This book provides an examination into the causes and prospects of desertification through a systematic review of 132 sub national case studies. It uses a meta-analytical model to determine whether proximate causes and underlying driving forces fall into any patterns, to identify mediating factors, feedbacks, cross-scalar dynamics and typical pathways. It shows a limited set of recurrent core variables in varying combinations to drive desertification. Most prominent root causes are climatic factors, institutions, national policies, population growth and remote economic influences that lead to local cropland expansion, overgrazing and infrastructure extension, associated with desertification as a potential but not necessary outcome. Some factors are geographically robust; most of them are region and time specific.