United Nations Department of Economic and Social Affairs Population Division.
For the first time in history, more people live now in urban than in rural areas. In 2010, urban areas are home to 3.5 billion people, or 50.5 per cent of the world’s population. In the next four decades, all of the world’s population growth is expected to take place in urban areas, which will also draw in some of the rural population through rural to urban migration.
Moreover, most of the expected urban growth will take place in developing countries, where the urban population is expected to double, from 2.6 billion in 2010 to 5.2 billion in 2050. In developed countries, the number of urban dwellers will grow more modestly, from 0.9 million in 2010 to 1.1 billion in 2050. During the same period, the world’s rural population will decline by 0.6 billion.
The level of urbanization varies significantly across regions and countries. Europe, Latin America and the Caribbean, Northern America and Oceania are highly urbanized, with proportions urban ranging from 70 to 82 per cent in 2010. Africa and Asia remain mostly rural, with only 40 and 42 per cent of their population living in urban settlements, respectively. By mid-century, however, all regions will be mostly urban, indeed more than 60 percent urban, according to current projections. The speed of urbanization is slower now than it was in past decades in all regions, largely because many countries have already reached high levels of urbanization. The rate of urban population growth is also declining and is expected to continue declining until 2050, although it is still very high in Africa,
where the urban population was growing at an annual rate of 3.4 per cent in 2005-2010, and in Asia, where urban population growth averaged 2.8 per cent in the same period.
Nevertheless, the absolute size of these increments is unprecedented: Africa gained an average 13 million additional urban dwellers per year in 2005-2010, and is expected to gain some 25 million per year in 2045-2050. Asia’s urban population increased by 38 million per year in 2005-2010, and is still projected to grow by an annual 35 million in 2045-2050. During the same period, Africa and Asia will be losing 2.5 million and 27.3 million rural inhabitants per year, respectively.
Migration from rural to urban areas has historically played a key role in the rapid growth of cities and, together with the reclassification of rural localities into urban centres, it continues to be an important component of city growth. However, natural increase, that is to say, the difference between births and deaths on site, can contribute significantly to urban growth, particularly in countries where fertility levels remain high. Today, natural increase makes a larger contribution to urban population growth than internal migration and reclassification in the majority of developing countries (United Nations, 2009).
The current levels of urbanization are unprecedented and so is the number and size of the world’s largest cities. In 1950, there were only two megacities, that is, cities with at least 10 million inhabitants, and five cities with populations ranging from 5 million to 10 million inhabitants. Today, there are 21 megacities, including 17 in the developing world. However, despite their visibility and dynamism, megacities account for less than 10 per cent of the world urban population. A majority of Africa’s urban population lives in small cities (with fewer than half a million inhabitants) and so does Europe’s. Urban dwellers in Asia, Latin America and the Caribbean and Northern America are more concentrated in large urban agglomerations, with about 20 per cent of their respective populations living in cities with at least 5 million inhabitants.
These transformations have been a major aspect, if not a driver, of economic development.
Cities are focal points of economic growth, innovation and paid employment. On average, urban residents have better access to education and health care as well as other basic services such as clean water, sanitation 1and transportation than rural populations.
If well managed, urbanization can continue to offer important opportunities for economic and social development. However, the speed and scale of urbanization in developing regions challenge the capacity of Governments to adequately plan and meet the needs of the growing number of urban dwellers. As cities grow, managing them becomes more complex and their
populations become more diverse. Developing countries will need to adjust to this process much faster than developed countries did in the past.