The world's population is projected to reach 11.2 billion by the turn of the next century, according to a new UN report published on Wednesday.
The current population of 7.6 billion is projected to reach around 9.8 billion by 2050 and keep on rising, with roughly 83 million people being added to the population each year.
Matthew Wells reports.
The latest World Population Prospects from the UN Department of Economic and Social Affairs (DESA) provides a comprehensive review of global demographic trends and prospects for the future.
From now until 2050, it's expected that half of the world's population growth will be concentrated in just nine countries: India, Nigeria, the Democratic Republic of the Congo, Pakistan, Ethiopia, Tanzania, the United States, Uganda and Indonesia.
In roughly seven years, India is expected to overtake China, while the two countries combined represent 37 per cent of the global population.
Between 2017 and 2050, the populations of 26 African countries are expected to at least double their current size.
Fertility has declined in nearly all regions of the world, according to the UN projection, even in Africa.
The report highlights that a reduction in fertility levels results not only in a slower pace of growth, but an increasingly elderly population.
The number of people aged 60 and above is expected to more than double by 2050, and more than triple by 2100.
Presenting the report at UN Headquarters, Director of the Population Division at DESA, John Wilmoth, said in the developing world. where the young far outnumber other generations currently, healthcare and education issues were a major challenge.
But there will also be opportunities later, he said.
"It creates this opportunity for what we call a demographic dividend, when there's this period of time over the course of this transition when the working-age population tends to be unusually large, before population ageing advances very far which creates opportunity for rapid growth and development. But it requires the investment up front, in the capacities of young people."
The report also notes there have been big gains in life expectancy.
In 2005, it was 65 years for men and 69 for women. By 2015 it was 69 for men, and 73 years for women.
Source: United Nations Radio