noun
A person who advocates for environmental protection. Neutral term, often used in political or social contexts.
彼は熱心な環境保護論者だ。
He is a passionate environmentalist.
環境保護論者たちが新しい政策を支持している。
Environmentalists are supporting the new policy.
Compound of 環境 (environment), 保護 (protection), and 論者 (advocate, theorist).