So often these giant conurbations and the challenges they pose to inhabitants, city-planners, businesses, politicians and more, are discussed in pejorative terms. On ‘The World Ahead’ we’re interested in hearing from people whose insights and experience show that bold decisions can make a positive difference – and on a huge scale. We discuss what cities are doing to affect positive change, the expansion of our urban environment and the role that both public and private resources should play in meeting challenges.