A Critique of Conceptual Frameworks and Models Applied in Climate Change-Driven Eco-Anxiety Research Focusing on Young Adults in OECD Countries: Guidelines for a Theoretical Trajectory of Future Eco-Anxiety Research

Eco-anxiety, commonly known as distress relating to perceived climate and ecological crises, is increasingly reported among young people, particularly in high-income and highly climate-exposed contexts such as Australia and other OECD countries. While empirical research on eco-anxiety has expanded rapidly, the underlying conceptual and theoretical frameworks remain fragmented, with limited consensus on definitions, mechanisms, and normative implications. This systematic conceptual review synthesises and critically evaluates the theoretical and conceptual models used to study eco-anxiety and related constructs among young adults in Australia and across OECD nations. By conducting a systematic search of multidisciplinary databases, the paper explores English-language studies published up to March 2026 that explicitly applied, developed, or implied conceptual frameworks of eco-anxiety or climate change anxiety in young adult samples. A broad array of models are grouped into a typology of seven families: (1) clinical and psychopathology-oriented models, (2) environmental attitudes and concern models, (3) risk perception and appraisal models, (4) existential and phenomenological frameworks, (5) socio-ecological and political-economy models, (6) coping and resilience frameworks, and (7) integrative and emergent eco-anxiety-specific frameworks. Across these families, eco-anxiety is variously conceptualised as a maladaptive symptom, a rational moral emotion, a driver of climate engagement, or a sociopolitical affect rooted in structural injustice. Major gaps include conflicting definitions, limited attention to developmental specificity in young adulthood, sparse cross-cultural and Indigenous perspectives in the Australian context, and insufficient theorisation of digital media, colonial histories, and policy in shaping eco-anxiety. The paper proposes a novel conceptual typology that locates eco-anxiety at the intersection of emotional, cognitive, relational, and sociopolitical processes. A future research trajectory underpinned by pragmatic theoretical bases that prioritise pluralistic, context-sensitive models and mixed-methods designs is suggested. Implications for measurement, intervention, and climate and mental health policy are discussed, with particular attention to young adults in Australia and OECD settings.