Despite a drop in the birthrate, the increase in world population continues at a steady pace, reconfiguring ancient demographic balances. The regions which, both now and in the decades to come, experience the highest rises, are those that are poorest, whose societies are the most fragile and most exposed to environmental, economic, social and health risks.

In the early sixteenth century, the human population numbered 500 million; by the early nineteenth century it was 1 billion, 1.5 billion by the early twentieth century, and 7.6 billion in 2017. According to the 2017Revision of the United Nations’ World Population Prospects, this upward trend will continue and is expected to reach 8.6 billion by 2030, 9.8 billion by 2050, and 11.2 billion by 2100.

Population of states and territories, 2017

Source: United Nations, Population Division, WPP 2017,

Comment: This map shows the total population of states in 2017. Only China and India exceed a billion inhabitants. The next most populated countries are the United States, Indonesia, and Brazil. These demographic weights much depend on the size of the country and its population density. Most of the heavyweights have a very large surface area as well, but Pakistan, Bangladesh and Japan are not continent-states. And densities are very unequally distributed within each country, which is not shown on the map.

How many people?

The progress made in civil registry services, the aid programs for carrying out and synchronizing census data in countries of the South, the systematization of information in revised databases, and increasingly powerful means of calculation now enable us to make relatively accurate demographic projections for the next twenty to thirty years. Beyond that, debates around the universality of the demographic transition model, uncertainty about the combined effects of ageing, epidemics, conflicts and environmental degradation are making forecasts more uncertain.

The continued growth of the world population is a challenge that does not affect all world societies in the same way. There are countless possible and evolving combinations between natural increase and net migration, and they interact with all other social and economic factors. Over the last half-century, the very contrasting demographic development of the world’s largest regions has had a long-term impact on world population balances.

Change in population, 1950-2050

Source: United Nations , Population Division, WPP 2017, https://esa 

Comment: The two graphs show how the population of continents evolved between 1950 and 2015, and the projections until 2050. The curves on the left reflect the changes: Africa shows the strongest growth over the whole period, and Europe the lowest. The histograms on the right indicate each continent’s share of the global population: the share of Europe and North America continues to fall, while Asia has reached its maximum and is now dropping. Only the population of Africa has grown over the entire period.

Africa, Latin America (except for Argentina and Chile) and Asia (except for China) are experiencing continued growth, whereas growth is low in North America, Europe and Australia, has slowed in China, and is even declining in Russia and Eastern Europe.

China, with 1.4 billion inhabitants or 19% of world population, and India, with 1.3 billion inhabitants or 18 %, remain the two most highly populated countries, but by around 2024 the population of India is expected to overtake that of China, where growth has been slowed by the consequences of more than thirty years of the one-child policy, as well as by an ageing population.

It is therefore the poorest populations in societies already in crisis that will grow the fastest, and will aggravate poverty and the challenges for development. Whereas the population of Europe as a whole is set to decline between now and 2050 (from 742 to 716 million), Africa will experience the strongest growth, with a doubling of the population during the same period (from 1,256 to 2,528 million).

Demographic growth and its sustainability can therefore not be considered independently of social, societal, economic, political, civil, and environmental conditions.

Population centers

State divisions form the basis of population censuses and enable comparisons, but they do not account for the diversity of situations within states, since the global population is often coastal and increasingly urban. Asia (with 60 % of the world’s population) is extremely urbanized and has very high rural densities, which encourage a seasonal or permanent exodus toward cities, fueled by the growing wealth gap.

Population density, 2015

Source: European Commission, Joint Research Centre (JRC); Columbia University, Center for International Earth Science Information Network - CIESIN (2015): GHS population grid, derived from GPW4, multitemporal (1975, 1990, 2000, 2015).

Comment: This map of global population densities has been compiled from a 20x20 km grid. This differs from the traditional representations by country, which iron out differences over the whole of each country’s territory. The map therefore shows just how unequally the population is spread over an area, ranging from vast empty spaces to great concentrations, generally along the coastlines except in the eastern part of China, Europe, and the valleys of the Nile and the Ganges.

Europe is intensely farmed, long since urbanized and industrialized, and organized around urban spaces with almost continuous production, trade and circulation – from London to Northern Italy with the Rhine axis in between. The population of the Americas is mainly coastal, and denser in the north than the south. For four centuries, the slave trade transported servile labor from Africa to the southern United States, the Caribbean, and Brazil. Then, in the late nineteenth century and early twentieth, the wholesale arrival of European migrants once again profoundly transformed these lands and societies. Westward expansion pushed back the settlement frontier and mapped out the main lines of present-day population density in the United States. In South America, the land was less deeply penetrated. There are very large built-up areas on the Brazilian coast, but the population only becomes dense in the axis of Rio de la Plata, and less so and more intermittently in the Andes. Africa, North Africa, the Nile valley, the Great Lakes region, and the Gulf of Guinea form chains of densely populated areas, while Nigeria is a demographic heavyweight (with 190 million inhabitants in 2017).

Empty spaces and pioneer frontiers

Empty spaces that are supposed to be virgin territory have, since the early twentieth century, been considered places where the demographic balance can be restored. More recently, they have also been annexed for agro-forestry and industry (Siberia, Central Asian deserts, the Amazon, the African forest, Indonesia) at the cost of heavy environmental, social, and cultural damage. As for the Sahara, considered empty in a traditional and deterministic view, represented by strips running west to east showing rainfall, it is in fact an area of historic North-South circulation involving traders, nomadic stockbreeders, warriors, and preachers, and nowadays armed groups and people, weapons, and drug smugglers as well.

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