today, just over half of the world's population lives in cities. According whith predictions , this proportion will rise to 70% by 2050.
in the past, urban population was mainly concentrated in developed countries. However, today it is increasing rapidly in emerging and less developed countries.
urban growth has led to an increase in the number of megacities(urban areas with more than 10 million inhabitants).
There were only five megacities in 1975 but today there are more than 20. By 2025, there will be over 30 of them, mainly in emerging and developing countries.
The urban hierarchy: global cities
cities can be clasificated according by several criteria, such as their influence, functions, population size and economic importance.This system of classification is called the urban hierarchy.
a small number of great metropolises, called global cities, are at the head of the world urban hierarchy. New York, London, Paris, Tokyo and Hong Konk are the leading global cities.
global cities have great influence on the global economy. They have:
- many of the world's main financial institutions, including stock exchanges and banks.
- national and international institutions.
- th eheadquarters of many leading multinational companies.
- key information and communications industries.