This dissertation uses a case study of the recently proposed dam on the Mary River at Traveston Crossing in South-East Queensland to consider how individuals can become empowered to effect change in the environmental decision-making processes of the state through citizen action in the public sphere. The theoretical framework chosen to guide the analysis is an adaptation of Judith Butler’s theory of performativity (1997) that I refer to as political performativity. I also draw on social movement theory and media theory to examine how the processes of performativity help explain the practices involved in the public sphere actions taken to stop the Queensland Government’s proposed dam. The case study demonstrates that the initial speech acts of the state government’s announcement, and the way in which these were carried out, impacted on the life worlds of people involved. The protesters’ actions were not only symbolic of their struggle but also part of the creation of an alternative life world vastly different to that imposed upon them through the various speech acts of the Queensland Government. Lessons for the future include the development of more conscious strategies for activists in public sphere actions. Potential research resulting from this study includes a closer examination of the relationship between speech acts, emotions and public sphere action. The usefulness of political performativity in understanding emotions, public sphere action and power may better be served through participatory research methodologies. Further research directions are outlined.