Cities will need to be denser and taller in the future. It's the only way to accommodate a global population of 9 billion-plus people and increasing demand for urban living (70% of us could live in cities by 2050, according to some projections). The alternative is surely worse: More sprawl taking up what little green space is left.
The concept of a "vertical city," as sketched out in a new book by architects Kenneth King and Kellogg Wong, is something more than a hyper-dense Gotham, though. Yes, there are a lot of towering buildings but also parks, schools, hospitals and restaurants at upper levels, as well. Essentially, it's a vision of a complete ecosystem in the sky—a place you never have to leave if you don't want to.