How and why people's environmental values change is a topical research issue, with major implications for sustainability policy. However, approaches based on individualistic models have had limited success in explaining the emergence of values, or developing interventions to change them. Work drawing on social practice theory takes an alternative approach, seeing values and practice as co-constructive. This paper examines how personal environmental values evolve through performance of practice, experience within specific contexts and social interaction. Drawing on a narrative-based study of UK climate change campaigners, it aims to contribute to a much-needed dialogue between sociological and psychological approaches to environmental values.