The information requested is not held centrally. The Department collects data on school absence, which includes authorised and unauthorised absence data, but does not include whether the absence is due to attending climate change protests. Our most recently published data on pupil absence can be found here:
Schools are required to take the attendance register each morning and afternoon. They must record whether each pupil is: present; absent; attending an approved educational activity; or unable to attend due to exceptional circumstances. Where a pupil is absent, it is for the school to decide whether the absence should be authorised or not.