For their excellent “Urban Planet” special online section, the BBC recently convened six leading thinkers on urban planning and the human environment to discuss the world in 2050, when well more than 50% of humanity will be living in cities — many of them hypercities — mostly in what is today the developing world. Among them, Stephen Graham of the University of Durham points out that urbanization is an unintended byproduct of technological progress: the more we use advanced technologies, the more our cities seem to grow, even as they should enable us to live anywhere.

Of particular note is the impressive data visualization (above) that shows the growth of large hypercities across the globe from 1955-2015. And be sure to read PopTech 2005 presenter Robert Neuwirth’s Shadow Cities: A Billion Squatters, A New Urban World, for a provocative look at the future of the urban experience.