Time travel may be the stuff of science fiction, but if you're curious to know how we'll be living years from now, look no further. From Malaysia to Mexico and the Maldives, all-new cutting-edge smart cities with outstanding green credentials are providing a blueprint for urban development. As the effects of climate change become increasingly devastating, these carbon-neutral utopias may be key to our species' chance of survival, if they're as virtuous as they appear.