Shanghai Tower

This handout shows an artist's impression of the 14.8-billion-yuan (2.2-billion-USD) "Shanghai Tower" (Tallest R) which is expected to be completed by 2014 in Shanghai's Pudong district. China's past 30 years of reforms planted seeds that will in the coming decades produce future coastal megacities, an urban population of one billion and possibly the world's biggest economy, and what the next 30 years of reforms have in store may be unclear but experts agree with widespread pollution problems and a tidal wave of migration set to hit China's cities, urbanisation will be the future's biggest challenge.