Data on the concentration of two GHGs associated with motor vehicle emissions- carbon dioxide and sulfur dioxide at different traffic volumes were collected at a location in Ipoh City, Malaysia. The concentration of the two gases was measured and summed to get the concentration of vehicular pollutants in parts per million for different traffic volumes. Table 1 below presents the data, while chart 1 represents the scatter plot of the same: Traffic volume per Pollutant conc. hour (No. of cars) (PPM) 10 400 20 900 30 1,200 40 3,700 50 10,800 60 24,900 Table 1: Pollutant concentration by traffic volume (Sadullah et al., 2013)