It hasn’t started happening yet, but the trend seems unstoppable: humanity is shrinking. By 2050, over three-quarters (155 out of 204) of the world’s countries will have fertility rates so low that they will not be able to maintain their population size. And this trend will be nearly complete by 2100, when 97% of countries (198 out of 204) will be in the same situation. Deaths will outnumber births, and there will be fewer and fewer people in the world.

This data comes from the Institute for Health Metrics and Evaluation and was published in the journal The Lancet. The authors warn governments to start planning for the threats that these changes may pose to the economy, health, the environment and geopolitics.

On November 15, 2022, the world’s population reached an unprecedented 8 billion people, but according to this study, that could be the peak before the curve bends and the population begins to decline. This is a global trend, but the pace differs from area to area. In rich countries, where fertility rates are already very low, rates will continue to decline.

Spain is an eloquent example of this trend. According to the study, Spain had a rate of 2.47 children per woman in 1950, which fell to 2.13 in 1980 and plummeted to 1.26 in 2021. If things continue this way, the rate will be 1.23 children per woman in 2050 and 1.11 in 2100. It is one of the countries with the steepest declines; by that year France (1.49), Germany (1.40) and the European average (1.37) will all be above that rate. The trend aligns with the one reported by Spain’s National Institute of Statistics, which last year recorded an all-time low in births in the country. 2023 was the seventh consecutive year in which Spain recorded more deaths than births, with a difference of 113,256 people.

Low-income environments follow the same trend, but start from a very different reality, with much higher birth rates. That is the only way to explain their importance in the total percentage of world births, which will nearly double in the coming years. They will go from representing 18% of the total in 2021 to 35% in 2100. In 2100, one out of every two children born in the world will be born in sub-Saharan Africa.

The study’s authors believe that, from a Western perspective, this trend can be seen as a way to sustain pensions, the labor force and demographic stability. And they conclude that it is a stopgap solution. “International migration can only be a temporary solution, as fertility decline is becoming a universal phenomenon.” Birth rates in developing countries are higher, but in the future, better access to contraceptives and female education will reduce them. The problem is not only demographic but multifactorial. Mariona Lozano Riera, a sociologist and researcher at the Centre d’Estudis Demogràfics de Catalunya, elaborates on this idea in an editorial on the subject published by Science Media Centre Spain (SMC). “It is true that the demographics are not very good for sustaining the current pension system, but that is not the reason; rather, the lack of political action and the structural conditions of the Spanish labor market are aggravating the problem,” she asserts.

The sociologist notes that the projected demographic trends are already causing changes. But she refrains from being alarmist. “I wouldn’t dare say that the welfare state is in danger in the sense that it will disappear,” she says. “But there will certainly be a change[…] In fact, there is already a silent transformation toward models in which everyone receives the same pension, and the extras depend on private pension plans or those established by collective agreements.”

This is not the only reaction SCM has published on the subject. In another paper, Teresa Castro Martín, a sociologist at the Spanish National Research Council (CSIC), observes that in 2020 the team behind this study received “some criticism from demographers for methodological inconsistencies.” Even so, the expert recognizes that the data it offers illustrates the global trends well. Castro underscores some of the differences between that research and other analyses. “This study estimates a decline in fertility worldwide, especially in sub-Saharan Africa, at a faster rate than the United Nations [study found],” she says. The current study predicts that the global fertility rate will fall below replacement level (2.1 children per woman) around 2030, “while the UN forecasts that this will occur around 2050.″

The researcher points out that births “will increasingly be concentrated in the areas of the world that are most vulnerable to climate change, resource scarcity, political instability, poverty and infant mortality.” Finally, she laments that the large group of experts who conducted the study did not include any specialists in the field of reproduction.

The study did not involve experts like Sara López, a gynecologist at the Center for Infertility and Human Reproduction (CIRH) in Barcelona, Spain, and author of the book Quiero quedarme embarazada [I Want to Get Pregnant]. Lopez confirms that the study points to macro trends that she sees daily at the micro level in her practice. “In Spain, the number of women who have their first child after the age of 40 has quadrupled,” she explains in a telephone conversation. That is 10% of the total and this advanced maternal age leads to a decrease in the birth rate for obvious reasons: “At that age, it may be too late to have children, or you may not be able to have more than one.”

Of possible solutions, Lopez explains that “promoting social policies, economic aid and work-life balance” are conducive to higher birth rates. She also notes that science, such as freezing eggs, has helped many women and will continue to do so. “But I think this is an individual solution and we should tend to look for a collective solution.” In any case, she does not believe that this should be approached as a positive or negative thing and observes that the problem occurs when a person’s reproductive aspirations are thwarted by extraneous causes like a lack of stability or support.

In an associated editorial, the study’s authors also reflect on the implications of this trend. They recommend that policymakers direct efforts toward analyzing “the causes of the decline in fertility, not just its consequences,” and they warn against a response that erodes women’s rights: “When talking about the decline in fertility, there is a risk that some countries will adopt measures that encourage childbearing and restrict rights related to sex and reproduction, including the right to choose whether or not to have a child, the timing of pregnancy, and access to sexual knowledge and assistance,” the authors lament. They go on to recommend that any policy response should be based on guaranteeing rights.

In recent years, different world leaders have tried to connect low birth rates to the right to abortion. The study calls for analyzing the causes of the decline in birth rate and facilitating the reproductive and family projects of those who want to have children, but that should not serve as an excuse to limit the rights of anyone else.

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