This chapter investigates the political–ideological context in which the contemporary Australian and international far right has emerged, which is characterised by growing recognition of ecological-environmental impacts and future climate scenarios among both radical social movements and mainstream political institutions. The analysis explores two related discourses on the threat of catastrophic climate change that shape and pattern far-right responses. First, we examine the Environment–Security–Development (ESD) nexus in intergovernmental approaches to security threats related to climate change, the far right and economic as well as human development. This discussion assesses the impact of ESD discourses on global heating, economic inequality and far-right political advancement, particularly regarding their treatment of migration, resource scarcity and intra-state conflict. The second section considers the emergence of ‘New Catastrophism’, as a category of (often) doomsday literature outlining proposals for systemic change in the face of the various possible outcomes of climate change. The aim in pursuing this investigation is not to equate ‘right’ and ‘left’ radical traditions but to identify social and political forces that either reinforce or provide alternatives to far-right environmentalist politics and the associated political tendencies of ethnonationalism and authoritarianism. Ultimately, drawing on insights from the ESD and New Catastrophism literature, the chapter signals suggestions for mitigating both climate change and the rise of far-right social movements.