This study empirically investigates the relationship between CO2 emission and four of its potentially contributing factors (i.e., energy consumption, income, trade openness and population) using time series data from 1971-2013 on five selected economies of South Asia. After confirming that all the series are stationary using unit root test process, the study incorporates three different and advance panel cointegration tests i.e. Pedroni-Kao-and Johansen-Fisher-panel cointegration. All the panel cointegration tests confirm that all the variables cointegrated. The long-run association between the variables is checked using FMOLS-grouped and individual cross-section country in the panel. The FMOLS grouped results show that energy consumption, trade openness and population increases environmental degradation in the panel countries with exception of income which has negative impact and sounds the existence of Environmental Kuznet curve between income and emission. The innovative accounting approach using variance decomposition test and impulse response function is applied to examine the causality amongst the underlined vectors. The results show that there is bidirectional causality between energy consumption and trade openness and unidirectional causality running from energy consumption, trade openness and population to CO2 emission. The results enumerate that the energy consumption and population density will increase in long-run and foresee further environmental degradation in the region.