China has the world's biggest urbanisation problem and Expo is promising the world's best solutions.

By 2030, China will have an urban population of 1bn, having added 350m by then – more than the entire current population of the US, according to a recent McKinsey study, Preparing for China's urban billion. Even five years before that, China is forecast to have 219 cities of more than 1m each, compared with 35 in Europe today, and 24 cities of more than 5m.

Shanghai, with nearly 20m already, is a living experiment in urbanisation – and one that is mostly failing. The polluted Huangpu river runs between banks crowded with concrete apartment complexes with little or no greenery (but lots of hanging laundry). Parks are few and playgrounds almost unheard of; pedestrianisation is limited and walking is deemed one of the city's most dangerous sports.