Experiences of 'climate anxiety' are considered an adaptive response to a real threat, as well as a potential cause of impairment. To date, little attention has been paid to how children and adolescents may be uniquely predisposed to climate anxiety, despite being an age cohort particularly vulnerable to the impacts of climate change. This Review uses a social-ecological framework to identify the influences on climate anxiety for young people. We explore the directionality and interplay between individual factors, the physical environment and the influence of micro- (family, peers), meso- (school, community), exo- (government, media) and macro- (culture) systems on children's and adolescents' experience of climate anxiety. The Review highlights future research considerations and key issues relevant to professionals working with youth. Children and adolescents may be the age cohort most vulnerable to climate anxiety. This Review uses a social-ecological theoretical framework to outline how they are uniquely susceptible to climate anxiety and identify potential protective factors.