The Inter-Commission Committee on Geodesy for Climate Research (ICCC) has been established by IAG in 2019. The Joint Working Group C.1 "Climate Signatures in Earth Orientation Parameters" of ICCC will focus on the detection of climatic signals in Earth orientation data, the modelling of climate-related trends in geodetic observations, and the assessment of angular momentum budgets in global Earth system models. JWG C.1 will hold its inaugural meeting during the EGU in Vienna to shape the agenda for the next four years.