In the 19th century, there were no satellites to document the depth of a night on Earth. Back then, only three per cent of the population lived in cities. Today, we have a nocturnal planisphere of lights revealing unrestrained development. The satellite images foretell demographic relationships and transformations of the land and reveal signs of change.
Human traces can be seen from above. According to the United Nations, more than fifty per cent of the world’s population lives in or is migrating to cities. Within a quarter of a century, two out of three people will live in urban areas. The Megalopolises, which have populations of ten million people or more, are crammed with human beings. But in some other parts of the world Cities are rethinking development. New experiments are beginning, from Masdar City, near Abu Dhabi, to PlanIT Valley in Portugal. Centres that, like organisms, will be able to manage and regulate the urban metabolism of their inhabitants: water, energy, waste. As Aristotle said: “A great city is not to be confounded with a populous one”. The age of the Ecopolis is coming.