Urban area

An urban area, built-up area or urban agglomeration is a human settlement with a high population-density and an infrastructure of built environment. This is the core of a metropolitan statistical area in the United States, if it contains a population of more than 50,000. Urban areas originate through urbanization, and researchers categorize them as cities, towns, conurbations or suburbs. In urbanism, the term "urban area" contrasts to rural areas such as villages and hamlets; in urban sociology or urban anthropology it contrasts with natural environment. The development of earlier predecessors of modern urban areas during the urban revolution of the 4th millennium BCE led to the formation of human civilization and ultimately to modern urban planning, which along with other human activities such as exploitation of natural resources has led to a human impact on the environment. In 1950, around the world, 764 million people lived in urban areas. By 2014, it was 3.9 billion. The change was driven by a combination of increased total population and increased percent of population living in urban areas. In 2009, the number of people living in urban areas (3.42 billion) surpassed the number living in rural areas (3.41 billion), and since then the world has become more urban than rural. This was the first time that the majority of the world's population lived in a city. In 2014 there were 7.3 billion people living on the planet, of which the global urban population comprised 3.9 billion. The Population Division of the United Nations Department of Economic and Social Affairs at that time predicted the urban population would occupy 68% of the world population by 2050, with 90% of that growth coming from Africa and Asia. By 2022, there are now about 8 Billion living on the planet Earth. Urbanization Urban areas are created and further developed by the process of urbanization. They are measured for various purposes, including analyzing population density and urban sprawl.