The Encyclopedia of Life Support Systems (EOLSS) is an integrated compendium of twenty one encyclopedias. The first Earth Summit of 1992, held in Rio de Janeiro, issued a document that is now famous as Agenda 21. This document refers to the Earth's life support systems, considering the whole of our planet as a grand intensive care unit that supports all forms of life (both natural and human-engineered systems). The EOLSS is based on this concept and the above definition of 'life support systems'. Unlike most encyclopedias, the contents of which are alphabetically arranged, EOLSS has a thematic organization (Theme Level, Topic Level and Article Level). It can be regarded as an 'encyclopedia of encyclopedias', presenting a wide range of major foundation subjects in a process of gradual development, from a broad overview to great detail.
Subjects covered include Earth and Atmospheric Sciences; Biological, Physiological And Health Sciences; Mathematical sciences and Physical Sciences; Chemical Sciences; Water sciences and Engineering; Energy sciences and Engineering; Biotechnology; Tropical Biology and Conservation Management; Land Use, Land Cover And Soil Sciences; Control Systems, Robotics, and Automation; Environmental and ecological sciences, and Engineering; Food and Agricultural Sciences; Human Resources Policy, Development, and Management; Natural Resources Policy; Development and Economic Sciences; Ships and Offshore Structures; Regional Sustainable Development; Social Sciences and Humanities; Institutional, Infrastructural Resources and Desalination and Water Resources.