Long term projections of energy use and emission require a good understand of long term population growth. India’s demographics have changed significantly in the last decade, and different possible future scenarios have different populations, and most importantly, population distribution in the country. There is a diversity of growth rates and fertility rates among the states of the country. This study is important not only for energy and environmental impacts but also for the study of urbanisation, migration and the political and social impacts of different population growth rates of states.