Research On Effects Of Rail Transit On Air Pollution And Household Carbon Emission

The environmental impact of rail transit is a hot topic in the field of urban,transportation and environment.Considering the increasingly serious air pollution and the urgency of the goal of "Carbon Peak and Carbon Neutralization",China takes the development of rail transit as one of the important ways to improve environmental quality.Under this background,this paper creatively tests the impact of rail transit on air pollution from the perspective of transportation substitution;And then,for the first time,this paper investigates the impact of rail transit on household carbon emissions and its impact mechanism based on the panel data at prefecture level in China.The research steps are as follows.Firstly,this paper conducts relevant theoretical analysis based on utility theory,so as to construct the theoretical framework of the correlations between rail transit and environmental quality.Based on the theoretical framework,this paper deduces the propositions that need to be tested empirically.Then,according to the service characteristics,rail transit is divided into two forms:inter-city and intra-city.High-speed rail and metro are taken as representatives,respectively.The main conclusions of the research on how high-speed rail affects air pollution and household carbon emissions include:(1)After the opening of the high-speed rail,the concentration of carbon monoxide within 10 km around the relevant highways can be decreased significantly by 0.047 mg/m3 compared with other highways,which means a reduction of 4.3%from the mean level.(2)The reduction effect of high-speed rail on air pollution mainly comes from the substitution effect of high-speed rail on traffic flow from relevant highways,that is,high-speed rail improves air quality by reducing the car emissions from its relevant highways.(3)Compared with cities without opened highspeed rail stations,the household carbon emissions of cities with high-speed rail will increase significantly by 2.3%-3.6%after the opening of high-speed railway.(4)Using mediation analysis,it is found that,after the opening of high-speed rail,people tend to reduce the proportion of expenditure on goods related to food,and increase the proportion of expenditure on health care,education,culture and entertainment,through which the high-speed rail can increase household carbon emissions.The main conclusions of the research on how metro affects air pollution and household carbon emissions include:(1)For each metro line opened in the cities,the average concentration of carbon monoxide will be reduced by 12.2%.After analysis,this effect mainly comes from the reduction effect of metro on the passenger flow from highways within the cities.(2)For each metro line opened in the cities,the household carbon emissions will be reduced by 5.9%.After analysis,the metro supply will make families tend to increase the proportion of expenditure on household facilities and services,and reduce the proportion of expenditure related to food,residence,transportation and communication,through which metro can significantly reduce household carbon emissions.(3)In view of the important environmental benefits from the metro,this paper also examines the impact of metro supply on residents’ commuting mode choice,and finds that,when the metro accessibility is improved,residents who originally choose other commuting modes will turn to take subway to commute,and this effect will have heterogeneity according to different individual attributes.The research conclusions of this paper can help local governments comprehensively understand the social benefits from rail transit.Based on the quantitative results of studies,this paper provides policy suggestions from the perspectives of rail transit infrastructure,station planning and site selection,environmental impact assessment and so on.