Population & UrbanizationAs of March 2008, the total number of human beings on the Earth is estimated to be more than 6.6 billion. The actual population is never known for certain, since these numbers rely on national censuses, which are conducted at different times. The United States Census Bureau’s currently estimates that the world population will increase to more than 9.4 billion people by 2050.
In 1800, only 3 percent of the world's population lived in cities. By the end of the 20th century, the percentage had risen to 47%. Later this year (2008), the world’s population will reach a major milestone: For the first time in history, more than half of the human population will live in urban areas (defined as a population center with more than 50,000 inhabitants). According to a recent United Nations report, the world’s urban population is expected to swell to almost 5 billion by 2030, when three out of five people will live in cities. By the year 2050, the percentage of urban dwellers worldwide is expected to reach 70 percent.
Although the world’s urban population grew very rapidly (from 220 million to 2.8 billion) during the 20th century, the developing world will experience an unprecedented rate of urban growth during the next
The next few decades will see an unprecedented amount of urban growth in the developing world. This will be particularly visible in Africa and Asia where the urban population is expected to double between 2000 and 2030. In fact, the accumulated urban growth of these two regions during the entire span of human history will be duplicated within a single generation. By 2030, the towns and cities of the developing world will make up 81 percent of urban humanity.