The past century has been defined by an epic migration of people from rural areas to the city. In 2008, for the first time in history, more of the Earth's population was living in cities than in the countryside.
This image gallery is designed "to present images from space [that] track the relentless spread of humanity." The 'slide bar' in the middle allows the viewer to scroll between before and after images of major metropolitan areas that have experienced dramatic growth in the last 10-30 years. The attached images is on Dubai, UAE. Notice the man-made islands, especially the 'archipelago' in the shape of the world that is 2.5 miles off the coast of Dubai.