Previous studies have shown that there is what has been called a "gap" between environmental knowledge and a willingness to act in a pro-environmental manner. For the individual, this gap is probably the result of the huge complexity of factors that affect behaviour. The way in which this "gap" is sometimes identified in the literature, however, is also partly a function of the fact that much of the research in this area has compared environmental attitudes in general with a willingness to take actions that are specific. In the present study, we have circumvented this latter issue by exploring links between a declared willingness to undertake specific actions and the level of belief in the efficacy of those particular actions in reducing global warming. Here we report findings on actions concerning personal transport. Because the questionnaire was designed to provide quantitative measures, novel indices could be constructed that indicate, for example, the extent to which persuading people that an action is effective might increase their willingness to undertake it. Responses were obtained from students in 11 countries with different cultural mores. This enabled us to explore possible associations between a readiness to undertake specific actions and previously published socio-cultural indices. The implications for education about these issues are explored.