Floating Lilypad cities of the future might make sense?
At least, that is what Architect Vincent Callebaut's vision is. Vincent designed each floating lilypad city so support 50,000 people.
The floating cities are completely self-sustaining and have a zero-emissions footprint.
They use wind, solar, tidal and biomass power to generate energy. Vincent's ark has skin made out of titanium dioxide that allows it to combat rising atmospheric CO2.
Now if he could just figure out how to make them fly, they would look like Independence Day all over again...