The aim of the proposed junior research group is to investigate current and future interrelations between human health and climate change in the context of active mobility (cycling, walking, public transport). The research group aims to assess and foster synergetic effects of behavior change towards active mobility for public health, climate change mitigation, and climate change adaption. Based on socio-ecological models, factors at the individual, organizational, societal, and environmental levels are investigated as interactive antecedents of active mobility. This includes a variety of psychological, behavioral, and organizational factors, context factors (e.g., air pollution as health risks) as well as model parameters on current and future urban climate in cities. Beyond the focus on individuals’ private sphere mobility behavior, also their role as change agents (i.e., public sphere behavior) as well as the transformative role of companies and civic organizations for a mobility transition are integrated as part of a transformative research approach. A key component within the junior research group refers to citizen science projects, in which citizens investigate and learn about active mobility, its health and climate impact in present and future climate conditions. They contribute high-resolution data for climate modelling scenarios. A mixed method approach on the role of public sphere behavior and organizations for a mobility transition is also included in the empirical portfolio. In an interdisciplinary and transdisciplinary research design, a complementary skill set of health psychology (Jan Keller), environmental psychology (Vivian Frick), sustainability management studies (Christina Klusch), meteorology (Siiri Tunn), and public health (Karsten Valerius) is combined with expertise from a scientific advisory board and practice partners.