tree hugger

noun2

1. •
   (slang, disapproving) An environmental campaigner, especially one who aims to restrict logging and especially one who uses dramatic, attention-grabbing methods of obstruction.
2. •
   (slang) A hippie.

   • She'd heard the term from American soldiers about these 'free love' people. 'Tree huggers' who reveled in sex, drink and drugs. — 2014