Where Are Those Eight Billion People?
With the UN estimating that the world population reached eight billion people on 15 November 2022, now is a good time to look at where those people live.
The World in 2020
First let’s look at populations in 2020, when the population was already very close to 8 billion. I divide the world into 7 regions, and carve up a rectangle to show the population of each region (see figure above). Below the rectangle is a scale showing billions of people, and above is a scale showing tenths of the whole (with 2% subdivisions also shown).
The dominance of South Asia (orange) and East Asia (red), together about 45% of the global population, is clear; including Pacific island nations such as Indonesia adds almost another 10%. The Americas and sub-Saharan Africa add around 13% each, and Europe and North Africa/West Asia add another 10% each.
The graph also shows population distributions within regions by dividing each rectangle into a stack of subregions. These subregions may contain multiple countries or, for large countries, a single country. Vertical scales show 20% divisions (and 5% subdivisions) within each region. Subregions are grouped by shading; for instance, South America is shown in dark purple and includes separate boxes for Tropical South America, Brazil, and the South (Chile, Argentina, Paraguay and Uruguay).
Subregions show the two hyper-populated nations of China and India, large countries such as the US, Indonesia, Nigeria, Brazil, Russia, and Pakistan, and mid-size countries such as Mexico, Germany, and Japan. The US was grouped with Canada rather than separated because Canada, with its 40 million people, is not large enough to be its own subregion.
Sixty Years of Population Growth
Snapshots of population (see figure below) show the enormous growth from just over 3 B in 1960 to almost 8 B by 2020. The growth rate itself is slowing: 74% increase in the 1st thirty years and 47% in the second. Looking at individual decades (not shown in figure), growth has decreased from 21% per decade in 1960-1970 to 12%/decade in the last decade. If we fit a line to decadal growth rates, it descends to 0%/decade around 2080.
Population growth has been broadly shared. For instance, East Asia went from 0.8 billion (B) to almost 1.6 B and the Americas went from 0.4 B to 1.0 B people. The share of global population has diverged however. East Asia’s dominance as a population center is not new, and in fact it dropped slightly from about 26% of the world to about 22%. The Americas slipped from 14% to 13% and the Pacific also slightly decreased. Europe fell more dramatically, from 20% to 10%, though even it had some population growth. South Asia grew from 19% to nearly 23%. Africa and West Asia grew even faster. The most dramatic change has been in sub-Saharan Africa, which grew from about 7% of global population in 1960 to nearly 14% in 2020.
Unlike the world as a whole, the fastest-growing regions do not show much sign of slowing down. Sub-Saharan Africa, which has gone from 0.2 B to 1.0 B people, has been growing at 30%/decade in the 2000’s, only slightly slower than the 32-33%/decade of the 1980s and 1990s. North Africa/West Asia dropped a bit more, from 30%/decade before 2000 to around 22%/decade after.
Within individual regions, the proportion of population in each subregion has been relatively stable. For instance, China is known for extreme population control policies, but its share of East Asian population only declined from about 83% to 80%. The main exceptions to stable subregion proportions have been the contrast between richer and poorer countries in the same region. Japan decline from 40% of Pacific population to 20%. The US and Canada went from about 47% of the total American population to 35%.
Though the US has had robust population growth (180 M in 1960 to 330 M in 2020) due to immigration and births, Canada has actually grown a little faster. Its population was 10% as big as the US in 1960 and over 11% in 2020. The US has gone from 6.0% of world population to 4.3%.
Global Division of Real Estate
The division of the world by surface area shows a different pattern than population. The figure below shows Earth’s entire land surface except for Greenland and Antarctica, about 130 million square kilometers (130 M km2) total. That’s about the same as a square that’s 11,000 km (7000 miles) on a side.
The regions shown in the area graph are the same as in the population graph with one exception: Russia is a separate region here. While almost three quarters of Russia’s population is concentrated in Europe, its Asian territory makes its area comparable to East Asia or sub-Saharan Africa.
Russia’s large area of sparse population is due to its extreme cold. The US/Canada subregion is also a much larger share of the world area than of world population because of the cold wilderness in Alaska and much of Canada, the rugged wilderness of the Rocky Mountains, and generally low population densities throughout the rest of the subregion. Deserts account for large low-population areas in North Africa/West Asia and in the Anglo Pacific subregion (the Australian Outback).
At the other extreme, South Asia has the smallest area of any of the regions, even though it has the highest population. This makes population density of this region far higher than the others, nearly 400 people/km2. This can be seen by representing both area and population density of each region with a rectangle, as shown in the figure below. Note that this figure uses 2015 population from a different source, and combines Pacific and East Asia as one region and Australia and New Zealand as another.
The tiny population densities of Russia and Australia are clear in the figure. Interestingly, East Asia and Europe have similar densities to each other, 100-140 people/km2. The rest of the world ranges from 20 to 60 people/km2. Note that the population density is very sensitive to how we divide the regions; Canada has a density more similar to Russia.
Final Thoughts
When we think of global environmental or economic issues such as climate change, it is important to have a picture in our head of who will be affected. A population chart is a quick way of getting an overview of how humanity is divided among different geographical regions.
To me, dividing a rectangle into the region/subregion segments is a good way of visualizing the world population. It is easier to compare sizes than in a pie chart or in a map with nation sizes adjusted to represent population. Other websites show divisions such as national population by subdividing a rectangle in a different way: fitting nation rectangles together so that none is too flat or too thin. My figures make a cleaner division between regions and subregions which makes it easier to compare the sizes of regions or the relative size of subregions within a given region. It is not as easy in my figure to compare subregions within different regions, but using the tick marks allows for a rough estimate.
Readers may already be familiar with the basic facts presented here such as the large population of Asia, rapid growth of Africa, and the decelerating population explosion of the last sixty years. These plots provide a visually striking image for bringing these population facts into sharper focus.
Data Sources
National population data from the World Bank. National area data from the CIA Factbook. Population density map based on 2015 data from the NASA SEDAC Gridded Population of the World (GPW) version 4.