Textbook authors were told last month that some references to “climate change” must be removed from science books before they could be accepted for use in Florida’s public schools, according to two of those authors.

A high school biology book also had to add citations to back up statements that “human activity” caused climate change and cut a “political statement” urging governments to take action to stop climate change, said Ken Miller, the co-author of that textbook and a professor emeritus of biology at Brown University.

Both Miller and a second author who asked not to be identified told the Orlando Sentinel they learned of the state-directed changes from their publishers, who received phone calls in June from state officials.

Miller, also president of the board of the National Center for Science Education, said the phrase “climate change” was not removed from his high school biology text, which he assumed happened because climate change is mentioned in Florida’s academic standards for biology courses.

But according to his publisher, a 90-page section on climate change was removed from its high school chemistry textbook and the phrase was removed from middle school science books, he said.