Carbon Emission Predictions and Carbon Reduction Targets of Xi'an Urban Rail Transit Operations
To address uncertainties in future operational carbon emissions and carbon reduction targets for urban rail transit networks,this study analyzes operational energy consumption data for the Xi'an urban rail transit system from 2018 to 2022.The carbon emission factor method is employed to calculate operational carbon emissions for the past five years.The index method is then used to predict energy consumption and carbon emissions for the next five years.Based on the binding energy intensity requirements outlined in China's Action Plan for Green Urban Rail Development,we quantitatively analyze the total energy saving target for Xi'an's urban rail transit operations over the next five years.Subsequently,the total carbon emission constraint and carbon reduction target are determined.The research results indicate that approximately 175.9×104 tCO2e of total carbon emissions were generated during the operation of the Xi'an urban rail transit system from 2018 to 2022.Under these conditions,it is expected that approximately 321.6× 104 tCO2e of total carbon emissions will be generated over the next five years of operations,with traction and station power consumption being the main sources of carbon emissions.If the comprehensive energy intensity reduction target proposed by the association is achieved,compared with the predicted carbon emissions,the carbon emissions of the entire network are expected to reduce by approximately 13%by 2025;the carbon emissions of the entire network are expected to reduce by approximately 15%by 2027;and in total,carbon emissions are expected to reduce by approximately 10%over the next five years.