Here's my entry for the Sustainable Cit contest. Some of these buildings may be entered and are fully furnished; the others are mostly filled with hardened clay. The island in the map is made of three of the contest map put together.

The inhabitants of a certain country had realized too late that their way of life was not sustainable in the slightest. Their cropland had had all of the nutrition drained from it through generations of poor farming practices. Their forests had been clear-cut to the point that they might take centuries to recover. And their towns had been destroyed by earthquakes as a result of mining too many minerals from the ground. Hungry and homeless, they came to Steve for help.

Steve thought hard. Then he produced an enormous floating island, and designed a sustainable city that would be built on it. Every home of the old country would be condensed into three massive apartment complexes, and every business into five giant office towers. Most buildings would be powered by solar panels, and the city's infrastructure would be powered by wind turbines. There would be no roads, but rather, a variety of walking paths. And much of the land would be left green, so that the island as a whole would absorb more greenhouse gases than it created.

So the poor refugees helped Steve to build their new city, and then the moved into it and settled down. They still live there. When they will be able to return home, or if they will want to, is anyone's guess.