Abstract
The significance of eco-religious communication is not limited to the ecological and bioethical discourse. Within the context of the Science of Religion (Religious Studies), contributions by groups and individuals affiliated with religious traditions to the discussion of environmental issues as well as religious exhortations and activities related to environmental concerns are treated as phenomena of contemporary religion that invite theoretical reflection and empirical research. This paper discusses the problem of determining the “religiousness” of eco-religious communication from the perspective of a Luhmannian systems theoretical approach to the study of religion. The paper explains the relevant concepts and premises of this approach, which will focus on the relation of eco-religious communication to the immanence/transcendence code of the religious system and the specific programs (teachings, regulations etc.) of particular religious traditions. According to the functionalist perspective of this approach, the religiousness of eco-religious communication is determined by its primary function within the self-referential network of communications.

Key words: Science of Religion, Religious Studies, Theory of Religion, Ecology and Religion, Systems Theory, Luhmann, Code, Immanence/Transcendence