This project aims to analyze the processes of transformation over time of the representations of the environment transmitted by the national mass media. In view of the development of new risks, such as climate change, and the persistence of old problems, such as basic sanitation, the aim is to keep a close watch on the recent dynamics of media information production, given the centrality of its impact in the public perception of environmental problems, as well as in scheduling these issues in the formation of public opinion. The background analysis of this subject in the scope of the Observations are useful to the comparability of the data, allowing the construction of a longitudinal perspective on the mediatization of the environment in Portugal.