Because the effects of climate change become increasingly evident, climate change related negative emotions like anxiety become more prominent, particularly among younger populations. This study introduces psychometric properties and validity of the German Climate Anxiety Scale for Adolescents (GCAS-A), a tool specifically designed to assess climate anxiety in German-speaking adolescents. Results of a sample of 136 adolescents (M_age = 18.21 years, SD = 2.92, range: 14 to 24 years, 66 % female) are presented. Confirmatory factor analysis supported a four-factor structure (factors affective, behavioral, physiological and impairment). Further analyses revealed significant associations between climate anxiety, gender, age, pro-environmental behavior, and awareness of climate change, thus aligning with previous research. The findings suggest that the GCAS-A is a valid and internally consistent tool for assessing climate anxiety in adolescents. This study highlights the importance of investigating climate anxiety in adolescents. Future research should focus on exploring the generalizability and validity of the scale across more diverse samples and on analyses of direction of effects in longitudinal studies.