How many people have lived on planet Earth?

Researchers estimate how many humans have ever lived.

Photo by Spencer Tunick.

It's easy to think that our lifetime and the world around us is unique and definitive. But thinking about how many people have ever lived on this planet can add some perspective to our instinctive self-centeredness. And it's not only a matter of how many people lived before we appeared, but how many have died.


So what's the answer? According to estimates by demographic researchers at the Population Reference Bureau (PRB), as of 2015, there have been 108.2 billion who have ever been born. Taking away the roughly 7.4 billion who are alive today, we get 100.8 billion who have died before us.

There are almost 14x more people dead than alive! That would make for one massive army of zombies, ghosts and White Walkers. Or, if you prefer to be more optimistic, you can think that the living are about 6.8% percent of everyone who'd ever lived. For the sake of simplicity (and to take into account the people born in the past year), lets round up the percentage to 7. We are the 7%. Let's make the most of it!

How do the researchers come up with these estimates? The starting point that the Population Reference Bureau takes for the beginning of what it considers human history is 50,000 BC, when the modern Homo Sapiens appeared. This date in itself is debatable as early hominids walked the earth millions of years ago. The date of 50,000 BC is taken from the United Nations Determinants and Consequences of Population Trends.

Coming up with how many people were born after that is certainly based on informed speculation. Plagued by low life expectancy (up to 10 years during the Iron Age) thanks to lack of medicine, food supply issues, climate changes, killing each other and other problems, human population grew at a slow rate. Early infant mortality was as high as 500 infant deaths per 1,000 births or higher.

Here's a chart from PBR estimating how population expanded (at least until 2011).

Interestingly, you can see how the rate of growth was lower from 1AD until 1650 AD, mainly due to such events as the outbreak of the plague, known as Black Death. You can also see the great population expansion from about the time of the Industrial Revolution to our current day. From 1850 till now, the planet's living population increased by about 6 times!

Certainly, some of these numbers are to be argued. The researchers made guesstimates on the birth rates and set a constant rate of population growth, which surely fluctuated. Still, this estimate gives us a useful perspective on our place in the life of our planet.

Here's Carl Haub from PRB talking about his methodology:

‘Designer baby’ book trilogy explores the moral dilemmas humans may soon create

How would the ability to genetically customize children change society? Sci-fi author Eugene Clark explores the future on our horizon in Volume I of the "Genetic Pressure" series.

Surprising Science
  • A new sci-fi book series called "Genetic Pressure" explores the scientific and moral implications of a world with a burgeoning designer baby industry.
  • It's currently illegal to implant genetically edited human embryos in most nations, but designer babies may someday become widespread.
  • While gene-editing technology could help humans eliminate genetic diseases, some in the scientific community fear it may also usher in a new era of eugenics.
Keep reading Show less

Massive 'Darth Vader' isopod found lurking in the Indian Ocean

The father of all giant sea bugs was recently discovered off the coast of Java.

A close up of Bathynomus raksasa

SJADE 2018
Surprising Science
  • A new species of isopod with a resemblance to a certain Sith lord was just discovered.
  • It is the first known giant isopod from the Indian Ocean.
  • The finding extends the list of giant isopods even further.
Keep reading Show less

These are the world’s greatest threats in 2021

We look back at a year ravaged by a global pandemic, economic downturn, political turmoil and the ever-worsening climate crisis.

Luis Ascui/Getty Images
Politics & Current Affairs

Billions are at risk of missing out on the digital leap forward, as growing disparities challenge the social fabric.

Keep reading Show less

Columbia study finds new way to extract energy from black holes

A new study explains how a chaotic region just outside a black hole's event horizon might provide a virtually endless supply of energy.

Credit: NASA's Goddard Space Flight Center
Surprising Science
  • In 1969, the physicist Roger Penrose first proposed a way in which it might be possible to extract energy from a black hole.
  • A new study builds upon similar ideas to describe how chaotic magnetic activity in the ergosphere of a black hole may produce vast amounts of energy, which could potentially be harvested.
  • The findings suggest that, in the very distant future, it may be possible for a civilization to survive by harnessing the energy of a black hole rather than a star.
Keep reading Show less
Mind & Brain

A psychiatric diagnosis can be more than an unkind ‘label’

A popular and longstanding wave of thought in psychology and psychotherapy is that diagnosis is not relevant for practitioners in those fields.

Scroll down to load more…
Quantcast