Introduction. Cities in World Politics. Local Responses to Global Challenges

Urbanisation is one of the most powerful trends of the modern era. Since 2007, for the first time in history over half the world’s population lives in cities, a proportion the United Nations (UN) estimates will rise to two-thirds by 2050 (UN, 2019). Much of this urban growth will take place in Africa and Asia, but other regions will also be deeply affected. New concepts such as the “urban age” (Burdett et al., 2018) and “planetary urbanisation” (Brenner, 2014) have been coined to capture the radical demographic shifts we are witnessing and to express a new reality in which the scale and generality of urbanisation processes leave few places free from their impact and render traditional urban-rural distinctions redundant.