It is often reported that today the population of this planet contains half of all humans that have ever lived. If we take a few moments to think about this, we can quickly work out that such a calculation contains some important deficits in information, making the statement pretty meaningless. However, what we can do is work through what we do know for sure and then investigate the numbers we do not have. It will not be very accurate but it should be a lot better than the first statement.
So, where do we start? The current population in 2023 is a little over 8 billion. However, if you check out the Worldometer on the internet, you will see the population growing by approximately 5 per second. If the first statement were true, then we would find that the total of all the people to have ever lived is about 4 billion. So, let’s this out.
Humans have been around since about e million years ago. But their numbers would have been very small. If we move forward in time to when humans were beginning to move out of East Africa, this will be a good point in time to start our calculations. We are looking at around 130,000 BCE and humans are hunter-gatherers. This lifestyle would mean that the population increase would be small. So, do we have a number to start us off 130,000 years ago? We do and it has been calculated to be a total of 200,000 humans.
At this time there would have been at least 3 human species living on the planet; Homo sapiens, Neanderthals and Homo floresiensis. Over the next 100,000 years or so, the latter two species died out leaving Homo sapiens. At this time, around 10,000 BCE, it is estimated the total population was about 3 million.
Hunter-gatherers began to set down roots and became farmers. Food was now easier and there was no need to travel looking for the next meal. This stability also led to an increase in population. Therefore, by 6,500 BCE, it had risen to around 10 million. That is quite a large increase and could have been partly due to not yet having invented the television!
Humans not only had more stability, it meant that they could keep animals and grow produce. It also meant that they had a safer existence. The population grew and by around 2,000 BCE the population was estimated to be about 50 million. It continued to grow quickly, so by the time we reached the Common Era, CE, the number of humans on the planet had increased to 200 million.
As the years passed, civilisations flourished, some better than others. The Greeks brought us the seeds of democracy and the Roman Empire brought changes in how people lived. Of course, not all of this went by without wars, famine and disease all helping to bring the numbers down. But by 1804, the world population had reached 1 billion.
Improvements in public health and medicine helped to allow people to live longer. This also led to a decrease in infant mortality. Big families were the usual during this time as parents would hope that when they were old, their children would be in a better position to look after them. The coming of modern pensions and social security meant that this reason no longer was apparent and so the birth rates in modern countries began to fall. But the world is not an equal place and there are large increases in population growth in parts of Africa, India and until recently, China.
We have also now reached a period when we are much clearer about world population. The following is a pretty accurate list of population increases.
| Billion | 1804 |
| 2 Billion | 1927 |
| 3 Billion | 1959 |
| 4 Billion | 1974 |
| 5 Billion | 1987 |
| 6 Billion | 1999 |
| 7 Billion | 2012 |
We know there is over 8 billion in 2023 and it is estimated that by 2050, we will have reached 9 billion. How long can this go on for? The Earth has a limit as to what it can provide. If the population was allowed to continue increasing, there would come a time when the starvation we still see today would be nothing to what was coming. That is the bad news.
The good news, maybe, is that as less developed countries become more modern, their birth rates will begin to reduce as we have seen in other countries. But this will mean that we will have an ageing population with fewer younger workers to keep everything going. This opens out a whole new area of questions such as will Artificial Intelligence, AI, save us or kill us?
All of these new questions may be discussed more fully in future articles. Watch this space.
John Pullen 