Africa, where poverty and lack of education persisted even longer, was the last continent to experience a decreasing fertility rate.
The History Database of the Global Environment (HYDE) – the data source of the population density estimates in the following maps – visualised the estimates of population density on an interactive world map here The most widely discussed projections are those published by the United Nations, the first of which were published already in 1951.
There are three primary determinants of global population growth: mortality, fertility, and population momentum.
The global improvement falling mortality – seen in increasing life expectancy around the world and falling child mortality in every country – contribute to an increase of the world population.
The visualization below shows the total fertility rate by the level of development and includes the UN projections through 2100.
Until 1950 the fertility rate in the ‘more developed regions’ had already declined to less than 3 children per woman.The WC-IIASA projections are taking into account the demographic structure of the educational attainment of the population.While other projections are only structuring the demographic data by sex and age-group, the WC-IIASA data is additionally breaking down the population data by the level of highest educational attainment of different parts of the population.The level of highest educational attainment is categorized in a system that aims to capture the structure of populations across the different country-specific educational systems.These categorizations are based on the the International Standard Classification of Education (ISCED), which was designed by the UNESCO to make education statistics comparable across countries.In contrast to this the WC-IIASA projections are also taking into account the qualitative assessments of 550 demographers from around the world which the WC-IIASA researchers have surveyed to gather their ideas on how the population change in different parts of the world will play out.They then combine the country specific expertise of these researchers with similar quantitative information that the UN and others rely on as well.Then in the 1960s the fertility rate in the ‘less developed regions’ started to fall and another decade later the fertility rate in the ‘least developed regions’ followed this decline.The fertility rate of the world was still at 5 children per woman until the mid-1960s.The decline of fertility rates on the other hand, – the number of children per woman – reduces population growth.The global average fertility rate was 5 children per woman until the end of the 1960s and has halved since then.