In 2008, for the first time in history, as many humans were living in cities as in rural areas. Over the decades, many cities have swelled to accomodate the growing human population as well as the growing trend toward urbanism. These are changes so extreme that they can be seen from space.
Wired collected these and eight other pairs of images from NASA and the US Geological Survey's Landsat program, which collects satellite images of Earth. These false color images give us a clear view of Las Vegas' sprawl, Dubai's coastal transformation, and the urban explosion of China's Pearl River Delta, which is now a major manufacturing region. (It's worth noting that, in the last image, the color red represents land covered by plants.)
Wired has far more examples of urban growth captured by satellite, from the web of roads spreading out from Tehran to the steady human colonization of the Chicago metro area to immense growth of Burkina Faso.
Pearl River Delta, China