This paper examines the rhetoric and argumentation of two prominent environmental activists, Greta Thunberg and Chris Packham. From the perspective of Ecolinguistics, Thunberg has given voice to a generational movement for change, galvanising young people everywhere through high-profile protests and speeches. Packham represents British mainstream environmentalism, notably as the presenter of the acclaimed nature documentary ‘Springwatch’. We argue that their influence partially stems from their alignment with dominant cultural narratives: Thunberg’s emphasis on intergenerational discord and Packham’s connection to the natural world. We analyse both figures via the lens of the ‘emotionalisation of media discourse’, highlighting argumentation strategies that feature expressions of negative emotions of which anger is a type. Thunberg’s famous ‘How dare you?’ outburst at the 2019 UN Climate Action Summit and Packham’s statement to Novara Media, ‘I am more angry now than at any point since my 20s’, exemplify this trend. We explore the pragmatic implications of their argumentative and discursive strategies, suggesting that while both have significantly elevated the profile of ecological activism, their discourse may also have a potentially divisive aspect.