This paper develops the concepts of the climate discourse complex, and national climate policy regime, in order to analyse significant patterns in Australian national climate politics over the twenty-five years from 1988 to 2013. Six major discursive fields — scientific, ethical, economic, technological, political/legal, and “everyday life”— contribute to the ensemble of discourses that constitute a climate discourse complex. The climate discourse complex in turn serves to frame and discipline climate debate and the articulation of a national climate policy regime. The composition of Australia's climate discourse complex has been dominated by the economic discursive field. Debates over “old” and “new” economic discourses have been the key drivers of and constraints on the trajectory of Australia's climate policy regime for much of the period under consideration. These debates have diminished and sometimes marginalized the influence of scientific, ethical and other discourses, contributing to Australia's weak mitigation ambition. The paper also suggests that significant changes in Australian climate discourses and Australia's climate discourse complex have largely been initiated by factors external to Australia, with the major shift occurring in the period 2006/2007.