This page was updated with new data and statistics in September 2021.
If you are looking for a glossary of population terms, you can find that here.
Nobody knows how many people Earth can support because this depends on so many different factors, especially those related to lifestyle and consumption habits. At Population Connection, we focus on quality, not quantity of life.
Maybe the question we should be asking is, “How many people can’t the Earth support?” For example, at present the Earth can’t support the 5.2 million children under 5 who die every year, mostly from preventable and treatable causes. The Earth can’t support the 2.25 billion people who don’t have access to safe drinking water. The Earth can’t support the 4.15 billion people who don’t have access to basic sanitation. The Earth can’t support the 702 – 828 million people who are chronically hungry.
More important than trying to figure out how much our Earth can endure, we must ask, Do people have access to food and water? Are they healthy? Safe? Educated? Content? In short, what is the quality of life for people around the world, including for those who are the most marginalized? It is within this last question that Population Connection finds its mission.
The United States has a long history of involvement in the health and development of low-income, developing countries around the world, through our foreign assistance and diplomatic relations. Hardly anything affects health and development more than the rate of growth of the population.
In addition, the environmental, economic, and social impacts of population growth do not recognize political or geographic boundaries. What occurs in Asia, Africa, and Latin America has implications for the United States (and this is certainly true vice versa).
An example of the interconnectedness of our planet’s environment is the rapid destruction of tropical rainforests, which is exacerbated by human population growth. The “lungs of the Earth,” rainforests benefit everyone through their ability to absorb carbon dioxide and expel oxygen. As population increases, so too does the demand on the wood and other goods rainforests provide. The demand on farmland and grazing land increases as well, and rainforests are often burned to the ground when cultivated land must expand to feed a growing population. This reduces the capacity of rainforests to help slow climate change, which affects us all, regardless of which country we call home.
The United States is the world’s largest donor to international family planning efforts, at $607.5 million in 2022. The Guttmacher Institute estimates that our annual investment at that level prevents 12 million unintended pregnancies, 4.5 million unplanned births, 4 million unsafe abortions, and 19,000 maternal deaths.
The Guttmacher Institute also calculates how much it would cost to satisfy the unmet need for contraception among the 218 million women in the developing world who want to avoid a pregnancy but are not using a modern method: $12.6 billion a year (compared to the $7.1 billion in current global expenditures). Based on a funding commitment the United States made at the 1994 International Conference on Population and Development in Cairo, we should be investing $1.74 billion a year—more than a billion more than we’re currently spending (see this PAI document for the math on that “fair share” calculation).
The U.S. also funds a domestic family planning program for low-income Americans through the Department of Health and Human Services (HHS), called Title X (ten). In 2022, appropriations for Title X were $286.5 million. President Biden proposed $400 million in his 2023 budget—a welcome increase, but still lower than the amount needed to serve all patients who can’t afford the full cost of their family planning services.
The differences in growth can be explained by different levels of development and different cultural customs and values. A country’s birth rate is strongly linked to its degree of industrialization, economic development, and availability of quality medical care. Also, cultural mores pertaining to educational attainment, women’s status, and family size affect fertility rates and therefore population growth rates.
Beginning after the Industrial Revolution, what we now consider developed nations improved living conditions through advancements in medicine, sanitation, and nutrition. This led to declining death rates, especially among infants and children. Along with increases in living standards came urbanization, which rendered large families less practical and more expensive. Machinery was used more frequently to plant and harvest food, reducing the need for rural families to have as many children to work on the farm. Over the course of the 19th and 20th centuries, birth rates dropped dramatically as people realized the advantages of having smaller families.
Developing regions—such as sub-Saharan Africa and parts of Asia and Latin America—while they are urbanizing rapidly, are home to large subsistence farming populations; therefore, real incentives for having larger families still exist. And without a social security system in place in most of the developing world, people have many children to ensure that there is someone to take care of them in their old age. While death rates have fallen in many developing regions over the past several decades, birth rates remain high, which causes the populations of many countries—especially the poorest, least developed ones—to grow rapidly.
As girls and women gain access to education and formal sector employment, their health improves, they marry later, they have more decision-making power, and they have smaller families.
The number of children a woman has is not determined by biology alone. Less tangible factors—health, education, religion, culture, and economic and social standing—are more influential. In many societies women are valued primarily for their role in reproduction, hold little or no political or economic power, and are provided with inadequate health care and education. Women in these societies tend to have higher fertility rates. But in areas where women have more autonomy, they generally have more power and resources to control their fertility, and birth rates go down. Elevating the status of women worldwide is vital to lowering fertility rates and, ultimately, stabilizing global population.
The key to such empowerment is education, one of the strongest forces of lasting change. Educated women have increased opportunities and are more likely to enter the labor force before marriage, thus marrying later, delaying childbearing, and having fewer children over their lifetimes. Additionally, educated women are usually more aware of and have better access to medical services, including family planning, and have greater confidence and ability to use them.
Population Connection firmly believes that family planning programs must be voluntary and dedicated to affirming human rights. Coercive measures, which include draconian incentives and repercussions—and, at the more extreme end, forced abortions and sterilizations—are unethical, immoral, and unequivocally unacceptable. Family planning programs must give people the freedom to choose whether, when, and with whom to have children, completely on their own terms.
Family planning programs should be developed and scaled up with respect for the fact that, quite often, people prefer to have fewer children, but simply lack the means to do so. Coercion is neither acceptable nor advantageous—giving women and couples the freedom to choose their own reproductive destinies is the best policy.
Proudly, yes. We believe the decision to carry a pregnancy to term is best left to each individual, with input from their partner and medical professional, if desired.
Safe, legal abortion should be available to anyone who seeks it. Of the estimated 73 million abortions that occur each year, over 25 million are unsafe—unsanitary, self-induced, or performed by poorly trained providers. These unsafe abortions—nearly all of which take place in the developing world—result in the deaths of up to 31,000 women each year. Those women who survive often experience long-term health problems, ranging from chronic pelvic pain to infertility.
At the 1994 Cairo International Conference on Population and Development (ICPD), world leaders agreed that unsafe abortion is a major public health concern, and that governments should work to eliminate the practice.
The UN-organized 1994 International Conference on Population and Development (ICPD), called the “Cairo conference” or simply “Cairo,” brought together 179 countries to reaffirm the importance of slowing population growth for social and economic development. The Cairo Conference was the third UN Conference on Population—the United Nations previously held international conferences on population in Bucharest (1974) and Mexico City (1984)—and was the first to focus on meeting the needs of individuals, rather than simply achieving demographic targets.
The result of ICPD was the creation of the Programme of Action, a 20-year plan promoting, among other things, universal access to quality and affordable reproductive health services; reductions in maternal, infant, and child mortality; and closing the “gender gap” in education. Cairo put an end to the concept of “population control.” It recognized that smaller families and slower population growth depend on free choice and the empowerment of women.
In acknowledging the importance of advancing women’s status worldwide, the Programme of Action underscores the “empowerment and autonomy of women and the improvement of their political, social, economic and health status,” not only as an end in itself, but also as a vital part of achieving a sustainable development. Population Connection supports the Cairo consensus and urges the United States government and other world leaders to fully implement its agenda.
Population Connection believes that the United States government should view immigration in a global context and focus its attention on the factors that compel people to leave their families and native homes in the first place.
Foremost among the root causes of international migration are population growth, economic stagnation, environmental degradation, climate change, resource scarcity, poverty, and political repression. Population Connection, therefore, calls on the United States to focus its foreign aid on these core issues and work cooperatively with other nations to address international migration.
The following is the official immigration policy of Population Connection, revised by the Board of Directors in 1994 and reaffirmed in 1997:
Because of its increasing importance and impact on annual population growth, immigration plays a significant role in our goal of stabilizing U.S. population. Immigration goals must be set within a larger framework of a U.S. population policy, which aims at slowing U.S., and world population growth and promoting a balance between U.S. population and the environment through increased energy efficiency, conservation of natural resources, and sustainable environmental practices.
It is Population Connection’s view that immigration pressures on the U.S. population are best relieved by addressing factors that compel people to leave their homes and families and emigrate to the United States. Foremost among these are population growth, economic stagnation, environmental degradation, poverty, and political repression. We believe unless these problems are successfully addressed in the developing nations of the world, no forcible exclusion policy will successfully prevent people from seeking to relocate into the United States.
We, therefore, call on the United States to focus its foreign aid on population, environmental, social, education, and sustainable development programs. Changing political conditions present opportunities to work cooperatively with other nations to address the root causes of international migration. Studies show that of the people who emigrate to the United States, the majority would have stayed in their home countries had there been economic opportunities or democratic institutions.
Population Connection believes that U.S. immigration policies should focus on reunification of immediate families, and that U.S. refugee policy should reaffirm our commitment to the United Nations Convention on the Status of Refugees. In addition, we support measures aimed at increasing resources for the Immigration and Naturalization Service so that all immigrants, refugees, and asylees are ensured timely due process and to enable the U.S. to enforce measures to prevent fraud and other violations of immigration laws.
We also recognize that there are many issues surrounding the formulation of U.S. immigration policy, including legal, civil rights, economic, cultural, and demographic concerns. Further, we believe that immigrants and refugees should be admitted equitably, without preference to race, national origin, color, religion, gender, or sexual preference.
Population Connection recognizes that the United States should preserve its ability to absorb reasonable numbers of refugees and legal immigrants. In order to accomplish this, the United States needs to maintain control, in a way consistent with basic human and civil rights, over illegal immigration.
Assuming these conditions, Population Connection believes that the United States should adopt an overall goal for immigration as a part of its national population policy. This goal should be set in the context of a federal commitment to plan for demographic changes and to slow population growth.
There are many things that individuals can do to help achieve population stabilization. Here are just a few:
Students writing papers about the population movement often ask us about an article they see referenced in their research, “30 Years of ZPG.” It was written by Nina Rao for the December 1998 issue of The Reporter, which is what our magazine was called until we changed the name to, simply, Population Connection, in 2014. A quarter-century after it was written, “30 Years of ZPG” continues to be a great resource for people wanting to learn about the first three decades of Zero Population Growth/ZPG (we didn’t change our name until 2002). The PDF of the entire issue is available for download here.