From Behaviour Change Wheel to Global Gaps: A Systematic Review of the Determinants of High-Impact Climate Action

High-impact climate action, such as reducing private car use, adopting plant-based diets, and improving home energy efficiency, offers substantial potential for reducing individual greenhouse gas emissions, yet evidence on what enables or constrains these behaviours remains fragmented. This systematic review synthesized 28 articles reporting 32 studies published between 1998 and 2025 and organized findings using the Behaviour Change Wheel and its COM-B system, which conceptualizes behaviour as arising from interactions between Capability, Opportunity, and Motivation. The literature was dominated by studies conducted in Western contexts, focused on adult populations, and reliant on cross-sectional self-report designs. Across behavioural domains, research overwhelmingly emphasized motivational factors, such as attitudes, values, identity, norms, and affect, while capability- and opportunity-related determinants received far less attention. Psychological capability, primarily operationalized as climate-related knowledge and perceived control, showed generally positive but inconsistent associations with behaviour, whereas physical capability and structural opportunity were rarely examined despite qualitative evidence of their importance. Intervention studies were scarce and largely limited to persuasion and education. By synthesizing evidence through the COM-B framework, this review highlights a marked imbalance in the current literature and underscores the need for future research and interventions that more fully address the capabilities and structural conditions required to enable sustained engagement in high-impact climate actions.