The aging population is now the largest in human history. The United Nations expects the rate of population ageing in the twenty-first century to exceed that of the previous century.
Figures from World Population Prospects: the 2019 Revision show that by 2050, 1 in 6 people worldwide will be aged 65 years (16%) or older, compared with 11 (9%) in 2019; and by 2050, 1 in 4 people in Europe and North America will be aged 65 years or older.
In 2018, for the first time ever, the number of people aged 65 or over exceeded the number of people under five globally. In addition, the number of people aged 80 or older is expected to triple, from 143 million in 2019 to 426 million in 2050.
Population aging is a phenomenon in which the distribution of a country's population is skewed toward higher ages. This is usually reflected in the average and median age of the population, with a declining proportion of children and a rising proportion of older people.
Population ageing is a worldwide phenomenon, occurring more frequently in developed countries but recently beginning to surface in developing countries as well. The trend is accelerating in developing regions, meaning that older people will be concentrated in developing regions. The Oxford Institute for Population Ageing believes that population ageing, which has slowed down in Europe, will have a huge impact in Asia in the future, especially in those Asian countries that are in demographic transition mode five.
In the developed countries currently recognized by the United Nations, which had a total population of 1.2 billion in 2005, the overall median age rose from 28 in 1950 to 40 in 2010, and is expected to be 44 in 2050. The corresponding values for the world are 24 years in 1950, 29 years in 2010 and 36 years in 2050. For developing regions, the median age is expected to rise from 26 years in 2010 to 35 years in 2050.
Global aging
Asia and Africa are the two regions with the highest number of countries facing aging populations. within 20 years, many of the countries in these regions will be faced with the largest number of people over the age of 65 and an average age approaching 50 years. According to research led by the University of Washington, 2.4 billion people will be over the age of 65 in 2100, compared with 1.7 billion under the age of 20.
The Oxford Institute for Population Ageing is a study of global population ageing. Its research suggests that many ideas about global aging are based on myths, and that the world will have considerable opportunities as the population matures, as the Institute's director, professor-like Sarah Harper, emphasizes in her book The Aging Society.
Most developed countries now have below-replacement fertility rates, and much of the population growth now depends on migration and population growth momentum, which also comes from the fact that previous generations now enjoy longer life expectancy.