The importance of mitigation of climate change due to greenhouse gas (GHG) emissions from various developmental and infrastructure projects have generated interest at global level to reduce environmental impacts. Life Cycle Assessment (LCA) may be used as a tool to assess GHG emissions and subsequent environmental impacts resulting from electricity generation from thermal power plants. This study uses life cycle approach for assessing GHG emissions and their impacts due to natural gas combined cycle (NGCC) and imported coal thermal power plants using the IPCC 2001 and Eco-Indicator 99(H) methods in India for the first time. The total GHG emission from the NGCC thermal power plant was 584 g CO₂ eq/kWh electricity generation, whereas in case of imported coal, it was 1127 g CO₂ eq/kWh electricity generation. This shows that imported coal has nearly ~2 times more impacts as compared to natural gas in terms of global warming potential (GWP) and human health as Disability Adjusted Life Years (DALY) from climate change due to GHG emissions such as carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O).