Converging trend of global urban land expansion sheds new light on sustainable development

TL;DR

This study reveals a converging pattern in global urban land expansion characterized by a shift from power law to exponential distributions, highlighting increased risks and the influence of globalization, with implications for sustainable urban development.

Contribution

It uncovers a universal converging trend in urban land expansion and links it to globalization effects, providing insights for sustainable urban planning.

Findings

Urban land distribution shifts from power law to exponential.

Globalization influences urban land expansion dynamics.

Increased risks of extreme heat and pollution exposure.

Abstract

Urban land growth presents a major sustainability challenge, yet its growth patterns and dynamics remain unclear. We quantified urban land evolution by analyzing its statistical distribution in 14 regions and countries over 29 years. The results show a converging temporal trend in urban land expansion from sub-country to global scales, characterized by a coherent shift of urban area distributions from initial power law to exponential distributions, with the consequences of reduced system stability and resilience, and increased exposure of urban populations to extreme heat and air pollution. These changes are attributed to the increased influence from external economies of scale associated with globalization and are predicted to intensify in the future. The findings will advance urban science and direct current land urbanization practices toward sustainable development, especially in developing regions and medium-size cities.