World population to peak and decline sooner than previously thought

The latest update of the UN’s World Population Prospects confirms we are now in sight of a time when the human population will cease to grow and be in ongoing decline.

In its 2017 update, the UN projected the world’s population would reach 11.2 billion in 2100 and still be growing. The 2019 revision indicated the world’s population may peak at 10.9 billion by 2100. The latest revision indicates the world’s population may peak at 10.4 billion by 2080.

The UN’s World Population Prospects indicates the world’s population may peak at 10.4 billion by 2080.Credit: Jacob Ammentorp Lund

In other words, the UN has reduced its projected peak world population by about 800 million and brought forward the date for this peak by 20 years.

The UN’s projections are now much closer to those by researchers at the University of Washington, who suggested two years ago that the human population would peak at significantly less than 10 billion by 2065, decline to less than 9 billion by 2100 and keep declining – the current world population is about 8 billion.

The UN projections are higher largely due to an assumption that fertility rates in low fertility nations such as China and Japan will gradually rebound.

Low fertility is predominantly the function of two major changes that started in the 1960s – increasing availability of affordable contraception and the rising education of girls.

The world’s fertility rate has fallen from five births per woman in 1950 to 2.3 births per woman today.Credit: iStock

The world’s fertility rate has fallen from five births per woman in 1950 to 2.3 births per woman today. This is projected by the UN to fall to the replacement level of 2.1 births per woman by 2050 if not substantially earlier.

The human population will keep growing after that because of the current youthful age structure in 46 less-developed nations. These nations, particularly in Sub-Saharan Africa, will have rapidly growing working age populations for many decades. Sub-Saharan Africa is projected to become the most populous region of the world by the late 2060s surpassing both China and India.

By contrast, the combination of an older age structure and below replacement fertility will result in the populations of more than 60 mainly developed nations declining by at least 1 per cent by 2050 – many are projected to shrink by more than 20 per cent by 2050.

Major economies such as the enlarged European Union, China, Russia and Japan will go into population decline this decade if they haven’t already.

Their older age structure, very low fertility rates and limited immigration makes this inevitable.

The share of the global population aged 65 or more is projected to increase from 10 per cent or 770 million in 2022 to 16 per cent or 1.6 billion in 2050.

The portion of the elderly populations of most developed nations are already larger than this and will grow more quickly. Ageing will slow briefly in developed nations during the 2030s as deaths rapidly outnumber births but it will resume after that.

The world’s most populous country, China, is projected to see its population almost halve by the end of this century with almost 50 per cent of its population aged 65 or over.

The share of the global population aged 65 or more is projected to increase from 10 per cent or 770 million in 2022 to 16 per cent or 1.6 billion in 2050.Credit: Rob Homer

There will be periods over the next two decades when the Chinese population will be shrinking by over 15 million per annum.

Despite now having a below replacement fertility rate, India’s population is projected to keep growing well past 2050 due to its youthful age structure.

The big contrast are traditional migrant settler nations such as the United States, Canada, Australia and New Zealand whose populations are projected to keep growing well into the second half of this century.

This is predominantly a function of ongoing immigration that has slowed the rate of ageing in these nations and pushed out the point in time that deaths will exceed births.

This provides these nations more time to make the transition to an older and slower-growing population.

Australia also has one of the world’s highest life expectancies at birth and at age 65. By contrast, life expectancy in the US has been in decline for a number of years. This decline accelerated during the pandemic.

All other things equal, a declining world population is good news for the environment, although it may only be of marginal benefit to limiting greenhouse gas emissions.

But significant population ageing and eventual population decline have major implications for both economic and social policy.

The slow speed at which demographic change affects nations unfortunately results in governments giving these issues little attention until very late.

The current crisis in our health and aged care systems is one consequence of this neglect of an ageing population.

Stagnating and eventually shrinking economies with massive government debts in developed nations, plus China and Russia, will be a long-term feature of population ageing and decline.

We need to start better preparing for this.

The federal government could start by helping Australians better understand the consequences of an ageing population for our labour force and immigration arrangements at Prime Minister Anthony Albanese’s upcoming jobs summit.