Population Distribution, Trends and Projections
Increasing population impacts on the global environment
Human Population on Earth
The Population Division of the United Nations estimated that in mid-2015 the world population was 7.3 billion. This is almost triple the 1950 value of 2.6 billion. As of 2015, both China and India have over 1 billion people. Combined, this represents nearly 40 % of the total world population and, together with the rest of Asia, over 60 % of the global population (4.4 billion) live in this region of the world. The remaining people are distributed across the rest of the world, with 16 % in Africa (1.2 billion), 10 % in Europe (738 million), 9 % in Latin America and the Caribbean (634 million) and the remaining 5 % in Northern America (358 million) and Oceania (39 million).
In 2015, the ten most populated countries in the world were located in Africa (Nigeria), Asia (Bangladesh, China, India, Indonesia and Pakistan), Latin America (Brazil and Mexico), Northern America (United States of America) and Europe (Russian Federation). By 2050, six of these countries are expected to exceed 300 million: China, India, Indonesia, Nigeria, Pakistan and the United States of America.
Projected Population Growth
According to UN estimates, the human population on Earth is projected to increase by 50 % by 2100, stabilising at about 11.2 billion2. Recent analysis of these data, however, suggest that a stabilisation of the world population this century is highly unlikely4. It is estimated that there is an 80 % probability that the range of increase will in fact be between 9.6 billion and 12.3 billion by 2100. Regardless of the actual figure, it is clear that Earth’s population is growing to unprecedented levels.
One of the striking features of the UN’s projected growth is its uneven distribution across the globe. Between 2015 and 2050, it is estimated that the global population will increase by 2.4 billion. Of this, an overwhelming 50 % will be concentrated in Africa (1.3 billion) and 38 % (or 0.9 billion) in Asia. The remaining will be distributed across Latin America (6 %), North America (3 %) and Oceania (1 %). In contrast, Europe will experience a 1 % drop in its population in 2050 as compared to 2015. Over the period covering 2015 to 2050, half of the world’s population growth will be concentrated in India, Nigeria, Pakistan, Democratic Republic of the Congo, Ethiopia, Tanzania, United States of America, Indonesia and Uganda (listed in order of the size of each country’s contribution to total growth).
Human population is taking its toll on the planet
The human imprint on the planet has a major impact on the functioning of the Earth system. The concept of the Anthropocene is commonly used to capture this shift in the relationship between humans and the global environment. Because the impact on the environment is closely intertwined with population dynamics, it is important to monitor and include these in the land degradation evaluation. Further to distribution, density and migration, population dynamics impact the planet in various ways:
- Economic stagnation. In poor societies, populations often double in size in two or three decades. Food production, industries, offices, housing, schools, health clinics and infrastructure must be built at least at the same rate. Many communities are unable to keep up — as is evident from high unemployment rates, explosive growth of slum populations, overcrowded schools and health facilities and dilapidated public infrastructure (such as roads, sewage systems and power grids). Furthermore, in rapidly growing regions, about half1 of the population is aged under 20. The low ratio of workers to dependents depresses living standards and makes it more difficult to invest in the human and environmental capital needed. The size of the formal labour force is also limited when women remain at home to care for large families.
- Political unrest. Youth unemployment becomes widespread when economies are unable to provide jobs. Vigorous competition for few jobs leads to low wages, which in turn contribute to poverty. Large numbers of unemployed and frustrated young people fuel socio-economic tensions, high crime rates and political instability and hamper environmental awareness and concern.
- Environmental degradation. Unprecedented global threats such as climate change and decreasing biodiversity have been building and will become more severe as populations, economies and consumption grow. Crucial local environmental problems — including shortages of fresh water and arable land, mounting waste and air, water and soil pollution —adversely affect health and threaten the expansion of food production required to feed more people a better diet. These local environmental impacts, linked to increased food, fibre and fuel production, affect global biogeochemical cycles.
Percentage of World Population in 2015.
(population figures in billions)
The status of the world population and continental subdivisions in 2015 and projections for the future.
Source: United Nations, Department of Economic and Social Affairs, Population Division (2015). World Population Prospects: The 2015 Revision. New York: United Nations.
Global distribution of human population in 2015 by climate subtypes.
Source: Safriel, U.
Global population trends. Project changes by region in projected population growth by 2100.
Source: UN DESA PD2
Projected changes in population growth by region by 2100.
Source: Bongaarts J., 2016 (AP).