With PortalU you can search for environmental information in metadata and environmental data catalogues of 14 federal states (German Länder) as well as the Federal Agency for Nature Conservation (BfN) and the Federal Environment Agency (UBA).
Have a look on the list of all accessible environmental data catalogues and associated metadata provided by the authorities. You can also sort the information by topic.
You can also view information (e.g. abstract of the data set, contact address, space-time reference) about selected catalogue objects by displaying metadata.
Search in the environmental thesaurus of the Federal Environment Agency.The thesaurus contains more than 30.000 controlled vocabulary terms of various environmental topics. Currently only available in German.