Climate Denial and Distrust of Science: An Analysis of Instagram Comments on Portuguese News Media During the 2026 European Heatwave

Social media platforms have become important arenas for public discussion of climate change, facilitating both the dissemination of scientific information and the contestation of climate-related claims. This study examines the discursive patterns through which climate change and extreme weather were contested in Instagram comments associated with news coverage of the June 2026 European heatwave. A qualitative research design based on inductive thematic analysis was employed, complemented by descriptive quantification of the resulting thematic categories. The corpus comprised 1197 top-level comments associated with 13 climate-related posts published by four prominent Portuguese news media outlets on Instagram. Seven thematic categories were identified: denial of human influence on climate change, normalization and trivialization of observed phenomena, discrediting of mass media, discrediting of science and experts, conspiracy narratives, anecdotal evidence and personal experience, and climate-affirming or neutral discourses. The most frequent categories were denial of human influence on climate change (31.4%) and normalization and trivialization of observed phenomena (21.0%), followed by discrediting of mass media (13.8%), climate-affirming or neutral discourses (11.5%), discrediting of science and experts (9.8%), conspiracy narratives (7.2%), and anecdotal evidence and personal experience (5.3%). The findings reveal a substantial presence of climate-dissent discourse within the analyzed corpus, expressed through both explicit rejection of anthropogenic influence and more indirect forms of contestation. However, the results should not be interpreted as representative of Portuguese Instagram users or the Portuguese population as a whole. The study highlights the importance of examining the discursive dynamics of social media comment sections for climate communication, science communication, and climate literacy.