"Save the earth." How often have you heard that slogan? Well, it is a noble thought, but it is misdirected! The earth is not in trouble and it does not need saving. Even if it did, there is absolutely nothing that people can do today to either save or destroy the earth. The earth is a planet of the sun. It consists of a mass of solids, liquids, and gases that occupy a very small corner of the universe. It provides a home for many billions of living organisms. The earth was fine long before people came; it will be fine long after we are gone. What we had better start being concerned about is how to "Save the humans." That is what this book is all about. How the environment works. How we humans relate to it. What we need to do today and in the future to have a sustainable and liveable world order. - Preface.