The large research infrastructure CzeCOS is a unique platform for undertaking comprehensive international interdisciplinary research on Global Change (GC) and its impacts on ecosystems. It substantially contributes to the fulfillment of international commitments of the Czech Republic in the field of research, adaptation and mitigation of Global Change impacts. As for the Czech Republic, CzeCOS is the only national component of the following European Research Infrastructures ICOS ERIC – Integrated Carbon Observation System- infrastructure for the research on the fluxes of greenhouse gases (founding member), AnaEE-ERIC – analytical and experimental infrastructure for ecosystems (founding member), EUFAR – EUropean Facility for Airborne Research - infrastructure for remote sensing within environmental monitoring. CzeCOS is also active member of ESFRI eLTER RI - long-term research on ecosystems, critical zones and socio-ecological systems a ESFRI DANUBIUS-ERIC - advanced studies on river-sea systems.