Simple Logic Warnings Improve Climate Argumentation Across Prior Beliefs and Political Identities

Collective climate action requires shared climate beliefs in line with the scientific consensus. However, climate discourse is flooded with fallacious information and people often fail to evaluate it correctly, accepting weak arguments and rejecting strong ones. Understanding these failures is critical for developing evidence-based interventions, yet it remains unclear whether they are driven by partisan identity protective tendencies, entrenched prior beliefs, or failures in logical reasoning. This opacity stems from a persistent empirical challenge: realistic climate argumentation inherently mixes these factors together, making it difficult to isolate their independent effects without sacrificing ecological validity. Across three preregistered studies (N = 3,000), we introduce a protocol that resolves this trade-off by orthogonally manipulating argument logicality and direction across realistic contexts. In neutral contexts, prior beliefs dominated judgments, with smaller effects of partisanship and logicality. Contrary to identity-protective accounts, embedding arguments in hostile partisan contexts did not increase partisan bias or impair logical reasoning. Instead, partisan attacks reduced reliance on prior beliefs, prompting participants to downgrade belief-consistent arguments. In a third study, minimal logic warnings—brief alerts indicating possible fallacies—enhanced discrimination between weak and strong arguments. These findings challenge single-factor accounts of climate argumentation, showing that argumentation is context sensitive and that this sensitivity can be exploited to improve climate argumentation by adding simple logic warnings that are effective, scalable, and politically neutral.