Toward a unified understanding of climate anxiety: Examining measures of climate and eco-anxiety

PLOS One | https://doi.org/10.1371/journal.pone.0339562 December 29, 2025 2 / 19 of climate-related harm as well as from the perception and awareness of climate change and its consequences [4]. A meta-analysis has shown that certain sociode- mographic characteristics, such as younger age or female gender, are more strongly associated with climate anxiety [5]. However, sociodemographic factors show weaker associations with climate anxiety compared to factors such as perceived direct expo- sure to climate change consequences, indirect exposure to climate change-related information, pro-environmental norms, and neuroticism [5]. Climate anxiety, just as any anxiety, can become clinically significant, affecting the ability to sleep, work, and socialize [6]. However, the literature emphasizes its adaptive functions and, in partic- ular, warns against pathologizing climate anxiety since it is a response to a real and urgent threat [4,7–9]. A key scientific challenge lies in the diverse definitions of this phenomenon. The terms climate and eco-anxiety themselves are used across multiple discourses, including as an everyday emotion related to worry and fear, a valuable emotional response to threats like climate change that may motivate climate action, as a psychodynamic concept linked to underlying conflicts, as an existential state, or as pathological condition [10,11]. Another aspect of this conceptual ambiguity concerns the temporal nature of these constructs, as existing measures do not clearly spec-

ify whether they capture state-like fluctuations or more stable, trait-like tendencies, although certain instruction anchors may hint at one or the other conceptualization. This definitional diversity contributes to the tension in measurement approaches: between capturing severe, life-impairing mental health consequences and a natural affective response that may facilitate the necessary climate action. This may have led to the paradox in current research that although measurement approaches have focused on mental health impairment, validation studies have so far been conducted exclusively in general population samples. Such samples typically show low levels of clinically impairing symptoms, resulting in restricted variance in symptom-related items and therefore potentially underestimating associations. Another challenge is the emergence of several seemingly similar measures within this field that claim to capture two distinct concepts. In addition to climate anxiety, eco-anxiety has been described as a similar construct with a broader context that extends beyond climate change to include anxiety related to other environmental cri- ses, such as species extinction and deforestation [12]. Although environmental psy- chology has historically examined a wider range of environmental issues, research on the social and psychological impacts of climate change has expanded rapidly in recent years. However, it is unclear whether climate anxiety and eco- anxiety are perceived as distinct concepts by individuals or whether people strug-

gle to differentiate between them. If respondents do not conceptually distinguish them, this would be reflected empirically in the very high correlations between the constructs and a joint measurement model outperforming separate measurement models. This would constitute a jangle fallacy, in which two labels are used for what is essentially the same construct [13]. Jangle fallacies pose several problems for scientific progress: they fragment the literature, obscure construct boundaries, hinder cumulative theory building, and make it difficult to compare findings across studies Funding: The project (project lead CB) is funded by the Klaus Tschira Foundation (#00.003.2022; https://klaus-tschira-stiftung. de/), the Federal Ministry of Health (BMG) via the Robert Koch Institute (RKI; https://www. rki.de/DE/Home/home_node.html), and the Federal Center for Health Education (BZgA now BiÖG; https://www.bioeg.de/). Additional internal funding comes from the University of Erfurt (UE) and the Bernhard Nocht Institute for Tropical Medicine (BNITM). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. Competing interests: The authors have declared that no competing interests exist.