Climate change is one of the greatest challenges of our time, and its consequences pose a severe threat to life on Earth. To address these challenges in the long term, we must adapt our behavior by making informed, climate-friendly decisions. In this regard, a growing body of research emphasizes the role of science education in fostering students' climate literacy. Drawing on a sample of 1276 upper-secondary students from Germany and Sweden, this questionnaire study investigates the role of climate literacy (i.e., knowledge, skills, and attitudes) as well as students' risk perception and value orientations in their climate-friendly intentions to act. Applying the method of sequential regression analysis, the results of our data analysis indicate that risk perception appears to be a key variable in explaining students' climate-friendly intentions to act. Cognitive factors (i.e., knowledge and skills) are also relevant to students' intentions, although less influential. For science education, the findings suggest that it may not be sufficient to focus exclusively on climate-related knowledge and skills, but that students might also need opportunities to engage in discussions about the potential consequences of climate change.