With the challenges of climate change and biodiversity crises, it is crucial to understand and identify the key influencing factors driving pro-environmental behavior (PEB). Research indicates that, in addition to environmental attitudes and involvement in nature-related activities, interest in nature plays a significant role in motivating individuals to engage in PEB. However, the relationship between interest in nature and PEB among adolescents is still not well-explored, even though the foundations for PEB are typically established during childhood. The aims of Anna-Lenas PhD were to (1) examine the level of interest in nature among lower secondary school students, (2) analyze the interrelationships between interest in nature, nature-related activities, and environmental attitudes, and (3) understand its collective impact on PEB. She first developed and validated the Scale of Interest in Nature (SIN), which was then used in a cross-sectional study investigating students interest in nature, nature-related activities and PEB in lower secondary school.