A21G-0238
Quantification and modelling of on-road CO2 emissions and its impacts on ambient CO2 concentrations in an Indian coastal city

Tuesday, 15 December 2015
Poster Hall (Moscone South)
Kishore KUMAR Madhipatla, Indian Institute of Technology Madras, Chennai, India
Abstract:
This paper presents the results of CO2 emission inventory, monitoring of CO2 concentrations and modelling of on road CO2 emissions in an Indian coastal city. Bottom up approach was adopted for quantifying the grid wise on road CO2 emissions of Chennai city at a finer resolution of 1Km x 1Km using the real time traffic data of 56 major roads. In addition, monitoring of ground level CO2 concentrations and vehicular traffic were carried out at a residential site in Chennai to understand the impact of vehicular emissions on the ambient CO2 levels. Further, AERMOD, a US EPA regulatory model, was deployed to find the spatial variation of CO2 concentrations due to the emissions from 38 major corridors of Chennai.

Results indicated that a total emission of 0.65 Tg/year of CO2 was emitted by the vehicular traffic from the major roads of Chennai. Cars were identified as the larger emitters of CO2 with a contribution of 25% of the total emissions followed by three wheelers (21%), trucks (16%), buses (15%), two wheelers (13%) and Light Commercial Vehicles (9%). Ground level CO2 concentrations at the study area were in the range 391.52 to 666.37 ppm, with a mean hourly concentration of 448 ± 33.45 ppm. It was observed that the CO2 concentrations were high during the morning and evening peak hours and low during the afternoons and further vehicular emissions were found to have a significant effect on the ambient CO2 concentrations during the morning peak hours (R2=0.78) and afternoons (R2=0.50). But, contrastingly, a weak correlation was observed between the vehicular emissions and CO2 concentrations during the evening peak hours (R2=0.02). In addition, night time COconcentrations were observed higher in the weekends corresponding to high vehicular traffic during the late evenings. From the modelling results, it was found that the considered 38 major corridors contribute 0.12 ppm of CO2 per year to the ambient atmosphere.