This paper uses the Autoregressive Distributed Lag(ARDL) method which allows for the combination of variables with mixed order of integration in a single regression model to the hypothesis that energy consumption matters in the carbon dioxide effect of economic growth. Using Nigerian dataset, our findings suggest that there is probable of a cointegrating relationship among the variables of interest. However, the estimation results refute the Environmental Kuznets Curve (EKC) in the context of the Nigerian economy. Essentially, we find the relationship between carbon dioxide (CO2) emissions and Gross Domestic Product (GDP) per capita to be monotonically increasing. We also find the response of CO2 emission to energy consumption to vary for different energy-mix.