The Projection of Temperature and Precipitation over China under RCP Scenarios using a CMIP5 Multi-Model Ensemble

Climate changes in 21st century China are described based on the projections of 11 climate models under Representative Concentration Pathway (RCP) scenarios. The results show that warming is expected in all regions of China under the RCP scenarios, with the northern regions showing greater warming than the southern regions. The warming tendency from 2011 to 2100 is 0.06°C/10 a for RCP2.6, 0.24°C/10 a for RCP4.5, and 0.63°C/10 a for RCP8.5. The projected time series of annual temperature have similar variation tendencies as the new greenhouse gas (GHG) emission scenario pathways, and the warming under the lower emission scenarios is less than under the higher emission scenarios. The regional averaged precipitation will increase, and the increasing precipitation in the northern regions is significant and greater than in the southern regions in China. It is noted that precipitation will tend to decrease in the southern parts of China during the period of 2011-2040, especially under RCP8.5. Compared with the changes over the globe and some previous projections, the increased warming and precipitation over China is more remarkable under the higher emission scenarios. The uncertainties in the projection are unavoidable, and further analyses are necessary to develop a better understanding of the future changes over the region.

Bayesian multi-model projections of extreme hydroclimatic events under RCPs scenarios

A Bayesian multi-model inference framework was used to assess the changes in the occurrence of extreme hydroclimatic events in four major river basins in China （i.e., Liaohe River Basin, Yellow River Basin, Yangtze River Basin, and Pearl River Basin） under RCP2.6, RCP4.5, and RCP8.5 scenarios using multiple global climate model projections from the IPCC Fifth Assessment Report. The results projected more summer days and fewer frost days in 2006-2099. The ensemble prediction shows the Pearl River Basin is projected to experience more summer days than other basins with the increasing trend of 16.3, 38.0, and 73.0 d per 100 years for RCP2.6, RCP4.5 and RCP8.5, respectively. Liaohe River Basin and Yellow River Basin are forecasted to become wetter and warmer with the co-occurrence of increases in summer days and wet days. Very heavy precipitation days （R20, daily precipitation ≥20 mm） are projected to increase in all basins. The R20 in the Yangtze River Basin are projected to have the highest change rate in 2006-2099 of 1.8, 2.5, and 3.8 d per 100 years for RCP2.6, RCP4.5 and RCP8.5, respectively.

The Projected Changes of Precipitations over Niger Under the Scenarios RCP 4.5 and RCP 8.5

The socio-economic activities of Niger rely on agriculture which is strongly affected by changes in precipitation during the rainy season.The ultimate aim of this study is to assess the projected changes of precipitation over Niger under the Representative Concentration Pathways(RCP)scenarios 4.5(RCP 4.5)and RCP 8.5 using multi-RCM(Multi-Regional Climate)model approach.The observation data are from CHIRPS(Climate Hazards Group InfraRed Precipitation with Station)and the RCMs are from the SMHI(Swedish Meteorological and Hydrological Institute)model(RCA4)driven by ten(10)different GCMs(General Circulation Model)(e.g.,CCCma,CSIRO,ICHEC,IPSL,MIROC,MOHC-HadGEM2,MPI,NCC-NorESM1,NOOA,and NRCM)within the framework of CORDEX(Coordinated Regional Climate Downscaling Experiment)Africa experiment.The reference and projections periods in this study are respectively 1981-2005 for the present and 2011-2100 for the near,medium and far future divided into three periods,2011 to 2040(P1),2041 to 2070(P2)and 2071 to 2100(P3).The methodology used,consists of assessing the performance of the multi-RCMs of RCA4 model(with respect of CHIRPS)in simulating the precipitations changes by computing the spatial distribution and anomalies of precipitations;and their indices of RMSE(Root Mean Square Error),the bias,SPI(Standardized Precipitation Anomaly Index),correlation coefficient,statistical t-test,spatial evolution rate and the rate of temporal change.After the validation of the multi-RCMs RCA4 models,the ensemble mean of the models is used to assess the projected changes of precipitations over Niger in the future.The results show that most of the multi-RCMs capture the four climatic zone except for IPSL.While the ensemble mean of the models simulates(as compared to CHIRPS)more accurately the monthly,annual precipitations anomalies and their indices than individual’s models in the reference period,some RCMs(e.g.,CSIRO-IPSL and CCCma-HadGEM)poorly reproduce them.The projected changes of precipitations indicate for the scenario RCP 4.5 respectively a moderately surplus of precipitation years in the period P1 and moderately deficit years in the period P2 while the period P3 shows a small upward precipitation trend.In contrary,for the scenario RCP 8.5,all the three periods(P1,P2 and P3)indicate an intensification of precipitation leading to a longer wet period which may lead to extreme precipitations and flooding.Moreover,both scenarios have projected an increase of total monthly precipitation in May and September and a decrease in July and August respectively which will likely lead to an early onset and late cessation of the rainy season;and a shift of the peak of the rainy season.Therefore,this study shows the need of a monitoring system for the projected changes of precipitation in the near future to anticipate urgent action in wet/dry periods to adapt to a changing climate.

The long-term trend of Bohai Sea ice in different emission scenarios

Based on a coupled ocean-sea ice model,this study investigates how changes in the mean state of the atmosphere in different CO2 emission scenarios (RCP 8.5,6.0,4.5 and 2.6) may affect the sea ice in the Bohai Sea,China,especially in the Liaodong Bay,the largest bay in the Bohai Sea. In the RCP 8.5 scenario,an abrupt change of the atmospheric state happens around 2070. Due to the abrupt change,wintertime sea ice of the Liaodong Bay can be divided into 3 periods: a mild decreasing period (2021–2060),in which the sea ice severity weakens at a near-constant rate;a rapid decreasing period (2061–2080),in which the sea ice severity drops dramatically;and a stabilized period (2081–2100). During 2021–2060,the dates of first ice are approximately unchanged,suggesting that the onset of sea ice is probably determined by a cold-air event and is not sensitive to the mean state of the atmosphere. The mean and maximum sea ice thickness in the Liaodong Bay is relatively stable before 2060,and then drops rapidly in the following decade. Different from the RCP 8.5 scenario,atmospheric state changes smoothly in the RCP 6.0,4.5 and 2.6 scenarios. In the RCP 6.0 scenario,the sea ice severity in the Bohai Sea weakens with time to the end of the twenty-first century. In the RCP 4.5 scenario,the sea ice severity weakens with time until reaching a stable state around the 2070s. In the RCP 2.6 scenario,the sea ice severity weakens until the 2040s,stabilizes from then,and starts intensifying after the 2080s. The sea ice condition in the other bays of the Bohai Sea is also discussed under the four CO_(2) emissions scenarios. Among atmospheric factors,air temperature is the leading one for the decline of the sea ice extent. Specific humidity also plays an important role in the four scenarios. The surface downward shortwave/longwave radiation and meridional wind only matter in certain scenarios,while effects from the zonal wind and precipitation are negligible.

Projected Changes of Palmer Drought Severity Index under an RCP8.5 Scenario

The potential change of drought measured by the Palmer Drought Severity Index （PDSI） is projected by using a coupled climate system model under a Representative Pathway 8.5 （RCP8.5） scenario.The PDSI changes calculated by two potential evapotranspiration algorithms are compared.The algorithm of Thomthwaite equation overestimates the impact of surface temperature on evaporation and leads to an unrealistic increasing of drought frequency.The PM algorithm based on the Penman-Monteith equation is physically reasonably and necessary for climate change projections.The Flexible Global Ocean-Atmosphere-Land System model,Spectral Version 2 （FGOALS-s2） projects an increasing trend of drought during 2051-2100 in tropical and subtropical areas of North and South America,North Africa,South Europe,Southeast Asia,and the Australian continent.Both the moderate drought （PDSI ＜-2） and extreme drought （PDSI ＜-4） areas show statistically significant increasing trends under an RCP8.5 scenario.The uncertainty in the model projection is also discussed.

Steric Sea Level Change in Twentieth Century Historical Climate Simulation and IPCC-RCP8.5 Scenario Projection: A Comparison of Two Versions of FGOALS Model

To reveal the steric sea level change in 20th century historical climate simulations and future climate change projections under the IPCC＇s Representative Concentration Pathway 8.5 （RCP8.5） scenario, the results of two versions of LASG/IAP＇s Flexible Global Ocean-Atmosphere-Land System model （FGOALS） are analyzed. Both models reasonably reproduce the mean dynamic sea level features, with a spatial pattern correlation coefficient of 0.97 with the observation. Characteristics of steric sea level changes in the 20th century historical climate simulations and RCPS.5 scenario projections are investigated. The results show that, in the 20th century, negative trends covered most parts of the global ocean. Under the RCPS.5 scenario, global-averaged steric sea level exhibits a pronounced rising trend throughout the 21st century and the general rising trend appears in most parts of the global ocean. The magnitude of the changes in the 21st century is much larger than that in the 20th century. By the year 2100, the global-averaged steric sea level anomaly is 18 cm and 10 cm relative to the year 1850 in the second spectral version of FGOALS （FGOALS-s2） and the second grid-point version of FGOALS （FGOALS-g2）, respectively. The separate contribution of the thermosteric and halosteric components from various ocean layers is further evaluated. In the 20th century, the steric sea level changes in FGOALS-s2 （FGOALS-g2） are largely attributed to the thermosteric （halosteric） component relative to the pre-industrial control run. In contrast, in the 21st century, the thermosteric component, mainly from the upper 1000 m, dominates the steric sea level change in both models under the RCPS.5 scenario. In addition, the steric sea level change in the marginal sea of China is attributed to the thermosteric component.

Climate Change over China in the 21st Century as Simulated by BCC_CSM1.1-RegCM4.0

Driven by the global model,Beijing Climate Center Climate System Model version 1.1(BCC_CSM1.1),climate change over China in the 21st century is simulated by a regional climate model(RegCM4.0)under the new emission scenarios of the Representative Concentration Pathways—RCP4.5 and RCP8.5.This is based on a period of transient simulations from 1950 to2099,with a grid spacing of 50 km.The present paper focuses on the annual mean temperature and precipitation in China over this period,with emphasis on their future changes.Validation of model performance reveals marked improvement of the RegCM4.0 model in reproducing present day temperature and precipitation relative to the driving BCC_CSM1.1 model.Significant warming is simulated by both BCC_CSM1.1 and RegCM4.0,however,spatial distribution and magnitude differ between the simulations.The high emission scenario RCP8.5 results in greater warming compared to RCP4.5.The two models project different precipitation changes,characterized by a general increase in the BCC_CSM1.1,and broader areas with decrease in the RegCM4.0 simulations.

Projected Shifts in Kppen Climate Zones over China and Their Temporal Evolution in CMIP5 Multi-Model Simulations

Previous studies have examined the projected climate types in China by 2100. This study identified the emergence time of climate shifts at a 1 o scale over China from 1990 to 2100 and investigated the temporal evolution of Koppen-Geiger climate classifications computed from CMIP5 multi-model outputs. Climate shifts were detected in transition regions （7%-8% of China＇s land area） by 2010, including rapid replacement of mixed forest （Dwb） by deciduous forest （Dwa） over Northeast China, strong shrinkage of alpine climate type （ET） on the Tibetan Plateau, weak northward expansion of subtropical winter- dry climate （Cwa） over Southeast China, and contraction of oceanic climate （Cwb） in Southwest China. Under all future RCP （Representative Concentration Pathway） scenarios, the reduction of Dwb in Northeast China and ET on the Tibetan Plateau was projected to accelerate substantially during 2010-30, and half of the total area occupied by ET in 1990 was projected to be redistributed by 2040. Under the most severe scenario （RCP8.5）, sub-polar continental winter dry climate over Northeast China would disappear by 2040-50, ET on the Tibetan Plateau would disappear by 2070, and the climate types in 35.9% and 50.8% of China＇s land area would change by 2050 and 2100, respectively. The results presented in this paper indicate imperative impacts of anthropogenic climate change on China＇s ecoregions in future decades.

Projection of PM_(2.5) and Ozone Concentration Changes over the Jing-Jin-Ji Region in China

Based on GISS-E2-R model simulations, the changes in PM2.5 and ozone concentrations during 2016– 35 are analyzed over the Jing-Jin-Ji region under different future emissions scenarios: 2.6, 4.5, 6.0, 8.5 Representative Concentration Pathways scenarios(RCP2.6, RCP4.5, RCP6.0, and RCP8.5), compared to the baseline periods of 1851–70(pre-industrial) and 1986–2005(present day). The results show that PM2.5 increases under all emissions scenarios, with the maximum value occurring in the southeastern part of the region under most scenarios. As for ozone, its concentration is projected to increase during 2016–35 under all emissions scenarios, compared to the baseline periods. The temporal evolutions of PM2.5 and ozone show PM2.5 reaching a peak during 2020–40, while ozone will likely increase steadily in the future.

Assessing the vulnerability of a forest ecosystem to climate change and variability in the western Mediterranean sub-region of Turkey：future evaluation

This study evaluates the multifactorial spatial modelling used to assess vulnerability of the Du¨ zlerc？am？（Antalya） forest ecosystem to climate change.This was done to produce data,to develop tools to support decisionmaking and the management of vulnerable Mediterranean forest ecosystems affected by climate change,and to increase the ability of these forest ecosystems to adapt to global change.Based on regionally averaged future climate assessments and projected climate indicators,both the study site and the western Mediterranean sub-region of Turkey will probably become associated with a drier,hotter,more continental and more water-deficient climate.This analysis holds true for all future scenarios,with the exception of RCP4.5 for the period from 2015 to 2030.However,the present dry-sub humid climate dominating this sub-region and the study area shows a potential for change towards more dry climatology and for it to become semiarid between 2031 and 2050 according to the RCP8.5 high emission scenario.All the observed and estimated results and assessments summarized in this study show clearly that the densest forest ecosystem in the southern part of the study site,characterized by mainly Mediterranean coniferous and some mixed forest and maquis vegetation,will very likely be influenced by medium and high degrees of vulnerability to future environmental degradation,climate change and variability.

Assessment of Future Climate Change Scenario in Halaba District, Southern Ethiopia

Climate change is one environmental threat that poses great challenges to the future development prospects of Ethiopia. The study used the statistically downscaled daily data in 30-years intervals from the second generation of the Earth System Model (CanESM2) under two Representative Concentration Pathways (RCPs): RCP 4.5 and RCP 8.5 for three future time slices;near-term (2010-2039), mid-century (2040-2069) and end-century (2071-2099) were generated. The observed data of maximum and minimum temperature and precipitation are a good simulation with the modeled data during the calibration and validation periods using the correlation coefficient (R2), the Nash-Sutcliffe efficiency (NSE), and the Root Mean Square Error (RMSE). The projected annual minimum and maximum temperatures are expected to increase by 0.091°C, 0.517°C, and 0.73°C and 0.072°C, 0.245°C, and 0.358°C in the 2020s, 2050s, and 2080s under the intermediate scenario, respectively. Under RCP8.5, the annual minimum and maximum temperatures are expected to increase by 0.192°C, 0.409°C, and 0.708°C, 0.402°C, 4.352°C, and 8.750°C in the 2020s, 2050s, and 2080s, respectively. Besides, the precipitation is expected to increase under intermediate and high emission scenarios by 1.314%, 7.643%, and 12.239%, and 1.269%, 10.316% and 26.298% in the 2020s, 2050s, and 2080s, respectively. Temperature and precipitation are projected to increase in total amounts under all-time slices and emissions pathways. In both emission scenarios, the greatest changes in maximum temperature, minimum temperature, and precipitation are predicted by the end of the century. This implies climate smart actions in development policies and activities need to consider locally downscale expected climatic changes.

Evaluation and Projection of Temperature Extremes over China Based on CMIP5 Model

Evaluation and projection of temperature extremes over China are carried out with 8 model datasets from CMIF5. Compared with the NCEP reanalysis data, multi-model weighted ensemble is capable of reproducing the 8 temperature extreme indices and 20-yeax return values of annual maximum/minimum temperatures. The time correlation coefficients of all the 8 indices between multi-model ensemble and the reanalysis can reach a significance level of 0.10. The spatial correlation coefficient of 20-year return level of annual maximum/minimum temperatures is greater than 0.98. Under the RCP4.5 scenario, more extreme warm events and less cold events are expected over China in multi-model ensemble. By the middle of the 21st century, the heat wave duration index will be multiplied 2.6 times. At the end of the 21st century, the cold wave duration index will decrease 71%, and the 20-year return value will increase 4℃ in parts of China for the maximum/minimum temperatures.

Climate change and potential distribution of zoonotic cutaneous leishmaniasis in Central Iran: Horizon 2030 and 2050

Objective: To investigate and predict the effects of climate change on the potential distribution of the main vector and reservoir hosts of the disease in Yazd province in the future.Methods: Distribution data for vector and reservoir hosts of zoonotic cutaneous leishmaniasis in Yazd province were obtained from earlier studies conducted in the area.MaxEnt ecological niche modeling was used to predict environmental suitability.BCC-CSM1-1(m) model and two climate change scenarios, RCP 4.5 and RCP 8.5 were used for horizons 2030 and 2050 climate projections.Future projections were based on data of a regional climate change model.Results: With both scenarios in 2030 and 2050, the results of jackknife test indicated that the mean temperature of wettest quarter and temperature annual range had the greatest effect on the model for the vector and the reservoir hosts, respectively.Conclusions: The climate conditions are the major determinants of zoonotic cutaneous leishmaniasis incidence rate in Yazd Province.These climate conditions provide favorable habitats for ease transmission of zoonotic cutaneous leishmaniasis in this endemic area.Habitats suitability for the vector and reservoir will be expanding in the coming years compared with the current conditions, such that, in horizon 2030 & 2050, the probability of the presence of the vector and reservoir within 38 580 and 37 949 km^2, respectively, from Yazd province is above 60%.Moreover, an increase is predicted in the presence of the vector in the western parts and the reservoir in the northern and central parts of the province in the future.Understanding the role of environmental and bioclimatic factors in zoonotic cutaneous leishmaniasis occurrence can provide a guide for policy-makers in the creation and implementation of more effective policies for prevention and control.

FUTURE CHANGE OF PRECIPITATION EXTREMES OVER THE PEARL RIVER BASIN FROM REGIONAL CLIMATE MODELS

Based on RegCM4,a climate model system,we simulated the distribution of the present climate(1961-1990)and the future climate(2010-2099),under emission scenarios of RCPs over the whole Pearl River Basin.From the climate parameters,a set of mean precipitation,wet day frequency,and mean wet day intensity and several precipitation percentiles are used to assess the expected changes in daily precipitation characteristics for the 21 st century.Meanwhile the return values of precipitation intensity with an average return of 5,10,20,and 50 years are also used to assess the expected changes in precipitation extremes events in this study.The structure of the change across the precipitation distribution is very coherent between RCP4.5 and RCP8.5.The annual,spring and winter average precipitation decreases while the summer and autumn average precipitation increases.The basic diagnostics of precipitation show that the frequency of precipitation is projected to decrease but the intensity is projected to increase.The wet day percentiles(q90 and q95) also increase,indicating that precipitation extremes intensity will increase in the future.Meanwhile,the5-year return value tends to increase by 30%-45%in the basins of Liujiang River,Red Water River,Guihe River and Pearl River Delta region,where the 5-year return value of future climate corresponds to the 8-to 10-year return value of the present climate,and the 50-year return value corresponds to the 100-year return value of the present climate over the Pearl River Delta region in the 2080 s under RCP8.5,which indicates that the warming environment will give rise to changes in the intensity and frequency of extreme precipitation events.

Projected changes in population exposure to extreme heat in China under a RCP8.5 scenario

Overall population exposure is measured by multiplying the annual average number of extremely hot days by the number of people exposed to the resultant heat. Extreme heat is also subdivided into high temperature（HT） and extremely high temperature（EHT） in cases where daily maximum temperature exceeds 35℃ and 40℃, respectively. Chinese population exposure to HT and EHT over four periods in the future（i.e., 2021–2040, 2041–2060, 2060–2081 and 2081–2100） were projected at the grid cell level in this study using daily maximum temperature based on an ensemble mean of 21 global climate models under the RCP8.5 scenario and with a population projection based on the A2 r socio-economic scenario. The relative importance of population and climate as drivers of population exposure was evaluated at different spatial scales including national and meteorological geographical divisions. Results show that, compared with population exposure seen during 1981–2010, the base period, exposure to HT in China is likely to increase by 1.3, 2.0, 3.6, and 5.9 times, respectively, over the four periods, while concomitant exposure to EHT is likely to increase by 2.0, 8.3, 24.2, and 82.7 times, respectively. Data show that population exposure to HT is likely to increase significantly in Jianghuai region, Southwest China and Jianghan region, in particular in North China, Huanghuai region, South China and Jiangnan region. Population exposure to EHT is also likely to increase significantly in Southwest China and Jianghan region, especially in North China, Huanghuai, Jiangnan, and Jianghuai regions. Results reveal that climate is the most important factor driving the level of population exposure in Huanghuai, Jianghuai, Jianghan, and Jiangnan regions, as well as in South and Southwest China, followed by the interactive effect between population and climate. Data show that the climatic factor is also most significant at the national level, followed by the interactive effect between population and climate. The rate of contribution of climate to national-level projected changes in exposure is likely to decrease gradually from ca. 70% to ca. 60%, while the rate of contribution of concurrent changes in both population and climate is likely to increase gradually from ca. 20% to ca. 40% over the four future periods in this analysis.

Assessment of climate damage in China based on integrated assessment framework

Developing a localized and consistent model framework for climate loss and damage assessment is crucial for the policy-making of climate change mitigation and adaptation.This study introduces a comprehensive,multidisciplinary Integrated Assessment Model(IAM)framework for evaluating climate damage in China,utilizing BCC-SESM climate model and FUND sectoral climate damage model under the SSP2-RCPs scenario.Employing a bottom-up approach,the research estimates climate damage across eight major sectors,recalibrates sectoral climate damage functions and parameters for China,and elucidates distinctions among direct climate loss,market climate loss,and aggregate climate loss.The findings reveal that the total climate damage function for China follows a quadratic pattern in response to temperature rise.By 2050,the estimated climate damage is projected to be 5.4%,5.7%,and 8.2%of GDP under RCP2.6,RCP4.5,and RCP8.5,respectively.Additionally,both direct and market climate losses are projected to remain below 2%of GDP by 2050,while the aggregate climate loss could reach as high as 8.2%,which is predominantly attributed to non-market sectors.From a sectoral perspective,under the RCP8.5 scenario,human health damage constitutes the largest share(61.9%)of the total climate loss by 2050,followed by sea-level rise damage(18.6%).This study sheds lights on the adaptation policy that should attach importance to the non-market sectors,particularly focusing on human health and sea-level rise.

A cellular automata downscaling based 1 km global land use datasets (2010–2100)

Global climate and environmental change studies require detailed land-use and land-cover （LULC） information about the past, present, and future. In this paper, we discuss a methodology for downscaling coarse-resolution （i.e., half-degree） future land use scenarios to finer （i.e., 1 km） resolutions at the global scale using a grid-based spatially explicit cellular automata （CA） model. We account for spatial heterogeneity from topography, climate, soils, and socioeconomic variables. The model uses a global 30 m land cover map （2010） as the base input, a variety of biogeographic and socioeconomic variables, and an empirical analysis to downscale coarse-resolution land use information （specifically urban, crop and pasture）. The output of this model offers the most current and finest-scale future LULC dynamics from 2010 to 2100 （with four representative concentration pathway （RCP） scenarios--RCP 2.6, RCP 4.5, RCP 6.0, and RCP 8.5） at a 1 km resolution within a globally consistent framework. The data are freely available for download, and will enable researchers to study the impacts of LULC change at the local scale.

The Dynamics and Future Scenarios of the Animal Husbandry System in Khutag-Undur from 2015 to 2050

Under the conditions of climate warming,grassland degradation,frequent sandstorms,and fast increases in livestock numbers,coordinating animal husbandry and ecological protection is an important issue facing Mongolia.Using Khutag-Undur as an example,this study explores the dynamic process,future scenarios,and optimization strategies of the animal husbandry system in a typical Soum of Mongolia from 2015 to 2050 under three future climate socioeconomic scenarios of CMIP 6:SSP1-RCP2.6,SSP2-RCP4.5,and SSP5-RCP8.5.First,the animal husbandry system was deconstructed into three subsystems:grassland primary production,livestock secondary production,and herder consumption.Based on the negative feedback mechanism of forage-livestock balance,a system dynamics model for the Khutag-Undur Soum animal husbandry system was developed.This model integrates spatial data such as land cover and NPP,as well as statistical data on livestock,herder income and expenditures,sample plot surveys,and herder questionnaires.The model was used to simulate the historical changes(2015-2022)in forage production and carrying capacity,livestock stock,and livestock output of Khutag-Undur,and then to forecast the future scenarios of those variables for 2022-2050.Second,the most suitable future scenario for the Soum was identified by comparing the three future scenarios using a pastural system sustainability evaluation method.Finally,based on three indicators of livestock numbers,a two-step livestock reduction strategy was proposed.The main conclusions are that the rapid growth of livestock numbers in Khutag-Undur places considerable pressure on the grassland,and the SSP1-RCP2.6 scenario is the most suitable future scenario for the Soum.However,even in this suitable scenario,grassland overloading remains evident.The continuous implementation of a livestock reduction strategy is recommended to maintain the sustainable development of animal husbandry and grassland conservation.

综合气候和土地利用变化协同效应的玉米产量估算——以中国吉林省为例

Yield forecasting can give early warning of food risks and provide solid support for food security planning.Climate change and land use change have direct influence on regional yield and planting area of maize,but few studies have examined their synergistic impact on maize production.In this study,we propose an analysis framework based on the integration of system dynamic(SD),future land use simulation(FLUS)and a statistical crop model to prefuture maize yield variation in response to climate change and land use change in a region of central Jilin province,China.The results show that the cultivated land is likely to reduce by 862.84 km^(2) from 2030 to 2050.Nevertheless,the total maize yield is expected to increase under all four RCP scenarios due to the promotion of per hectare maize yield.the scenarios,RCP4.5 is the most beneficial to maize production,with a doubled total yield in 2050.Notably,the yield gap between different counties will be further widened,which necessitates the differentiated policies of agricultural production and farmland protection,e.g.,strengthening cultivated land protection and crop management in low-yield areas,and taking adaptation and mitigation measures to coordinate climate change and production.

Projections of surface air temperature and precipitation in the 21st century in the Qilian Mountains,Northwest China,using REMO in the CORDEX

Qilian Mountains(QM)is an important ecological security barrier in China and has been significantly affected by climate change,it is therefore of great importance and necessity to project its future climate change using high-resolution climate models because of mountainous areas in the QM and relatively few targeted simulation analyses.In this study,we used the simulations of the regional climate model REMO with 25 km spatial resolution,driven by three different global climate models(MPI-ESM-MR,NorESM1-M,and HadGEM2-ES),to evaluate how annual and seasonal mean surface air temperature and precipitation in the QM are likely to change for three future periods(2011-2040,2041-2070,and 2071-2100)under two representative concentration pathways(RCP2.6 and RCP8.5).The REMO model,shows noticeable cold and wet biases compared to observations for the reference period(1971-2000)and air temperature simulation outperforms precipitation simulation.The REMO simulations exhibit a warm and wet centre around lake,indicating that the simulation are likely influenced by lake.Projections under RCP2.6 show regional warming reaching 1.74℃ during 2011-2100,characterized by an initial increase and a decrease afterwards.Under RCP8.5,air temperatures increase monotonously from 2011 to 2100,with a warming magnitude of 5.36℃ for 2071-2100 relative to 1971-2000.The overall change in regional-average annual precipitation is not evident during 2011-2100,with some increases or decreases in certain time periods.In the 2071-2100 both the strongest warming and precipitation increase are projected to occur in winter under both scenarios,while precipitation in summer and autumn is projected to decrease in the east of the QM for the three future periods.The results suggest that the QM is likely to experience drought conditions in warm seasons in the future,which could impact agricultural and livestock production.