Affective dynamics of online climate change denial

Climate change represents one of the most pressing challenges of our time, yet efforts to address it are still persistently obstructed by climate change denial. While emotions are recognized as crucial drivers of such denial, a comprehensive understanding of their dynamics and underlying affective dimensions is lacking. Here, we analyze over one million tweet cascades from a 10-year period (2013-2023) to compare the affective landscapes of climate denial and climate action posts. Our findings reveal that climate denial tweets consistently exhibit stronger negative affective signals, particularly anger and disgust, which have intensified over time and are strongly associated with higher user engagement. In contrast, climate action tweets show lower, more stable levels of negativity and are more frequently characterized by positive emotions like optimism and trust. A meta-regression analysis, framed by the Valence-Arousal-Dominance (VAD) model of affect, demonstrates that valence is the primary dimension explaining these affective differences, their evolution over time, and their impact on engagement. Results suggest that the sustained spread of climate denial is increasingly driven by a strategic mobilization of negative emotional valence. These findings offer a unified, theory-driven perspective on the affective mechanisms that shape the online climate change discourse and the propagation of climate misinformation.