This special issue of Geoscience Communication showcases contributions from a dedicated session at the EGU General Assembly 2025 called Citizen Science and Co-creating with Communities, which focused on the vital role of knowledge co-creation in participatory and transdisciplinary research. The session highlighted how co-creation, co-production, and co-design serve as collaborative methods that bridge academia and society, embodying the ethos of science with society rather than science for society. In addition, new submissions outside of the presentations in the EGU conference session are welcome in order to reflect a collective effort to promote participatory engagement and knowledge co-creation in the geosciences.

As societal challenges such as climate change become increasingly complex, these approaches encompassing citizen science, public engagement, and community-led initiatives are recognized as essential strategies for developing sustainable solutions through inclusive participation of communities, enterprises, governments, and indigenous groups. By sharing key lessons and strategies, the issue seeks to promote wider adoption of participatory methods within mainstream scientific activities and to foster equitable collaborations that empower underrepresented communities. Overall, this collection underscores the importance of recognizing researchers as facilitators of knowledge exchange and communities as equal partners, advancing transdisciplinary co-creation as a means to produce more effective, sustainable, and enduring solutions to societal and environmental issues.