In this paper, we report some reflections on science and education, in relation to teaching and research in the field of complex and controversial socio-environmental issues. Starting from an examination of the literature on the epistemological aspects of the science of controversial issues, and introducing the perspective of complexity, the article argues for a complexity of content, context, and method in understanding current problems. Focusing on a model of learning which includes dialogical and reflective approaches, the final part of the article reports on aspect of the authors' experimental practice with role-play for dealing with complex issues. The review of the literature and our experience of action-research introduce a view of education which promotes young people's awareness of multiple points of view, an ability to establish relationships between processes, scales, and contexts which may be nonlinearly related, and practice with creative and nonviolent forms of interrelations with others. Such an approach in science education is coherent with a scenario of planet sustainability based on ecological webs and equity principles.