How did cities emerge? Where were they located? How did they change over the course of human civilization? How did they change their surroundings?
The answers to these questions are available, but hard to access. The United Nations World Urbanization Prospects, for example, only tracks urban populations and their locations from 1950 on, and so offers only a small, relatively recent snapshot of urbanization. The work of the historian Tertius Chandler and the political scientist George Modelski is much more extensive. The two painstakingly gathered population and archeological records from as far back as 2250 B.C. The problem, however, is that their data exist in the form of tables that are stuffed with hard-to-decipher numbers and notes.