Uncivil climate: the politicization of environmental discourse on Reddit (2008–2025)

Despite growing concern that the politicization of climate change has fostered increasingly uncivil online discourse, long-term trends in incivility across environmental topics on Reddit remain poorly understood. To address this gap, our study analyzed 17 years of Reddit on the r/environment subreddit (2,019,703 comments and 411,106 submissions) through a deep learning topic modeling (BERTopic) approach for incivility detection. Results indicate an abrupt but uneven spike in incivility in comments from 2016, mainly from politically salient topics (climate politics, protests, and climate talks). Comment network community detection revealed no evidence that incivility was concentrated within particular communities, thereby indicating a broad distribution of incivility throughout the network. We propose that incivility in environmental discourse largely arises as a collective reaction within politically salient environmental topics instead of being the product of a vocal minority. As climate change becomes increasingly politicized, we see the deterioration of productive discussions amidst sharply increasing incivility, yet the underlying comment networks remain cohesive. This suggests that politicization of climate change on Reddit may have redefined interaction norms without necessarily producing network fragmentation.