This paper explores how scientists entangle themselves in between keywords and buzzwords when they make use of concepts like sustainability. It sketches out theoretical distinctions between keywords and buzzwords. Then it turns to the concept of nature discussing the paradox that nature embraces the same fuzzy, slippery and contingent character as does sustainability, yet the former has a deep ontological status, the latter does not. The paper explores a related paradox: natural sciences claim we live in the Anthropocene, in which humans have transformed geochemical cycles, e.g. of methane and carbon dioxide as much as they changed between glacial and interglacial periods. Yet, science favors (external) nature as a keyword, sustainability as a buzzword. This should cause deep reflections on how scientists make use of the power of reference in between keywords and buzzwords – as well as critical reflection on the institutionalization of such concepts.