Earth Protect Blog

By Daniel Victor

The New York Times

Until 1804, fewer than 1 billion people roamed our planet. More than a century later, in 1927, we crossed 2 billion.

Since then, the world 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 Tuesday, when the United Nations said the world population had reached 8 billion, just 11 years after it passed 7 billion. (It is an inexact number, since there is no official count, but the international organization said its projections crossed the line Tuesday.)

The growth rate, which is expected to slow globally over the coming decades, has been uneven around the world. Slowing growth rates in populous nations such as China and the United States have caused some alarm, threatening to upend their societies. Rising birthrates in poorer nations threaten to strain already struggling systems. Here are a few of the challenges ahead.

• Much of the population growth comes from the poorest countries, especially in sub-Saharan Africa.

About 70% 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 United Nations said. The trend is expected to become even 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% of global growth,” the organization said.

The fertility rate has dropped globally; in high-income nations, the number of people younger than 65 is expected to decline in the coming years, the United Nations said. But the fertility rate has remained high in poorer countries, where more women and girls lack access to sexual and reproductive health care, including contraception.

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

• The environmental impact: Our levels of production and consumption are unsustainable.

The growing population has helped fuel consumption at what experts say is an unsustainable pace. It has contributed to environmental challenges, including climate change, deforestation and the loss of biodiversity, the United Nations said.

Lower-income countries, where the population growth is concentrated, have contributed far less to climate change. But as poorer populations grow, “their energy consumption will need to increase substantially if they are to develop economically,” the organization said.

• Experts are forecasting slower growth ahead.

While it took 11 years for the population to grow to 8 billion from 7 billion, the United Nations said it expected 15 years to pass before we reach 9 billion, in 2037, and another 22 to pass before 10 billion, in 2058.

India is expected to surpass China as the world’s most populous nation in 2023, the United Nations said in July.