In public discourses on climate change and the future, children are often included as a metaphor for “future citizens”, the ones that will take the consequences for consumption and lifestyles of today. At the same time the discourse define them as excluded from the category “citizens of today”, since they lack experience, knowledge and responsibility. The question is, how do children themselves use their experiences and knowledge to handle the climate change issue and how do they express responsibility for their lifestyles and actions? In this study, 9-10 year olds in Sweden discuss issues about carbon dioxide reduction. We analyses how they use different discursive repertoires to legitimise or question their ‘normal’ everyday lifestyles. Conversations from 25 groups of children were audio-recorded, transcribed and coded. Six repertoires were identified: Everyday life; Self Interest; Environment; Science and Technology; Society; Justice. The everyday life repertoire was for example used when they related to the image of ‘normal’ lifestyle. Science and technological solutions were often suggested as ‘magic bullets’ to maintain or improve these. Arguments related to environment were commonly superior to other. Findings show that the children were able to negotiate real-world science of the kind used by engaged citizens, and able to discursively handle this complex issue. When the repertoires became in conflict, the children had to ‘renegotiate’ their own identities, and showed responsibility to change their lives. They positioned themselves as active contributors to society, using scientific ideas, among others, to understand the problems that affected their normal everyday lives.