Pakistan, whose total population is approximately 220.9 million, is among the top two fastest growing countries in the South Asian region with an annual fertility rate of 3.6 children per couple, according to a new report by a US-based private non-profit organisation.
Strife-torn Afghanistan topped the chart among the South Asian countries with 4.5 children per couple, according to the 2020 World Population Data Sheet released recently by the US Population Reference Bureau.
With 1.4 billion people, India has the second largest population in the world but has reduced its fertility rate to 2.2, it said in a recent report.
At Pakistan's growth rate -- 3.6 -- a population doubles in 19.4 years. A country needs to bring its growth rate down to 2 per cent a year to reduce its population. The replacement fertility rate is 2.1, the average number of children a couple needs to have to replace themselves, the Dawn News reported citing the study.
According to the study, South Asia is among the fastest growing regions in the world. Within the region, it marked Afghanistan and Pakistan as the fastest growing populations.
Afghanistan has a faster growth rate than Pakistan, 4.5 per couple. But because of high death rates and low life expectancy, the country's total population is still 38.9 million, the report noted.
The total population of Bangladesh, another South Asian country, in 2020 is estimated at 169.8 million, with an annual fertility rate of 2.3. It the third fastest growing nation in the region, followed by Maldives at fourth position, India and Nepal at fifth and Sri Lanka and Bhutan sharing the last slot.
The study noted Asia as the world's most populous region and its overall population is projected to increase by 15 per cent - from 4.6 billion in 2020 to 5.3 billion in 2050.
However, the pattern of future population change varies within the region from a 3 per cent decline in East Asia to a 38 per cent increase in Western Asia. Asia's total fertility rate is below replacement level at 2.0.
Interestingly, the report projected China's population, currently the highest in the world, to decrease by 2050.
With a total of 1.424 billion people, China still has the largest population in the world but has been able to reduce its fertility rate to 1.5, the study noted.
The US has 329.9 million population and between 2020 and 2050 its population is projected to increase, but at a much slower pace than recent decades. The US has an annual fertility rate of 1.7, which forces it to allow immigrants to strengthen its work force.
The data estimate the current global population at 7.8 billion. People aged 65 and above account for 9 per cent of the global population, in part because of the declining fertility rates, the report said.
According to the report Middle Africa is the youngest region where 46 per cent of the population is under the age of 15 years, while Southern Europe is the world's oldest region with 23 per cent of the population aged 65 or above.
The world population is projected to reach 9.9 billion by 2050, an increase of more than 25% from 2020.
"In 91 countries and territories, nearly 45 per cent of the world's population, total fertility rates are below replacement level, the average number of children at which a population exactly replaces itself from one generation to the next in the absence of migration.
And in 21 countries and territories, including several that have suffered devastating loss during the COVID-19 pandemic, people ages 65 and older account for at least 20 per cent of the population," it said.
This trend is most pronounced in Europe and East Asia. In contrast, many countries in sub-Saharan Africa and some in Asia continue to experience rapid population growth and high fertility rates. The population of 25 countries is expected to at least double between 2020 and 2050.
The global total fertility rate is 2.3 births per woman, while the replacement level is 2.1 births per woman, the report said.
Referring to the coronavirus crisis, the report warned that "population density in urban areas, household size, and population aging contribute to our vulnerability to pandemics".