6 How will methodological developments for young children global demography change? Our articles and data visualizations rely on work from many different people and organizations. When citing this entry, please also cite the underlying data sources. 200 years ago there were less than one billion humans living on earth.
Today, according to UN calculations there are over 7 billion of us. 1 Recent estimates suggest that today’s population size is roughly equivalent to 6. How the world population is changing is of great importance for humanity’s impact on the Earth’s natural environment, but it also gives reasons to hope for a good future. This is because we have a bigger team of better educated people who can contribute to the solutions that improve global well-being. A picture of the world population in the very long-run shows extremely rapid growth. Indeed, for a long time the world population grew at an increasing rate.
However, if we focus on the last couple of decades, we see that this pattern no longer holds, as the annual rate of population growth has been recently going down. 1962 saw the growth rate peak at 2. A long historical period of accelerated growth has thus come to an end. Based on these observations, world history can be divided into three periods marked by distinct trends in population growth. The first period, pre-modernity, was a very long age of very slow population growth.
The second period, beginning with the onset of modernity—which was characterized by rising standards of living and improving health—had an increasing growth rate that continued to rise through 1962. In order to study how the world population changes over time, it is useful to consider the rate of change rather than focusing only on the total population level. This means that while the world population quadrupled in the 20th century, it will not double in the 21st century. What is striking about this chart is of course that almost the entire action happened just very recently. Historical demographers estimate that around the year 1800 the world population was only around 1 billion people. After 1800 this changed fundamentally: The world population was around 1 billion in the year 1800 and 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. Hovering your mouse over the plotted line will show you population figures for each year. For the long period from the appearance of modern Homo sapiens up to the starting point of this chart in 10,000 BCE it is estimated that the total world population was often well under one million. 5 In this period our species was often seriously threatened by extinction. How often does the world population double? The visualisation below presents a different perspective on the long-term increase of the world population and asks how long it took for the world population to double.