A new approach to scenarios focused on environmental concerns, changes and challenges, i.e. so-called 'environmental scenarios', is necessary if global environmental changes are to be more effectively appreciated and addressed through sustained and collaborative action.

On the basis of a comparison of previous approaches to global environmental scenarios and a review of existing scenario typologies, we propose a new scenario typology to help guide scenario-based interventions. This typology makes explicit the types of and/or the approaches to knowledge ('the epistemologies') which underpin a scenario approach.

Drawing on previous environmental scenario projects, we distinguish and describe two main types in this new typology: 'problem-focused' and 'actor-centric'. This leads in turn to our suggestion for a third type, which we call 'RIMA'—'reflexive interventionist or multi-agent based'. This approach to scenarios emphasizes the importance of the involvement of different epistemologies in a scenario-based process of action learning in the public interest. We suggest that, by combining the epistemologies apparent in the previous two types, this approach can create a more effective bridge between longer-term thinking and more immediate actions. Our description is aimed at scenario practitioners in general, as well as those who work with (environmental) scenarios that address global challenges.