The Changing Geography of Global Cities: A Spatiotemporal Analysis of Urban Population Growth from 1950 to 2035.

Abstract

In the era of global urbanization, the spatial dispersion, the size and the rank of cities around the world have changed. The current study aims to explore the new geography of the world's cities by a spatiotemporal analysis of urban population growth between 1950 and 2035. A quantitative longitudinal approach was employed to estimate the population change, the continental distribution, the city-rank transitions and the growth of megacities in the main continents of the world. Long term trends and projections were identified by using descriptive statistics, comparative ranking, growth measurement, and graphical visualization. The results show significant growth in the total population of the big urban agglomerations and a significant change in the global urban hierarchy. Asia became the main hub of urban growth; Africa had the highest rates of proportional growth and more and more megacities. There was strong population growth and upward rank mobility in cities like Delhi, Dhaka, Kinshasa, Lagos, and Cairo. By contrast, other cities that have been historically dominant have seen their relative position wane, even whilst maintaining their urban importance, in Europe and North America. The number of megacities grew significantly, with most expected to be in Asia by 2035. The study finds that the global urban system is in a critical moment of dramatic transformation towards the Global South. The implications for metropolitan governance, infrastructure, housing, public services, adaptation to climate change and sustainable urban planning are significant.