We Will Soon See a Decline in the World Population and We Must Prepare for it, Says Study

A new study published in the scientific journal The Lancet shows that births around the world will not be able to exceed the number of deaths, leading to a gradual reduction in the world's population. Know the details in detail.

Population, births.
The world population will experience a decline, as births cannot exceed deaths.

The study of fertility is fundamental to solving the geopolitical, environmental, economic and social challenges caused by changes in population age trends and migration. They impact policies that address resource and healthcare needs, education, labor supply, family planning and gender equality. The problem lies in our planet's ability to provide the necessary resources that guarantee the survival and well-being of the global population, including vital aspects such as access to drinking water, nutritious food, sustainable energy and waste management, among others.

Accurate estimates and future predictions of fertility rates and their impact on population age structures are therefore essential to anticipate potential economic and geopolitical consequences, and to inform the development of effective health, environmental and economic policies.

There was particularly rapid population growth in the 19th centuries, where unprecedented population growth was witnessed. The 20th saw the most significant population explosion in the history of Humanity was experienced. In the 21st century where we surpass the 8,000 million threshold, the scenario will begin to change.

According to data from the Institute for Health Metrics and Evaluation (IHME) at the University of Washington, published in the scientific journal The Lancet, a significant demographic change is expected in the coming years, a decline in the world population.

In the current study, researchers explored global fertility trends in 204 countries between 1950 and 2021, with predictions for 2100. Researchers analysed data from the Global Burden of Diseases, Injuries, and Risk Factors Study 2021, from IHME, which show current and future regional, national and global trends in fertility and live births.

World population decline.
A scientific study points to a reduction in the world's population, which suggests several side effects.

Fertility rates: can they sustain population size?

In general, countries need to have a fertility rate of 2.1. This means that the minimum limit for generation renewal is at least 2.1 children per woman. Now, the study shows that global fertility rates are decreasing, with more than half of all countries in 2021 recording rates below the renewal level. This trend, observed since 2000, reveals significant variations in the rate of decline, with only a few countries showing a small recovery.

The study predicts that by 2050, more than three-quarters of countries will not have fertility rates high enough to sustain their population size over time. By 2100, this number will increase to 97% of countries, which is unsustainable for population renewal.

This means that, in these places, populations will decline unless low fertility is compensated by effective immigration or policies that offer greater birth support. Between 1950 and 2021, the global fertility rate fell by more than half, from 4.8 to 2.2 children.

The global annual number of live births peaked at 142 million in 2016, falling to 129 million in 2021. Fertility rates have fallen in every nation over the past 70 years. In 1950, this rate was about five children for each woman. In 2021, it rose to 2.2 children per woman. The trend is particularly worrying in South Korea and Serbia, where the rate is less than 1.1 children. In Chad, the fertility rate is the highest in the world, with seven births per woman.

We are facing surprising social changes throughout the 21st century (…) the world will simultaneously face a 'baby boom' in some countries and a 'baby bust' in others." Emil Vollset Stein, professor at IHME and co-author of the study.

The new study predicts major changes in the global pattern of live births between developed and developing countries. In 2021, 29% of the world's babies were born in Sub-Saharan Africa. According to the analysis, the estimate is that this number will increase by more than half (54%) by 2100.

According to forecasts, the list of nations with fertility rates above renewal will fall from 24% in 2050 to 2.90% in 2100, which would result in a global rate of 1.6 children. It is estimated that only 26 countries will continue to experience population growth in 2100, with the number of newborns exceeding the number of deaths, as is the case in Angola, Zambia and Uganda.

A new planet?

In theory, the decline in the world's population appears to be good news. The problem is that population decline also brings other side effects that must be addressed, namely at an age level and, consequently, economic, health, environmental and geopolitical.

Low fertility levels have the potential to result, over time, in inverted population pyramids, with a growing number of older people and a decreasing working-age population. It is, therefore, essential to think about potential threats to global economies, since a decreasing population, in theory, translates into a reduced workforce, which affects productivity and economic growth.

Likewise, health systems must adapt to the ageing of the population, which will imply greater demands for long-term care and an increase in the prevalence of age-related diseases. With regard to the environment, although the decline in the global population will, in theory, result in lighter pressure on natural resources, it is also crucial to consider how changes in population distribution can impact the management of these resources and biodiversity.

In the geopolitical scenario, new power dynamics must be considered, which can change significantly with variations in the size and structure of countries' populations. This could reconfigure alliances, zones of influence and priorities in international politics.

Reference of the news:

GBD 2021 Fertility and Forecasting Collaborators (2024). Global fertility in 204 countries and territories, 1950–2021, with forecasts to 2100: a comprehensive demographic analysis for the Global Burden of Disease Study 2021. The Lancet.