Anthropogenic climate change is a scientific fact, but U.S. public discourse around the issue remains mired in controversy, including in education. Our study leverages natural language processing methods to give a precise look into the extent to which climate change-related topics are covered in 30 of the most widely used high school history textbooks in California and Texas. We find that history textbooks situate climate change-related topics within narratives of U.S. progress and development, and focus on the role of government in climate action. Consistent with analyses of science curricula, we also find that history textbooks emphasize controversy in climate discussions. Despite differences in state-level standards, the content of textbooks in California and Texas is surprisingly similar in the extent and nature of climate change-related discourse. Our study indicates that history textbook reform is an important arena for expanding and improving climate change education.