Controversial, and often discussed with passion and vehemence, desertification is a problem on whose solution the survival of millions of humans is dependent. This book aims at an understanding of what is commonly called "desertification" - a term which has a connotation of irreversibility, spreading and emergence of desert-like landscapes: "land degradation" is proposed to replace it. The purpose is to present what has happened in reality, and what might be done. Illustrative worldwide analyses allow a more realistic evaluation of global land degradation. Each level of technology, excessive or insufficient, creates its own mismanagement. This is reflected in a decrease in soil productivity and eventually land degradation. The benefit to the reader is an awareness of the ecozones which have undergone the most severe land degradation, and a global overview of the phenomena, mechanisms and existing solutions.