The desserts and jungles are littered with abandoned ancient cities from civilizations that failed without explanation. The synopsis on the back of the book says that it analysis why the great civilizations declined in terms of changes in their environment. The book starts off at Easter Island where explorers found evidence of an advanced culture demonstrated by the huge statues but the current inhabitants were living in caves and had no idea how the statues …showed first 75 words of 805 total…

…showed last 75 words of 805 total…playing Civilization and Age of Empires for a few days. In Civilization you need workers to bring resources in and each city can only access the surrounding eight land areas. Irrigation improves things and in the modern era intensive irrigation is possible. A surpass of food allows entertainers, tax collectors and scientists to be supported. Large cites, after the invention of industrialization, produce pollution that reduces the yield from the land. Quite simple stuff a