["Developmental Science, Volume 29, Issue 4, July 2026. ", "\nABSTRACT\n\nYoung people can be agents of change for urgently needed sustainable transitions. We combine survey data from the Urban Rotterdam Project (2021 sample: N = 1152, age range = 12–28 years, Mage = 19.07, SDage = 2.87, 54% female, 16% bi‐ or multicultural background; 2023 sample: N = 327, age range = 13–28, Mage = 19.24, SDage = 2.86, 67% female, 24% bi‐ or multicultural background) with youth participatory data (2024 sample: N = 114, age range = 16–26, Mage = 20, 51% female, 37% bi‐ or multicultural background) to examine youths’ climate‐related worry, affective wellbeing, motivations for pro‐environmental behavior and preferences for climate change communication. First, drawing on self‐determination theory, we tested whether associations between climate‐related worry, pro‐environmental behavior, and affective wellbeing depend on the quality of youths’ motivation to engage in pro‐environmental behavior. We found that climate‐related worry was associated with increased pro‐environmental behavior for youth who acted out of interest and enjoyment (i.e., intrinsic motivation) or internal pressure (i.e. introjected motivation). Youth who had internalized pro‐environmental behavior as personally important (i.e. identified motivation) showed high levels of pro‐environmental behavior regardless of worry. Climate‐related worry was also robustly associated with reduced affective wellbeing, irrespective of motivation type. Additionally, adopting a youth participatory approach, we explored youths’ preferences for climate change communication and pro‐environmental behaviors. We found that youth were more motivated by collective‐systemic than individual pro‐environmental actions because of benefits for motivation (“Alone it feels useless”), affective wellbeing (“Doing something together gives me hope”), and sustainability (“Cheaper public transport would make my choices matter”). We also found that youth preferred risk‐emphasizing, positive, and empowering communication strategies over approaches including humor and purely factual information. Overall, our research illustrates the importance of supporting youths' motivation to help them turn their climate‐related worry into pro‐environmental behavior, presents youths' perspectives on what motivating climate communication and action pathways might look like, and highlights the value of involving youth as active contributors to research and evidence‐informed climate action.\n\n\nSummary\n\nThe present study combined survey and participatory methods to examine youths' climate‐related worry, affective wellbeing, motivations for pro‐environmental behavior and preferences for climate change communication.\nClimate‐related worry was more strongly linked to pro‐environmental behavior when youth were motivated by interest and enjoyment (intrinsic) or by internal pressure such as guilt (introjected), though introjected motivation may carry wellbeing costs.\nYouth who had internalized pro‐environmental behavior as personally important (identified motivation) engaged in more pro‐environmental behavior regardless of their worry levels.\nClimate‐related worry was robustly associated with reduced affective wellbeing, irrespective of motivation type.\nYouth preferred collective‐systemic over individual pro‐environmental behaviors, while also recognizing the interconnectedness between the two.\nYouth preferred climate communication that is direct, positive, and empowering.\n\n\n"]