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 1 / 19 OPEN ACCESS Citation: Hempel LM, Geiger M, Betsch C (2025) Toward a unified understanding of climate anxiety: Examining measures of climate and eco-anxiety. PLoS One 20(12): e0339562. https://doi.org/10.1371/journal.pone.0339562 Editor: Paweł Larionow, Wyższa Szkoła Kształcenia Zawodowego: University College of Professional Education, POLAND Received: August 14, 2025 Accepted: December 8, 2025 Published: December 29, 2025 Copyright: © 2025 Hempel et al . This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Data availability statement: Supplementary information on the PACE study is accessible at www.pace-studie.de. The supplement material is available at the Open Science Framework (OSF) https://osf.io/wvbd3/, including original items of the PACE study, data, code and output. RESEARCH ARTICLE Toward a unified understanding of climate anxiety: Examining measures of climate and eco-anxiety Lisa Marie Hempel 1,2*, Mattis Geiger1,2, Cornelia Betsch 1,2 1 Implementation Science, Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany, 2 Institute for Planetary Health Behavior, University of Erfurt, Erfurt, Germany * lisa-marie.hempel@bnitm.de Abstract Despite recent research efforts to understand climate anxiety, related measurement

is challenged by multiple definitions and the emergence of several seemingly similar measures, warranting a thorough and joint investigation of their validity. This study (N = 1003) examined the factor structure of existing measures, namely the Climate Anxiety Scale (CAS) and the Hogg Eco-Anxiety Scale (HEAS), and tested their over- lap in joint measurement models. The results showed that CAS and HEAS indeed seem to capture the same overarching construct, climate anxiety. A joint measure- ment model with a single higher-order general factor indicated by a CAS g-factor and four HEAS factors had good fit. This overarching climate anxiety factor was related to but still distinct from nomologically related constructs (e.g., climate- related risk perception, neuroticism). Climate anxiety was also strongly correlated with political participation, an aspect of the readiness for climate action. A small correlation with self-efficacy to show individual emission-reducing behavior and no association with climate-change-related fatigue suggests that high levels of climate anxiety are not accompanied by paralysis but instead by mild activation. The results showed generally low levels of climate anxiety in the general population. These findings are discussed regarding the resulting challenges for validation efforts and experimental work, accompanied with recommendations for further steps in measure- ment development. Introduction Given the existential threat of climate change [1], there is a growing body of research

on emotional responses to climate change, mostly regarding climate anxiety [2]. As defined by the Climate Psychology Alliance, climate anxiety refers to “height- ened emotional, mental or somatic distress in response to dangerous changes in the climate system” [3, p.25]. Climate anxiety can arise from direct experiences