Addressing climate change requires people in the Global North to avoid high-impact behaviors like car use and air travel. Late adolescents, whose engagement in such behaviors may be restricted by age and parental decision-making, are in a crucial stage for developing a sense of moral responsibility for climate change. Understanding why some adolescents cultivate this responsibility is vital, as responsibility relates to both climate engagement and well-being. Therefore, this study aims to identify factors associated with late adolescents' sense of moral responsibility. Nature connectedness, parental social norms, and climate-change worry have been positively linked to pro-environmental behavior in previous research, but their role in relation to moral responsibility for climate change remains less clear. Similarly, the relationship between distancing coping and moral responsibility is yet to be fully understood. In this study we explore ways that these factors are associated with late adolescents´ moral responsibility, and examine whether these relationships differ between girls and boys. In 2023, we surveyed 619 Swedish high school students (ages 16-19), and used structural equation modeling to answer our research questions. Connection to nature, parents' norms, climate-change worry, and distancing coping positively influenced responsibility, with parents' norms having a stronger effect on boys. Climate-change worry partially mediated how parents’ norms and nature connectedness influenced responsibility, with a stronger mediation effect for girls in the latter relationship. Distancing coping did not moderate the relationship between worry and responsibility. Limitations are discussed, and we propose fostering moral responsibility through nature experiences, role modeling, and constructive worry management.