Why do the designers of environmental education do what they do towards the environment through education? More importantly, how do they account for their design decisions (plans and actions)? Using the theoretical and methodological framework of discourse analysis, we analyse environmental education designers' discourse in terms of the discursive resources--or "interpretive repertoires"--that they use to (a) make their position, (b) make their talk do work and (c) tell a story about events, situations and who they are (identity). Drawing on observations and interviews from a larger programme concerned with understanding environmentalism and environmental education, we identified five main repertoires: "relevance," "knowledge transferability and translatability," "emotionality," "expertise" and "empiricism." The approach provides us with a more refined characterization of the culture of environmental education curriculum design through the ways designers in the field explain their doings, and we explore the important implications for curriculum design in this field. (Contains 1 figure and 1 note.)