Economic growth and industrialization often default to a great dependency on fossil fuels (FF) to supply power needs. The carbon rich nature of FF combustion can impact global warming. Therefore, it is conducive to transition from FF to renewable energy (RE). The present study aimed to address if replacement of a single FF by RE can mitigate carbon emissions. We conduct the study in a country undergoing mass urbanization and challenging energy demands. Data from energy resources in the Power & Energy Sector Master Plan (PSMP2016; Bangladesh) are analyzed over the 2017-2021 trajectory. Two scenarios for imports, oil and coal are assessed. Environmental input output (E-IO) analysis and percentage equivalence analysis measured data variables. The data is then further disaggregated into an emission reduction (ER) model with sensitivity analysis to measure carbon emission reduction when each FF source is substituted by RE. Results show the percentage share of energy generation capacity by both coal and RE increase over time. Solar and wind power contribute to the increase in RE. When oil is imported a 1% increase in oil, coal, and gas-based energy generation capacity increases carbon emissions by 1.25%, 1.48% and 0.93%, respectively. 1% increase in RE produces negligible carbon emissions (0.0042%). There was little difference in the percentages of carbon emissions when coal is imported. Substituting any FF with RE of equal energy capacity does not, in the short term, reduce carbon emissions in either scenario. Therefore, we conclude that for long term clean energy prospects in Bangladesh, RE needs to be developed to operate at greater capacity in conjunction with other carbon management factors. The research findings herein offer insights for clean energy implementation in developing nations.