The world’s population has increased steadily since the arrival of humans in Africa more than 2 million years ago. This is despite only brief pauses due to the ever-growing number of people living on Earth.
As the global population teeters on 8 billion – a milestone expected to be reached in mid-November – AFP takes a look at the main chapters in the growth of humanity.
First humans
The oldest fossils dated back to the earliest humans are 2.8 million year old and were found in east Africa.
However, estimates of the population of the Earth were not reliable until the 19th Century.
Our ancestors were hunters and gatherers. They had fewer children than the later settled population to continue their nomadic lifestyle.
The planet’s population was sparse also partly because hunter-gatherers needed a lot of land to feed themselves – around 10 square kilometers per person, according to Herve Le Bras, a researcher at the French Institute for Demographic Studies (INED).
While the population of the globe did grow over time, it was very slow.
First baby boom
Around 10,000 BCE, the Neolithic era saw the introduction of agriculture, which brought about the first major population increase.
Sedentarization, the ability to store food and agriculture brought about a boom in birth rates.
Le Bras explained, “Mothers could feed infants greek, which sped the weaning and reduced the time between the births. It meant that more children per mother.”
However, the development of permanent settlements brought with it risks, such as the domestication and spread of deadly diseases to humans.
The child mortality rate was particularly high with a third of all children experiencing death before their first birthday and another third dying before turning 18.
Eric Crubezy, an anthropologist from the University of Toulouse in France explained, “There was enormous mortality but also permanent baby boom.”
From around 6 million in 10,000 BCE, the global population leapt to 100 million in 2000 BCE and then to 250 million in the first century CE, according to INED estimates.​
Black Death
The Black Death brought an abrupt halt to the Middle Ages’ population.
The pandemicThe first known instance of a Central Asian swarm, located in modern-day Kyrgyzstan. It reached Europe via ships that carried goods from the Black Sea in 1346.
It decimated up to 60% of Europe’s Middle East and North African populations in just eight years.
The Black Death caused a drop in the human population of between 1300 to 1400 and 429 to 374 millions.
Other events such as the Plague of Justinian which struck the Mediterranean over two centuries, from 541 to767, and wars of western Europe’s early Middle Ages caused temporary drops in human numbers.
Eight billion people and counting
The rise in population was largely due to modern medicine and industrialization of agriculture. This boosted global food supplies.
The world’s population grew eight-fold between 1800 and 2008, to an estimated 1 billion people compared to 8 billion in 2008.
For Crubezy, the development of vaccines was key, with the smallpox jab particularly helping zap one of history’s biggest killers.​
In the 1970s and 1980s, another small breakthrough was made in the field of heart disease treatment, which contributed to a decrease in mortality among those over 60.
