There are over 7 billion people on the planet, a massive number that paints an image of human life sprawling densely over the planet. But that picture doesn’t tell the whole story: humans are unevenly distributed across the planet, leaving some areas that are densely populated and others that are largely void of life. The densely populated areas are, in themselves, uneven. Some imagine large cities like New York or Mexico City, but not all of the world’s most densely populated areas contain the kind of infrastructure that one would expect from a city. Slums often contain more people per square mile than the world’s most famous cities, yet contain little infrastructure to support them.
Where New York City has a population density of 69,000 people per square mile, Kibera, Kenya’s capital, houses 190,000-300,000 people per square mile, and many live in large slums without sanitation or water. By contrast, huge areas exist with nearly no human inhabitants. Take, for instance, the Australian Outback: though it physically covers over 75 percent of Australia, only ten percent of its population lives there. Only one continent on the planet, however, has absolutely no permanent human residents: Antarctica.