BRUSSELS (Pakistan Point News / Sputnik - 16th July, 2020) The findings of a fresh demographic study published in The Lancet, which estimated that the global population in 2100 could be two billion below UN estimates, raises many questions and concerns over how the world's economy will develop in this time given the regional discrepancies observed in the data, experts told Sputnik.
On Tuesday, the Institute for Health Metrics and Evaluation (IHME), which is based at the University of Washington in the United States and funded by the Bill & Melinda Gates Foundation, published a scientific article in The Lancet journal which revises many prior predictions over the size of the world's population.
Falling birth rates worldwide will see the populations of more than 20 countries, including Italy, Japan, Poland, and South Korea, halve by 2100. The total global population will stand at 8.8 billion by the end of the century, dropping from a peak of 9.7 billion in 2064. the researchers predicted.
The United Nations has previously estimated the world's population to stand at 10.9 billion by 2100.
According to the IHME researchers, Japan's population is expected to fall from 128 million in 2017 to 59.7 million at the end of the century, a fall of 53 percent.
The IHME also estimated that the number of people aged 80 years or more will jump from 141 million in 2017 to 866 million at the start of the 22nd century, which raises many questions over how social security systems will develop in the coming decades, particularly as the numbers of working-age people decline.
One of the Primary reasons for the predicted drop in population growth in many developed countries is the fall in the number of children being born, which IHME researchers said is often caused by increases in female educational attainment and access to contraception.
However, while developing countries may expect their population sizes to decline rapidly, the IHME estimated that the number of people living in sub-Saharan Africa will increase threefold over the next 80 years, which may potentially lead to significant shifts in the global economy.
The IHME's findings, to a certain extent, correspond with research conducted by the United Nations. Low fertility rates in European countries, which are often below the so-called replacement level of 2.1 births per woman, could see the region's population fall over the upcoming decades.
Demographer Bruno Masquelier, based at Belgium's UCLouvain University, told Sputnik that this recent study is the first time that the IHME has delved into this line of research.
"This is the first time that�Washington's Institute for Health Metrics and Evaluation has ventured into demographic and fertility studies. They are best known for their life expectancy studies and love the challenge. Their study differs quite markedly from the biennial United Nations study, in that they predict the peak of world population much earlier. The population replacement rate falls more sharply in their projections," Masquelier remarked.
The IHME researchers made several assumptions that human fertility is linked to both per capita income and educational attainment, particularly when it came to making comparisons across regions, Masquelier said, adding that these variables could be subject to change.
"For the IHME, the world population will level off faster and at a much lower level. But there are many unknowns in their calculations. They make per capita income assumptions (the higher the income, the fewer children there will be), on the education and work of women. These variables leave a great deal of uncertainty," the demographer said.
Fellow UCLouvain scholar Bruno Schoumaker, a professor of social sciences, told Sputnik that the IHME study does not reveal anything particularly groundbreaking.
"This American study does not reveal much. We have known for decades that fertility will drop, also in developing countries, and will stabilize. We know the evolution of the aging of the population, which will crumble a bit in the West, because of HIV and perhaps COVID-19, but which will create great tensions for the public health systems whose costs are on the rise," Schoumaker told Sputnik.
The professor shared Masquelier's concerns over the IHME's methodology, especially given the uncertainties and lack of accuracy that comes with making such long-term predictions.
"From a methodological standpoint, this is not complex but the uncertainty which accompanies long-term projections (up to 2100) is enormous. You have to take the announced results with tweezers; there are too many unknowns in the parameters measured," Schoumaker remarked.
These concerns may have their grounding in historical reality. In the 1960s, leading demographic experts, who were cited by the United Nations, estimated that the world's population would reach 6.5 billion by the year 2000. In fact, these forecasts proved to be seven percent too high.
The same research also predicted that the world's population would reach 11 billion by 2050. These figures have since been revised down, as in 2019, the UN said that it predicts the world to have 9.7 billion residents by this date, indicating the challenges in precisely predicting long-term demographic trends.
If the IHME's predictions end up becoming reality, the world may be a very different place by 2100. While birth rates and population sizes fall in Europe and many countries in Asia, Nigeria is predicted to become the world's second-largest country in terms of population.
As of 2017, women in sub-Saharan Africa were giving birth, on average, to 4.62 children. This rate is expected to begin falling dramatically in the 2030s and 2040s, although the impact it will have on population size will not be seen by the end of the century.
"For Africa, for example, the birth rate is very high and the population is young, hence the very high fertility. But will economic growth go to meet the cost of caring for these millions of children? Will the growth be sufficient?" UCLouvain demographer Masquelier said.
For African countries to sustain such a large population, significant economic development must take place, the demographer said, citing the example of South Korea, which became one of the world's great economic powers at the same time as the country's population doubled in size.
"There is a window of opportunity for these countries if they can, as South Korea has done, take off by coupling population growth with economic growth and give young people an adequate level of education," Masquelier remarked.
According to Schoumaker, the key to the world's future demographic trends lies in sub-Saharan Africa.
"It is true that the key questions for the world of tomorrow lie in sub-Saharan Africa where women still have 4.5 to 5 children, with no sign of weakening yet. We are far from fertility in the very developed and rich city-state of Singapore: 1.1 children per woman. This is one of the lowest figures in the world, but it is artificial, compared to neighboring Malaysia where the birth rate remains high," the professor of social sciences said.
Growing population sizes in Africa may raise a lot of concerns in the neighboring continent of Europe, which is already making a concerted effort to limit migration, particularly following the migrant crisis of 2015.
However, according to Masquelier, the bulk of African migration takes place within the continent itself, meaning that the impact felt in Europe will be less pronounced.
"Migration is a hot issue today and many in Europe fear invasion, but migration is primarily inter-African; south to south. If we find five percent of the population in Europe who would come from sub-Saharan Africa, this remains manageable without tensions, by managing urbanization well," Masquelier stated.
Demographers may try to predict the quantitative changes to the world's population, but what remains less clear is how society itself will change, Schoumaker indicated.
"We could see the world evolve very differently. What is certain, for example, is that contraceptive methods are widely available to everyone today. This has a very big impact on fertility: women choose their number of children and the age at which they will have them. While child mortality is falling sharply, couples are having fewer children in developing countries as well. Sanitary developments therefore also have an impact," he stated.
However, it does seem for certain that many countries across the world are going to be dealing with aging populations in the years to come, coupled with a drop in the number of productive members of the workforce, Masquelier stated.
"Europe, China and Japan are aging and must learn to live with a shrinking workforce, which will put social protection under pressure. It will not be easy," the demographer remarked.
Whether the peak in the world's population takes place in 2064, 2084, or 2104, it appears to be clear that the global landscape will change as we know it. It remains to be seen if the international community is ready for the shocks it will receive.
