1923, as a psychological theory (in the nature vs. nurture debate), from environmental + -ism. The ecological sense is from 1972. Related: Environmentalist (n.), 1916 in the psychological sense, 1970 in the ecological sense.
enviable
envious
environ
environment
environmental
environmentalism
environs
envisage
envision
envoy
envy
)window.location='https://www.paypal.com/cgi-bin/webscr?cmd=_donations&business=byronic106@yahoo.com&lc=US&item_name=Donation+to +Help+Keep+Etymonline+Free+and+Open&no_note=0&cn=&curency_code=USD&bn=PP-DonationsBF:btn_donateCC_LG.gif:NonHosted'){kind=link}