July 11 is World Population Day—a day designated annually by the United Nations that should prompt us, in the words of the International Institute for Sustainable Development, to “focus attention on the urgency and importance of population issues.”

Examining population trends helps describe where we’ve been and suggests where we’re headed. Yet these facts about human existence on our planet also offer insights into how we got here—including a window into places where inequities exist and rights have been denied.

The latest revision of global population projections released today by the UN Population Division will make headlines for the big picture they offer: the world’s population continues to grow by about just under 1 percent annually. While this sounds like a slow growth rate, it results in the addition of nearly 65 million people per year—the equivalent of about eight New York Cities. This growth rate has slowed significantly since a peak of about 2.2 percent in the late 1960s. The projections indicate that growth will continue to slow and may end by the end this century (though there is a wide range of possible population futures).

Yet there are many diverse and discrete regional trends woven through this global picture. In some places, including the United States, observers lament slow population growth and its implications for the economy. Persistently high population growth rates bump up against local natural resource constraints in other regions, hampering efforts to address core challenges people are facing related to poverty, pandemic recovery, and limited access to education and health services.

An examination of population trends offers signposts for future needs, whether these are near-term needs to expand housing and other infrastructure, or longer-term investments to boost education, public health, and care for an aging population. But such examination should not simply be a dispassionate planning exercise. Thoughtful interpretation of population trends can direct long-overdue attention and resources to address chronic inequities that darken the prospects for a more just and sustainable future.

The Collective Impact of Individual Rights

Last month’s U.S. Supreme Court decision overturning Roe v. Wade has brought reproductive rights squarely into the spotlight in the U.S. and around the world. Much of the discussion revolves around the basic human right to reproductive autonomy—allowing individuals to freely determine whether and when to become parents, and also obtain the information and services that enable them to actualize those intentions. These rights have their foundation in the global agreement stemming from the 1968 International Conference on Human Rights, and they have been affirmed in multiple international agreements ever since.

But this individual right to agency in one’s own reproductive life remains unrealized for much of the world’s population. Multiple barriers—insufficient health systems, social stigma, educational barriers, and political roadblocks—stand in the way, and these obstructions disproportionately affect people with limited financial resources, those who live in rural areas, and other marginalized groups.

This lack of individual rights results in significant collective impact. More than 218 million women in low and middle income countries would like to end or delay childbearing, but are not using an effective method of family planning. This unmet need for family planning results in high rates of unintended pregnancy, with its myriad of complexities, as outlined in this year’s UNFPA State of World Population Report.

Unsurprisingly, countries with high proportions of women with an unmet need for family planning also have some of the highest population growth rates. For example, according to the latest USAID Demographic and Health Surveys, about one in three women have an unmet need for family planning in Angola, Burundi, and Uganda; the population in each of these countries is growing close to 3 percent per year. While this may seem insignificant, it’s important to remember that such growth compounds rapidly over time: a population that is growing at 3 percent annually will double in just 23 years.

The Sahel: Gender Inequity and Persistent Youthful Age Structure

High population growth rates and very young age structure are hallmarks of many countries in the Sahel region of Africa, including Niger, Burkina Faso, Mali, and Chad. In these nations, more than half of the population is under the age of 18, and high fertility means that each new cohort added is larger than the one before it. This rapidly expanding youth population strains—and in many cases, overwhelms—the ability of governments to provide even the most basic services related to education and health care. A persistently youthful age structure in the region drives and exacerbates mutually reinforcing crises, including deep food insecurity, widening income inequality, and acute political instability.

The Sahel is also a region of vast gender inequity. The UN Development Programme’s Gender Inequality Index, a composite measure of gender-based disadvantage in reproductive health, empowerment, and the labor market, ranks the countries of the Sahel at or near the bottom of its  global list. When girls are not afforded opportunities to go to school or enter the labor market, marrying young can become commonplace. Child marriage is widespread in Niger, for example, where 28 percent of girls marry by the time they are 15 years old.

High rates of child marriage are tightly linked to rapid population growth and youthful age structure. Across the Sahel, six in ten child brides give birth before age 18, and nearly nine in ten give birth before age 20. For girls and women who are not yet fully grown, pregnancy and childbirth carry greatly increased risk of major complications, including prolonged or obstructed labor that can cause stillbirth, obstetric fistula, uterine rupture, and maternal death.

The scourge of child marriage and early childbirth also has implications for fertility rates: a recent study of 15 countries estimated that a girl marrying at 13 will have 26 percent more children over her lifetime than if she had married at 18 or later.

In a recent conversation, Rachida Issoufou Mani, executive director of Lumière des Filles et des Femmes (Light of Girls and Women), a program that provides safe spaces for married adolescent girls in southern Niger told me, “When girls become mothers it is hard for them to see opportunities in life.”

Overlooking the Last Mile

Although Guatemala is classified as a “middle-income country,” this designation masks significant inequities within its population, particularly relating to women’s health. Inequities faced by youth and rural, Indigenous populations are evident in Guatemala’s population growth trends. Guatemala has the highest population growth rate in Latin America; the projections released today by the UN Population Division indicate that Guatemala’s population could grow from 17.5 million today to anywhere between 22-27 million by 2050.

While there has been laudable progress in recent decades, health indicators among rural Indigenous populations remain bleak. Maternal mortality rates among Indigenous women are three times higher than for non-Indigenous women, and can reach up to 221 deaths per 100,000 deliveries in some regions. People living in remote rural communities suffer from isolation, poverty, low visibility, and low institutional support from health institutions.

Guatemala also has one of the highest teen pregnancy rates in Latin America—and is one of the few places where it is on the rise. The average age for women to first give birth is 20, and 21 percent of young women ages 15–19 are pregnant or parenting. In rural areas, this percentage rises to 24 percent.

Indeed, pregnancy among the youngest girls in Guatemala has become common enough that civil society pushed the government’s statistical agency to create a new statistical bracket to register pregnancies among girls between the ages of 10 and 14. And the gaps in supporting teenage girls are particularly severe. Surveys indicate that 22 percent of teen girls have an unmet need for family planning.

“Recent disruptions in education and health systems brought by the COVID-19 pandemic left an entire generation of adolescent girls with inconsistent access to in-person learning and limited to no guarantees to protect their sexual and reproductive health,” said Ángel del Valle, Guatemala Country Director for the Population Council.

The Population Council’s response? A targeted, evidence-based approach taken in its Abriendo Oportunidades program, which offers mentoring, comprehensive sexuality education, and other skills building that enables girls to claim their human rights and increase prospects for decent livelihoods. “Investing in the poorest girls at the right time—at the onset of puberty and before negative outcomes like school dropout and child marriage start to rise—continues to be a critical goal,” de Valle said.

Intersecting Inequities at the Global Level

As we have seen, injustices related to health inequities, gender inequities, and inequities faced by youth and other marginalized groups described above are also driving population growth in many places. Add the growing frequency and intensity of weather-related disasters, and the need to understand population trends for planning is especially obvious.

Earlier this year, UN Secretary-General António Guterres noted that one-third of the world’s people, mainly in least developed countries and small island developing states, are not covered by the early warning systems that enable communities to anticipate storms, heatwaves, floods, and droughts. This is only one stark illustration of climate injustice in which those who bear little responsibility for the atmospheric build-up of greenhouse gases that is wreaking havoc with the climate system are offered the least protection from this impending disaster.

Overlaid on this reality is the fact that many of the nations and communities that lack coverage from early warning systems, such as most of the population of Africa, are also experiencing population growth at rates higher than the global average. Today one-third of the population is vulnerable, but without action, that proportion will be even larger a decade or two from now.

World Population Day invites us to not only assess the implications of population trends for society, but also to seek out the signposts in those trends that point toward stories of persistent inequities faced by people around the world. As the human family continues to expand, we owe it to ourselves and to each other to better understand how inequities are both a cause and consequence of population trends—so that we can better direct our energies and resources toward forging a more just and sustainable future for all.