China is often accused of all but destroying its environment in the name of economic growth. But the same naked capitalism that has poisoned Chinese skies and waterways is hard at work in the streets of Shanghai, cleaning up the mess.

China has a 10m-strong illegal army of rubbish entrepreneurs and in Shanghai they can seem ubiquitous.

Three-wheeled bicycles piled impossibly high with plastic, cardboard and Styrofoam ply the streets. Pensioners pick through rubbish bins for drinks cans, or beg empty water bottles from tourists. Grannies brave the subway at rush hour to collect commuters' discarded newspapers. Migrant workers go door to door like rag men, buying up the cast-offs of Shanghai's conspicuous consumption, designer water bottles and flat screen television boxes which would otherwise clog up the city's landfills.