Recognizing that over the past decade transnational environmental activism focusing on climate change has radicalized in public tactics and discourse, this project employs a mechanism-process approach to analyze and explain processes of tactical and discursive radicalization within the global climate justice movement(s) over time. As global activists within this movement construct and pursue public, as well as covert, campaigns directed at states, international institutions, corporations, the media and society at large, it asks why, how and to what effect specific sectors of the broader movement have radicalized from the period 2006-2010. Utilizing longitudinal quantitative protest event and political claims analysis and ethnographic field work and participant action research, it aims to provide a descriptive and comparative account of tactical and discursive variations at international climate change protests situated within the context of a broader cycle of transnational global justice contention.