Radical climate protests shaped portrayals of moderate activists and reader attitudes in German news media

Radical climate protests have been theorized to shape perceptions of moderate climate groups, a dynamic known as the radical flank effect (RFE). We examine this phenomenon through a longitudinal analysis of German media discourse on climate protests. Using validated large language model prompts, we annotated stances and anger in 2376 news articles and 225,121 user comments covering the moderate activist group Fridays for Future (FFF) and the more radical Last Generation (LG). Short- term increases in LG protest coverage were associated with increased support for FFF in news articles and left-leaning outlets’ user comments, but with decreased support in right-leaning comments. However, these patterns were not observed over longer time periods. Although anger expressed in the general coverage of climate protests impacted subsequent support for FFF, this effect was not specific to coverage of radical protests. These findings highlight the temporally bounded and ideologically contingent nature of RFEs in media discourse.