Study On Spatial-temporal Patterns Of Energy Carbon Emissions And Carbon Footprint In China

The global environment issue resulting from carbon emission is being a great worldwide concern for governments,the public and scientific communities to be addressed.A precise measurement of the time-resolved and spatial distribution characteristics of carbon dioxide（CO₂）and carbon footprint as well as its long-period evolution mechanism,can help clarify the relationship between environmental carbon load and economic growth,and are critical references to the formulation of scientific carbon reducing emission targets with reasonable and differential reducing emission policies.In this study,the mainland of China is taken as the research object,according to the quantitative correlations between DMSP-OLS nighttime light image data and carbon emission statistics,the carbon emission panel data model was simulated for China’s carbon emissions in the period of 2000 to 2013,then the spatio-temporal evolving trend and spatial distribution characteristics of carbon emissions in the research period were discussed using Theil-Sen Median trend analysis and Mann-Kendall test method.Based on the framework of exploratory spatial-temporal data analysis（ESTDA）,the spatial pattern and spatial-temporal dynamic evolution of carbon footprint from 2001 to 2013 were analyzed from the perspective of spatial-temporal interaction.In three different periods,the decoupling effects between environmental carbon load and economic growth of 336 prefecture level cities were analyzed using the improved Tapio decoupling model.The results show that:（1）By correcting the DMSP-OLS nighttime light image data systematically,the simulation here of long-time serial carbon emissions shows high accuracy.Based on the correction of continuity data,the saturation correction,the remove of the outliers and the extract of urban built-up areas,the central regions of China were taken as the sample areas to be simulated.The determination coefficients value-R2,from the multi-scale regression test for the years of 2002,2007,2012 are 0.893,0.955 and 0.951,respectively.（2）The overall carbon emissions in China have been on the rise from 2000 to 2013,in which the stable-slow rise type is dominant,while the rapid rise type spatially exhibits a‘hollow structure’or‘centered structure’,they accounted for 77.6%and 19.4%of the total area of carbon emissions,respectively.It also indicates that cities which show an obvious variation of carbon emissions are mainly located in the southeast side of Hu Huanyong population line.While cities of the rapid rise type show a clear directional difference due to the level of the city size and urbanization.China’s urban agglomeration is the main contributing region of carbon emissions,and the overall trend of rapid growth.The multi-index of carbon emissions of urban agglomeration shows a clear spatial different trend.（3）China’s carbon footprint and carbon deficit were increasing year by year,and the central and western regions have become the focus of the growth of carbon footprint and carbon deficit from 2001 to 2013.At scales of different administrative units,the spatial patterns of carbon footprint and carbon deficit show obvious administrative orientated and spatial zonal differentiation.The annual average of global Moran’s I index of each level unit is 0.491,which indicates that there is a significant spatial auto-correlation feature in the carbon footprint of China’s prefecture Level units.The relative length of the LISA time path in the north is greater than in the south,and it tends to increasing from the coastal regions to the central and western regions,the curvature of LISA time path decreasing from coastal areas to inland areas on the whole.The curvature of northeast and central areas is higher,while the curvature of eastern and western areas is lower.（4）There is a certain different trend of the decoupling effect of environmental carbon load in China.Meanwhile the expansion-connection and expansion of negative decoupling regions continuously increased and spatially agglomerated,there is an‘E’-shaped distribution pattern from the north to the south.The national average decoupling elastic value is gradually increasing,the coefficient of variation continues to decline,and the decoupling type has a significant evolution trend.Therefore,the unbalanced trend of economic growth and carbon emissions in China will remain for a certain period.（5）This study proposes that the essential transformation of economic growth pattern and the development mode,as well as the implementation of different carbon reducing emission measures adapted to local conditions and provinces-regions linked strategy are the vital approach to achieve the‘targeted emission alleviation’.