An electronic reference about the Earth, its natural environments, and their interaction with society. The EoE is a free, expert-reviewed collection of content contributed by scholars, professionals, educators, practitioners and other experts who collaborate and review each other's work. The types of the content are Articles, Definitions, Reports, Ebooks, Images, videos and sound files which are presented in a style intended to be useful to students, educators, scholars, professionals, as well as to the general public.