Thomas grew up in Saint Louis, Missouri, 10 minutes from where the shooting of Michael Brown by police happened.[6] She found no one was talking about the intersection of environmental and social injustices, such as the Flint, Michigan water crises where 57% of the population is Black.[7]
She gained notoriety after an Instagram post of hers that used the phrase "intersectional environmentalism" and called for environmental activists to support Black Lives Matter in the wake of the murder of George Floyd.[2][8][9]
She runs Intersectional Environmentalist, a website targeted towards people interested in the relationship between the environment and social justice.[2] She is the author of The Intersectional Environmentalist: How to Dismantle Systems of Oppression to Protect People + Planet, which provides advice to environmental activists and describes theories of relationships between race, privilege, social justice, and the environment.[10][11]