Study On The Climate Change Impact On Chinese Rice Production

With the influences of both natural factors and human activities,global warming has become an unquestioned fact.IPCC AR5 in 2014(the 5th Assessment Report of Intergovernmental Panel on Climate Change)once again pointed out that global warning was unmistakable,considering the fact that global temperature had increased by 0.85? in the past 130 years,and the number of extreme weather and climate events including drought,flood and high temperature had been on the rise since the 1950 s,seriously threatening human production and life.Actually,climate change has exerted increasingly serious influences on the environmental,ecological and socio-economic systems.Agricultural production,as one of the most sensitive and vulnerable fields facing climate change,has been suffering under climate change,which has been verified by a lot of researches.The influences of climate change on agricultural production have been gradually manifested in China,which is a large agricultural country.If China failed to take adaptation measures,stated by the Climate Change and Poverty in 2009,it was likely that China's overall agricultural productivity will fall by 5%-10% resulted from global warming by 2030.The output of three major food crops,namely wheat,rice and corn,would be mainly on the decline.Till the second half of the 21 st Century,the per unit area yield of crops,such as wheat,rice and corn,would fall by 24%-37% at most.In 2015,China' rice planting area was 30,215,740 hectares and the total rice yield was up to 208.2252 million tons,ranking 1st and 2nd respectively in the world.Changes in China's rice production will influence not only the domestic grain supply,but also the domestic and foreign grain prices and the international rice market.At present,researches on the influences of climate change on food security in academic world have been prevailing,but attention has not been enough on the influences of climate change on the production of specific crop variety,especially that on rice.As to the influences of climate change on the production layout evolution and productivity of rice,related researches have been few due to the lack of micro foundation.Against the background of climate warming and frequent occurrence of extreme climate,what substantial influences will climate change have on China's rice production? It requires comprehensive and systematic research.For example,how will climate change influence paddy rice yield per unit? Are there any regional differences? And what influences will climate change have on the rice planting area and the production layout? What is the relation between climate change and rice total factor productivity? Besides,what typical characteristics do extreme climate events show,such as high temperature,drought and flood,etc.? What influences will they bring on paddy rice yield per unit? Deeply researching and answering these questions is not only conducive to the improvement of the ability of rice production to cope with climate change,but also to the food security and maintenance of social stability.Based on the aforesaid questions and focusing on the influences of climate change on China's rice production,the paper firstly defines the related concepts and proposes research hypotheses based on the related logical reasoning,then sets forth the theoretical basis for the paper and makes comprehensive collation and review of related literature.Based on it,the paper analyzes the characteristics of climate change during China's rice growing seasons with the linear trend estimation and Mann-Kendall test methods.Secondly,it introduces climatic factors to the building of the extended C-D production function model,analyzing empirically the influences of the climate change in growing seasons on paddy rice yield per unit area,especially the investigation of the influences of climatic factors on non-linearity and regional differences on paddy rice yield per unit area.Then,with the main rice production region of Hubei Province as an example,it builds the integrated indexes of high temperature disaster with temperature data and the Logistic curve equation,and constructs the hierarchical estimation model for paddy rice yield per unit area and influencing factors based on the analysis of the spatial and temporal change characteristics of high temperature disaster in the rice growing seasons in this area,and emphatically discusses the influences of temperature,precipitation and extreme high temperature on paddy rice yield per unit area in Hubei.Next,it investigates the spatial layout changes of China's rice production since the 1980 s with GIS.By combining both micro and macro factors and comprehensively considering about natural factors,comparative gains,non-agricultural employment and other social-economic factors,it analyzes the influences of climate change on the production layout evolution of rice.Afterwards,it looks into the influence mechanism of climate change on the total factor productivity of rice,analyzes the spatial and temporal change characteristics of the total factor productivity of rice,and investigates the influences of precipitation and temperature on the total factor productivity of rice.Lastly,according to the major research conclusions,it proposes the policy suggestions for rice production in coping with the climate change from two aspects of “mitigation” and “adaption”,hoping to provide reference bases for China to make policies in coping with climate change and promoting the sustainable development of rice production.Through the aforesaid systematic research,the paper reaches the following main conclusions:(1)The average monthly temperature in the rice growing seasons in the Northeast,East,Central,South and Southwest China shows a significant rising trend and the increasing ranges are different in the regions;the average monthly precipitation in the rice growing seasons in the East,Central and South China is on the increase,while it declines in the Northeast and Southwest China,but the trends of precipitation changes are non-significant in all regions.(2)The climate change in the rice growing seasons are to the disadvantages of the paddy rice yield per unit area in most regions.The rise of temperature negatively influences the paddy rice yield per unit area in East,Central,South and Southwest China,but has significant positive influences on that in the Northeast China.The rise of precipitation negatively influences the paddy rice yield per unit area in Northeast,East,Central and South China,but has significant positive influences on that in the Southwest China.(3)High temperature disaster has significant negative influences on the paddy rice yield per unit area.From 2003 to 2011,Hubei Province suffered from serious high temperature disasters,of which the trend was decreasing then increasing.Spatially,high temperature disaster was lighter in Western Hubei and Jianghan Plain,and more serious in Central and East Hubei.(4)Climatic factors are closely connected with the production layout evolution of rice,especially temperature which plays an important role in the production layout evolution of rice.Specifically,the rise of temperature promotes the increase of rice planting area in the Northeast China,but leads to the decrease of rice planting area in the East,Central,South and Southwest China.Besides,the increase of precipitation plays a non-significant role in increasing the rice planting area.(5)Temperature promotes the growth of the total factor productivity of rice,in which precipitation exerts no significant influence.Concretely speaking,temperature rise significantly improves the rice total factor productivity in the Northeast and East China,but inhibits it in the Central,South and Southwest China.Except for the Southwest China,the rise of precipitation is unfavorable to the enhancement of the total factor productivity of rice in the Northeast,East,Central and South China.As a summary,the paper finds that there are significant regional differences in the influences of climate change on China's rice production,which are closely connected with local natural resources endowment and agricultural production conditions,as well as the adaptability of climate change in different regions.Therefore,when making policies in coping with climate change,flexibility should be taken into consideration.According to the different characteristics of the climate and natural resources endowment in different regions,targeted response to climate change should be adopted and "one size fits all" should not be chosen,otherwise it will go the opposite way.There are four aspects worth consideration:(1)Adjusting the rice planting systems and optimizing the production layout of rice.The rice planting system should be adjusted scientifically according to the changes of rice planting systems and planting areas in various regions on one hand,and the production layout and planning of rice should be optimized according to the changes of light,heat and water resources in various regions on the other hand.(2)Increasing the scientific research input in agriculture,and developing and improving new rice species and technologies.Scientific research and the input of funds in agriculture should be increased,thus new stress-resistant species which are characterized by resistance to drought and water logging,high temperature resistance,disease and pest resistance,etc.could be actively developed,and the development of new pesticides and pragmatic disease pest and weed prevention and control technologies could be strengthened.(3)Strengthening the rice production management.More attention should be paid to irrigation optimization,fertilization control and pest prevention and control in order to intensify the adaptability of rice to climate change.(4)Completing the construction of water conservancy facilities,and improving the defense of meteorological disaster.Through improving meteorological disaster forecasting,pre-warning system and water conservancy facilities,etc.,in actively coping with climate change.The possible innovation points are mainly embodied in the following three aspects:(1)The paper constructs the integrated indexes of high temperature disaster,thus investigating the influences of high temperature disaster on paddy rice yield per unit area on both the theoretical and empirical levels.Based on the accumulated temperature of high temperature disaster and duration of high temperature,it constructs the integrated indexes of high temperature disaster with the Logistic curve equation so as to effectively quantify high temperature disaster,which has not been solved by previous researches.The paper discusses the influence mechanism of high temperature disaster on paddy rice yield per unit area in theory.It applies the hierarchical linear model in the study of the influence of high temperature disaster on paddy rice yield per unit area in Hubei Province.It not only considers the element input factors on the level of farmers,but also fully controls the social adaptive behavior factors among different regions,thus combining both the macro and micro analyses so as to effectively solve the problem of spatial heterogeneity and make the research outcomes more accurate and reliable.(2)The paper verifies the relation between climate change and the production layout evolution of rice empirically with the historical climatic data and panel data models on the basis of the control of socio-economic,agricultural production technologies,policy guidance and other factors.At present,there are little literature about the research on the relation between climate change and the production layout evolution of rice in the economic field,while in the field of natural science,the influences of climatic factors on rice planting regions and areas are often analyzed solely,and the influences of socio-economic factors on rice planting areas are seldomly considered,and a systematic research on the production layout evolution of rice is missing.In this sense,the paper,while integrating the research outcomes in the fields of both natural science and economics science,and considering both natural factors and socio-economic factors,builds a panel data model in the investigation of the relation between climate change and the production layout evolution of rice emphatically.Compared with existing literatures,its estimation method is more stable and its conclusions more reliable.Besides,it fully investigates the characteristics of the production layout changes of rice with GIS to master the spatial change trends of the production layout of rice in a more comprehensive manner.(3)The paper analyzes the influence mechanism of climate change on the TFP of paddy rice on theoretical level,thus analyzing the influences of climate change on the TFP of rice in the adoption of the two-way fixed effects model,based on the systematic measurement of the rise of the TFP of rice,thus understanding and clarifying the influences of climate change on rice production.Existing literatures studying the relation of climate change and TFP have not considering a specific crop,which make this paper a good supplement to the related research in the field to a certain degree.While measuring the TFP of rice,this paper overcomes the paradox of “technology regression” that the cutting-edge technology progress index measured by the traditional contemporaneous DEA method is often less than 1,by adopting the “historical memory” hypothesis and Sequential DEA method and introducing the technologies in earlier stages to effectively avoid the no-solution defect of linear programming and the phenomenon of “technology regression”,and measure technology progress more accurately.Compared with the existing literatures,this paper has shown deeper economic meaning and stronger theoretical foundation.