“…Both projects, "k.i.d.Z.21" and "eKidZ", are based on theories related to CCE and ESD, e.g., science-education cooperation, transdisciplinarity, moderate constructivism and research-based learning settings [12,37]. In "k.i.d.Z.21", students gain more knowledge and higher attitudes in Both projects, "k.i.d.Z.21" and "eKidZ", are based on theories related to CCE and ESD, e.g., science-education cooperation, transdisciplinarity, moderate constructivism and research-based learning settings [12,37]. In "k.i.d.Z.21", students gain more knowledge and higher attitudes in various educational modules, but climate-friendly actions are not yet measurable.…”