This study empirically investigates how the presence of CETA (Comprehensive Economic and Trade Agreement) may affect per capita emissions of four air pollutants. It follows closely the empirical work of (Qirjo et al., 2019), but it focuses in each category of GHGs. It finds statistically significant evidence suggesting that trade openness between the EU and Canada could help reduce per capita emissions of CO2, CH4, and N2O in a typical CETA member, respectively. In the case of CO2, the presence of CETA may help reduce per capita emissions in almost all CETA members. However, there is empirical evidence that suggests that per capita emissions of CH4 could move from the EU towards Canada due to the implementation of CETA. There is also empirical evidence implying that there could be a shift of emissions per capita of N2O from Canada towards 8 former EU members due to the implementation of CETA. There is mainly statistically insignificant evidence of a positive relationship between the trade intensity of each EU member and Canada and per capita emissions of HFCs/PFCs/SF6. Furthermore, the study reports unambiguous empirical evidence in support of the Pollution Haven Hypothesis originating from national population density variations (PHH2) for Canada, in the case of CH4. Moreover, there is also clear evidence consistent with the Pollution Haven Hypothesis due to national income differences (PHH1) for 8 former Communist EU members, in the cases of N2O and HFCs/PFCs/SF6.