The development of this new transnational climate action movement also raises familiar questions about the efficacy of particular strategies. The history of social movement activity suggests that reforms are more likely to be achieved when sections of a social movement demand more than mere reforms and behave in confrontationist ways. Moderate sections of a social movement might claim achievements are solely theirs, but evidence suggests that it is extremist claims and militant tactics, which incline governments and corporations to accede to moderate demands in order to weaken extremist challenges. With respect to the Australian Government’s Carbon Pollution Reduction Scheme, moderates have accepted it as ‘better than nothing’ and something to develop steeper mitigation strategies. In contrast, militants organized in local Climate Action Groups have called for considerably more ambitious mitigation strategies; and some climate activists have embarked on militant direct actions at coal ports, coal mines and coal-fired power plants. This paper examines the emergent climate action movement in Australia to inquire whether social movements’ prospects are impeded or enhanced by extremist demands and confrontationist strategies.