Unique in the reference literature, this Companion provides students with an introduction to all the major concepts and contemporary issues in the environmental sciences. The text is divided into six sections: Environmental Sciences, Environments, Paradigms and Concepts, Processes and Dynamic, Scales and Techniques, and, Environmental Issues, along with over 200 entries alphabetically organized and authored by key names in the environmental science disciplines. The entries are concise, informative, richly visual, and fully referenced and cross referenced. They introduce key concepts and processes that are included in the index, cite relevant websites, and reflect the latest thinking.