The climate change conspiracy belief scale: Development and validation of a multidimensional measure

Climate change conspiracy beliefs are increasingly implicated in public resistance to climate action, yet their measurement remains conceptually imprecise and psychometrically limited. Existing work has relied on ad hoc instruments that blur conspiracist claims with broader forms of climate scepticism, distrust, or misinformation. In the current research, we developed and validated the Climate Change Conspiracy Belief Scale (CCCBS), a multidimensional measure designed to capture the defining and ideologically distinct structure of climate conspiracism. Across three studies, we tested the scale’s dimensionality, reliability, and validity in both Western and non-WEIRD contexts. Study 1 generated and refined an initial item pool, identifying a three-factor structure comprising denialist (climate change is fabricated or deliberately exaggerated), warmist (climate evidence is suppressed or manipulated), and alarmist (catastrophic climate risks are concealed) climate conspiracy beliefs. Study 2a provided a preregistered test of this structure and demonstrated strong internal consistency, measurement invariance across gender groups, and construct validity. Study 2b further established temporal stability through test–retest reliability and longitudinal measurement invariance. Study 3 replicated the three-factor structure in Trinidad and Tobago, although weaker internal consistency and factor loadings suggested that climate conspiracism may be less ideologically consolidated in this non-Western context. These findings advance the conceptualisation and measurement of climate conspiracism as a multidimensional and context-sensitive belief system.