The world in 1950 looked very different from how it does now. Europe was home to 22% of the world\’s 2.5 billion people. Germany, Britain, Italy and France all counted among the 12 most populous countries. But strong economic growth in Asia coupled with high fertility rates in Africa have contributed to a big regional shift in the global population. The UN\’s latest World Population Prospects expects the world to grow from 7.2 billion people today to 9.6 billion in 2050. This is 300m more than it had previously estimated, and reflects increases to the fertility rates in sub-Saharan countries such as Nigeria and Ethiopia, and other populous countries. More than half of the extra 2.4 billion people in 2050 will be African. India will swell to 1.6 billion people; it is on track to overtake China in 2028. China\’s population will peak in 2030; India\’s is predicted to do so around 2063. By 2100 the UN forecasts the population to reach 10.9 billion—and still be rising. It will also be much older. The median age is forecast to rise to 41 years old from 29 today, and around 28% of the world (almost 3 billion people) will be over 60.
Below is the list of 5 most populous Nation by 2050: