At the age of 15, Margolin founded the youth climate action organization Zero Hour and serves as the co-executive director of the organization. She is also a plaintiff in the Aji P. v. Washington case, suing the state of Washington for their inaction against climate change on the basis of a stable climate being a human right. Her writing about climate change has appeared in many publications including HuffPost, Teen Ink, and CNN. She was part of Teen Vogue’s 21 Under 21 class of 2018. In 2018, she was also named as one of People Magazine's 25 Women Changing the World.