Whether we eat vegetarian, ride bicycles, or install solar panels: we constantly make decisions in favor of the environment – or not. What guides and motivates us in these choices is explored by environmental psychology. The Handbook of Psychology in Environmental Protection explains, using a psychological model, how we can better understand and promote sustainable behavior. As the first German-language work, it scientifically and practically summarizes the knowledge of applied environmental psychology. Important topics such as self-efficacy, social norms, and emotions each receive their own chapter. Guiding questions and everyday examples allow for direct application in environmental protection. This handbook is aimed at anyone who wants to make their environmental protection projects and communication more effective – whether in education, urban gardening, or other areas of environmental protection.