Within the major Australian cities - where the majority of people live - the immediacy and potentially catastrophic nature of climate risk (i.e. storm surge, fire, drought) pose considerable challenges to contemporary models of governance. In response to climate change conditions that Spratt and Sutton (2008) describe as having entered the realm of a ‘code red’ emergency, there are growing calls for a much stronger national security role. This paper draws on critical securitization theory to explore the democratic dilemmas and potential of a greater national adaptation role for Australian cities within a climate constrained future. The paper concludes by highlighting the theoretical and practical implications of this approach to climate governance for Australian cities.