From Population Explosion to Decline: How the World Reached 8 Billion—and What Comes Next

Back in the 1960s, many scientists and policymakers feared the world was heading for disaster—not because of climate change or artificial intelligence, but because of too many people. Paul Ehrlich’s 1968 bestseller The Population Bomb warned of mass starvation and ecological collapse if human numbers weren’t brought under control. These fears shaped national policies, global aid, and even coercive sterilization programs in some countries.

And the numbers did seem alarming. The global population rose from 3 billion in 1960 to 5 billion by 1987, then to 6 billion by 1999, and 8 billion by 2022. Since the mid‑1970s, we’ve been adding about 1 billion people every 12 years.

The animated map below, created by VividMaps.com using World Bank data, shows how population changed in each country from 1960 to 2022:

The map makes it clear: Asia has long led the world in population size, growing from about 1.7 billion in 1960 to 4.7 billion by 2022. Africa’s population grew even faster—up nearly sixfold, from 257 million to nearly 1.5 billion, overtaking Europe in the early 1990s. Latin America more than doubled, and North America, fueled in part by immigration, jumped from 240 million to over 600 million.

In contrast, Europe’s growth has slowed to a crawl. The continent grew from 606 million in 1960 to just 743 million by 2022. And some countries—like Bulgaria—have actually shrunk. Bulgaria's population dropped by more than 17%, the largest relative decline of any country during this period (World Bank).

While this map captures the rapid growth of the last 60 years, the trend is now changing direction.

Today, population growth is slowing around the world. And in dozens of countries—from Japan and South Korea to Italy and Thailand—populations are shrinking. One major reason: declining birth rates.

In the 1960s, the average woman had more than five children. By 2024, the global fertility rate had dropped to 2.3, just above the replacement level of 2.1, and still falling.

Even in countries that once had high fertility, the numbers are falling fast:

• In the United States, the birth rate hit a record low in 2023, with just 3.59 million births and a fertility rate of 1.62 children per woman.
• Japan recorded only 720,000 births in 2024, the lowest since records began in 1899.
• South Korea holds the global record for lowest fertility, at 0.72 in 2023, and a modest rise to 0.75 in 2024.

Even developing countries like India, Brazil, and Iran are experiencing fertility declines. Many Indian states now report fertility below replacement level.

Alongside lower birth rates, people are living longer. In 1960, global life expectancy was just 52 years. Today it’s over 73 years, and in many wealthy countries, it's well above 80. That’s a demographic double punch: fewer births and more elderly people.

The result? Aging societies, shrinking workforces, and growing concern about the long-term sustainability of pension systems, healthcare, and caregiving.

So, where is all this headed?

According to the United Nations’ World Population Prospects, the global population will peak at around 10.3 billion in the mid‑2080s, then begin to gradually decline to 10.2 billion by 2100. But some researchers argue the peak may come sooner. A 2023 report by Earth4All, supported by the Club of Rome, predicts a population peak of 8.5 to 9 billion by the 2040s—if investments in education and health accelerate.

We’ve entered an era where the question isn’t just “how many people?” but “how will societies adapt?” From debates over immigration and baby bonuses to rethinking work and retirement, countries are scrambling to adjust.

It’s a quiet turning point in human history. We’ve spent the last century managing the pressures of rapid growth, and now we face a new set of questions around slowdown and aging. Some see this shift as an opportunity to rebalance our relationship with the environment. Others worry about economic stagnation, loneliness, or the unraveling of social systems built for larger, younger populations.

Either way, this is no longer a story about more—it’s a story about change. A change shaped not by disaster, but by millions of personal decisions about family, future, and what it means to thrive.

Recommended Reads:
(The following product links go to Amazon.com)

• “The Coming Population Crash” by Fred Pearce – A thoughtful take on global fertility decline and its consequences.
• “Population 10.0” by Danny Dorling – Explores the future with fewer people, longer lives, and changing values.