The Analysis Of Spatiotemporal Dynamics Of Carbon Dioxide Emissions From Energy Consumption At Different Scales In China

The use of fossil fuel for living and production by human beings has significantly affected our environment and human health.According to the IPCC report,the CO₂ released from the fossil fuel combustion and industrial activities can account for 78%of the total emission of all greenhouse gases.How to mitigate CO₂ emission has become the hot research topic worldwide.China is one of the nations emitting substantially amount of CO₂globally,and the greatest developing country around the world.On one hand,the total CO₂emission of China is projected to be increased in the near future;on the other hand,the different social development model and energy consumption structure in different regions of China will be will be existence for a long time.The above two factors have contributed to the large spatial and temporal variation in CO₂ emissions from energy consumption and could have led large uncertainties in the practice of policy-making to mitigate carbon emission.Therefore,it is important to investigate the spatio-temporal variations and its mechanism of CO₂ emissions from energy consumption in different regions of China.Although previous studies have assessed the CO₂ emission from energy consumption from different regions of China,the problems associated with CO₂ emission from energy consumption at different scales are still need be more discussions.Based on the current methods,this study systematically estimated CO₂ emissions from energy consumption rom different provinces,regions and cities in China,and quantified the sptaio-temporal variations and its patterns of CO₂ emission,investigated the CO₂ emission from different provinces,regions and cities in China,to provide scientific evidences for making policy to mitigate carbon emission among different regions in China.This study is comprised of three main aspects:the budget and analysis of CO₂ emission from energy consumption at the provincial scale;the budget and controlling factors of CO₂emission from energy consumption at the regional scale;and the budget and case study of CO₂ emission from energy consumption at the city scale.Firstly,we examined the spatial and temporal patterns of the CO₂ emission from energy consumption from electricity trade for 30 provinces in China from 1995 to 2016.Secondly,by including the impacts of population,economy and technology,we analyzed the essential effect of population size on CO₂ emission.Lastly,this study investigated the spatial and temporal patterns of CO₂emission from four municipalities directly under the central government in China.The main findings were shown as following:?1?There was an increasing trend of CO₂ emission from energy consumption,which had been gone through different phases of stabilization,dramatically increasing and moderately increasing from 1995 to 2016.The energy processing sectors?including electricity and heating?and industry sectors were the main sources of CO₂ emission.After2012,the CO₂ emission from the industry sector started to decrease but the emission from communal facilities,resident activities and construction business has been increased.?2?The CO₂ emission from electricity trade among provinces has increased from4885.5 Mt to 12092.9 Mt from 1995 to 2016,with the provinces of Shandong,Jiangsu,Hebei,Guangdong and Henan as the main sources.The CO₂ emission from net electricity trade accounted for a large proportion of the total emission from energy consumption,after the energy processing sector and the industry sector.In 2016,the carbon emission from net electricity trade accounted for over 10%of the total emission over half of the regions.The CO₂ emissions from net electricity import were mainly from Beijing and Guangdong Province,whereas the CO₂ emissions from net electricity export were mainly from Inner Mongolia and Shanxi Province.There was a spatial shift in the CO₂ emission from net electricity trade,with a fast increase in CO₂ emission from net electricity import in Jiangsu and Zhejiang provinces in eastern China and net electricity export in Sichuan and Yunnan provinces in western China.According to the 13th Five-year Plan,the west-to-east electricity transmission projects will be reinforced.Therefore,the provinces and cities in the eastern regions should take more responsibility to decrease carbon emission and optimize the investment and consumption structure,and advance technical innovation of local clean energy utilization and the application of energy-saving technique.The provinces and cities in the western regions can take less responsibility of CO₂ emission mitigation but at the same time,they should optimize the industrial and energy consumption structure to reduce the use of coal.?3?There was no consistent pattern of the CO₂ emission from energy consumption as affected by population size.Instead,there was remarkable variation among different regions over time.From 1995 to 2016,the coefficient of elasticity of population size decreased by12%and 16%in the eastern and western China,respectively,while it increased by 30%in the central China.Although there was a substantial fluctuation of the coefficient of elasticity in the megalopolis,it remained relative unchanged compared to that in 1995.The eastern regions should develop innovative clean energy and high and new technology industry to remain sustainable development with low carbon emission and resource-saving model.The central and western regions should adjust the energy and industrial structure to improve the energy use efficiency and reduce the CO₂ emission resulting from the positive effect as affected by population size.The megalopolis should coordinate with the surrounding cities and optimize resources for regional collaboration,and disperse the population and resources to the surrounding cities.?4?There was an increasing trend of the CO₂ emission from energy consumption in the administrative region of the four municipalities directly under the Central Government.There was difference in the spatial pattern of the CO₂ emission from energy consumption between the central urban area and the suburbs,which was decreased in the former with a decreasing proportion relative to the administrative region of the city.In 1995,the proportions of the CO₂ emission from the central urban area relative to the administrative region in Beijing,Tianjin,Shanghai and Chongqing were 53.69%,17.56%,58.42%and34.53%,respectively,and they were decreased to 39.01%,13.06%,49.02%and 9.53%,respectively,in 2010.However,the CO₂ emission from energy consumption in the municipal district increased at a faster pace.Except for Shanghai,the CO₂ emission of the four municipalities directly under the Central Government showed an increased trend from the central urban area to the suburbs and then to the whole area.From 1995 to 2016,the industry was still the most important contributor to the CO₂ emission from energy consumption in the central urban area of the four municipalities directly under the Central Government.From 1995 to 2016,the decreasing of CO₂ emission from industry sector was the main reason for the decreased CO₂emission per capita in the central urban area in Beijing and Chongqing.It is still a tough challenge to reduce the carbon emission from industry sector to maintain a low carbon emission development in cities.The spatial pattern of the CO₂ emission from energy consumption in Beijing has been shifted from high emission in the central urban area and low emission in the suburbs to the dispersion of high emission to the nearby countries.The spatial autocorrelation analyses showed that the CO₂ emission has been changed from being spatially heterogeneous to aggregative.In 2010,the central urban area and the surrounding countries have become contiguously high CO₂ emission areas,and the counties with high CO₂ emission have been more than doubled.It indicates that there was a fast increase of the CO₂ emission in these counties which are close to the central urban area.Given the spatially aggregated high CO₂emission,special attention should be paid to these hot spots and control these essential areas to achieve effective management over the whole area.?5?In summary,the investigation of the CO₂ emission from energy consumption from the perspective of electricity consumption at the provincial scale provides practical significance for policy-making with the consideration of spatial difference.The study on the controlling factors of CO₂ emission at the regional scale could provide scientific basis for making region-specific policy to mitigate carbon emission.The assessment of the spatial pattern of the CO₂ emission at the city scale would provide guidance for future city.