The Hogg Eco-Anxiety Scale: Development and validation of a multidimensional scale

•We developed and validated a brief four-dimensional measure of eco-anxiety.•Eco-anxiety is distinct from other mental health outcomes, and multifaceted.•Eco-anxiety encompasses more than affective and behavioural symptoms.•Rumination and anxiety about personal impact on the planet are also dimensions.•Some dimensions of eco-anxiety are more stable over time than others. Anxiety relating to a multitude of ecological crises, or eco-anxiety, is a subject of growing research significance. We used a multi-study mixed-methods design to explore eco-anxiety in Australia and New Zealand, validating a new eco-anxiety scale. In Study One, we developed and tested a 7-item eco-anxiety scale (n = 334), finding that this captured some, but not all, experiences of eco-anxiety. We found that people were anxious about a range of environmental conditions and their personal negative impact on the planet. Notably, people’s anxiety about different environmental conditions (e.g., climate change, environmental degradation, pollution) were interconnected, lending support for the existence of eco-anxiety (a broader construct that encompasses climate change anxiety). These results informed further scale development in Study Two. Exploratory (n = 365) and Confirmatory Factor Analysis (n = 370) supported a final 13-item scale that captured four dimensions of eco-anxiety: affective symptoms, rumination, behavioural symptoms, and anxiety about one’s negative impact on the planet, which were each distinct from stress, anxiety and depression. A further longitudinal sample (n = 189) established the stability of these factors across time. Findings support eco-anxiety as a quantifiable psychological experience, reliably measured using our 13-item eco-anxiety scale, and differentiated from mental health outcomes.