It is hard to think of an American film that provoked a greater backlash in 2020 than “Planet of the Humans.” Focused on the theme of planetary extinction and fanciful proposals to ward it off, the documentary was released for free on YouTube on April 21. Even before “Planet of the Humans” was released, however, the producers of the film had fallen under pressure to retract it. Upon the film’s release, a who’s who of self-styled climate justice activists proceeded to blanket the internet with accusations that it was a racist, “eco-fascist” screed that deliberately advanced the interests of the oil and gas industry. When “Planet of the Humans” was briefly yanked from YouTube thanks to a questionable copyright claim by an angry climate warrior, the free speech organization Pen America issued a remarkable statement characterizing the demands for retraction as a coordinated censorship campaign. What had this documentary done to inflame so much opposition from the faces and voices of professional climate justice activism?