Almost all countries will have smaller populations by the end of the century, a major study warned on Wednesday, as baby booms in developing countries and busts in rich countries drive lifestyle changes.
Scientists have tried to predict the future of the world’s population using large amounts of global data on births, deaths and fertility rates.
According to research by the US-based Institute for Health Metrics and Evaluation (IHME), by 2050, three-quarters of the population of all countries will decrease.
By the end of the century, 97 percent, or 198 out of 204 countries and regions, will do so, according to researchers.
According to the study, only Samoa, Somalia, Tonga, Niger, Chad and Tajikistan are expected to have a fertility rate higher than 2.1 births per woman in 2100.
Through this century, birth rates will increase in developing countries, especially in sub-Saharan Africa, although they will decrease in rich and old countries.
The results are huge.”
“We are facing surprising social changes in the 21st century,” he said.
IHME researcher Natalya Bhattacharjee said the “results are amazing”.
However, experts from the World Health Organization urged caution in the forecast.
They noted several limitations of the model, particularly the lack of data for many developing countries.
Communication about the numbers “must be a balance between gloom and optimism, not sensationalism,” World Health Organization experts wrote in The Lancet.
It also suggests that smaller populations can be beneficial for the environment and food security. However, there are weaknesses such as labor supply, social security and “nationalist geopolitics”.
Teresa Castro Martin, a researcher at Spain’s National Research Council, who was not involved in the work, said this was just speculation.
The Lancet study found that the global birth rate will fall below replacement level by 2030, “while the World Health Organization predicts this will happen in 2050.”
This study is an update to the IHME Global Burden of Disease Study. Founded by the Bill and Melinda Gates Foundation at the University of Washington, the organization has become a global reference for health statistics.
