According to the United Nations (UN) 2019 World Population report, by 2027, India's population will surpass China. India will be the most populous country in the world.

Sixty percent of the global population lives in Asia (4.4 billion), 16 per cent in Africa (1.2 billion), 10 per cent in Europe (738 million), 9 per cent in Latin America and the Caribbean (634 million), and the remaining 5 per cent in Northern America (358 million) and Oceania (39 million).

China (1.43 billion) and India (1.37 billion) remain the two largest countries of the world, both with more than 1 billion people, representing 19 and 18 percent of the world’s population, respectively.

The two countries make up 38 percent of the world's population.

The change is expected to occur as the death rate in China exceeds the birth rate.

Meanwhile, Nigeria, which will reach a population of 733 million in the next 30 years, is expected to follow India and China. The US ranks fourth with 434 million, while Pakistan is expected to be fifth with a population of 404 million.

The world population is projected to increase by more than one billion people within the next 15 years, reaching 8.5 billion in 2030, and to increase further to 9.7 billion in 2050 and 11.2 billion by 2100.

As with any type of projection, there is a degree of uncertainty surrounding these latest population projections. The results presented above are based on the medium projection variant, which assumes a decline of fertility for countries where large families are still prevalent, as well as a slight increase of fertility in several countries with fewer than two children per woman on average. Survival prospects are also projected to improve in all countries.

The UN report also points out that Sub-Saharan Africa will double by 2050.

More than half of the global population growth between now and 2050 is expected to occur in Africa.

Africa has the highest rate of population growth among major areas, growing at a pace of 2.55 percent annually in 2010-2015.

A rapid population increase in Africa is anticipated even if there is a substantial reduction of fertility levels in the near future. 

Regardless of the uncertainty surrounding future trends in fertility in Africa, the large number of young people currently on the continent, who will reach adulthood in the coming years and have children of their own, ensures that the region will play a central role in shaping the size and distribution of the world’s population over the coming decades.

Asia is projected to be the second largest contributor to future global population growth, adding 0.9 billion people between 2015 and 2050.

In sharp contrast, the populations of 48 countries or areas in the world are expected to decrease between 2015 and 2050.

Several countries are expected to see their populations decline by more than 15 percent by 2050, including Bosnia and Herzegovina, Bulgaria, Croatia, Hungary, Japan, Latvia, Lithuania, Republic of Moldova, Romania, Serbia, and Ukraine.

Fertility in all European countries is now below the level required for the full replacement of the population in the long run (around 2.1 children per woman), and in the majority of cases, fertility has been below the replacement level for several decades. (ILKHA)