This text features the lectures and results of a workshop on environmental monitoring that took place in Munich in June 1994. The organizer of the workshop was the Harmonization of Environmental Measurement Office (HEM) of the UN section dealing with this aspect of the protection of the environment. The volume presents the basic requirements for establishing an international network of environmental monitoring. It deals with the factors necessary for harmonizing environmental measures and setting up parameters for the comparability of data gained. Finally, it offers a concept for the establishment of such a terrestrial network. The book includes the names of the workshop participants and an index of already existing monitoring systems.