Traffic induced emission estimates and trends (2000–2005) in megacity Delhi

Transport sector emission inventory for megacity Delhi has been developed for the period 2000–2005 to quantify vehicular emissions and evaluate the effect of relevant policy reforms on total emissions of various air pollutants like CO2, CO, HC, NOx, TSP, SO2, Pb and VOC’s over the years to assist in future policy formulations. Emission factor and vehicle utilization factor based approach as recommended by IPCC (2006) have been used for estimating emissions. CO level were found to increase continuously during the study period, other pollutants like CO2, TSP, NOx and SO2 declined in the initial years, which clearly seem to be the result of stricter emission norms and compressed natural gas conversion of public transport. The levels of NOx and TSP did not show appreciable rise during the study period, which is an indicator of CNG effectiveness as an alternative fuel. However, two-wheelers population were found to be a major contributor towards the air pollution load.