Ruffin expands the reach of ecocriticism by analyzing the ecological experiences, conceptions, and desires seen in African American writing. Ruffin examines African American ecological insights from the antebellum era to the twenty-first century, considering WPA slave narratives, neo-slave poetry, novels, essays, and documentary films.

Identifying themes of work, slavery, religion, mythology, music, and citizenship, "Black on Earth" highlights the ways in which African-American writers are visionary ecological artists.