Press contributing to environment (4)
I believe the answer is:
iron
'press' is the definition.
(I know that iron is a more specific form of press)
'contributing to environment' is the wordplay.
'contributing to' says the answer is hidden in the clue (the answer contributes to part of the clue ).
'IRON' can be found hidden inside 'environment'.
(Other definitions for iron that I've seen before include "Revolver" , "used in the evening" , "A magnet attracts it" , "Metal (that may be pumped?)" , "Club; element" .)