Population Change and Ageing

In short: People are living longer and having fewer children. The world population, now about 8.2 billion, is expected to peak at around 10.3 billion in the 2080s and then slowly fall. Many countries are already ageing fast. This changes who does the work, who needs care, how pensions are paid for, and why migration matters.

The Question

Most of the forces in this section are about technology and the planet. This one is about people themselves: how is the make-up of the population changing, and what does that mean for society?

Two Big Changes

• Longer lives: worldwide life expectancy has more than doubled since 1900. That is one of humanity’s greatest successes.
• Fewer children: the average woman in the world now has about 2.2 children, compared with about 5 in 1960. In much of Europe and East Asia it is between about 1.0 and 1.6, well below the 2.1 needed to keep a population stable without migration. South Korea is the lowest in the world, at 0.75 in 2024.

Put together, these mean the population is getting older. The United Nations expects that by the late 2070s there will be more people over 65 in the world than children under 18.

Big Differences Between Regions

• Europe, East Asia and North America are ageing fastest. Some, like Japan and Italy, are already shrinking.
• Sub-Saharan Africa is still young and growing fast. More than half of the growth in world population until 2050 is expected there.

This contrast is one reason migration will matter more and more. See Managing Regional Migration.

What It Changes

• Care: more older people need care, while families are smaller and more women work outside the home. See the care example in Who Keeps Society Running?.
• Pensions and health costs: fewer working-age people pay in for each retired person. In the European Union, there are now about three people of working age for every person over 65, and that is expected to fall towards two by 2050.
• Work: some sectors already lack workers, from nursing to building. Automation may help fill the gap. See Enhanced Automation.
• The planet: a population that peaks and then falls eases some pressure on resources over the long run, though how much we each consume matters more than how many we are.

Examples

• Japan: almost three in ten people are over 65. Japan uses robots in care homes, encourages older people to keep working, and has slowly opened up to more foreign workers.
• Raising the pension age: many European countries have linked the pension age to life expectancy, so that it rises as people live longer. It eases the costs, but is often unpopular, especially for people in physically hard jobs.

The Human Side

Longer lives are a gift, if those years are healthy and connected. Loneliness among older people is a growing problem, and many people want to keep contributing long after retirement age. At the same time, many young adults would like more children than they have, but are held back by housing costs, insecure jobs or lack of childcare. See Connection and loneliness in the Personal Guide.

Open Questions

• How should the cost of an ageing society be shared between generations?
• Should societies try to raise birth rates, and if so, how, without pressuring anyone?
• How can care for older people be both affordable and humane?

Where Next

• Previous: Managing Regional Migration
• Next: Enhanced Automation
• Related: Social Redistribution, Life After Automation

Sources

• United Nations, World Population Prospects 2024
• Eurostat, old-age dependency ratio data
• OECD, Pensions at a Glance (2023)
• Statistics Korea, births and fertility statistics (2024)
• Our World in Data, “Population Growth” and “Fertility Rate”