Human activities have caused significant changes in the Earth system, emphasizing the need for a cultural reorganization towards sustainable societies. In particular, the progressive change in climatic conditions and the unprecedented loss of biodiversity require a fundamental shift in human perspectives as well as practices, based on a transformation of both the cognitive and affective perceptions of global environmental phenomena. In light of this, recent years have seen a proliferation of research exploring the pivotal role of photography in enabling individual awareness and behavioral change. However, despite their relevance for shaping the visual environmental discourse, the communication strategies of civil society actors as well as their (potential) decision- and action-guiding effects have not yet been sufficiently explored. The dissertation addresses this research desideratum by applying the concept of (visual) framing. Focus lies on the acquisition of theoretical as well as empirical knowledge about latent meaning structures and effects of visual climate and biodiversity communication by environmental non-governmental organizations. In addition to broadening the attention horizon of current communication research, the aim is to involve interest groups in the project development, and thus to strengthen the practical relevance of the results generated.