*Disagree with the proposed move.  There's enough material about the environmental movement in the U.S. to justify a separate article on that subject, without lumping it in with other countries, but the title of that separate article should make it clear that it's specifically about the U.S., which the current title does.  If the title is merely "Environmentalism", someone will come along and complain that it's too U.S.-centric and start adding international stuff.  Also, at some point we might want to have Environmentalism discuss the principles of and objections to environmental thought, while Environmental movement talked about the leading individuals and organizations in the field and chronicled their successes and failures.  For now, Environmentalism as a redirect to Environmental movement is OK, but down the road we might find it useful to have a separate article there, so let's keep it clear.