Future communities such as the solar-powered Babcock Ranch in Florida or PlanIT Valley in Portugal will have to prove that they are actually livable cities that people want and demand for.
"If there is market demand for these communities, these developments may prove to be scalable and replicable. Only the early residents who buy in can determine if these places are truly livable. However, it remains to be seen whether these new developments will actually be sustainable when all construction CO2 emissions are factored in on these greenfield sites. How are these developers accounting for those emissions?
In contrast with these bold visions, pragmatic New York City, already one of the world's most sustainable cities, is focused on improving what it has. The city's model climate change mitigation and adaptation plan, PlaNYC, is being used to guide smart investments in the environment, and water and energy infrastructure."