Over the last decade, East Asia has seen an anarchic expansion of urban development, and a new kind of city has taken shape. Will this affect architecture across the world in the next century? How will economic growth affect environmental improvement? And what of the artist's role within such a megalopolis? Laura Cumming and guests discuss Cities on the Move - Urban Chaos and Global Change, an exhibition that opens this week at the Hayward Gallery on London's South Bank.
Plus news from the opening of this year's Cannes Film Festival. Producer Lawrence Pollard