environmentalism vs environmentalist

environmentalism and environmentalist both are nouns.

Word	Noun	Adjective	Verb	Adverb
environmentalism	Yes	No	No	No
environmentalist	Yes	No	No	No

environmentalism (noun)	environmentalist (noun)
the activity of protecting the environment from pollution or destruction	someone who works to protect the environment from destruction or pollution
the philosophical doctrine that environment is more important than heredity in determining intellectual growth