The age demographic of the world we are living in is changing at a dramatic rate unprecedented in human history. This will have widespread implications for future generations.
As fertility declines and life expectancy rises, the proportion of the population above a certain age rises. This phenomenon, known as population ageing, is occurring throughout the world.
In 1950, the median age in the developed World was 29. This is expected to reach 46 by 2050. This is a permanent change and will have dramatic implications on the economy and social structure.
The ageing population is the result of two factors: people having less children and people living longer. With fewer babies being born, and more people living longer, it is inevitable that the population will get progressively older.
People are having less children. Fertility decline has been the largest contributing factor to our ageing population. Low birth rates largely reflect increased choices available to women, including access to birth control, access to education and employment, and higher living standards.
The total fertility rate of a population is the average number of children born to a woman in her lifetime. This assumes that she survives from birth through to the end of her reproductive life.
Replacement level fertility is the number of babies a female would need to have over her reproductive life to replace both herself and her partner. The global average is 2.1.
Fertility is well below the replacement level in all developed regions of the world. It is estimated that 48 per cent of the world’s population live in “low-fertility” countries, where women have fewer than 2.1 children on average over their lifetimes.
Low-fertility countries now include all of Europe except Iceland, plus 19 countries of Asia, 17 in the Americas, two in Africa and one in Oceania. The largest low-fertility countries are China, the United States, Brazil, the Russian Federation, Japan and Viet Nam.
Fertility decline in the less developed regions of the world started later but is occurring at a much faster rate than was the case for the developed world. This means they will have a much briefer opportunity to prepare for an older population.
People are living longer. The chances of surviving to old age has improved dramatically in the past century - in fact the 20th century witnessed the most rapid decline in mortality in human history.
Over the past 50 years, global life expectancy has increased by almost 20 years, from 47 years in 1950-1955 to 69 years in 2005-2010.
By 2050, life expectancy is expected to have risen to 82 years in the developed regions of the world and 75 years in less developed regions.
in 2011 (years)
Red indicates that the number of children born per woman is below the replacement rate of 2.1
Population ageing will present widespread implications for future generations.
Read more: Implications of an Ageing Population