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-Editorial
The United States is edging toward population decline as birth rates fall, the population ages, and immigration slows, removing the country’s longtime demographic safety valve. Under lower-immigration scenarios, the U.S. population could shrink to as few as 226 million by 2100, according to data from the U.S. Census Bureau.
This trend mirrors a global shift already reshaping Europe and East Asia. Two-thirds of humanity lives in countries with fertility below the replacement rate of 2.1 children per family. By 2100, populations in some major economies will fall by 20 to 50 percent, based on UN projections.
Dr. Ana Langer, director of the Women and Health Initiative at the Harvard T.H. Chan School of Public Health, said global fertility rates have declined sharply over the past five decades, a trend she described as “undeniable” and driven by complex social, economic, and policy factors.
Speaking during a presentation to American Community Media, Langer emphasized the importance of media engagement, saying she values “any opportunity I have to interact with journalists, because I fully acknowledge the importance of your work.”
Langer noted that worldwide fertility rates have dropped from about five children per woman in 1970 to approximately 2.2 in 2024. Similar declines have occurred across regions, including sub-Saharan Africa, Asia, Latin America, and the United States, which now has an average fertility rate of about 1.6.
“Births are declining everywhere,” Langer said. “Most regions and countries are now at or below replacement fertility, which is about 2.1 children per woman.”
She identified four main factors influencing population growth: fertility rates, mortality rates, migration, and age structure. Fertility decisions, she said, are shaped by a wide range of influences, including education, women’s rights, access to health care and family planning, labor market participation, housing costs, childcare availability, and broader concerns such as climate change and global instability.
Using the United States as an example, Langer cited surveys showing that high childcare costs, difficult pregnancy experiences, and economic pressures are major reasons people delay or forgo having children. She said many Americans also express concern about raising children in an uncertain world.
Turning to China, Langer described how decades of restrictive population policies, followed by efforts to encourage higher birth rates, have failed to reverse declining fertility. Despite financial incentives and expanded parental benefits, China’s fertility rate remains among the lowest in the world.
“Ending the one-child policy did not return fertility to replacement levels,” she said, citing ongoing cultural and economic pressures.
Langer added that pronatalist policies in other countries have produced limited results and argued that improving maternal and reproductive health outcomes should remain a priority.
“People are more concerned about population growth than low fertility rates,” she said. “Focusing on women’s health, education and rights is essential.”
Dr. Philip Cafaro, an associate professor of philosophy at Colorado State University, said continued population growth and economic expansion are central drivers of global environmental degradation, arguing that sustainability efforts must confront consumption levels and population size more directly.
Cafaro said public discussion about population trends often focuses on hypothetical future declines while overlooking current realities. “For now, population is growing in the United States,” he said, noting the nation’s population has risen from about 281 million in 2000 to roughly 343 million today.
Globally, Cafaro cited United Nations data showing the world population increased by 60-70 million last year and now exceeds 8.2 billion. While growth is expected to level off later this century, Cafaro said there is no immediate risk of population collapse.
Cafaro, who studies sustainability and environmental ethics, said the environmental outlook is worsening. He pointed to melting glaciers, acidifying oceans, record-setting wildfires, intensifying storms, droughts, coral reef loss, and sharp declines in birds and insects.
“The underlying cause of all of it is pretty clear,” Cafaro said. “We’ve got an immense and rapidly growing human economy serving the needs and wants of unprecedented numbers of people.”
He said rising wealth and powerful technologies have amplified humanity’s ecological footprint, displacing wildlife and fragmenting habitats. “We’re demanding too much, and we’re polluting too much,” he said.
Cafaro expressed concern that policymakers often emphasize technological fixes while avoiding what he called a fundamental issue: overconsumption tied to population size. He said economic growth rates of 2.5% to 3% annually pose a greater threat to ecosystems than modest declines in fertility.
“One area where we seem to be making progress is in declining fertility,” Cafaro said, suggesting societies should view lower birth rates as an opportunity rather than a problem.
He proposed that population reduction be considered as part of long-term sustainability planning, including reevaluating immigration levels in developed countries. Cafaro said reducing net immigration could help nations reach population peaks sooner and gradually lower total numbers.
Using U.S. projections, Cafaro said maintaining net immigration at about 1 million people annually could stabilize the population near 370 million by 2100. Increasing net immigration to 2 million per year, he said, could push the population close to 500 million, a level he described as “nothing close to sustainable.”
“Eight billion people are not sustainable on planet Earth,” Cafaro said. “No amount of clever technology is going to make it sustainable.”
He acknowledged that immigration does not directly reduce global population but said it can influence fertility decisions and long-term demographic patterns. Cafaro said debates over immigration and population are complex but essential.
“If you’re a citizen of the United States, you should be focusing on how we can reduce the population in the United States,” he said. “That’s part of creating a sustainable society.”
Cafaro concluded by urging journalists to frame environmental coverage around limits to growth and sufficiency rather than endless expansion.
