'post-environmental' is formed from the prefix 'post-' (from Latin 'post', meaning 'after') combined with the adjective 'environmental' (from 'environment').

'environmental' derives from 'environment', which comes via Old French 'environer'/'environ' (to surround) from Latin roots; the modern compound 'post-environmental' is a recent formation using the productive prefix 'post-'.

Initially the elements meant 'after' (for 'post-') and 'to surround/conditions' (for 'environment'); together in modern usage they convey the idea 'after the environmental phase' or 'relating to consequences following environmental conditions/policies'.