Abstract
The climate attitude–behaviour gap persists, with individual variables explaining limited behavioural variance. To address this problem, we develop and validate the Climate Stance Inventory (CSI), a continuous measure of 15 recurring orientations towards climate change and climate action derived from the Norm Activation Model. In a three-wave longitudinal study, 1,503 adults from the United Kingdom completed the CSI and measures of climate appraisals and environmental behaviour over approximately 10 weeks. Across waves, exploratory and confirmatory factor analyses identified a 15-factor solution that exhibited good fit (CFI = .979, RMSEA = .034), high internal consistency (α/ω = .69–.88) and test-retest correlations (r = .58–.89) and full longitudinal measurement invariance. Climate stances showed theoretically coherent associations with threat certainty, responsibility-related appraisals, efficacy, institutional trust and pro-environmental behaviour. In hierarchical regressions, they explained substantial additional variance beyond demographic characteristics and climate change anxiety in pro-environmental voting (14.2%), workplace behaviour (19.5%) and behaviour outside work (22.4%). The Bystander stance also explained unique variance beyond a conceptually adjacent established barrier measure. These findings support the CSI as a reliable, temporally stable and substantively valid measure that can distinguish different psychological routes to climate (in)action and support the development and evaluation of more targeted climate-belief interventions.