Terraforming began as a fantasy about making other planets earthlike, then returned to earth as a frame for what humans have done, are doing, or will do to the planet. Toward a reading of the phrase “terraforming earth” that would prove fruitful for criticism and theory, I analyze it into three forms of recursivity: formal, historical, and ecological. The three-loop analytic illuminates examples from science fiction and contemporary culture: H.G. Wells’s novel The War of the Worlds, Kim Stanley Robinson’s novel Green Mars, and Elon Musk’s desire to terraform Mars. The political theory of Sylvia Wynter offers a way of conceptualizing terraforming in terms of the difference between those who do and do not have access to optimal, immunized ecosystems and those who do and do not have agency over the earth system. I draw conclusions about terraforming’s scale-specificity and political implications, especially for understanding subject-formation in the Anthropocene.