The world population will decline from the second half of the century to reach $ 8.8 billion by 2100, 2 billion less than the projections of the UN, according to a study that predicts an upheaval in the balance of the world and within societies.
“It is a good news for the environment (less pressure on food production systems and less CO2 emission) “, tells theAFP Christopher Murray, director of the respected Institute for Health Metrics and Evaluation (IHME) in Seattle, who led the study published Wednesday in The Lancet.
But ” the inversion of the age pyramid will have far-reaching consequences and negative on the economy and the organization of families, communities and societies “, says he. Even if these projections are not “carved in stone” and that changes in policy might alter the trajectories of the different countries.
According to the latest UN report on the world population, the Earth should be 9.7 billion people in 2050 and 10.9 billion in 2100, compared with 7.7 billion currently.
But the new study challenges this growth continues throughout the Twenty-first century.
Researchers at the IHME, which is funded by the Bill and Melinda Gates foundation, which is a reference for its global studies in public health, predict a peak from 2064, to 9.7 billion people, before a decline of up to 8.8 billion in 2100.
The decline in Europe
This decline will be linked in large part to the development of girls ‘ education and access to contraception will lower the fertility rate to 1.66 children per woman in 2100, against of 2.37 today, according to the study. A falling fertility rate much faster than what is stipulated in the united nations.
In 183 countries out of the 195 studied, this rate would fall by 2100 under the 2.1 children per woman to maintain the population without the contribution of immigration.
But the demographic development, also integrating the mortality and migration, will vary according to regions and countries, according to the researchers. They anticipate a possible redistribution of the cards of economic and geopolitical, even if the power of a State does not necessarily reduce to the single size of its population.
Thus, China could lose nearly half of its population (1.4 billion today, 730 million in 2100), with a decline in the number of people of working age who is going to “impede” economic growth.
The United States, called to soon be lost their place as the world’s largest economy, could iron in front of the China by the end of the century, if immigration continues to reverse the fertility decline, according to the study.
Asia and Europe are expected to lose inhabitants. They are home to a large portion of the 23 countries that are expected to see their population reduced by at least half: Japan (128 to 60 million), Thailand (71 to 35), Spain (46 to 23), Italy (61 to 31), Portugal (11 to 4.5), South Korea (53 to 27). Even if a few countries such as France are (65-to-67 million).
Rights of women
In contrast, sub-saharan Africa could see triple its population (1 to 3 billion), driven in particular by Nigeria (206 790 million people), which would, in 2100 the second most populated country in the world behind India, but ahead of China.
“This will truly be a New World, a world to which we should prepare today,” commented the editor-in-chief of the Lancet Richard Horton.
In this world where the working age population would have declined, but where the more than 80 years of age are six times more likely (141 to 866 million), it would be necessary to “re-evaluate the current structure of the systems of social assistance and health services,” insists Christopher Murray.
“The response to this decline of the populations at risk of becoming one of the key political concerns in many countries “, says in a statement his colleague Stein Emil Vollset. “But this should not undermine efforts to improve the reproductive health of women or the progress of women’s rights “, he insists.
To change the demographic trajectory, they evoke the opposite of the “social policies” to help the women to work while having the number of children they want.
But also of the “immigration policies” liberal “. “We believe that later in the century, the countries that need migrant workers will have to compete to attract these migrants,” which should come primarily from sub-saharan Africa and the arab world, says Christopher Murray.