Anxious about the failure of decisionmakers to significantly reduce 'the human impact' on Earth, many global change researchers are looking for ways and means to influence public policy, business strategy and civil society more strongly. As part of this, there is a greater emphasis on understanding and altering the 'human dimensions' of global environmental change. A number of physical and society-environment geographers are involved in this endeavour, building on some valuable past achievements. But what lies ahead? I address this question by examining the rich idea of a 'social contract' - one little used in disciplinary debates about Geography's past, present and future, but now relatively common in certain wider discussions of anthropogenic global change. I suggest that there are currents of thinking in contemporary Geography that can offer something both new and much needed in the world of global change research. That 'something' is not ever more integrated, accurate analysis of dynamic, coupled human-environment interactions - as if we live in just one world requiring ever more 'joined-up' and granular description, explanation and prediction. Instead, it is an approach to research that eschews ontological holism, epistemological monism and the fact-value dualism. This approach suggests that taking the human dimensions of environmental change seriously requires a new kind of global change research that is at once overtly political and intellectually plural. Far from being a charter for 'bias' or 'relativism', I show that this approach expresses the rich senses of responsibility, accountability and representation contained in the version of a new social contract I advocate here. A wider implication of my argument is that Geography needs new stories about the nature and merits of 'intra-disciplinarity', ones better attuned to the role of research in fostering democracy in our 'post-normal' times. Thinking afresh about how research should influence society promises to alter many geographers' sense of self while usefully repurposing global change research across several disciplines.