The World Population: Distribution, Density and Growth — Class 12 Geography

People are a country's real wealth, yet the world's population is very unevenly distributed — about 90 per cent of people live on only 10 per cent of the land, and ten countries hold roughly 60 per cent of the total. Population distribution describes how people are spaced over the earth, while density of population is the ratio of people to land, measured in persons per square kilometre. Distribution is shaped by geographical factors (availability of water, landforms, climate and soils), economic factors (minerals, urbanisation and industrialisation), and social, cultural and political factors. Population change over time may be positive or negative and has three components: births, deaths and migration. The crude birth rate and crude death rate measure births and deaths per thousand people; natural growth equals births minus deaths, while actual growth also adds in-migration and subtracts out-migration. Migration involves push factors at the place of origin and pull factors at the place of destination, and a person is both an emigrant and an immigrant. The demographic transition theory describes a society moving from high birth and death rates (stage one) through falling death rates with high births (stage two) to low birth and death rates (stage three) as it becomes urban, industrial and literate. Thomas Malthus warned that population could outrun food supply, so family planning and population control are important for sustainability.