The diagram illustrates world population growth over three centuries and the urban populations in various global regions over a 25-year period. The figures are expressed in billions.
Overall, there has been a significant increase in global population growth since the mid-20th century, with a predicted decline by the year 2100. While the urban population in developing regions has steadily increased, the population in developed regions has remained stable and is expected to continue to do so over the next quarter-century.
At the beginning of the 19th century, world population growth was gradual and steady, but a substantial increase was observed by 1950. This growth is expected to continue, with the population reaching 9 billion by 2050—an 80% increase from the initial figure. Forecasts suggest a decline of 20% by the end of the 21st century.
In developing regions, the urban population started at just over 2 billion in 2005 and has shown a steady increase, projected to reach 4 billion by 2030—essentially a two-fold increase from the initial measurement. In contrast, the urban population in industrialized regions was just above 1 billion in 2005 and has remained stable until 2025, with projections indicating that it will continue at that level until 2030.