This article begins by clarifying and discussing the concept of 'pro-environmental behaviour', which (implicitly) constitutes the central concept--or aim--of environmental education in the article. This is followed by a discussion of the concept of knowledge per se and its position in working with environmental problems. These two concepts require further refinement if research efforts are to make a contribution to the development of environmental education. A few examples and conceptual models will be proposed to clarify the discussion. Finally, comments and suggestions are offered for an elaboration of the model proposed by Kollmuss and Agyeman. This present article primarily draws on research and insights into environmental education in schools. Furthermore, the article primarily explores work with environmental problems in Danish schools and focuses on the general pedagogical dimensions of work done in schools in order to relate these directly to issues discussed by Kollmuss and Agyeman.