Many fiction films about the dark future of humankind have come from a simple idea: Our population is growing so fast that the planet is exhausted because there is not enough space and resources to feed them all.
It sounds plausible at first, but a new study published in the Lancet suggests it’s not a probable scenario, at least in this century. According to the scientists’ prediction, as soon as the human population increases to a critical point, it will decline rapidly because the human birth rate will also decrease.
In addition to inherent aging, some countries like Japan and Italy can reduce their population by half. This decrease will solve the burden placed on the planet’s food system and resources. But on the other hand, it will also entail many uncertainties including a decline in the workforce, the burden of insurance and health care due to taking care of an older population, while having fewer taxpayers.
It is difficult to know what a period of such population decline will cause. But scientists say it is possible that our generation will be witnesses to that period. By most likely it will start happening in 2064.
The study was conducted by scientists from the Institute of Health Measurement and Evaluation (IHME) and the University of Washington, USA. In particular, they used the data obtained in the 2017 Global Disease Research project to assess the speed and characteristics of population movements across the planet.
The results show that from now until 2064, the population will continue to increase from 7.8 billion to 9.7 billion. But then, our population will slow down before falling to 8.8 billion people at the end of the decade.
This scenario is completely different from many previous estimates, which say the human population will increase continuously until it reaches 12.3 billion by 2100 without a leveling off. So which research should we believe in?
To be able to assess which scenario predicts more accurately, we have to look at the mathematical tools they are used. Projections of steady population growth without a stop are usually based only on the total fertility rate of women, that is, the number of children a woman can produce in her lifetime.
However, the new study on Lancet uses a different method of cohort fertility – the average number of children a woman has in a given population by the age of 50. This calculation can determine the population of each region of the world, based on each population.
This new calculation clearly gives us more variables and results to draw a more accurate population growth model for the whole world. It even allows scientists to estimate how migration patterns affect the population growth trajectory of each country.
For example, sub-Saharan African countries currently have a cohort fertility of 4.7 births per woman. But the number is estimated to decline in 2010. Based on the trend, in 2017, Nigeria held a record in fertility with 7 births per mother. Under the new model, that number will fall to 1.8 by 2100.
In other places, cohort fertility is causing a more significant population decline. For example, Japan’s population may decline from 128 million in 2017 to 60 million by 2100. Even China’s population may fall below one billion by the end of the century, estimated to be more than 730 million.
The year in which countries face fertility rates is not enough to replace the lost population.
Population decline can have many major impacts. For example, the Chinese economy is expected to surpass the United States in gross domestic product. But if their working-age population drops as expected, economic growth will slow down.
The United States could return to its leading position after 2100, if it was able to maintain its population through immigration rather than fertility.
“For high-income countries with fertility below the ability to replace the aging population, the best solution to maintain the current population level, to keep economic growth and geopolitical security is to expand the import policy. and social policies to support families giving birth “, IHME director Christopher Murray said.
However, population maintenance is not the only challenge in this scenario. If what scientists predict is true, after the 1950s, the proportion of the population over 80 years old will begin to explode and increase to 6 times the current level.
This is not only a social challenge, but also a challenge for the health system and insurance. The distribution of labor and wealth in an aging population society also suffers from instability.
The researchers said the population reduction scenario they built was a timely warning to policymakers. Although it does not cause an apocalyptic vision like the ever-increasing population of the planet, the aging and declining population process also poses new problems for humanity and the current economy. our.
Watching and preparing for it is still the best way that mankind can do right now. We have learned from the COVID-19 pandemic, that without preparedness for the future, the consequences of any global upheaval can be devastating.