8 Billion!

Fewer than 1 billion people roamed our planet until 1804. Then, it took a little more than a century for the world to reach 2 billion inhabitants. Since that time, the global population has shot up in the shape of a hockey stick, boosted by the triumphs of modern medicine and public health.

The latest marker was passed in November, when the United Nations declared the world population had reached 8 billion—just 11 years after it passed 7 billion.

U.N. Secretary General António Guterres called it “a landmark moment in human history,” a testament to scientific breakthroughs and improvements in nutrition and public health. “In the world we strive to build, 8 billion people means 8 billion opportunities to live dignified and fulfilled lives,” Guterres said.

The growth rate, expected to slow globally in the coming decades, has been uneven around the world, presenting different challenges and opportunities. Here are a few of those that a world with 8 billion people will face.

Fewer than 1 billion people roamed our planet until 1804. Then, it took a little more than a century for the world to reach 2 billion inhabitants. Since that time, the global population has shot up in the shape of a hockey stick. The population has grown because of the triumphs of modern medicine and public health.

The latest marker was passed in November, when the United Nations declared the world population had reached 8 billion. It grew by a billon in just 11 years.

U.N. Secretary General António Guterres called it “a landmark moment in human history.” It is a testament to scientific breakthroughs and improvements in nutrition and public health. “In the world we strive to build, 8 billion people means 8 billion opportunities to live dignified and fulfilled lives,” Guterres said.

The growth rate has been uneven around the world and is expected to slow globally in the future. It presents different challenges and opportunities. Here are a few of those that a world with 8 billion people will face.

About 70 percent of the growth to 8 billion from 7 billion happened in low- and lower-middle-income countries, most of which are in sub-Saharan Africa, the U.N. said. The trend—fueled by a very young population, improving mortality rates, and high fertility—is expected to become more pronounced in the years ahead.

“When the next billion is added between 2022 and 2037, these two groups of countries are expected to account for more than 90 percent of global growth,” the U.N. said.

Meeting the needs—including education, public health, and employment—created by that growth requires “a significant increase in public expenditures,” said the organization.

About 70 percent of the growth to 8 billion from 7 billion happened in low- and lower-middle-income countries. Most of the countries are in sub-Saharan Africa, the U.N. said. The trend is fueled by a very young population, improving mortality rates, and high fertility. It is expected to become more pronounced in the years ahead.

“When the next billion is added between 2022 and 2037, these two groups of countries are expected to account for more than 90 percent of global growth,” the U.N. said.

Meeting the needs—including education, public health, and employment—created by that growth requires “a significant increase in public expenditures,” said the organization.

The growing population has helped fuel consumption at what experts say is an unsustainable pace, due to the utilization of an increasing amount of the planet’s natural resources. That has contributed to environmental challenges, including climate change, deforestation, and the loss of biodiversity.

“We are using more energy, more water, more forests,” says Ian Fry, an expert on environmental law and policy. “We are consuming at a much greater rate and [depleting] the earth’s resources.”

Lower-income countries, where the population growth is concentrated, have contributed far less to climate change than the richest nations. But as poorer populations grow, so does their economic development, their energy consumption, and therefore their emissions.

The growing population has helped fuel consumption at what experts say is an unsustainable pace. Increased use of the planet’s natural resources has contributed to environmental challenges, including climate change, deforestation, and the loss of biodiversity.

“We are using more energy, more water, more forests,” says Ian Fry, an expert on environmental law and policy. “We are consuming at a much greater rate and [depleting] the Earth’s resources.”

Lower-income countries, where the population growth is concentrated, have contributed far less to climate change than the richest nations. But as poorer populations grow, so does their economic development. This increases their energy consumption and emissions.

While the population grew by a billion in the past 11 years, the next billion isn’t expected to arrive for another 15 years. The slowdown may cause problems. China, the world’s most populous nation, reached a historic low in birthrates in 2021, a fact that could lead to labor shortages and hampered economic growth. In the U.S., the birthrate is growing at the slowest rate since the 1930s, raising concerns that a future shortage of young workers will make strong economic growth unsustainable and lead to insufficient resources to care for an aging population.

While the population grew by a billion in the past 11 years, the next billion isn’t expected to arrive for another 15 years.

The slowdown may cause problems. China, the world’s most populous nation, reached a historic low in birthrates in 2021. This could lead to labor shortages and reduced economic growth. In the U.S., the birthrate is growing at the slowest rate since the 1930s. This slowing is raising concerns that a future shortage of young workers will make strong economic growth unsustainable. This could lead to insufficient resources to care for an aging population.

As some countries see population declines and others experience increases, the world is undergoing major demographic changes. India is expected to surpass China as the world’s most populous nation in 2023, and Nigeria, with 230 million people, could surpass the U.S. as the third most populous nation by mid-century.

“When we think about these big population milestones, we have to think about how they feel differently depending on where you are in the world,” says Jennifer Sciubba, author of 8 Billion and Counting. “The life of someone in a poorer country can look quite different as those global numbers change.”

As some countries see population declines and others experience increases, the world is undergoing major demographic changes. India is expected to surpass China as the world’s most populous nation in 2023. Nigeria, with 230 million people, could surpass the U.S. as the third most populous nation by mid-century.

“When we think about these big population milestones, we have to think about how they feel differently depending on where you are in the world,” says Jennifer Sciubba, author of 8 Billion and Counting. “The life of someone in a poorer country can look quite different as those global numbers change.”

The world’s population is growing mainly because life conditions are improving: We’re living longer, thanks to remarkable advances in health and nutrition.

The discovery of therapies for fatal diseases has lowered mortality; improved access to food, clean water, and medical care has made poorer societies healthier overall. Education has changed lives, especially for
girls and women.

As a result, income inequality has gradually lessened, and the share of people living in extreme poverty (on less than $2.15 per day) has declined, from 40 percent in 1980 to below 10 percent in 2017.

However, wide disparities between and within countries persist, as do serious issues such as ongoing conflicts, climate change, and the fallout from the Covid-19 pandemic.

“We can fix these problems, we can continue to have a healthy population, even at 8 billion or more, but we can’t do it simply by doing the same things we did the last 50 years,” says Jack Goldstone, a professor of public policy at George Mason University, in Virginia, adding that young people will play a crucial role.

“We need to change our idea of getting richer,” he says, “so it’s not just having more things, it’s living a better quality of life, and living a better quality of life needs to be in reach for everyone in the world.”

The world’s population is growing mainly because life conditions are improving. We’re living longer. This is due to remarkable advances in health and nutrition.

The discovery of therapies for fatal diseases has lowered mortality. Improved access to food, clean water, and medical care has made poorer societies healthier overall. Education has changed lives, especially for girls and women.

As a result, income inequality has gradually lessened. The share of people living in extreme poverty (on less than $2.15 per day) has declined. It dropped from 40 percent in 1980 to below 10 percent in 2017.

However, wide disparities between and within countries persist. There are also other serious issues such as ongoing conflicts, climate change, and the fallout from the Covid-19 pandemic.

“We can fix these problems, we can continue to have a healthy population, even at 8 billion or more, but we can’t do it simply by doing the same things we did the last 50 years,” says Jack Goldstone, a professor of public policy at George Mason University, in Virginia. Young people will play a crucial role.

“We need to change our idea of getting richer,” he says, “so it’s not just having more things, it’s living a better quality of life, and living a better quality of life needs to be in reach for everyone in the world.”