The Environmental Impact Assessment (EIA) encompasses the scientific core of an Environmental Impact Study (EIS). Until now, the literature has predominantly discussed the legal and administrative aspects of the EIS. This book presents, for the first time, a systematically grounded methodology of the EIA, highlighting both the historical context and international development trends. Of particular interest are the USA and Canada, from where the global spread of the EIS originated in the early 1970s. The book explains theories, professional connections, and focal points of application. Numerous case studies provide inspiration for conducting environmental impact assessments in practice.