"Consider a modern city, the product of the human-generated information used to build the housing, businesses, infrastructure and transportation networks that allow millions to live in close quarters, often with exciting results (both constructive and destructive). All that excitement leads us to ignore the fact that these cities of the industrial age are made possible only through massive expenditures of fossil energy and other resources, some of which come from the other side of the planet. Meanwhile, natural ecosystems are home to a much more expansive variety of creatures living in far more complex relationships, requiring none of that fossil energy to maintain. Natural ecosystems can maintain themselves for countless millennia using only solar flows, while cities draw down millions of years of concentrated energy in a relative blink of an eye."