subject of an address

environment, surroundings / the natural environment

he / distal demonstrative, something far off removed from both speaker and listener: that / boyfriend

distal demonstrative, something far off removed from both speaker and listener: that, yon / particularly, male personal third person pronoun: he / by extension from he: boyfriend

he; boyfriend

protection; safeguard

to shield (to protect, to defend)

ecologist

natural environment

environmental pollution