Cosmos
Cosmos is a quarterly science magazine. We aim to inspire curiosity in ‘The Science of Everything’ and make the world of science accessible to everyone.
By Cosmos
The world is facing a fertility rates crisis according to a series of newly published articles in the influential medical journal The Lancet, which suggest “dramatic declines” in global fertility will transform populations by the end of the century.
The data used to make the claims shows that, by 2050, more than three-quarters (155 of 204) of countries will not have high enough fertility rates to sustain population size over time. This will increase to all but 6 countries by 2100.
In general, countries need to have a total fertility rate (TFR) of 2.1 children per fertile person to sustain long-term generational replacement.
The article draws on new methods for forecasting mortality, fertility, and key drivers of fertility, including level of education, unmet need for modern contraception, child mortality, and living in urban areas.
The article is aimed at policymakers, saying: “…populations will shrink unless low fertility can be offset by ethical and effective immigration. The extent of low fertility may also be mitigated in part by policies that offer greater support for parents”.
Fertility rates: global population will slow
Fertility outcomes, they say, will transform global patterns of migration.
In 2021, more than a quarter of the world’s babies were born in sub-Saharan Africa. By 2100, this is projected to rise to more than half.
In an accompanying news release senior author Professor Stein Emil Vollset from Institute for Health Metrics and Evaluation (IHME) says “we are facing staggering social change through the 21st century”.
“The world will be simultaneously tackling a ‘baby boom’ in some countries and a ‘baby bust’ in others.
“As most of the world contends with the serious challenges to the economic growth of a shrinking workforce and how to care for and pay for ageing populations, many of the most resource-limited countries in sub-Saharan Africa will be grappling with how to support the youngest, fastest-growing population on the planet in some of the most politically and economically unstable, heat-stressed, and health system-strained places on earth.”
The global fertility rate has more than halved over the past 70 years, from around 5 children for each female in 1950 to 2.2 children in 2021. (See data which does not form part of The Lancet article, from World Bank above.)
South Korea and Serbia’s fertility rate is less than 1.1 child for each female.
In the research from the IHME, which is based at the University of Washington’s School of Medicine, the authors write that “over the coming decades, global fertility is predicted to decline even further, reaching around 1.8 in 2050, and 1.6 in 2100 – well below replacement level.
“By 2100, only 6 of 204 countries and territories (Samoa, Somalia, Tonga, Niger, Chad, and Tajikistan) are expected to have fertility rates exceeding 2.1 births per female. In 13 countries, including Bhutan, Bangladesh, Nepal, and Saudi Arabia, rates are even predicted to fall below one child per female.”
Recent data to 2021 from the World Bank backs up the findings.
