Synergistic Mechanism And Control Countermeasures Of Air Pollutants And Carbon Emissions In Northwest China

The rapid growth of China’s economy over the past 30 years is significantly related to fossil fuel consumption（especially coal）,and fossil fuels are also the largest source of greenhouse gas such as carbon dioxide（CO₂）and air pollutant emissions.China is now the largest energy consumer and CO₂emitter of the world,contributing 23.2%of global energy consumption and 27.6%of global CO₂ emissions in China in 2017.In addition,the emissions of sulfur dioxide（SO₂）,nitrogen oxides（NOx）and primary fine particulate matter(PM_2.5)also reached their historical peak points in 2007、2012 and2006,respectively,in China.At present,China is facing the dual pressure of addressing climate change and improving air quality.The emission reduction of air pollutants and carbon dioxide（CO₂）needs to be carried out simultaneously due to they will be emitted from the same sources,providing a sound theoretical basis for the synergistic governance for their emissions.As a strategic corridor for the construction of the"the Belt and Road",the issues of environmental quality in Northwest China have gradually caused concern under the policies of China’s Western Development and east-west relocation of pollution industries as well as west-east transmission of energy and resource industrial products.Therefore,it is urgent to strengthen the coordinated emission reduction of air pollutants and carbon as well as to promote the synergistic governance of pollution reduction and carbon reduction in northwest China.In this thesis,firstly,the primary driving factors of carbon emissions in the five northwest provinces were explored based on the improved Kaya identity model and Logarithmic Mean Divisia Index（LMDI）factor decomposition method.Next,the spatial agglomeration of various substances was analyzed using both global autocorrelation and local autocorrelation methods.Finally,the GWR model was employed to analyze the synergistic mechanism between CO₂ and air pollutants in various regions in detail,and then the collaborative governance strategies and suggestions were proposed.The major findings from this thesis are summarized below:（1）The current situation and trend of air pollutants and CO₂ emissions:From the perspective of time trend,the emissions of CO,NOx,PM₁₀,PM_2.5 and SO₂ in the five provinces and autonomous regions in northwest China from 2008 to 2017 show a trend of first increasing and then decreasing,and reached its peak point between 2011 and2014,while CO₂ emissions increase year by year;From the perspective of spatial distribution,the emissions of CO₂ and the five kinds of air pollutants exhibit the highest distribution in Xinjiang Autonomous Region and Shaanxi Province,indicating the two regions need to be paid attention to the emission reduction of air pollutants and CO₂among the northwest regions.（2）The decomposition analysis of carbon emission influencing factors based on LMDI model:the carbon emission data of five provinces and autonomous regions in northwest China from 2011 to 2017 were decomposed to obtain five primary driving factors affecting the growth of carbon emissions.The results reveal that the economic development effect plays a vital role in the changes in carbon emissions.Meanwhile,the energy intensity also helps to curb carbon emissions except for Xinjiang.For other influencing factors,regions can formulate differently emission reduction measures based on local special characteristics.（3）Spatial correlation analysis between CO₂ and air pollutants:The spatial correlation between CO₂ and five air pollutants in various prefecture-level cities（prefectures）in northwest China from 2008 to 2017 was analyzed using the spatial analysis module of Geo Da software.The Moran scatter map and LISA cluster map directly reflected the spatial agglomeration effect of various substances,in which the focus should be on the areas with"high-high"and"low-high"clustering characteristics.The regions where CO、PM₁₀ and PM_2.5 exhibit the characteristics of"high-high"concentration are mainly concentrated in Shaanxi Province and Qingyang.The regions exhibited the characteristics of"low-high"agglomeration are Shangluo and Tongchuan cities in Shaanxi Province.Given the numbers of this kind of cities has been increased,and it should also raise government future concerns.（4）Synergistic mechanism analysis between CO₂ and air pollutants based on GWR model:A geographically weighted regression model were built based on the CO,NOx,PM₁₀,PM_2.5 and SO₂ emissions（Y）of 51 cities（prefectures）in the northwest region from 2008 to 2017 as the dependent variables,and the carbon emissions（X1）and carbon emission intensity（X2）as the independent variables to obtain the regression coefficients between the emissions of five air pollutants and CO₂ emissions.The results show that the regression coefficients between the emissions of five air pollutants and the emission of CO₂ exhibit positive synergy,that is,the increase of CO₂ emission would promote the emissions of air pollutants;In terms of carbon emission intensity,except for the positive regression coefficient of NOx and CO₂ emission intensity,most of the others are negative,that is,most of them are negative synergy.However,in terms of time dimension,the magnitude of synergy has shown a significant downward trend.（5）Countermeasures and suggestions for collaborative governance:Based on a comprehensive study of the influencing factors of carbon emissions and the synergistic mechanism between air pollutants and carbon emissions in northwest China,measures and suggestions are proposed to promote regional air pollution prevention and control,formulate collaborative strategies tailored to local conditions,accelerate energy structure adjustment and industrial structure upgrading,and strengthen technological innovation.The results from this dissertation could also provide scientific support to the ideas and strategies of collaborative governance of air pollutant emissions and carbon emissions in the five provinces and autonomous regions of northwest China.