The world's regions are all growing at different rates and many of the fastest growing nations are the ones which are among the poorest, according to the United Nations World Population Prospects 2019 .
Many poor nations also have higher rates of population density, thereby putting more pressure on resources like land and water. This also means that achieving Sustainable Development Goals like equality and eradication of poverty is tougher.
At the other end of the spectrum, 27 countries or areas have experienced a reduction in the size of their populations (1% or more) since 2010. This is due to low levels of fertility and, in some places, high rates of emigration (Syria, for instance).
Overall, the world’s population is projected to grow from 7.7 billion in 2019 to 8.5 billion in 2030 (10% rise). In 2020, the world's population will be three times what it was in 1950. India and China alone account for 36% of the world's population.
While China's population growth has been steadily declining due to the strict implementation of the one-child policy, India's population has been constantly on the rise, and the gap between the two has been narrowing.
In 1950, the population gap between the giant Asian neighbours was about 17 crore. In 2020, the gap will be just six crore people; in a matter of eight years, India is set to overtake China and become the world's most populous nation.
The animated bar chart below shows the ten countries with the highest population since 1950. Notice how the gap between India and China steadily decreases, while that of Japan's also falls. Japan is set to be replaced by Mexico among the top 10.
In regional terms, Africa has seen a tremendous increase in population (almost six-fold), while Europe has seen the smallest rise. Latin America, the Caribbean and Asia are the other regions that have seen a three-fold growth in the past 70 years.
In terms of population density too, African nations pack a far larger number of people per square kilometre compared to other regions -- nearly 150 persons per sq. km., compared to the global average of 60. High population density in countries like Burundi and Ethiopia puts additional strain on resources like land and water.
The chart below plots the growth rate in population between 2010 and 2020 (vertical axis) against the population density (vertical axis). The colours indicate regions. As can be seen from the chart, African nations have higher growth rates, and several of them have higher than average population densities.
