tropical regions, especially in summer, with a larger spatial influence mainly to the southeast of the farming-pastoral region. ETo change has distinct impacts on earth surface ecosystems and environment depending on different determining factors. [ABSTRACT FROM AUTHOR]

As a consequence of recent global warming and its social impact, regional climate change is attracting an increasing amount of attention from scientists. A May-July temperature proxy extending back to 1836 was developed from tree-ring width of Chinese pine (Pinus tabulaeformis Carr.) found in the middle Lüliang Mountains, northern China. Correlations with climatic data from six nearby meteorological stations range from -0.58 to -0.65, indicating a strong response of tree-ring index to May-July mean temperatures, which were subsequently reconstructed. The reconstruction captures 45% (F=38.474, P<0.001) of the regional variance in the instrumental data over the calibration period 1955-2003. Reconstructed warm and cold periods were verified by additional temperature reconstructions based on tree-ring data from northern China. In addition, the reconstruction was significantly correlated with May-July mean temperatures from 13 other meteorological stations in northern China, suggesting that our reconstruction is also representative of north-central China. The warming trend during the second half of the 20th century is seen in the reconstruction, but only the 1994-2002 mean temperature seems unprecedented over the whole reconstructed period. [ABSTRACT FROM AUTHOR]

A high-resolution fossil pollen record from the sedimentary cores of Balikun Lake, northwestern China, combined with modern surface pollen data, is used to reconstruct the history of vegetation and climatic change since 16.7 cal. ka BP. Fossil pollen assemblages and lithology indicate that the study area was dominated by desert. The desert had extremely arid climate and lower effective moisture during 16.7--7.9 cal. ka BP, especially from 16.7 to 8.9 cal. ka BP when the lake maybe dried up. During 8.9--7.9 cal. ka BP, the environment gradually recovered in this area. It was then followed by the optimum period from 7.9 to 4.3 cal. Ka BP, when the effective moisture obviously increased. It was characterized by the typical desert-steppe/steppe vegetation and was accompanied with several patch-birch woodlands around the lake. After that, a short but extremely arid climatic event occurred during 4.3--3.8 cal. ka BP, and the vegetation quickly changed from desert-steppe/steppe to desert. It was a relatively optimum period from 3.8 to 0.53 cal. ka BP showing typical desert-steppe/meadow-steppe landscape. Since 0.53 cal. ka BP, the climate has shown signs of deteriorating again. Furthermore, regional comparison shows that the characteristics of climatic and environmental evolution in this area were clearly different from East Asia monsoonal area during the last 16.7 cal. ka BP. It was characterized by the arid climate during the late-glacial and early Holocene, and relatively wet during the mid-late Holocene. [ABSTRACT FROM AUTHOR]

Global surface temperature has dramatically increased in the past decades. It is critical to evaluate such a change using appropriate approaches. The previous studies for assessment of the change usually used overall trends of temperature series (i.e. slopes of simple linear regression of temperature versus year based on a least-square analysis) for entire study period. Temperature trends, however, differ among different periods, i.e. there are often breakpoints in the temperature series. Therefore, the overall linear trend of a temperature series may conceal some of the temporal characteristics of the temperature change. To precisely characterize the temporal and spatial patterns of air temperature change in China, we analyze the annual mean temperature series between the year of 1961-2004 for 536 meteorological stations across China, using piecewise linear regression approach. We found remarkable breakpoints in the annual mean temperature during the study period across the country. The annual mean temperature started to increase in 1984 at a rate of 0.058°C/a at the country level. The year when warming started appeared to be gradually later from the north to the south: temperature increased since the 1970s in the north (north of 40°N), and did not rise until the 1980s in most areas of the south (south of 40°N), with warming starting in 1983 in the Tibetan Plateau. The trends in annual mean temperatures showed a large spatial heterogeneity across China: a relatively small rising with a rate of 0.025-0.05°C/a in the Sichuan Basin, Central China and South China; the greatest increase in some parts of northwest China (i.e. Xinjiang) with up to a rate of 0.1°C/a; and rising at a rate of >0.05°C/a for most regions of the country. The feedbacks of cold waves and snow may be responsible for such regional differences in the timing and rates of warming in China. [ABSTRACT FROM AUTHOR]

We have used the China Homogenized Historic Temperature dataset and some long-term station series of the neighbor countries from CRUTEM3, a 5°×5° gridded dataset of monthly mean temperature since 1900, to provide a 107-year record of surface temperature trends and variability. We derived a comprehensive set of uncertainty estimates to accompany the data: measurement and sampling errors, uncertainties in temperature bias estimates, and uncertainties arising from limited observational coverage on large-scale averages have all been estimated. We reanalysed the temperature changes during the period of record. The best estimates of trends for 1900--2006 with uncertainties at 95% confidence range are about 0.09±0.017°C/decade for the year as a whole, and 0.14±0.021°C/decade, 0.11±0.021°C/decade, 0.04±0.017°C/decade, and 0.07±0.017°C/decade for winter, spring, summer and autumn respectively. For 1954--2006, the trends for annual, winter, spring, summer and autumn are: 0.26±0.032°C/decade, 0.35±0.046°C/decade, 0.25±0.051°C/decade, 0.16±0.037°C/decade and 0.22±0.055°C/decade. Winter saw the most significant warming trend in both 1900--2006 and 1954--2006, while during the most recent period (the satellite era, 1979--2006), all the seasons show similar warming trends: 0.45±0.13°C/decade, 0.51±0.11°C/decade, 0.52±0.16°C/decade, 0.37±0.10°C/decade and 0.50±0.16°C/decade for annual, winter, spring, summer and autumn. Trends arising from urbanization have been evaluated as less than 5% of the total warming trend for 1951--2001, so this bias was not removed. [ABSTRACT FROM AUTHOR]

This study, based on environmental archaeological studies focused on Qin'an County and Li County in Gansu Province, China, shows that during 8-7.3 ka BP few cultivated crop seeds were found. After 6.4 ka BP, during the Banpo period, many crop seeds appeared, indicating the development of agriculture. Millet agriculture in this area appeared and flourished a little later than in the Central Plain of China. Climate change is an important factor that influenced the development of agriculture in this area. The rapid expansion of agriculture during late Yangshao and Changshan benefited from the humid and warm climate in the mid-Holocene, especially the emergence of rice. After 4 ka BP, climate became drier, and agriculture began to decline. So Siwa Culture is characterized by pastoral economy, until the Eastern Zhou period, agriculture began to recover, when wheat and barley appeared in Li County, indicating diversification of agriculture of this time. [ABSTRACT FROM AUTHOR]

The causal correlation or linkage between the East Asian Monsoon (EAM) intensity and rise/fall of Chinese dynasties recently proposed by high-resolution paleoclimate reconstructions is examined in detail. Aside from many exceptions to the correlation, both instrumental and historical climate records show strong spatial variations of rainfall on annual-to-decadal scales over eastern China. The relationship between rainfall and EAM intensity also exhibits regional disparity. These observations suggest: (1) Taking paleo-proxy records from a single locality in eastern China to imply changes in drought/wetness as to affect the cultural and political history of China is fraught with uncertainty. (2) On annual-to-decadal scales, the thesis that δ18O in speleothems can be used as a proxy for the EAM strength lacks empirical underpinnings. [ABSTRACT FROM AUTHOR]

The West Sichuan Plateau is located in the southeast margin of the Tibetan Plateau, where the climate is mainly influenced by the Indian southwest summer monsoon and the Tibetan Plateau monsoon. In this study, detailed geochemical analysis has been carried out on Ganzisi loess-paleosol sequence in Ganzê County of western Sichuan Province. The results indicate that Ganzê loess and paleosol have experienced the incipient stage of chemical weathering in dust source regions, characterized by the decomposition of plagioclase which caused the depletion of mobile elements Na and Ca. The post-depositional chemical weathering is characterized by carbonate dissolution and oxidation of Fe2+. The variations of some geochemical indexes (such as CIA values, Na/K and Fe2+/ Fe3+ ratios) in Ganzisi loess-paleosol sequence indicate a gradually decreased chemical weathering intensity in the dust source regions and deposition areas since 1.15 Ma BP consistent with the general increase of global ice volume, reflecting that the arid trend since 1.15 Ma BP in the southeast Tibetan Plateau is a regional response to the global climate change. The geochemical indexes in this section also reveal an obvious drying step occurred at about 250 ka BP in this region. We interpret this drying step as a result of decreased influence of the Indian southwest summer monsoon. This decrease in monsoon moisture is probably attributable to the uplift of the southeast margin of the Tibetan Plateau at about 250 ka BP. [ABSTRACT FROM AUTHOR]

The Qinghai Lake is the largest inland lake in China. The significant difference of dielectric properties between water and ice suggests that a simple method of monitoring the Qinghai lake freeze-up and break-up dates using satellite passive microwave remote sensing data could be used. The freeze-up and break-up dates from the Qinghai Lake hydrological station and the MODIS L1B reflectance data were used to validate the passive microwave remote sensing results. The validation shows that passive microwave remote sensing data can accurately monitor the lake ice. Some uncertainty comes mainly from the revisit frequency of satellite overpass. The data from 1978 to 2006 show that lake ice duration is reduced by about 14-15 days. The freeze-up dates are about 4 days later and break-up dates about 10 days earlier. The regression analyses show that, at the 0.05 significance level, the correlations are 0.83, 0.66 and 0.89 between monthly mean air temperature (MMAT) and lake ice duration days, freeze-up dates, break-up dates, respectively. Therefore, inter-annual variations of the Qinghai Lake ice duration days can significantly reflect the regional climate variation. [ABSTRACT FROM AUTHOR]

We made multi-proxy analysis of 14C, grain size, microfossils, plant seeds, and geochemical elements on samples from a profile in the central West Lake of Lop Nur. The grain size suggests relatively stable sedimentary environment around the Medieval Warm Period (MWP) with weak storm effect, which is followed by frequent strong storm events. Abundant microfossils and plant seeds in this stage indicate a warm and humid fresh to brackish lake environment. C, N, and stable elements are high in content in the sediments while Rb/Sr, Ba/Sr, and Ti/Sr are in a steady low level. In addition, plenty of red willows lived here prior to about 700 a B.P., indicating a favorable environmental condition. The results indicate that the environment in Lop Nur and its west bank turned to be favorable at about 2200 a B.P., where the Loulan Culture began to thrive. Then the climate and environment came to be in the good condition in the Tang and Song Dynasties, when the storm effect became weaker, rainfall increased and the salty lake water turned to be brackish to fresh lake water. Hence, limnic biomass increased with higher species diversity. [ABSTRACT FROM AUTHOR]

The maritime glaciers are sensitive to climate change because of high annual precipitation and high air temperature in the region. A combined comprehensive study was carried out based on glacier mass balance observation, GPS-based glacier terminus position survey, glacier Ground Penetrating Radar, topography maps and RS satellite images in the Kangri Karpo Mountains, Southeast Tibet. The study revealed a strong ice mass loss and quick glacier retreat since the 1970s. Ata Glacier, one glacier from the south slope of the Kangri Karpo Mountains, has formed a 6-km-long terminal moraine zone at the end of the glacier since the 1970s, and the accelerating retreat is largely due to the strong glacier surface melting. Mass balance study on the other four glaciers on the northern side of the Kangri Karpo Mountains shows that they are in large negative mass balance and the glaciers had retreated 15-19 m from May 2006 to May 2007. The in-situ glacier observation also shows that the glacier retreat is more obvious in small glaciers. The enhanced ice mass deficit caused by climate warming and the ongoing extinction of many small glaciers in this region could seriously affect the water resources, environments, local climate and regional sustainable development in the near future. [ABSTRACT FROM AUTHOR]

Empirical Orthogonal Function (EOF) analysis and the related Principal Components (PC) analysis are used to extract valuable vegetation cover derived information from the National Oceanic and Atmospheric Administration (NOAA-AVHRR)'s Leaf Area Index (LAI) satellite images. Results suggest that from 1982 to 2000 global climate change has contributed to an increase in vegetation cover in the Qinghai-Tibet Plateau. The correlation between rainfall and LAI EOF PC1 and PC2 indicates that rainfall is the major climatic factor influencing interannual variations of average vegetation cover throughout the entire Plateau. However, annual mean vegetation cover trends in the Qinghai-Tibet Plateau are mainly out of phase with air temperature increasing, which is primarily responsible for nonsynchronous changes of vegetation cover. In the southern ridge of the Qinghai-Tibet Plateau, recent warming trends contribute to humid weather and favorable conditions for vegetation growth. By contrast, higher temperatures have led to arid conditions and insufficient rainfall in the northern part of the Plateau, leading to drought and other climatic conditions which are not conducive to increased vegetation cover. [ABSTRACT FROM AUTHOR]