Despite the widespread recognition of climate change as the single biggest global threat, the willingness of people to change their behaviour to mitigate its effects is limited. Past research, often focussing on specific categories of behaviour, has highlighted a very significant gap between people’s intentions to behave more sustainably and their actual behaviour. This paper presents a new approach to this issue, by using more open-ended questions to map a much broader range of cognitions and emotions about good environmental behaviour. Two key findings emerged. Firstly, participants were aware of the contradiction between their level of concern about the environment and their willingness to act in more sustainable ways. The qualitative analysis further revealed that this discrepancy often hinged on a lack of knowledge about how to act more sustainably; the analysis also revealed a desire for more information about genuinely green behaviour. Secondly, pro-environmental behaviour was often conceptualised by participants in essentially ‘social’ terms; anticipated emotions relating to sustainable/non-sustainable behaviour were as closely tied to the behaviour of one’s peers as to one’s own behaviour. This finding suggests that we must highlight the social dimension in any interventions to increase sustainable behaviours amongst the public.