The Day of 8 Billion

The world’s population is projected to reach 8 billion people on 15 November 2022 (view the current world population estimate here). Improvements in health care, nutrition, medicine, living standards, and high birth rates in some countries have contributed to this milestone.

It has taken the global population 12 years to grow from 7 to 8 billion. However, it will take approximately 15 years to reach 9 billion in 2037, indicating that the population growth rate is slowing.

How has the world population changed over time?

The chart above shows the increasing number of people living on our planet over the last 12,000 years. A mind-boggling change: the world population today is 1,860 times the size of 12,000 ago when the world population was around 4 million – just under half of the current population of London.

What is striking about this chart is that almost all of this growth happened very recently. Historical demographers estimate that in 1800, the world population was only around 1 billion. This implies that, on average, the population grew very slowly over this long time from 10,000 BCE to 1700 (by 0.04% annually). After 1800 this changed fundamentally: the world population was around 1 billion in the year 1800 and has increased 7-fold since then.

Around 108 billion people have ever lived on our planet. This means that today’s population size makes up 6.5% of the total number of people ever born.

How has the world population changed by region?

Two hundred years ago, the world population was just over one billion. Since then, the number of people on the planet grew more than 7-fold to around 8 billion today. Asia and Africa drove much of that growth and are expected to drive the next billion in 2037; Europe’s contribution will be negative due to a declining population.

The chart above shows historical population estimates by region from 1820 to today. These estimates are published by the History Database of the Global Environment (HYDE) and the United Nations Population Division from 1950 onwards.

Most people have always lived in Asia: today, it represents 60% of the global population; two hundred years ago, it was 68%.

The world region that saw the fastest proportional population growth over the last two centuries was North America. The population grew 31-fold. South America saw the second-largest increase (28-fold). Over the same period, the population in Europe of increased 3-fold, in Africa 14-fold, and Asia 6-fold.

India, the largest contributor to the 8 billion (177 million), will pass China, the second largest contributor (73 million) and whose contribution to the next billion will be negative, as the world’s most populated nation by 2023.

Why has the world population grown so rapidly?

From the 19th century, the population began to explode due largely to modern medicine’s development and agriculture’s industrialisation, which boosted global food supplies.

Since 1800, the world’s population has jumped eightfold, from an estimated 1 billion to 8 billion.

The development of vaccines was key in increasing life expectancy, with the smallpox jab helping deal with one of history’s biggest killers.​

The 1970s and 1980s brought another small revolution in the form of treatment for heart disease, which helped reduce mortality among those over-60s.

Are there too many people for Earth to support?

Many experts say that this is the wrong question. Instead of fearing overpopulation, we should focus on the overconsumption of the planet’s resources by the wealthiest among us.

How many people Earth can support has two sides: natural limits and human choices.

Our choices result in humans consuming far more biological resources, such as forests and land, than the planet can regenerate each year.

For example, overconsumption of fossil fuels leads to more carbon dioxide emissions, which are responsible for climate change.

We would need the biocapacity of 1.75 Earths to meet the needs of the current population sustainably, according to the Global Footprint Network and WWF NGOs.

If everyone on the planet lived like a citizen of India, we would only need the capacity of 0.8 Earths a year, according to the Global Footprint Network and WWF. If we all consumed like a resident of the United States, we would need five Earths a year.