Climate change is a complex phenomenon. Responses in the form of decisions and actions on mitigation and adaptation measures, what balance among these should be preferred and how preferred options might be implemented are needed across many different levels in the governance structure and across many contexts of application. These will have to be developed from a very low starting position, often in conditions of ignorance of the urgency of the issues, uncertainty and dispute. If society is to respond effectively, climate change will need to be 'mainstreamed' into routine forward planning and decision-making activities. We argue that this calls for a generic 'capacity' that would be applicable across scales and contexts to explore responses. Most usefully, this should be built around principles of participation, experimentation and social learning, with appraisal conceptualised as an active process used instrumentally to transform the prospects for responding effectively to climate change. Copyright © 2006 Inderscience Enterprises Ltd.