In 50 years from now, cities will be home to 70% of all human beings. They will have seven billion mouths to feed and will face an immense challenge in terms of food supply. Are hydroponics and vertical farming going to solve this challenge?

Megalopolises are spreading out and becoming denser -- and there is nowhere left to park. Luckily, the technology is there to deal with this growing chaos. Technological urbanism promises hyper-rational cities that are 100% sustainable and perfectly safe. They are known as smart cities.

In South Korea, China and Saudi Arabia, in Abu Dhabi and in Russia, a new kind of city is now under construction. These are prototypes of green, hyper-connected cities that are stuffed with digital technology and ecological equipment.