This study considered the dynamic relationship between urbanization and CO<sub>2</sub> emission on longevity in West African countries. The importance of urbanization to developing countries cannot be overemphasized; but it comes with a cost (CO<sub>2</sub> emission). Hence the need to observe the effect of CO<sub>2</sub> emission on longevity becomes necessary. This study incorporated the theory of health production into Environmental Kuznets Curve (EKC) and explored the Fully Modified (FM) and Dynamic Ordinary Least Square (DOLS) methods to conduct the social scientific enquiry. The outcomes of the panel co integration analysis are confirmed using the Pooled Mean Group (PMG) estimator to reaffirm the results of this study. The estimated coefficient for FMOLS presents urbanization (1.538) with CO<sub>2</sub> emission (-11.38) and DOLS reaffirmed urbanization (1.126) with CO<sub>2</sub> (-18.10) at 1% significant respectively. PMG indicated that the confirmatory test of a priori expectation is correct. The result showed that CO<sub>2</sub> emission and urbanization had negative and positive significant effect on longevity respectively. Therefore, the study re-validates that at long run the threshold for CO<sub>2</sub> emission must be established as developing countries especially West African countries yearn for development. The study concluded that in ECOWAS countries, urbanization spur longevity while CO<sub>2</sub> emission retards it.